Stochastic hydration of a high-nitro­gen-content molecular compound recrystallized under pressure

Partial hydration of organic compounds can be achieved by high-pressure crystallization. This has been demonstrated for the high-nitro­gen-content compound 6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C₄H₂N₅Cl), which becomes partly hydrated by isochoric crystallizations below 0.15 GPa. This hydrate, C₄H₂N₅Cl·xH₂O, is isostructural with the ambient-pressure phase α of C₄H₂N₅Cl, but the crystal volume is somewhat larger than that of the anhydrate. At 0.20 GPa, the α-C₄H₂N₅Cl anhydrate phase transforms abruptly into a new higher-symmetry phase, α′; the transformation is clearly visible due to a strong contraction of the crystals. The hydrate α-C₄H₂N₅Cl·xH₂O can also be isothermally compressed up to 0.30 GPa before transforming to the α′-C₄H₂N₅Cl·xH₂O phase. The isochoric recrystallization of C₄H₂N₅Cl above 0.18 GPa yields a new anhydrous phase β, which, on releasing pressure, transforms back to the α phase below 0.15 GPa. The structural transition from the α to the β phase is destructive for the single crystal and involves a large volume drop and significant elongation of all the shortest intermolecular distances which are the CH⋯N and CH⋯Cl hydrogen bonds, as well as the N⋯N contacts. The α-to-α′ phase transition increases the crystal symmetry in the subgroup relation; however, there are no structural nor symmetry relations between phases α and β.

1. Introduction

High-nitro­gen organic compounds have relatively high density, but short intermolecular contacts are usually absent in their structures (Bernstein, 2002; Fabbiani & Pulham, 2006; Millar et al., 2010; Zakharov & Boldyreva, 2019). The strong interdependence of the density and properties generally involves intermolecular interactions (Gao & Shreeve, 2011; Nair et al., 2010) and thermodynamic conditions (Fabbiani & Pulham, 2006; Boldyreva, 2008, 2014; Resnati et al., 2015). We report a pressure and temperature dependence of the crystal structure of the pyridazine-based compound 6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C₄H₂N₅Cl), hereafter CTP. It can transform between the azide and tetrazole forms in the gaseous and liquid states (Fig. 1). Azido-tetrazole tautomerism is common for many high-nitro­gen content compounds, widely applied as energetic materials and active pharmaceutical ingredients (Katrusiak et al., 1996, 2005; Bałoniak & Katrusiak, 1994; Yang et al., 2015; Olejniczak et al., 2019). We determined the crystal structure of C₄H₂N₅Cl under normal conditions in order to gain information about the tautomeric and molecular forms, and we noted relatively large voids, accommodating a probing sphere of 0.65 Å radius. Under ambient conditions the studied compound assumes the tetrazole form. We established that isothermal compression, isobaric cooling and high-pressure recrystallization result in new unexpected forms of CTP.

Figure 1 Structural formula of CTP and its azide tautomer.

2. Methods

The effect of high pressure on CTP was studied in a diamond anvil cell (DAC) (Merrill & Bassett, 1974) modified by mounting the anvils directly on steel disks with conical windows. Two procedures were applied (Fig. S1 of the supporting information): (i) isothermal compression (Figs. 2, S2 and S3) in Daphne oil and (ii) high-pressure recrystallizations performed from saturated solutions (Figs. 2 and S4). Method (i) resulted in monotonic compression of the ambient-pressure phase α up to 0.20 GPa, whereby the sample crystal visibly became shorter and transformed to a new phase α′ (Fig. 2). X-ray diffraction confirmed this to be a single-crystal-to-single-crystal phase transition of the subgroup–group symmetry relation, and clearly discontinuous in character.

Figure 2 Single-crystal C4H2N5Cl in the α phase (0.1 MPa), compressed to the α′ phase (0.24 GPa) and decompressed to the α phase again (0.05 GPa). The vertical double arrows compare the initial and final vertical dimension of the crystal along its x direction in the α phase and corresponding y direction in the α′ phase (cf. Table 1).

For the high-pressure recrystallization, solvents were chosen according to their freezing pressure and the compound solubility. The highest solubility was found for water. The initial trials revealed that the concentration in the saturated solution is not sufficient for obtaining single crystals large enough for X-ray diffraction measurements. Therefore before loading the solution, some additional crystals were placed in the high-pressure chamber to increase the concentration at high temperature. After increasing the pressure to the required value, the DAC was heated until all seeds except one dissolved and a single crystal was grown by controlled slow cooling of the sample to room temperature (Fig. 3). High-pressure recrystallizations were performed from aqueous, methanol, ethanol and acetone solutions or from mixtures of them. Temperatures higher than 473 K caused the sample to decompose.

Figure 3 Stages of isochoric recrystallization of C4H2N5Cl in the β phase from acetone solution at 0.33 GPa: (a)–(b) a single crystal nucleated and growing in the DAC at 363 K; (c) the same crystal at 353 K and (d) at 296 K. Several ruby chips are mainly located close to the gasket edge.

Pressure in the DAC chamber was calibrated by the ruby-fluorescence method (Mao et al., 1985) with a photon control spectrometer affording an accuracy of 0.02 GPa; the calibration was performed before and after the diffraction measurements. The crystal sample in the DAC was centered on the diffractometer by the gasket shadowing method (Budzianowski & Katrusiak, 2004). For the low-temperature measurements an Oxford Cryosystems 700 Series attachment and SuperNova diffractometer using Cu Kα radiation and a CCD plate Atlas detector was used. The high-pressure diffraction data were measured with a KUMA KM4-CCD diffractometer using Mo Kα radiation and a CCD two-dimensional Eos detector. CrysAlisPro (171.40.67a; Rigaku Oxford Diffraction, 2019) was used for recording reflections and preliminary data reduction. Reflection intensities were corrected for the DAC absorption and sample shadowing by the gasket, the sample absorption and reflections overlapping with diamond reflections were eliminated. OLEX2 (version 1.2, Dolomanov et al., 2009), SHELX-T (Sheldrick, 2015a) and SHELX-L (Sheldrick, 2015b) were used to solve the structural models by direct methods, and then refine the models by full-matrix least-squares. Anisotropic temperature factors were applied for non-hydrogen atoms, but the isotropic thermal parameters were occasionally retained for the atoms with unreasonable anisotropic thermal ellipsoids. Hydrogen atoms were located from the molecular geometry, with the C—H distance equal to 0.93 Å and their U_iso factors constrained to 1.2 × U_eq of the carriers. The crystal data and refinement details are summarized in Tables 1 and S1–S3 of the supporting information; the experimental and structural details have been deposited in CIF format in the Cambridge Structural Database as supporting publications (CCDC deposition Nos. CCDC 2102408–2102436). Structural drawings were prepared using the X-Seed interface of POV-Ray (Barbour, 2001; Persistence of Vision Raytracer, 2004) and the program Mercury (Macrae et al., 2020).

Table 1
Selected data of C₄H₂N₅Cl recrystallized from different solutions (cf. Tables S1–S3 in the supporting information)

Formula	C4H2N5Cl	C4H2N5Cl·xH2O	C4H2N5Cl	C4H2N5Cl
p (GPa), T (K)	0.0001, 300.0 (1)	0.10 (2), 296 (2)	0.24 (2), 296 (2)	0.40 (2), 296 (2)
Phase	α	α	α′	β
Space group	P212121	P212121	Pnma	P21/c
Unit-cell parameters
a (Å)	7.0651 (2)	7.0733 (6)	10.697 (4)	7.824 (4)
b (Å)	8.7859 (2)	8.7965 (6)	6.2545 (7)	13.0789 (6)
c (Å)	10.0906 (2)	10.042 (8)	8.8012 (10)	5.6290 (4)
β (°)	–	–	–	100.793 (19)
Volume (Å^3)	626.36 (3)	624.8 (5)	588.8 (3)	565.8 (3)
Z, Z′	4/1	4/1	4/0.5	4/1
Dcalc (g cm^−3)	1.650	1.654	1.755	1.826
Final R1/wR2 (I > 2σ1)	0.0340/0.0893	0.0339/0.0493	0.0249/0.0378	0.0619/0.1476
Solvent	–	MeOH:H2O (1:1)	–	Acetone

3. Results and discussion

High-pressure recrystallization revealed several crystalline forms of CTP. The β phase can easily be distinguished from phases α and α′ by the crystal morphology, but X-ray diffraction measurements were required for detecting the uptake of water molecules.

Crystals of the orthorhombic α phase were obtained from methanol solution under ambient conditions exclusively. The single-crystal sample isothermally compressed to 0.20 GPa displays an abrupt strong visible strain marking the transition to α′ (Figs. S2 and S3); subsequent X-ray measurements revealed the single crystal retains its high quality after the transformation is complete. This new high-pressure α′ phase remains orthorhombic, but its space group symmetry increases to Pnma (Table 1). On releasing pressure, α′ transforms back to α at 0.12 GPa. The α′ phase can be compressed to 0.6 GPa, when its transformation to the monoclinic β phase damages the single crystal. Single crystals of β were grown under isochoric conditions above 0.15 GPa. On releasing pressure, β transforms back to α at 0.15 GPa and the single crystal was pulverized again.

The high-pressure isochoric recrystallizations of CTP from aqueous solution up to 0.15 GPa yielded single crystals, which initially appeared to be identical to the α phase; however, their volume was markedly larger by about 3 ų per C₄H₂N₅Cl molecule compared with that of the α phase grown at atmospheric pressure (Fig. 4). Moreover, the volume dependence on pressure displays clearly a convex shape, and the crystals could be compressed to 0.3 GPa before undergoing transformation to the α′ phase in an analogous way to that observed for the α phase. We concluded that the high-pressure recrystallization forces some water molecules into the crystal structure, so the inclusion compound C₄H₂N₅Cl·xH₂O is obtained, with H₂O contents too small to be visible in our X-ray diffraction analysis. From isochoric recrystallizations above 0.16 GPa β was obtained, which is stable up to 0.80 GPa at least and on releasing pressure transforms back to α.

Figure 4 (a) Compression and thermal expansion of the molecular volume and (b) compression of the unit-cell dimensions of C4H2N5Cl (open symbols) and C4H2N5Cl·xH2O (full symbols). The compression line for the partial hydrate α′-C4H2N5Cl·xH2O (through one experimental point) is drawn parallel to that of the anhydrate α′-C4H2N5Cl as a guide for the eye only. All estimated standard deviations are smaller than the plotted symbols; the highlighted sections mark the corresponding dimensions of the α and α′ phases.

The low-temperature behavior of CTP crystals at atmospheric pressure was also studied by X-ray diffraction. Over the temperature range down to 130 K the crystal remained in the α phase and it contracted to about 98% of the volume at 296 K. Such a volume compression was achieved at 296 K under a pressure of 0.10 GPa (Fig. 4).

3.1. Symmetry relations

It is quite unusual and inconsistent with the rule of temperature and pressure inverse effects (Tapie) (Hazen & Finger, 1982; Cai & Katrusiak, 2014) that the space-group symmetry of the low-pressure phase α-CTP increases on transforming to the α′ phase, from P2₁2₁2₁ to Pnma. Tapie states that the effects of increased pressure are usually the inverse of those of increased temperature (usually increasing volume and symmetry). Indeed, there are numerous examples of symmetry reduction in high-pressure phases (Olejniczak et al., 2009, 2010; Svitlyk & Mezouar, 2021, Guńka et al., 2021; Roszak & Katrusiak, 2021). The β phase is monoclinic (space group P2₁/c), however its structure is very different from those of phases α and α′. The structure of β is built from double layers, which are absent in other phases (Figs. 5 and S5). The transition around 0.20 GPa between α and α′ can be observed visually, because the longest dimension of the crystal along the x direction of α is shortened by ca 10% at the transition to α′ (Fig. 4, Table 1). This visible strain precisely indicating the transition point on increasing and releasing the pressure was helpful for measuring the transition hysteresis (of about 0.08 GPa) as well as the higher transition pressure of the partial hydrate CTP·xH₂O at 0.30 GPa.

Figure 5 Molecular packing and the short contacts CH⋯N and N⋯N (dotted lines) in the C4H2N5Cl (a) α phase, (b) α′ phase and (c) β phase. Consecutive single layers (α and α′) and double layers (β) are marked in pink and green.

Both phase transitions are accompanied by a volume reduction. The molecular volume of the β phase is over 10 ų smaller than that of the α phase (Fig. 4). At the α-to-α′ transition the molecular volume is reduced by about 3 ų. The unit-cell volume of the isothermally compressed α phase is smaller compared with that of the sample recrystallized in situ under pressure. The in situ crystallized sample has the same symmetry and nearly identical structure and lattice as the α phase. The volume increase can be attributed to the presence of some small amount of water (Glasser, 2019) randomly distributed in the structure of α. We postulated that the presence of water in CTP·xH₂O increases the crystal volume, reduces the compressibility of CTP·xH₂O, and the transition to the α′ phase of CTP·xH₂O occurs at pressures higher than that of the anhydrate (Fig. 4). Due to the absence of the water molecule electron-density peak in the ΔF maps, we were able to assess the value of x from only the volume increase of the in situ recrystallized crystals compared with those obtained under ambient conditions and compressed without recrystallization. This assessment has been based on the formula x = [V_m(hydrate) − V_m(anhydrate)]/V_w, where V_w is the volume of one water molecule in a hydrate (Glasser, 2019). According to this assessment the water admixture coefficient x is about 0.14 for 0.10 GPa, 0.30 for 0.20 GPa and 0.08 for 0.49 GPa.

The structures of α and α′ are closely related (Fig. 5) and their lattice vectors are connected through the following matrix equations:

where primes refer to the α′ phase. The corrugated sheets of CH⋯N bonded molecular aggregates in α at the phase transition become perfectly planar in α′ (Fig. 5). Consequently, the lattice becomes elongated along the undulation of the sheets (unit-cell parameters c/a′), the other dimension along the sheets remains unchanged (b/c′) and the dimension between the sheets (a/b′) is shortened, as shown in the plot in Fig. 4(b).

In the tetrazole form the CTP molecules are rigid and planar under ambient conditions and these features are preserved in the high-pressure phases. All the structures are governed mainly by short CH⋯N bonds, while non contacts N⋯N, CH⋯Cl or Cl⋯Cl are shorter than the sum of van der Waals radii (Bondi, 1964) (Fig. 6). The arrangement of the molecules is clearly related between α and α′, but different from that in β (Fig. 5 and S10). All specific types of contacts in α become longer in β. Though the change in the CH⋯N distance is small (it is about 0.05 Å longer in phase β than it is in phase α), the elongation of distances N⋯N and CH⋯Cl is of the order of about 0.1 and 0.3 Å, respectively. This is due to the molecular arrangement becoming more optimized for denser packing rather than changes in the directional interactions under high pressure (Figs. S7 and S8).

Figure 6 The shortest intermolecular distances plotted as a function of pressure in C4H2N5Cl (open symbols) and C4H2N5Cl·xH2O (full symbols): α phase (circles), α′ phase (squares), β phase (diamonds); distances H⋯N (black), C⋯N (gray), H⋯Cl (green), C⋯Cl (dark green), N⋯N (blue), sum of van der Waals radii (dash-dot lines).

The CH⋯N bonded corrugated sheets in α and the planar sheets in α′ are connected by N⋯N contacts between the sheets (Fig. 5). In β the two shortest CH⋯N bonds connect molecules into ribbons running along [100]; these ribbons are connected by other short CH⋯N bonds into double layers. There are short N⋯N contacts between these double layers. The patterns of molecules connected by the shortest CH⋯N contacts are rings that can be described as R₄⁴(17) in α and α′, and R₂²(8) and R₄⁴(12) in β (Fig. 5 and S9) according to graph notation (Etter et al., 1990).

Some similarities can be observed between the structures of CTP phases and previously studied compounds 6-azido-1,2,4-triazolo[4,3-b]pyridazine (C₅H₃N₇, ATriP) (Olejniczak et al., 2019) and 6-azido-1,2,3,4-tetrazolo[1,5-b]pyridazine (C₄H₂N₈, TAPYR) (Olejniczak et al., 2020). Both CTP and TAPYR transform into new phases with considerably reduced volume. Moreover, the α-to-β transformation occurs only when the compounds are recrystallized in situ under high-pressure and high-temperature conditions. In TAPYR, the new β phase exists in the low-pressure range, then transforms to the ambient-condition α phase. In CTP at the low-pressure range the ambient-condition α phase is present, which further transforms to a new phase β. Unlike in TAPYR, where the new phase could be recovered after releasing the pressure, the β phase of CTP exists only under high-pressure conditions. In these three compounds, the molecules aggregate into sheets in phases α and α′ of CTP, in phase α of TAPYR, and in ATriP (planar in the α′ phase of CTP and in the α phase of TAPYR, while corrugated in the α phase of CTP and ATriP). The hydrogen-bond patterns are somewhat different (Fig. S9). In TAPYR the CH⋯N short contacts connect molecules into ribbons, which further extend through short N⋯N contacts into sheets. In CTP phases α and α′ and in ATriP the molecules aggregate into sheets only via CH⋯N bonds; however, in ATriP the N⋯N interactions are additionally present within the sheets. In all these structures N⋯N contacts are present between neighboring sheets, but they are longer than N⋯N contacts within the sheets.

The pressure-induced sorption of water molecules in small voids in the molecular crystal of CTP in some respect resembles the sorption in large pores of metal–organic frameworks (McKellar & Moggach, 2015), however access to the pores in CTP is hindered and requires dissolution.

4. Conclusions

With the exception of the three least-high-pressure phases of C₄H₂N₅Cl we have revealed the different behavior of this compound compressed and recrystallized under high-pressure conditions. At ambient pressure and low temperature only the α phase was obtained. It transforms into the higher-symmetry α′ phase at 0.20 GPa and to phase β at about 0.70 GPa. The high-pressure recrystallization of C₄H₂N₅Cl yields its stochastic hydrate α·xH₂O when water is present in the solvent. This stochastic hydrate closely resembles the pure α phase, but its volume is somewhat larger; the volume–pressure dependence displays an unusual convex shape and the α·xH₂O phase transforms into the α′·xH₂O phase at a pressure about 0.1 GPa higher than the pure α-C₄H₂N₅Cl phase. The presence of water can be also deducted from the voids present in the structure of phases α and α′, although their size is significantly smaller than that required for accommodating water molecules under ambient-pressure conditions.

Supporting information

Computing details

For all structures, data collection: CrysAlis PRO 1.171.40.67a (Rigaku OD, 2019); cell refinement: CrysAlis PRO 1.171.40.67a (Rigaku OD, 2019); data reduction: CrysAlis PRO 1.171.40.67a (Rigaku OD, 2019). Program(s) used to solve structure: SHELXT 2018/2 (Sheldrick, 2018) for C4H2N5Cl1@300K_phase_alpha, C4H2N5Cl1@275K_phase_alpha, C4H2N5Cl1@250K_phase_alpha, C4H2N5Cl1@225K_phase_alpha, C4H2N5Cl1@200K_phase_alpha, C4H2N5Cl1@190K_phase_alpha, C4H2N5Cl1@175K_phase_alpha, C4H2N5Cl1@160K_phase_alpha, C4H2N5Cl1@150K_phase_alpha, C4H2N5Cl1@130K_phase_alpha, C4H2N5Cl1@0_0001GPa_phase_alpha, C4H2N5Cl1@0_12GPa_phase_alpha, C4H2N5Cl1@0_24GPa_phase_alpha_prim, C4H2N5Cl1@0_49GPa_phase_alpha_prim, C4H2N5Cl1@0_09GPa_phase_alpha_xH2O, C4H2N5Cl1@0_10GPa_phase_alpha_xH2O, C4H2N5Cl1@0_17GPa_phase_alpha_xH2O, C4H2N5Cl1@0_18GPa_phase_alpha_xH2O, C4H2N5Cl1@0_20GPa_phase_alpha_xH2O, C4H2N5Cl1@0_30GPa_phase_alpha_xH2O, C4H2N5Cl1@0_54GPa_phase_alpha_prim_xH2O, C4H2N5Cl1@0_20GPa_phase_beta, C4H2N5Cl1@0_25GPa_phase_beta, C4H2N5Cl1@0_33GPa_phase_beta, C4H2N5Cl1@0_40GPa_phase_beta, C4H2N5Cl1@0_48GPa_phase_beta, C4H2N5Cl1@0_55GPa_phase_beta, C4H2N5Cl1@0_80GPa_phase_beta; SHELXT 2018/2 (Sheldrick, 2018)' for C4H2N5Cl1@0_17GPa_phase_beta. For all structures, program(s) used to refine structure: SHELXL 2018/3 (Sheldrick, 2015); molecular graphics: Olex2 1.3 (Dolomanov et al., 2009); software used to prepare material for publication: Olex2 1.3 (Dolomanov et al., 2009).

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@300K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.650 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2612 reflections
a = 7.0651 (2) Å	θ = 6.7–64.6°
b = 8.7859 (2) Å	µ = 4.77 mm^−1
c = 10.0906 (2) Å	T = 300 K
V = 626.36 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1046 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	997 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.018
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.7°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→10
Tmin = 0.688, Tmax = 1.000	l = −10→11
3680 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.034	w = 1/[σ^2(Fo^2) + (0.0448P)^2 + 0.1954P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.091	(Δ/σ)max < 0.001
S = 1.10	Δρmax = 0.13 e Å^−3
1046 reflections	Δρmin = −0.22 e Å^−3
91 parameters	Absolute structure: Flack x determined using 378 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.489 (6)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29048 (16)	0.33468 (10)	0.32125 (12)	0.0758 (4)
N4	0.3556 (4)	0.7485 (3)	0.4123 (3)	0.0481 (7)
N5	0.3659 (4)	0.5953 (3)	0.4188 (3)	0.0525 (7)
N3	0.4277 (5)	0.8396 (4)	0.5062 (3)	0.0686 (9)
N2	0.3893 (6)	0.9774 (4)	0.4657 (4)	0.0783 (11)
N1	0.2970 (6)	0.9804 (3)	0.3494 (3)	0.0674 (9)
C9	0.2765 (5)	0.8343 (4)	0.3156 (3)	0.0484 (7)
C7	0.2014 (6)	0.6048 (4)	0.2090 (3)	0.0568 (9)
H7	0.149172	0.548711	0.139977	0.068*
C6	0.2869 (5)	0.5305 (4)	0.3177 (3)	0.0501 (8)
C8	0.1965 (6)	0.7577 (4)	0.2068 (3)	0.0574 (9)
H8	0.142695	0.810517	0.136344	0.069*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0849 (7)	0.0417 (5)	0.1009 (8)	−0.0018 (5)	0.0238 (6)	−0.0037 (5)
N4	0.0582 (16)	0.0460 (15)	0.0401 (14)	−0.0028 (13)	−0.0016 (13)	−0.0018 (12)
N5	0.0617 (17)	0.0464 (15)	0.0494 (15)	0.0017 (14)	0.0012 (15)	0.0071 (13)
N3	0.085 (2)	0.068 (2)	0.0531 (17)	−0.014 (2)	−0.0108 (16)	−0.0105 (19)
N2	0.097 (3)	0.059 (2)	0.079 (2)	−0.014 (2)	0.005 (2)	−0.0217 (18)
N1	0.084 (2)	0.0458 (15)	0.0728 (19)	−0.0022 (17)	0.008 (2)	−0.0049 (15)
C9	0.0582 (18)	0.0418 (16)	0.0453 (16)	0.0019 (17)	0.0065 (15)	0.0039 (14)
C7	0.067 (2)	0.061 (2)	0.0418 (17)	−0.0055 (18)	−0.0006 (19)	−0.0090 (15)
C6	0.0553 (19)	0.0422 (16)	0.0529 (18)	−0.0003 (16)	0.0110 (18)	−0.0028 (14)
C8	0.066 (2)	0.064 (2)	0.0415 (17)	0.0038 (19)	−0.0031 (18)	0.0080 (15)

Geometric parameters (Å, º)

Cl1—C6	1.721 (3)	N1—C9	1.336 (4)
N4—N5	1.350 (4)	C9—C8	1.406 (5)
N4—N3	1.341 (4)	C7—H7	0.9300
N4—C9	1.354 (4)	C7—C6	1.411 (5)
N5—C6	1.295 (5)	C7—C8	1.344 (5)
N3—N2	1.306 (5)	C8—H8	0.9300
N2—N1	1.343 (5)
N5—N4—C9	127.8 (3)	C6—C7—H7	120.4
N3—N4—N5	122.7 (3)	C8—C7—H7	120.4
N3—N4—C9	109.5 (3)	C8—C7—C6	119.1 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.6 (3)
N2—N3—N4	104.7 (3)	N5—C6—C7	126.4 (3)
N3—N2—N1	113.1 (3)	C7—C6—Cl1	119.0 (3)
C9—N1—N2	104.9 (3)	C9—C8—H8	121.5
N4—C9—C8	117.5 (3)	C7—C8—C9	117.1 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.5
N1—C9—C8	134.7 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	0.1 (5)
N4—N5—C6—C7	1.3 (5)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	−0.5 (5)	N2—N1—C9—C8	−178.9 (4)
N4—C9—C8—C7	1.5 (6)	N1—C9—C8—C7	−179.3 (4)
N5—N4—N3—N2	−179.6 (3)	C9—N4—N5—C6	−0.4 (5)
N5—N4—C9—N1	179.6 (3)	C9—N4—N3—N2	0.7 (4)
N5—N4—C9—C8	−1.0 (6)	C6—C7—C8—C9	−0.7 (6)
N3—N4—N5—C6	179.9 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.6 (4)	C8—C7—C6—N5	−0.7 (6)
N3—N4—C9—C8	178.8 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@275K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.655 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2552 reflections
a = 7.0604 (2) Å	θ = 6.7–64.7°
b = 8.7800 (2) Å	µ = 4.78 mm^−1
c = 10.0712 (2) Å	T = 275 K
V = 624.32 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1044 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	999 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.018
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.8°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −10→9
Tmin = 0.674, Tmax = 1.000	l = −11→10
3674 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.033	w = 1/[σ^2(Fo^2) + (0.0395P)^2 + 0.2676P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.085	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.13 e Å^−3
1044 reflections	Δρmin = −0.19 e Å^−3
91 parameters	Absolute structure: Flack x determined using 380 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.486 (7)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29038 (15)	0.33417 (10)	0.32067 (11)	0.0694 (4)
N4	0.3563 (4)	0.7482 (3)	0.4120 (3)	0.0445 (7)
N5	0.3668 (4)	0.5951 (3)	0.4184 (3)	0.0483 (7)
N3	0.4287 (5)	0.8389 (4)	0.5063 (3)	0.0631 (8)
N2	0.3906 (6)	0.9774 (4)	0.4658 (4)	0.0714 (10)
N1	0.2975 (6)	0.9806 (3)	0.3493 (3)	0.0620 (9)
C9	0.2766 (5)	0.8344 (4)	0.3153 (3)	0.0445 (7)
C7	0.2011 (6)	0.6048 (4)	0.2086 (3)	0.0525 (8)
H7	0.148917	0.548741	0.139328	0.063*
C6	0.2869 (5)	0.5303 (4)	0.3175 (3)	0.0462 (8)
C8	0.1959 (6)	0.7579 (4)	0.2065 (3)	0.0531 (8)
H8	0.141406	0.810760	0.136232	0.064*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0785 (6)	0.0383 (5)	0.0913 (7)	−0.0018 (5)	0.0213 (5)	−0.0032 (5)
N4	0.0550 (16)	0.0411 (14)	0.0373 (14)	−0.0038 (13)	−0.0005 (13)	−0.0018 (12)
N5	0.0573 (16)	0.0424 (15)	0.0452 (15)	0.0006 (14)	0.0013 (15)	0.0059 (12)
N3	0.079 (2)	0.0607 (19)	0.0493 (16)	−0.011 (2)	−0.0091 (16)	−0.0101 (18)
N2	0.090 (3)	0.053 (2)	0.070 (2)	−0.0122 (19)	0.005 (2)	−0.0191 (17)
N1	0.078 (2)	0.0424 (15)	0.0661 (19)	−0.0016 (16)	0.0071 (19)	−0.0039 (14)
C9	0.0542 (18)	0.0387 (16)	0.0406 (15)	0.0020 (17)	0.0051 (15)	0.0044 (14)
C7	0.061 (2)	0.058 (2)	0.0385 (17)	−0.0058 (18)	−0.0004 (18)	−0.0087 (14)
C6	0.0516 (19)	0.0389 (16)	0.0480 (17)	−0.0010 (16)	0.0115 (18)	−0.0029 (14)
C8	0.061 (2)	0.059 (2)	0.0399 (17)	0.0032 (18)	−0.0027 (18)	0.0070 (15)

Geometric parameters (Å, º)

Cl1—C6	1.722 (3)	N1—C9	1.336 (4)
N4—N5	1.348 (4)	C9—C8	1.406 (5)
N4—N3	1.340 (4)	C7—H7	0.9300
N4—C9	1.356 (4)	C7—C6	1.413 (5)
N5—C6	1.294 (5)	C7—C8	1.345 (5)
N3—N2	1.311 (5)	C8—H8	0.9300
N2—N1	1.345 (5)
N5—N4—C9	127.9 (3)	C6—C7—H7	120.4
N3—N4—N5	122.5 (3)	C8—C7—H7	120.4
N3—N4—C9	109.6 (3)	C8—C7—C6	119.1 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.8 (3)
N2—N3—N4	104.6 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	113.0 (3)	C7—C6—Cl1	118.9 (3)
C9—N1—N2	104.9 (3)	C9—C8—H8	121.5
N4—C9—C8	117.4 (3)	C7—C8—C9	117.0 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.5
N1—C9—C8	134.7 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	0.0 (5)
N4—N5—C6—C7	1.6 (5)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	−0.3 (5)	N2—N1—C9—C8	−179.0 (4)
N4—C9—C8—C7	1.3 (6)	N1—C9—C8—C7	−179.5 (4)
N5—N4—N3—N2	−179.8 (3)	C9—N4—N5—C6	−0.6 (5)
N5—N4—C9—N1	179.8 (3)	C9—N4—N3—N2	0.5 (4)
N5—N4—C9—C8	−0.8 (6)	C6—C7—C8—C9	−0.4 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.1 (3)
N3—N4—C9—N1	−0.5 (4)	C8—C7—C6—N5	−1.2 (6)
N3—N4—C9—C8	178.9 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@250K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.660 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2554 reflections
a = 7.0533 (2) Å	θ = 6.7–64.7°
b = 8.7742 (2) Å	µ = 4.80 mm^−1
c = 10.0552 (2) Å	T = 250 K
V = 622.29 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1038 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1006 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.017
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.6°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −10→9
Tmin = 0.705, Tmax = 1.000	l = −11→10
3654 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.033	w = 1/[σ^2(Fo^2) + (0.0428P)^2 + 0.2471P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.086	(Δ/σ)max < 0.001
S = 1.08	Δρmax = 0.12 e Å^−3
1038 reflections	Δρmin = −0.18 e Å^−3
91 parameters	Absolute structure: Flack x determined using 379 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.487 (7)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29021 (15)	0.33374 (10)	0.32018 (10)	0.0632 (3)
N4	0.3572 (4)	0.7481 (3)	0.4117 (3)	0.0409 (6)
N5	0.3675 (4)	0.5948 (3)	0.4182 (3)	0.0444 (7)
N3	0.4304 (5)	0.8389 (4)	0.5062 (3)	0.0576 (8)
N2	0.3923 (6)	0.9773 (4)	0.4659 (3)	0.0655 (10)
N1	0.2981 (5)	0.9807 (3)	0.3492 (3)	0.0570 (8)
C9	0.2768 (5)	0.8344 (3)	0.3152 (3)	0.0409 (7)
C7	0.2005 (6)	0.6046 (4)	0.2083 (3)	0.0484 (8)
H7	0.147632	0.548551	0.139069	0.058*
C6	0.2867 (5)	0.5299 (4)	0.3171 (3)	0.0427 (7)
C8	0.1958 (6)	0.7579 (4)	0.2061 (3)	0.0491 (8)
H8	0.141421	0.810960	0.135661	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0723 (6)	0.0348 (5)	0.0826 (7)	−0.0019 (5)	0.0189 (5)	−0.0032 (4)
N4	0.0512 (15)	0.0377 (14)	0.0337 (13)	−0.0028 (12)	−0.0009 (13)	−0.0019 (12)
N5	0.0537 (16)	0.0388 (15)	0.0406 (14)	0.0007 (13)	0.0022 (14)	0.0053 (12)
N3	0.073 (2)	0.0551 (19)	0.0443 (15)	−0.0099 (19)	−0.0085 (15)	−0.0086 (17)
N2	0.083 (2)	0.0499 (19)	0.063 (2)	−0.0113 (18)	0.0037 (19)	−0.0164 (16)
N1	0.071 (2)	0.0391 (15)	0.0605 (18)	−0.0010 (16)	0.0066 (18)	−0.0029 (14)
C9	0.0507 (17)	0.0349 (16)	0.0371 (15)	0.0019 (16)	0.0054 (14)	0.0037 (13)
C7	0.058 (2)	0.0521 (19)	0.0348 (16)	−0.0044 (17)	0.0001 (18)	−0.0083 (14)
C6	0.0488 (18)	0.0352 (16)	0.0442 (17)	−0.0006 (15)	0.0102 (17)	−0.0022 (13)
C8	0.057 (2)	0.054 (2)	0.0356 (16)	0.0027 (17)	−0.0014 (17)	0.0065 (14)

Geometric parameters (Å, º)

Cl1—C6	1.722 (3)	N1—C9	1.336 (4)
N4—N5	1.348 (4)	C9—C8	1.408 (5)
N4—N3	1.343 (4)	C7—H7	0.9300
N4—C9	1.355 (4)	C7—C6	1.413 (5)
N5—C6	1.297 (4)	C7—C8	1.346 (5)
N3—N2	1.308 (5)	C8—H8	0.9300
N2—N1	1.349 (5)
N5—N4—C9	127.9 (3)	C6—C7—H7	120.4
N3—N4—N5	122.4 (3)	C8—C7—H7	120.4
N3—N4—C9	109.6 (3)	C8—C7—C6	119.1 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.7 (3)
N2—N3—N4	104.6 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	113.0 (3)	C7—C6—Cl1	118.9 (3)
C9—N1—N2	104.9 (3)	C9—C8—H8	121.5
N4—C9—C8	117.5 (3)	C7—C8—C9	117.0 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.5
N1—C9—C8	134.7 (3)
N4—N5—C6—Cl1	−178.8 (2)	N3—N2—N1—C9	−0.1 (4)
N4—N5—C6—C7	1.6 (5)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	−0.2 (4)	N2—N1—C9—C8	−178.7 (4)
N4—C9—C8—C7	1.7 (6)	N1—C9—C8—C7	−179.4 (4)
N5—N4—N3—N2	−179.7 (3)	C9—N4—N5—C6	−0.5 (5)
N5—N4—C9—N1	179.7 (3)	C9—N4—N3—N2	0.3 (4)
N5—N4—C9—C8	−1.1 (6)	C6—C7—C8—C9	−0.7 (6)
N3—N4—N5—C6	179.6 (3)	C8—C7—C6—Cl1	179.4 (3)
N3—N4—C9—N1	−0.4 (4)	C8—C7—C6—N5	−1.1 (6)
N3—N4—C9—C8	178.8 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@225K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.666 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2569 reflections
a = 7.0476 (2) Å	θ = 6.7–64.0°
b = 8.7682 (2) Å	µ = 4.82 mm^−1
c = 10.0363 (2) Å	T = 225 K
V = 620.19 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1034 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1003 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.017
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.7°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −10→9
Tmin = 0.649, Tmax = 1.000	l = −11→10
3647 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.032	w = 1/[σ^2(Fo^2) + (0.0408P)^2 + 0.2669P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.085	(Δ/σ)max < 0.001
S = 1.12	Δρmax = 0.14 e Å^−3
1034 reflections	Δρmin = −0.18 e Å^−3
91 parameters	Absolute structure: Flack x determined using 383 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.490 (7)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29001 (14)	0.33334 (10)	0.31975 (10)	0.0570 (3)
N4	0.3581 (4)	0.7481 (3)	0.4117 (3)	0.0373 (6)
N5	0.3680 (4)	0.5944 (3)	0.4182 (3)	0.0406 (7)
N3	0.4316 (4)	0.8387 (4)	0.5061 (3)	0.0521 (8)
N2	0.3940 (6)	0.9774 (4)	0.4659 (3)	0.0592 (9)
N1	0.2988 (5)	0.9809 (3)	0.3491 (3)	0.0515 (8)
C9	0.2768 (5)	0.8345 (4)	0.3150 (3)	0.0373 (7)
C7	0.1997 (6)	0.6048 (4)	0.2078 (3)	0.0443 (8)
H7	0.145998	0.548842	0.138690	0.053*
C6	0.2870 (5)	0.5296 (4)	0.3166 (3)	0.0390 (7)
C8	0.1955 (6)	0.7583 (4)	0.2057 (3)	0.0446 (8)
H8	0.141301	0.811515	0.135118	0.054*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0656 (6)	0.0315 (4)	0.0738 (6)	−0.0017 (5)	0.0167 (5)	−0.0030 (4)
N4	0.0463 (15)	0.0344 (14)	0.0311 (13)	−0.0022 (12)	−0.0008 (13)	−0.0014 (11)
N5	0.0496 (16)	0.0349 (14)	0.0373 (14)	0.0009 (13)	0.0033 (14)	0.0050 (12)
N3	0.0669 (19)	0.0491 (18)	0.0402 (15)	−0.0101 (18)	−0.0072 (15)	−0.0082 (17)
N2	0.076 (2)	0.0442 (18)	0.0577 (19)	−0.0104 (17)	0.0037 (18)	−0.0152 (15)
N1	0.064 (2)	0.0359 (14)	0.0547 (17)	−0.0012 (15)	0.0052 (17)	−0.0038 (13)
C9	0.0457 (17)	0.0328 (16)	0.0334 (15)	0.0019 (16)	0.0050 (14)	0.0039 (13)
C7	0.052 (2)	0.0486 (19)	0.0317 (16)	−0.0045 (17)	0.0006 (18)	−0.0079 (14)
C6	0.0455 (18)	0.0318 (16)	0.0396 (17)	−0.0005 (15)	0.0089 (17)	−0.0022 (13)
C8	0.052 (2)	0.0493 (19)	0.0321 (16)	0.0026 (17)	−0.0002 (17)	0.0063 (14)

Geometric parameters (Å, º)

Cl1—C6	1.721 (3)	N1—C9	1.338 (4)
N4—N5	1.351 (4)	C9—C8	1.407 (5)
N4—N3	1.341 (4)	C7—H7	0.9300
N4—C9	1.358 (4)	C7—C6	1.416 (5)
N5—C6	1.299 (4)	C7—C8	1.347 (5)
N3—N2	1.309 (4)	C8—H8	0.9300
N2—N1	1.351 (5)
N5—N4—C9	127.8 (3)	C6—C7—H7	120.4
N3—N4—N5	122.5 (3)	C8—C7—H7	120.4
N3—N4—C9	109.7 (3)	C8—C7—C6	119.2 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.7 (3)
N2—N3—N4	104.7 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	112.9 (3)	C7—C6—Cl1	119.0 (3)
C9—N1—N2	104.9 (3)	C9—C8—H8	121.5
N4—C9—C8	117.7 (3)	C7—C8—C9	117.0 (3)
N1—C9—N4	107.7 (3)	C7—C8—H8	121.5
N1—C9—C8	134.6 (3)
N4—N5—C6—Cl1	−178.8 (2)	N3—N2—N1—C9	−0.1 (4)
N4—N5—C6—C7	1.2 (5)	N2—N1—C9—N4	0.2 (4)
N4—N3—N2—N1	0.0 (4)	N2—N1—C9—C8	−178.4 (4)
N4—C9—C8—C7	2.0 (6)	N1—C9—C8—C7	−179.5 (4)
N5—N4—N3—N2	−179.7 (3)	C9—N4—N5—C6	−0.1 (5)
N5—N4—C9—N1	179.6 (3)	C9—N4—N3—N2	0.1 (4)
N5—N4—C9—C8	−1.5 (6)	C6—C7—C8—C9	−1.1 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.4 (3)
N3—N4—C9—N1	−0.2 (4)	C8—C7—C6—N5	−0.6 (6)
N3—N4—C9—C8	178.7 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@200K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.672 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2643 reflections
a = 7.0422 (2) Å	θ = 5.0–64.7°
b = 8.7617 (2) Å	µ = 4.83 mm^−1
c = 10.0158 (2) Å	T = 200 K
V = 617.99 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1032 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	999 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.017
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.8°, θmin = 6.7°
ω scans	h = −8→6
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→10
Tmin = 0.652, Tmax = 1.000	l = −11→10
3628 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.0387P)^2 + 0.3157P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.080	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.16 e Å^−3
1032 reflections	Δρmin = −0.18 e Å^−3
91 parameters	Absolute structure: Flack x determined using 384 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.474 (6)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28981 (13)	0.33294 (9)	0.31932 (9)	0.0512 (3)
N4	0.3589 (4)	0.7476 (3)	0.4115 (3)	0.0334 (6)
N5	0.3688 (4)	0.5941 (3)	0.4179 (3)	0.0368 (7)
N3	0.4329 (4)	0.8383 (4)	0.5060 (3)	0.0470 (7)
N2	0.3951 (5)	0.9772 (4)	0.4661 (3)	0.0535 (9)
N1	0.2994 (5)	0.9809 (3)	0.3491 (3)	0.0464 (8)
C9	0.2775 (5)	0.8348 (3)	0.3149 (3)	0.0342 (7)
C7	0.1995 (5)	0.6047 (4)	0.2074 (3)	0.0398 (8)
H7	0.145827	0.548787	0.138122	0.048*
C6	0.2871 (5)	0.5293 (3)	0.3163 (3)	0.0353 (7)
C8	0.1950 (5)	0.7585 (4)	0.2054 (3)	0.0402 (8)
H8	0.139924	0.811820	0.135026	0.048*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0592 (5)	0.0283 (4)	0.0662 (6)	−0.0016 (4)	0.0150 (4)	−0.0028 (4)
N4	0.0420 (14)	0.0311 (13)	0.0272 (12)	−0.0022 (12)	−0.0004 (12)	−0.0005 (11)
N5	0.0451 (15)	0.0320 (14)	0.0335 (14)	0.0009 (13)	0.0025 (14)	0.0049 (11)
N3	0.0605 (17)	0.0448 (17)	0.0357 (14)	−0.0092 (17)	−0.0071 (14)	−0.0076 (16)
N2	0.070 (2)	0.0395 (17)	0.0513 (18)	−0.0090 (16)	0.0031 (17)	−0.0127 (14)
N1	0.058 (2)	0.0325 (14)	0.0492 (16)	−0.0008 (14)	0.0063 (16)	−0.0031 (12)
C9	0.0415 (16)	0.0302 (15)	0.0310 (14)	0.0021 (15)	0.0047 (14)	0.0032 (13)
C7	0.0469 (18)	0.0440 (18)	0.0285 (16)	−0.0046 (15)	0.0003 (17)	−0.0070 (13)
C6	0.0406 (17)	0.0289 (15)	0.0364 (16)	−0.0005 (14)	0.0083 (17)	−0.0021 (13)
C8	0.0467 (18)	0.0456 (18)	0.0283 (15)	0.0023 (16)	−0.0006 (16)	0.0059 (13)

Geometric parameters (Å, º)

Cl1—C6	1.721 (3)	N1—C9	1.335 (4)
N4—N5	1.349 (4)	C9—C8	1.409 (5)
N4—N3	1.341 (4)	C7—H7	0.9300
N4—C9	1.359 (4)	C7—C6	1.417 (5)
N5—C6	1.299 (4)	C7—C8	1.348 (5)
N3—N2	1.308 (4)	C8—H8	0.9300
N2—N1	1.353 (4)
N5—N4—C9	128.0 (3)	C6—C7—H7	120.4
N3—N4—N5	122.5 (3)	C8—C7—H7	120.4
N3—N4—C9	109.5 (3)	C8—C7—C6	119.2 (3)
C6—N5—N4	112.0 (3)	N5—C6—Cl1	114.7 (2)
N2—N3—N4	104.9 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	112.9 (3)	C7—C6—Cl1	119.0 (2)
C9—N1—N2	104.9 (3)	C9—C8—H8	121.6
N4—C9—C8	117.5 (3)	C7—C8—C9	116.9 (3)
N1—C9—N4	107.9 (3)	C7—C8—H8	121.6
N1—C9—C8	134.6 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	−0.2 (4)
N4—N5—C6—C7	1.3 (5)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	0.0 (4)	N2—N1—C9—C8	−178.7 (4)
N4—C9—C8—C7	1.6 (5)	N1—C9—C8—C7	−179.4 (4)
N5—N4—N3—N2	−179.7 (3)	C9—N4—N5—C6	−0.3 (5)
N5—N4—C9—N1	179.6 (3)	C9—N4—N3—N2	0.2 (4)
N5—N4—C9—C8	−1.2 (5)	C6—C7—C8—C9	−0.7 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.4 (4)	C8—C7—C6—N5	−0.9 (6)
N3—N4—C9—C8	178.9 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@190K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.668 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2441 reflections
a = 7.0473 (2) Å	θ = 5.0–64.4°
b = 8.7636 (2) Å	µ = 4.82 mm^−1
c = 10.0299 (2) Å	T = 190 K
V = 619.44 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1032 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1001 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.018
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.8°, θmin = 6.7°
ω scans	h = −8→6
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −10→9
Tmin = 0.661, Tmax = 1.000	l = −10→11
3643 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.034	w = 1/[σ^2(Fo^2) + (0.0473P)^2 + 0.3109P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.091	(Δ/σ)max < 0.001
S = 1.09	Δρmax = 0.27 e Å^−3
1032 reflections	Δρmin = −0.19 e Å^−3
91 parameters	Absolute structure: Flack x determined using 381 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.484 (7)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28971 (15)	0.33299 (10)	0.31933 (10)	0.0552 (4)
N4	0.3589 (5)	0.7478 (3)	0.4117 (3)	0.0377 (7)
N5	0.3688 (5)	0.5941 (3)	0.4178 (3)	0.0409 (7)
N3	0.4329 (5)	0.8385 (4)	0.5061 (3)	0.0508 (8)
N2	0.3953 (6)	0.9770 (4)	0.4662 (4)	0.0578 (10)
N1	0.2998 (6)	0.9809 (4)	0.3491 (3)	0.0500 (9)
C9	0.2776 (5)	0.8349 (4)	0.3150 (3)	0.0381 (7)
C7	0.1999 (6)	0.6050 (4)	0.2074 (3)	0.0437 (9)
H7	0.146702	0.549069	0.138065	0.052*
C6	0.2869 (5)	0.5295 (4)	0.3166 (3)	0.0394 (8)
C8	0.1952 (6)	0.7586 (4)	0.2054 (3)	0.0441 (9)
H8	0.140148	0.811878	0.135199	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0675 (6)	0.0293 (5)	0.0689 (6)	−0.0015 (5)	0.0148 (5)	−0.0029 (4)
N4	0.0512 (17)	0.0317 (14)	0.0304 (14)	−0.0029 (13)	−0.0007 (14)	−0.0010 (12)
N5	0.0529 (17)	0.0328 (15)	0.0369 (15)	0.0002 (14)	0.0029 (15)	0.0047 (12)
N3	0.069 (2)	0.0449 (18)	0.0387 (16)	−0.0094 (18)	−0.0064 (15)	−0.0062 (17)
N2	0.078 (3)	0.0407 (18)	0.0544 (19)	−0.0084 (18)	0.0029 (19)	−0.0124 (16)
N1	0.065 (2)	0.0335 (15)	0.0513 (17)	−0.0014 (16)	0.0057 (18)	−0.0032 (13)
C9	0.0503 (19)	0.0306 (17)	0.0334 (16)	0.0012 (17)	0.0046 (15)	0.0034 (14)
C7	0.055 (2)	0.0451 (19)	0.0314 (17)	−0.0035 (17)	0.0008 (19)	−0.0076 (14)
C6	0.049 (2)	0.0303 (17)	0.0392 (18)	−0.0014 (16)	0.0085 (18)	−0.0024 (14)
C8	0.055 (2)	0.047 (2)	0.0313 (17)	0.0033 (18)	−0.0003 (18)	0.0059 (15)

Geometric parameters (Å, º)

Cl1—C6	1.722 (3)	N1—C9	1.334 (4)
N4—N5	1.350 (4)	C9—C8	1.411 (5)
N4—N3	1.342 (4)	C7—H7	0.9300
N4—C9	1.361 (4)	C7—C6	1.418 (5)
N5—C6	1.298 (5)	C7—C8	1.347 (5)
N3—N2	1.305 (5)	C8—H8	0.9300
N2—N1	1.354 (5)
N5—N4—C9	127.9 (3)	C6—C7—H7	120.4
N3—N4—N5	122.6 (3)	C8—C7—H7	120.4
N3—N4—C9	109.5 (3)	C8—C7—C6	119.2 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.7 (3)
N2—N3—N4	104.8 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	113.0 (3)	C7—C6—Cl1	118.9 (3)
C9—N1—N2	104.8 (3)	C9—C8—H8	121.6
N4—C9—C8	117.6 (3)	C7—C8—C9	116.9 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.6
N1—C9—C8	134.6 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	−0.1 (5)
N4—N5—C6—C7	1.7 (6)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	−0.1 (5)	N2—N1—C9—C8	−178.7 (4)
N4—C9—C8—C7	1.5 (6)	N1—C9—C8—C7	−179.6 (4)
N5—N4—N3—N2	−179.8 (3)	C9—N4—N5—C6	−0.5 (6)
N5—N4—C9—N1	179.8 (3)	C9—N4—N3—N2	0.2 (4)
N5—N4—C9—C8	−1.1 (6)	C6—C7—C8—C9	−0.5 (6)
N3—N4—N5—C6	179.6 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.3 (4)	C8—C7—C6—N5	−1.3 (7)
N3—N4—C9—C8	178.8 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@175K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.677 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2763 reflections
a = 7.0342 (1) Å	θ = 5.1–64.2°
b = 8.7569 (2) Å	µ = 4.85 mm^−1
c = 10.0049 (2) Å	T = 175 K
V = 616.28 (2) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1029 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1004 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.016
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.9°, θmin = 6.7°
ω scans	h = −8→6
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −10→9
Tmin = 0.555, Tmax = 1.000	l = −10→11
3623 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.0364P)^2 + 0.3837P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.077	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.15 e Å^−3
1029 reflections	Δρmin = −0.15 e Å^−3
91 parameters	Absolute structure: Flack x determined using 384 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.481 (6)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28970 (13)	0.33255 (9)	0.31896 (9)	0.0457 (3)
N4	0.3593 (4)	0.7477 (3)	0.4115 (3)	0.0307 (6)
N5	0.3695 (4)	0.5940 (3)	0.4178 (3)	0.0333 (6)
N3	0.4343 (4)	0.8381 (4)	0.5060 (3)	0.0423 (7)
N2	0.3966 (5)	0.9773 (4)	0.4659 (3)	0.0480 (8)
N1	0.2999 (5)	0.9812 (3)	0.3491 (3)	0.0420 (7)
C9	0.2777 (5)	0.8346 (3)	0.3148 (3)	0.0310 (6)
C7	0.1992 (5)	0.6047 (4)	0.2071 (3)	0.0363 (7)
H7	0.145246	0.548720	0.137845	0.044*
C6	0.2873 (5)	0.5291 (3)	0.3161 (3)	0.0322 (7)
C8	0.1947 (5)	0.7588 (4)	0.2051 (3)	0.0365 (7)
H8	0.139520	0.812296	0.134748	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0529 (5)	0.0259 (4)	0.0584 (5)	−0.0013 (4)	0.0130 (4)	−0.0027 (4)
N4	0.0386 (14)	0.0283 (13)	0.0253 (13)	−0.0026 (11)	−0.0003 (12)	−0.0009 (11)
N5	0.0411 (15)	0.0283 (13)	0.0304 (14)	0.0001 (12)	0.0026 (13)	0.0040 (11)
N3	0.0540 (17)	0.0404 (17)	0.0326 (14)	−0.0081 (16)	−0.0056 (13)	−0.0069 (15)
N2	0.061 (2)	0.0359 (17)	0.0466 (17)	−0.0077 (15)	0.0026 (16)	−0.0107 (14)
N1	0.0522 (19)	0.0300 (13)	0.0440 (16)	−0.0014 (14)	0.0050 (16)	−0.0031 (12)
C9	0.0376 (16)	0.0277 (15)	0.0275 (14)	0.0021 (15)	0.0047 (13)	0.0041 (13)
C7	0.0434 (18)	0.0398 (17)	0.0258 (15)	−0.0040 (15)	0.0004 (17)	−0.0069 (13)
C6	0.0368 (17)	0.0259 (15)	0.0339 (16)	0.0002 (14)	0.0077 (17)	−0.0018 (13)
C8	0.0421 (18)	0.0411 (18)	0.0264 (16)	0.0023 (16)	0.0006 (16)	0.0049 (13)

Geometric parameters (Å, º)

Cl1—C6	1.722 (3)	N1—C9	1.337 (4)
N4—N5	1.350 (4)	C9—C8	1.410 (5)
N4—N3	1.341 (4)	C7—H7	0.9300
N4—C9	1.358 (4)	C7—C6	1.418 (5)
N5—C6	1.301 (4)	C7—C8	1.350 (5)
N3—N2	1.311 (4)	C8—H8	0.9300
N2—N1	1.353 (4)
N5—N4—C9	127.9 (3)	C6—C7—H7	120.4
N3—N4—N5	122.3 (3)	C8—C7—H7	120.4
N3—N4—C9	109.7 (3)	C8—C7—C6	119.2 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.8 (2)
N2—N3—N4	104.7 (3)	N5—C6—C7	126.3 (3)
N3—N2—N1	113.0 (3)	C7—C6—Cl1	118.9 (2)
C9—N1—N2	104.8 (3)	C9—C8—H8	121.7
N4—C9—C8	117.8 (3)	C7—C8—C9	116.7 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.7
N1—C9—C8	134.4 (3)
N4—N5—C6—Cl1	−178.6 (2)	N3—N2—N1—C9	−0.4 (4)
N4—N5—C6—C7	1.5 (5)	N2—N1—C9—N4	0.5 (4)
N4—N3—N2—N1	0.1 (4)	N2—N1—C9—C8	−178.4 (4)
N4—C9—C8—C7	1.7 (5)	N1—C9—C8—C7	−179.5 (4)
N5—N4—N3—N2	−180.0 (3)	C9—N4—N5—C6	−0.4 (5)
N5—N4—C9—N1	179.8 (3)	C9—N4—N3—N2	0.2 (4)
N5—N4—C9—C8	−1.1 (5)	C6—C7—C8—C9	−0.8 (6)
N3—N4—N5—C6	179.8 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.5 (4)	C8—C7—C6—N5	−0.9 (6)
N3—N4—C9—C8	178.7 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@160K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.676 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2653 reflections
a = 7.0336 (2) Å	θ = 5.1–64.8°
b = 8.7575 (2) Å	µ = 4.85 mm^−1
c = 10.0065 (2) Å	T = 160 K
V = 616.37 (3) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1028 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1009 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.016
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.9°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→10
Tmin = 0.664, Tmax = 1.000	l = −10→11
3626 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.031	w = 1/[σ^2(Fo^2) + (0.0382P)^2 + 0.3868P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.080	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.15 e Å^−3
1028 reflections	Δρmin = −0.15 e Å^−3
91 parameters	Absolute structure: Flack x determined using 383 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.480 (7)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28963 (13)	0.33241 (9)	0.31888 (9)	0.0455 (3)
N4	0.3598 (4)	0.7476 (3)	0.4114 (3)	0.0310 (6)
N5	0.3696 (4)	0.5938 (3)	0.4178 (3)	0.0335 (7)
N3	0.4347 (4)	0.8380 (4)	0.5061 (3)	0.0420 (7)
N2	0.3972 (5)	0.9772 (4)	0.4660 (3)	0.0474 (8)
N1	0.3004 (5)	0.9812 (3)	0.3490 (3)	0.0417 (7)
C9	0.2780 (5)	0.8348 (4)	0.3149 (3)	0.0313 (7)
C7	0.1988 (5)	0.6048 (4)	0.2069 (3)	0.0363 (8)
H7	0.144391	0.548941	0.137751	0.044*
C6	0.2873 (5)	0.5291 (3)	0.3161 (3)	0.0325 (7)
C8	0.1949 (5)	0.7589 (4)	0.2050 (3)	0.0366 (8)
H8	0.140145	0.812521	0.134631	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0538 (5)	0.0254 (4)	0.0571 (5)	−0.0015 (4)	0.0123 (4)	−0.0024 (4)
N4	0.0400 (15)	0.0273 (13)	0.0258 (13)	−0.0026 (12)	−0.0001 (12)	−0.0013 (11)
N5	0.0422 (15)	0.0279 (14)	0.0305 (14)	−0.0002 (13)	0.0023 (14)	0.0040 (11)
N3	0.0553 (17)	0.0385 (17)	0.0321 (14)	−0.0073 (17)	−0.0054 (14)	−0.0050 (15)
N2	0.062 (2)	0.0349 (17)	0.0450 (17)	−0.0072 (15)	0.0034 (16)	−0.0106 (14)
N1	0.0522 (19)	0.0295 (14)	0.0434 (16)	−0.0008 (14)	0.0050 (16)	−0.0027 (12)
C9	0.0387 (16)	0.0270 (15)	0.0281 (14)	0.0016 (16)	0.0049 (14)	0.0034 (13)
C7	0.0430 (19)	0.0392 (18)	0.0267 (16)	−0.0039 (15)	0.0007 (17)	−0.0065 (13)
C6	0.0373 (17)	0.0266 (15)	0.0334 (16)	−0.0003 (15)	0.0084 (17)	−0.0019 (13)
C8	0.0428 (19)	0.0407 (18)	0.0265 (16)	0.0018 (16)	0.0008 (17)	0.0046 (13)

Geometric parameters (Å, º)

Cl1—C6	1.723 (3)	N1—C9	1.336 (4)
N4—N5	1.350 (4)	C9—C8	1.411 (5)
N4—N3	1.343 (4)	C7—H7	0.9300
N4—C9	1.359 (4)	C7—C6	1.421 (5)
N5—C6	1.301 (4)	C7—C8	1.350 (5)
N3—N2	1.310 (4)	C8—H8	0.9300
N2—N1	1.354 (5)
N5—N4—C9	128.0 (3)	C6—C7—H7	120.5
N3—N4—N5	122.4 (3)	C8—C7—H7	120.5
N3—N4—C9	109.7 (3)	C8—C7—C6	119.1 (3)
C6—N5—N4	112.0 (3)	N5—C6—Cl1	114.7 (2)
N2—N3—N4	104.6 (3)	N5—C6—C7	126.4 (3)
N3—N2—N1	113.0 (3)	C7—C6—Cl1	118.9 (2)
C9—N1—N2	104.8 (3)	C9—C8—H8	121.6
N4—C9—C8	117.7 (3)	C7—C8—C9	116.8 (3)
N1—C9—N4	107.9 (3)	C7—C8—H8	121.6
N1—C9—C8	134.4 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	−0.3 (4)
N4—N5—C6—C7	1.3 (5)	N2—N1—C9—N4	0.4 (4)
N4—N3—N2—N1	0.1 (4)	N2—N1—C9—C8	−178.4 (4)
N4—C9—C8—C7	1.9 (5)	N1—C9—C8—C7	−179.5 (4)
N5—N4—N3—N2	−179.9 (3)	C9—N4—N5—C6	−0.3 (5)
N5—N4—C9—N1	179.7 (3)	C9—N4—N3—N2	0.1 (4)
N5—N4—C9—C8	−1.3 (5)	C6—C7—C8—C9	−1.0 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.3 (3)
N3—N4—C9—N1	−0.3 (4)	C8—C7—C6—N5	−0.7 (6)
N3—N4—C9—C8	178.7 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@150K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.680 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2774 reflections
a = 7.0291 (1) Å	θ = 5.1–64.2°
b = 8.7539 (1) Å	µ = 4.86 mm^−1
c = 9.9932 (2) Å	T = 150 K
V = 614.90 (2) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1023 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1010 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.016
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.8°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→10
Tmin = 0.675, Tmax = 1.000	l = −10→11
3613 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.031	w = 1/[σ^2(Fo^2) + (0.038P)^2 + 0.4114P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.078	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.14 e Å^−3
1023 reflections	Δρmin = −0.15 e Å^−3
91 parameters	Absolute structure: Flack x determined using 380 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.491 (6)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28958 (13)	0.33211 (9)	0.31862 (9)	0.0407 (3)
N4	0.3602 (4)	0.7477 (3)	0.4113 (3)	0.0275 (6)
N5	0.3700 (4)	0.5937 (3)	0.4176 (3)	0.0300 (6)
N3	0.4355 (4)	0.8380 (4)	0.5059 (3)	0.0377 (7)
N2	0.3977 (5)	0.9771 (4)	0.4662 (3)	0.0426 (8)
N1	0.3007 (5)	0.9813 (3)	0.3490 (3)	0.0375 (7)
C9	0.2781 (5)	0.8347 (3)	0.3148 (3)	0.0282 (6)
C7	0.1987 (5)	0.6047 (4)	0.2067 (3)	0.0329 (7)
H7	0.144544	0.548845	0.137277	0.039*
C6	0.2871 (5)	0.5290 (3)	0.3160 (3)	0.0293 (7)
C8	0.1945 (5)	0.7589 (4)	0.2050 (3)	0.0329 (7)
H8	0.139126	0.812618	0.134733	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0471 (5)	0.0235 (4)	0.0514 (5)	−0.0013 (4)	0.0111 (4)	−0.0024 (3)
N4	0.0348 (14)	0.0250 (13)	0.0228 (13)	−0.0030 (11)	−0.0001 (12)	−0.0008 (11)
N5	0.0367 (14)	0.0259 (13)	0.0273 (13)	−0.0002 (12)	0.0027 (13)	0.0035 (11)
N3	0.0483 (16)	0.0362 (16)	0.0287 (14)	−0.0062 (16)	−0.0045 (13)	−0.0051 (14)
N2	0.0546 (19)	0.0328 (16)	0.0405 (16)	−0.0062 (15)	0.0028 (15)	−0.0089 (13)
N1	0.0460 (18)	0.0276 (13)	0.0389 (15)	−0.0012 (14)	0.0048 (15)	−0.0027 (12)
C9	0.0336 (16)	0.0256 (15)	0.0254 (14)	0.0012 (15)	0.0051 (13)	0.0032 (13)
C7	0.0391 (18)	0.0363 (17)	0.0232 (15)	−0.0034 (15)	0.0009 (17)	−0.0062 (12)
C6	0.0330 (17)	0.0246 (15)	0.0303 (16)	−0.0005 (14)	0.0076 (16)	−0.0021 (13)
C8	0.0372 (18)	0.0374 (18)	0.0241 (15)	0.0026 (15)	0.0008 (16)	0.0040 (13)

Geometric parameters (Å, º)

Cl1—C6	1.724 (3)	N1—C9	1.337 (4)
N4—N5	1.351 (4)	C9—C8	1.411 (5)
N4—N3	1.342 (4)	C7—H7	0.9300
N4—C9	1.358 (4)	C7—C6	1.421 (5)
N5—C6	1.300 (4)	C7—C8	1.351 (5)
N3—N2	1.308 (4)	C8—H8	0.9300
N2—N1	1.355 (4)
N5—N4—C9	127.9 (3)	C6—C7—H7	120.5
N3—N4—N5	122.4 (3)	C8—C7—H7	120.5
N3—N4—C9	109.7 (3)	C8—C7—C6	119.0 (3)
C6—N5—N4	112.1 (3)	N5—C6—Cl1	114.8 (2)
N2—N3—N4	104.8 (3)	N5—C6—C7	126.4 (3)
N3—N2—N1	112.9 (3)	C7—C6—Cl1	118.8 (2)
C9—N1—N2	104.8 (3)	C9—C8—H8	121.6
N4—C9—C8	117.8 (3)	C7—C8—C9	116.8 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.6
N1—C9—C8	134.4 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	−0.1 (4)
N4—N5—C6—C7	1.6 (5)	N2—N1—C9—N4	0.3 (4)
N4—N3—N2—N1	−0.1 (4)	N2—N1—C9—C8	−178.5 (4)
N4—C9—C8—C7	1.7 (5)	N1—C9—C8—C7	−179.6 (4)
N5—N4—N3—N2	−179.8 (3)	C9—N4—N5—C6	−0.4 (5)
N5—N4—C9—N1	179.8 (3)	C9—N4—N3—N2	0.3 (4)
N5—N4—C9—C8	−1.2 (5)	C6—C7—C8—C9	−0.7 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.3 (4)	C8—C7—C6—N5	−1.1 (6)
N3—N4—C9—C8	178.7 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@130K_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.684 Mg m^−3
Mr = 155.56	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121	Cell parameters from 2782 reflections
a = 7.0245 (1) Å	θ = 5.1–64.2°
b = 8.7517 (1) Å	µ = 4.87 mm^−1
c = 9.9817 (2) Å	T = 130 K
V = 613.64 (2) Å^3	Plate, colourless
Z = 4	0.50 × 0.20 × 0.15 mm
F(000) = 312

Data collection

SuperNova, Single source at offset/far, Atlas diffractometer	1019 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	1010 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.016
Detector resolution: 10.5357 pixels mm^-1	θmax = 64.4°, θmin = 6.7°
ω scans	h = −6→8
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→10
Tmin = 0.602, Tmax = 1.000	l = −10→11
3602 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.029	w = 1/[σ^2(Fo^2) + (0.034P)^2 + 0.4512P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.074	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.14 e Å^−3
1019 reflections	Δρmin = −0.14 e Å^−3
91 parameters	Absolute structure: Flack x determined using 383 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.485 (6)
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.28953 (12)	0.33187 (9)	0.31839 (8)	0.0365 (3)
N4	0.3606 (4)	0.7476 (3)	0.4114 (3)	0.0253 (6)
N5	0.3705 (4)	0.5934 (3)	0.4173 (3)	0.0275 (6)
N3	0.4365 (4)	0.8378 (4)	0.5059 (3)	0.0340 (7)
N2	0.3987 (5)	0.9774 (3)	0.4660 (3)	0.0387 (7)
N1	0.3009 (5)	0.9814 (3)	0.3489 (3)	0.0340 (7)
C9	0.2782 (4)	0.8347 (3)	0.3146 (3)	0.0257 (6)
C7	0.1985 (5)	0.6045 (4)	0.2063 (3)	0.0299 (7)
H7	0.144393	0.548657	0.136859	0.036*
C6	0.2870 (5)	0.5288 (3)	0.3158 (3)	0.0268 (7)
C8	0.1942 (5)	0.7590 (4)	0.2046 (3)	0.0299 (7)
H8	0.138600	0.812696	0.134356	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0427 (5)	0.0211 (4)	0.0457 (5)	−0.0011 (4)	0.0097 (4)	−0.0022 (3)
N4	0.0328 (14)	0.0222 (13)	0.0210 (13)	−0.0025 (11)	0.0000 (12)	−0.0004 (11)
N5	0.0333 (14)	0.0239 (13)	0.0253 (13)	0.0001 (12)	0.0027 (13)	0.0037 (11)
N3	0.0438 (15)	0.0326 (16)	0.0256 (13)	−0.0058 (16)	−0.0040 (12)	−0.0047 (14)
N2	0.0500 (18)	0.0294 (16)	0.0366 (16)	−0.0052 (14)	0.0027 (14)	−0.0079 (13)
N1	0.0419 (17)	0.0255 (13)	0.0344 (15)	−0.0011 (14)	0.0046 (14)	−0.0023 (11)
C9	0.0315 (15)	0.0231 (14)	0.0226 (14)	0.0017 (15)	0.0046 (13)	0.0033 (13)
C7	0.0345 (17)	0.0335 (17)	0.0216 (15)	−0.0028 (14)	0.0014 (16)	−0.0057 (12)
C6	0.0307 (16)	0.0218 (15)	0.0279 (15)	−0.0005 (14)	0.0066 (16)	−0.0018 (13)
C8	0.0336 (17)	0.0343 (17)	0.0219 (15)	0.0019 (15)	0.0011 (16)	0.0036 (13)

Geometric parameters (Å, º)

Cl1—C6	1.724 (3)	N1—C9	1.339 (4)
N4—N5	1.352 (4)	C9—C8	1.412 (5)
N4—N3	1.341 (4)	C7—H7	0.9300
N4—C9	1.360 (4)	C7—C6	1.421 (5)
N5—C6	1.300 (4)	C7—C8	1.352 (4)
N3—N2	1.311 (4)	C8—H8	0.9300
N2—N1	1.357 (4)
N5—N4—C9	127.7 (3)	C6—C7—H7	120.5
N3—N4—N5	122.5 (3)	C8—C7—H7	120.5
N3—N4—C9	109.8 (3)	C8—C7—C6	119.1 (3)
C6—N5—N4	112.2 (3)	N5—C6—Cl1	114.8 (2)
N2—N3—N4	104.7 (3)	N5—C6—C7	126.4 (3)
N3—N2—N1	112.9 (3)	C7—C6—Cl1	118.8 (2)
C9—N1—N2	104.8 (3)	C9—C8—H8	121.6
N4—C9—C8	117.9 (3)	C7—C8—C9	116.7 (3)
N1—C9—N4	107.8 (3)	C7—C8—H8	121.6
N1—C9—C8	134.3 (3)
N4—N5—C6—Cl1	−178.7 (2)	N3—N2—N1—C9	−0.3 (4)
N4—N5—C6—C7	1.8 (5)	N2—N1—C9—N4	0.4 (4)
N4—N3—N2—N1	0.0 (4)	N2—N1—C9—C8	−178.4 (4)
N4—C9—C8—C7	1.6 (5)	N1—C9—C8—C7	−179.6 (4)
N5—N4—N3—N2	−180.0 (3)	C9—N4—N5—C6	−0.6 (5)
N5—N4—C9—N1	179.8 (3)	C9—N4—N3—N2	0.3 (4)
N5—N4—C9—C8	−1.2 (5)	C6—C7—C8—C9	−0.6 (6)
N3—N4—N5—C6	179.7 (3)	C8—C7—C6—Cl1	179.2 (3)
N3—N4—C9—N1	−0.5 (4)	C8—C7—C6—N5	−1.3 (6)
N3—N4—C9—C8	178.6 (3)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_0001GPa_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.647 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 958 reflections
a = 7.0753 (7) Å	θ = 4.2–22.9°
b = 8.7825 (7) Å	µ = 0.53 mm^−1
c = 10.099 (10) Å	T = 296 K
V = 627.5 (6) Å^3	Plate, colorless
Z = 4	0.30 × 0.30 × 0.11 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	475 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	347 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.0°, θmin = 4.2°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −8→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −11→11
Tmin = 0.301, Tmax = 1.000	l = −3→3
3465 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.032	w = 1/[σ^2(Fo^2) + (0.0239P)^2 + 0.1128P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.061	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.09 e Å^−3
475 reflections	Δρmin = −0.09 e Å^−3
91 parameters	Absolute structure: Flack x determined using 108 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.54 (7)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.0001 GPa (100 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2905 (2)	0.33485 (15)	0.3207 (5)	0.080 (3)
N4	0.3563 (8)	0.7499 (6)	0.4125 (16)	0.045 (10)
N5	0.3668 (7)	0.5951 (6)	0.4211 (17)	0.075 (11)
N3	0.4281 (7)	0.8395 (7)	0.5062 (15)	0.078 (9)
N2	0.3878 (11)	0.9788 (8)	0.466 (3)	0.067 (12)
N1	0.2968 (11)	0.9789 (7)	0.347 (2)	0.063 (12)
C9	0.2772 (9)	0.8345 (6)	0.3177 (17)	0.055 (10)
C7	0.2018 (10)	0.6036 (8)	0.208 (2)	0.059 (13)
H7	0.150825	0.546684	0.138571	0.070*
C6	0.2876 (10)	0.5319 (6)	0.3192 (19)	0.057 (11)
C8	0.1973 (9)	0.7594 (7)	0.206 (2)	0.061 (12)
H8	0.144889	0.813322	0.135649	0.073*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0792 (10)	0.0387 (7)	0.122 (8)	−0.0016 (8)	0.023 (2)	−0.0034 (17)
N4	0.047 (3)	0.043 (2)	0.04 (3)	−0.004 (2)	−0.013 (5)	0.002 (6)
N5	0.052 (3)	0.041 (3)	0.13 (3)	−0.001 (2)	0.007 (6)	0.000 (7)
N3	0.077 (4)	0.066 (3)	0.09 (3)	−0.014 (4)	−0.008 (6)	−0.005 (8)
N2	0.089 (6)	0.056 (4)	0.06 (4)	−0.014 (4)	−0.007 (11)	−0.025 (7)
N1	0.078 (6)	0.045 (3)	0.07 (4)	−0.007 (3)	−0.002 (10)	−0.011 (7)
C9	0.045 (3)	0.041 (3)	0.08 (3)	0.001 (3)	−0.003 (7)	0.003 (8)
C7	0.060 (4)	0.060 (3)	0.06 (4)	−0.009 (3)	−0.008 (9)	−0.016 (7)
C6	0.048 (4)	0.039 (3)	0.08 (3)	−0.001 (3)	0.010 (10)	0.007 (7)
C8	0.056 (4)	0.064 (4)	0.06 (4)	0.008 (3)	0.007 (8)	0.017 (8)

Geometric parameters (Å, º)

Cl1—C6	1.731 (6)	N1—C9	1.310 (9)
N4—N5	1.364 (6)	C9—C8	1.42 (2)
N4—N3	1.332 (16)	C7—H7	0.9300
N4—C9	1.335 (17)	C7—C6	1.43 (2)
N5—C6	1.30 (2)	C7—C8	1.369 (8)
N3—N2	1.320 (12)	C8—H8	0.9300
N2—N1	1.36 (3)
N3—N4—N5	121.6 (13)	C6—C7—H7	121.3
N3—N4—C9	109.9 (7)	C8—C7—H7	121.3
C9—N4—N5	128.5 (14)	C8—C7—C6	117.4 (16)
C6—N5—N4	110.7 (14)	N5—C6—Cl1	114.6 (11)
N2—N3—N4	104.2 (13)	N5—C6—C7	128.4 (8)
N3—N2—N1	112.1 (12)	C7—C6—Cl1	117.0 (11)
C9—N1—N2	104.3 (10)	C9—C8—H8	121.8
N4—C9—C8	118.5 (7)	C7—C8—C9	116.3 (15)
N1—C9—N4	109.5 (13)	C7—C8—H8	121.8
N1—C9—C8	131.9 (13)
N4—N5—C6—Cl1	−179.3 (6)	N3—N2—N1—C9	2 (2)
N4—N5—C6—C7	1 (2)	N2—N1—C9—N4	−1.5 (16)
N4—N3—N2—N1	−1.7 (18)	N2—N1—C9—C8	−178.6 (15)
N4—C9—C8—C7	2.5 (15)	N1—C9—C8—C7	179.4 (11)
N5—N4—N3—N2	−178.6 (11)	C9—N4—N5—C6	0.7 (19)
N5—N4—C9—N1	179.8 (11)	C9—N4—N3—N2	0.7 (13)
N5—N4—C9—C8	−2.7 (18)	C6—C7—C8—C9	−0.8 (16)
N3—N4—N5—C6	179.9 (9)	C8—C7—C6—Cl1	179.4 (8)
N3—N4—C9—N1	0.5 (13)	C8—C7—C6—N5	−1 (2)
N3—N4—C9—C8	178.1 (10)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_12GPa_phase_alpha)

Crystal data

C4H2ClN5	Dx = 1.697 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 923 reflections
a = 6.9340 (5) Å	θ = 4.2–22.0°
b = 8.7568 (6) Å	µ = 0.54 mm^−1
c = 10.029 (7) Å	T = 296 K
V = 609.0 (4) Å^3	Plate, colorless
Z = 4	0.30 × 0.30 × 0.11 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	487 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	360 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
Detector resolution: 16.2413 pixels mm^-1	θmax = 26.8°, θmin = 4.3°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −8→8
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −11→10
Tmin = 0.348, Tmax = 1.000	l = −4→4
3365 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.0294P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.059	(Δ/σ)max < 0.001
S = 1.03	Δρmax = 0.10 e Å^−3
487 reflections	Δρmin = −0.09 e Å^−3
91 parameters	Absolute structure: Flack x determined using 117 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.49 (8)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.12 GPa (120000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2929 (2)	0.33348 (13)	0.3228 (4)	0.0746 (19)
N4	0.3555 (7)	0.7512 (5)	0.4137 (14)	0.055 (9)
N5	0.3685 (7)	0.5951 (5)	0.4233 (13)	0.057 (9)
N3	0.4256 (6)	0.8428 (6)	0.5096 (13)	0.065 (7)
N2	0.3845 (9)	0.9812 (7)	0.465 (2)	0.070 (9)
N1	0.2924 (10)	0.9803 (6)	0.3481 (19)	0.064 (10)
C9	0.2749 (8)	0.8338 (6)	0.3169 (15)	0.053 (8)
C7	0.2011 (10)	0.6025 (7)	0.2073 (17)	0.053 (10)
H7	0.150037	0.545129	0.137678	0.064*
C6	0.2875 (9)	0.5309 (6)	0.3192 (17)	0.066 (8)
C8	0.1951 (8)	0.7585 (6)	0.2049 (16)	0.044 (9)
H8	0.141638	0.812069	0.133815	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0758 (9)	0.0341 (7)	0.114 (6)	−0.0007 (7)	0.0193 (18)	−0.0023 (14)
N4	0.041 (3)	0.040 (2)	0.08 (3)	−0.002 (2)	−0.013 (5)	0.006 (5)
N5	0.048 (3)	0.040 (2)	0.08 (3)	0.002 (2)	0.001 (6)	0.011 (5)
N3	0.070 (3)	0.062 (3)	0.06 (2)	−0.015 (3)	−0.009 (6)	−0.004 (7)
N2	0.077 (5)	0.053 (4)	0.08 (3)	−0.013 (3)	0.004 (9)	−0.019 (6)
N1	0.068 (5)	0.039 (3)	0.08 (3)	−0.003 (3)	0.016 (8)	−0.007 (6)
C9	0.042 (3)	0.037 (3)	0.08 (2)	0.002 (3)	−0.006 (6)	−0.005 (7)
C7	0.056 (4)	0.057 (3)	0.05 (3)	−0.010 (3)	0.006 (8)	−0.017 (6)
C6	0.041 (3)	0.034 (3)	0.12 (3)	0.000 (3)	0.019 (9)	0.007 (6)
C8	0.056 (4)	0.055 (3)	0.02 (3)	0.006 (3)	0.004 (7)	0.016 (6)

Geometric parameters (Å, º)

Cl1—C6	1.730 (6)	N1—C9	1.326 (8)
N4—N5	1.373 (6)	C9—C8	1.415 (19)
N4—N3	1.343 (15)	C7—H7	0.9300
N4—C9	1.334 (14)	C7—C6	1.419 (18)
N5—C6	1.312 (19)	C7—C8	1.367 (7)
N3—N2	1.321 (11)	C8—H8	0.9300
N2—N1	1.34 (3)
N3—N4—N5	121.4 (11)	C6—C7—H7	121.0
C9—N4—N5	128.2 (11)	C8—C7—H7	121.0
C9—N4—N3	110.4 (6)	C8—C7—C6	117.9 (13)
C6—N5—N4	110.0 (11)	N5—C6—Cl1	113.7 (10)
N2—N3—N4	103.3 (12)	N5—C6—C7	128.4 (7)
N3—N2—N1	113.1 (10)	C7—C6—Cl1	117.8 (9)
C9—N1—N2	104.9 (9)	C9—C8—H8	122.0
N4—C9—C8	119.3 (6)	C7—C8—C9	116.1 (13)
N1—C9—N4	108.3 (10)	C7—C8—H8	122.0
N1—C9—C8	132.4 (10)
N4—N5—C6—Cl1	−179.1 (5)	N3—N2—N1—C9	0.0 (16)
N4—N5—C6—C7	1.7 (16)	N2—N1—C9—N4	−0.2 (12)
N4—N3—N2—N1	0.2 (15)	N2—N1—C9—C8	−178.5 (13)
N4—C9—C8—C7	2.3 (14)	N1—C9—C8—C7	−179.5 (8)
N5—N4—N3—N2	−179.4 (8)	C9—N4—N5—C6	0.1 (14)
N5—N4—C9—N1	179.3 (8)	C9—N4—N3—N2	−0.3 (11)
N5—N4—C9—C8	−2.1 (15)	C6—C7—C8—C9	−0.8 (14)
N3—N4—N5—C6	179.0 (9)	C8—C7—C6—Cl1	179.4 (6)
N3—N4—C9—N1	0.3 (10)	C8—C7—C6—N5	−1.4 (17)
N3—N4—C9—C8	178.9 (9)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_24GPa_phase_alpha_prim)

Crystal data

C4H2ClN5	Dx = 1.755 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 651 reflections
a = 10.697 (4) Å	θ = 4.4–22.7°
b = 6.2545 (7) Å	µ = 0.56 mm^−1
c = 8.8012 (10) Å	T = 296 K
V = 588.8 (3) Å^3	Plate, colorless
Z = 4	0.30 × 0.26 × 0.11 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	263 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	187 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 16.2413 pixels mm^-1	θmax = 26.9°, θmin = 4.4°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −4→4
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −7→7
Tmin = 0.383, Tmax = 1.000	l = −11→10
2687 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.025	H-atom parameters constrained
wR(F^2) = 0.043	w = 1/[σ^2(Fo^2) + (0.0185P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
263 reflections	Δρmax = 0.08 e Å^−3
61 parameters	Δρmin = −0.09 e Å^−3
6 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.24 GPa (240000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.61551 (16)	0.750000	0.91127 (9)	0.0760 (13)
C6	0.624 (2)	0.750000	0.7158 (5)	0.033 (6)
C7	0.7471 (17)	0.750000	0.6526 (7)	0.050 (9)
H7	0.818559	0.750000	0.712702	0.060*
N6	0.5353 (13)	0.750000	0.4928 (5)	0.035 (5)
N1	0.6188 (12)	0.750000	0.2671 (6)	0.043 (7)
N5	0.5216 (12)	0.750000	0.6465 (5)	0.052 (6)
C8	0.7523 (17)	0.750000	0.4976 (5)	0.069 (7)
H8	0.829630	0.750000	0.449439	0.083*
N2	0.4917 (12)	0.750000	0.2617 (6)	0.069 (8)
N3	0.4408 (11)	0.750000	0.3956 (4)	0.074 (5)
C9	0.6492 (18)	0.750000	0.4150 (6)	0.051 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.115 (4)	0.0785 (5)	0.0346 (5)	0.000	−0.0036 (8)	0.000
C6	0.016 (19)	0.0469 (19)	0.036 (2)	0.000	−0.009 (5)	0.000
C7	0.03 (3)	0.059 (2)	0.066 (5)	0.000	−0.006 (6)	0.000
N6	0.019 (19)	0.0432 (14)	0.044 (3)	0.000	0.005 (5)	0.000
N1	0.02 (2)	0.071 (2)	0.040 (2)	0.000	−0.005 (5)	0.000
N5	0.07 (2)	0.0505 (15)	0.036 (3)	0.000	0.002 (3)	0.000
C8	0.09 (2)	0.061 (2)	0.051 (4)	0.000	0.024 (5)	0.000
N2	0.10 (2)	0.0609 (19)	0.042 (2)	0.000	−0.025 (6)	0.000
N3	0.106 (19)	0.0557 (16)	0.059 (3)	0.000	−0.023 (4)	0.000
C9	0.07 (2)	0.0469 (17)	0.036 (3)	0.000	0.002 (6)	0.000

Geometric parameters (Å, º)

Cl1—C6	1.723 (5)	N6—C9	1.40 (3)
C6—C7	1.43 (3)	N1—N2	1.36 (2)
C6—N5	1.26 (3)	N1—C9	1.341 (10)
C7—H7	0.9300	C8—H8	0.9300
C7—C8	1.365 (8)	C8—C9	1.32 (3)
N6—N5	1.360 (6)	N2—N3	1.298 (12)
N6—N3	1.324 (17)
C7—C6—Cl1	116.0 (16)	C6—N5—N6	112.9 (15)
N5—C6—Cl1	116.0 (16)	C7—C8—H8	119.5
N5—C6—C7	128.0 (6)	C9—C8—C7	121 (2)
C6—C7—H7	122.4	C9—C8—H8	119.5
C8—C7—C6	115.3 (19)	N3—N2—N1	112.7 (8)
C8—C7—H7	122.4	N2—N3—N6	105.5 (13)
N5—N6—C9	125.5 (16)	N1—C9—N6	105.3 (17)
N3—N6—N5	124.1 (14)	C8—C9—N6	117.3 (7)
N3—N6—C9	110.4 (5)	C8—C9—N1	137.4 (18)
C9—N1—N2	106.0 (13)
Cl1—C6—C7—C8	180.000 (2)	N5—N6—C9—C8	0.000 (3)
Cl1—C6—N5—N6	180.000 (2)	N2—N1—C9—N6	0.000 (1)
C6—C7—C8—C9	0.000 (3)	N2—N1—C9—C8	180.000 (1)
C7—C6—N5—N6	0.000 (3)	N3—N6—N5—C6	180.000 (3)
C7—C8—C9—N6	0.000 (3)	N3—N6—C9—N1	0.000 (2)
C7—C8—C9—N1	180.000 (2)	N3—N6—C9—C8	180.000 (1)
N1—N2—N3—N6	0.000 (1)	C9—N6—N5—C6	0.000 (3)
N5—C6—C7—C8	0.000 (5)	C9—N6—N3—N2	0.000 (1)
N5—N6—N3—N2	180.000 (2)	C9—N1—N2—N3	0.000 (1)
N5—N6—C9—N1	180.000 (2)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_49GPa_phase_alpha_prim)

Crystal data

C4H2ClN5	Dx = 1.782 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 710 reflections
a = 10.654 (3) Å	θ = 4.4–22.8°
b = 6.1954 (6) Å	µ = 0.57 mm^−1
c = 8.7823 (8) Å	T = 296 K
V = 579.69 (17) Å^3	Plate, colorless
Z = 4	0.30 × 0.26 × 0.11 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	268 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	191 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.044
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.0°, θmin = 4.5°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −4→4
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −7→7
Tmin = 0.391, Tmax = 1.000	l = −10→11
2828 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.029	H-atom parameters constrained
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.0336P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.14	(Δ/σ)max < 0.001
268 reflections	Δρmax = 0.12 e Å^−3
61 parameters	Δρmin = −0.14 e Å^−3
12 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.49 GPa (490000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.6141 (2)	0.750000	0.91216 (12)	0.0694 (17)
C6	0.6262 (19)	0.750000	0.7176 (6)	0.039 (8)
C7	0.7457 (19)	0.750000	0.6521 (7)	0.054 (9)
H7	0.817347	0.750000	0.712599	0.065*
N6	0.5351 (14)	0.750000	0.4922 (5)	0.033 (3)
N1	0.6181 (17)	0.750000	0.2665 (6)	0.045 (9)
N5	0.5193 (13)	0.750000	0.6462 (5)	0.039 (4)
C8	0.7543 (18)	0.750000	0.4982 (6)	0.047 (9)
H8	0.832342	0.750000	0.450604	0.056*
N2	0.4905 (15)	0.750000	0.2608 (8)	0.056 (10)
N3	0.4401 (14)	0.750000	0.3946 (5)	0.065 (6)
C9	0.648 (2)	0.750000	0.4152 (7)	0.042 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.104 (5)	0.0725 (7)	0.0319 (6)	0.000	−0.0041 (9)	0.000
C6	0.04 (3)	0.042 (2)	0.031 (3)	0.000	−0.006 (5)	0.000
C7	0.06 (3)	0.055 (3)	0.053 (5)	0.000	−0.005 (6)	0.000
N6	0.021 (11)	0.0390 (16)	0.039 (2)	0.000	0.007 (5)	0.000
N1	0.05 (3)	0.056 (2)	0.033 (2)	0.000	−0.007 (6)	0.000
N5	0.032 (12)	0.0480 (17)	0.036 (2)	0.000	0.008 (4)	0.000
C8	0.03 (3)	0.057 (3)	0.057 (5)	0.000	0.023 (5)	0.000
N2	0.06 (3)	0.061 (2)	0.044 (2)	0.000	−0.027 (7)	0.000
N3	0.09 (2)	0.0502 (19)	0.053 (3)	0.000	−0.024 (4)	0.000
C9	0.04 (3)	0.046 (2)	0.037 (4)	0.000	−0.004 (5)	0.000

Geometric parameters (Å, º)

Cl1—C6	1.714 (5)	N6—C9	1.38 (3)
C6—C7	1.40 (3)	N1—N2	1.36 (2)
C6—N5	1.30 (3)	N1—C9	1.344 (10)
C7—H7	0.9300	C8—H8	0.9300
C7—C8	1.356 (8)	C8—C9	1.35 (3)
N6—N5	1.363 (6)	N2—N3	1.291 (13)
N6—N3	1.33 (2)
C7—C6—Cl1	118.6 (15)	C6—N5—N6	111.7 (14)
N5—C6—Cl1	114.5 (14)	C7—C8—H8	120.6
N5—C6—C7	126.9 (7)	C9—C8—C7	119 (2)
C6—C7—H7	120.9	C9—C8—H8	120.6
C8—C7—C6	118.2 (19)	N3—N2—N1	112.5 (11)
C8—C7—H7	120.9	N2—N3—N6	105.7 (16)
N5—N6—C9	126.5 (16)	N1—C9—N6	105.7 (19)
N3—N6—N5	123.2 (15)	N1—C9—C8	136 (2)
N3—N6—C9	110.4 (5)	C8—C9—N6	117.9 (8)
C9—N1—N2	105.8 (15)
Cl1—C6—C7—C8	180.000 (2)	N5—N6—C9—C8	0.000 (3)
Cl1—C6—N5—N6	180.000 (2)	N2—N1—C9—N6	0.000 (2)
C6—C7—C8—C9	0.000 (3)	N2—N1—C9—C8	180.000 (2)
C7—C6—N5—N6	0.000 (3)	N3—N6—N5—C6	180.000 (2)
C7—C8—C9—N6	0.000 (2)	N3—N6—C9—N1	0.000 (2)
C7—C8—C9—N1	180.000 (2)	N3—N6—C9—C8	180.000 (1)
N1—N2—N3—N6	0.000 (2)	C9—N6—N5—C6	0.000 (3)
N5—C6—C7—C8	0.000 (5)	C9—N6—N3—N2	0.000 (2)
N5—N6—N3—N2	180.000 (2)	C9—N1—N2—N3	0.000 (1)
N5—N6—C9—N1	180.000 (2)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_09GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.652 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1187 reflections
a = 7.0542 (4) Å	θ = 3.7–21.7°
b = 8.7774 (14) Å	µ = 0.53 mm^−1
c = 10.1041 (5) Å	T = 296 K
V = 625.62 (11) Å^3	Plate, colorless
Z = 4	0.39 × 0.29 × 0.18 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	764 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	561 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.2°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −8→8
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −6→6
Tmin = 0.421, Tmax = 1.000	l = −12→12
3890 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.036	w = 1/[σ^2(Fo^2) + (0.0387P)^2 + 0.0855P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.084	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.15 e Å^−3
764 reflections	Δρmin = −0.11 e Å^−3
91 parameters	Absolute structure: Flack x determined using 194 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.21 (4)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.09 (2) GPa (90000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29094 (18)	0.3347 (3)	0.32212 (14)	0.0727 (10)
N4	0.3549 (5)	0.7495 (10)	0.4133 (4)	0.047 (3)
N5	0.3656 (5)	0.5974 (11)	0.4187 (4)	0.046 (2)
N3	0.4259 (6)	0.8387 (12)	0.5058 (4)	0.058 (3)
N2	0.3883 (8)	0.9788 (11)	0.4665 (6)	0.072 (4)
N1	0.2961 (7)	0.9829 (10)	0.3471 (5)	0.059 (4)
C9	0.2757 (6)	0.8368 (11)	0.3166 (4)	0.037 (3)
C7	0.2010 (7)	0.6045 (12)	0.2088 (5)	0.053 (3)
H7	0.148234	0.547882	0.140270	0.063*
C6	0.2870 (6)	0.5322 (11)	0.3175 (4)	0.040 (2)
C8	0.1970 (7)	0.7580 (11)	0.2067 (5)	0.051 (3)
H8	0.144484	0.810539	0.135687	0.061*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0781 (9)	0.043 (3)	0.0974 (10)	−0.0017 (10)	0.0241 (7)	−0.0016 (13)
N4	0.050 (2)	0.052 (10)	0.038 (2)	−0.003 (2)	0.0016 (16)	−0.007 (3)
N5	0.055 (2)	0.031 (9)	0.050 (2)	0.001 (3)	0.0024 (18)	0.001 (3)
N3	0.081 (3)	0.038 (10)	0.056 (2)	−0.012 (3)	−0.008 (2)	−0.016 (4)
N2	0.090 (4)	0.038 (14)	0.088 (4)	−0.015 (3)	0.011 (3)	−0.021 (4)
N1	0.072 (3)	0.033 (12)	0.071 (3)	−0.006 (3)	0.008 (2)	−0.010 (4)
C9	0.050 (2)	0.016 (11)	0.044 (2)	−0.001 (3)	0.0043 (18)	0.010 (4)
C7	0.059 (3)	0.059 (11)	0.040 (2)	−0.007 (4)	−0.003 (2)	−0.010 (4)
C6	0.054 (3)	0.012 (8)	0.055 (2)	−0.003 (3)	0.012 (2)	0.005 (4)
C8	0.057 (3)	0.059 (11)	0.038 (2)	0.001 (3)	−0.002 (2)	0.005 (4)

Geometric parameters (Å, º)

Cl1—C6	1.735 (9)	N1—C9	1.327 (11)
N4—N5	1.338 (6)	C9—C8	1.421 (8)
N4—N3	1.318 (10)	C7—H7	0.9300
N4—C9	1.362 (9)	C7—C6	1.406 (9)
N5—C6	1.296 (8)	C7—C8	1.348 (8)
N3—N2	1.319 (10)	C8—H8	0.9300
N2—N1	1.371 (8)
N5—N4—C9	127.8 (6)	C6—C7—H7	120.9
N3—N4—N5	122.8 (6)	C8—C7—H7	120.9
N3—N4—C9	109.3 (8)	C8—C7—C6	118.2 (6)
C6—N5—N4	112.6 (6)	N5—C6—Cl1	114.4 (6)
N4—N3—N2	105.3 (6)	N5—C6—C7	127.0 (10)
N3—N2—N1	112.6 (8)	C7—C6—Cl1	118.6 (6)
C9—N1—N2	103.3 (7)	C9—C8—H8	121.1
N4—C9—C8	116.6 (8)	C7—C8—C9	117.8 (6)
N1—C9—N4	109.4 (5)	C7—C8—H8	121.1
N1—C9—C8	134.0 (7)
N4—N5—C6—Cl1	−178.2 (3)	N3—N2—N1—C9	1.3 (5)
N4—N5—C6—C7	1.4 (7)	N2—N1—C9—N4	−0.8 (5)
N4—N3—N2—N1	−1.3 (5)	N2—N1—C9—C8	−178.5 (5)
N4—C9—C8—C7	2.2 (8)	N1—C9—C8—C7	179.8 (5)
N5—N4—N3—N2	−180.0 (4)	C9—N4—N5—C6	−0.7 (7)
N5—N4—C9—N1	−179.2 (4)	C9—N4—N3—N2	0.7 (5)
N5—N4—C9—C8	−1.0 (7)	C6—C7—C8—C9	−1.7 (8)
N3—N4—N5—C6	−179.9 (4)	C8—C7—C6—Cl1	179.4 (4)
N3—N4—C9—N1	0.0 (5)	C8—C7—C6—N5	−0.2 (8)
N3—N4—C9—C8	178.2 (4)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_10GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.654 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1101 reflections
a = 7.0733 (6) Å	θ = 3.7–21.9°
b = 8.7965 (6) Å	µ = 0.53 mm^−1
c = 10.042 (8) Å	T = 296 K
V = 624.8 (5) Å^3	Plate, colorless
Z = 4	0.38 × 0.29 × 0.21 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	491 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	361 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.049
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.2°, θmin = 3.7°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −8→9
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −11→10
Tmin = 0.061, Tmax = 1.000	l = −3→3
3715 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.034	w = 1/[σ^2(Fo^2) + (0.0252P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.056	(Δ/σ)max < 0.001
S = 1.11	Δρmax = 0.10 e Å^−3
491 reflections	Δρmin = −0.08 e Å^−3
91 parameters	Absolute structure: Flack x determined using 112 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
6 restraints	Absolute structure parameter: −0.06 (6)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.10 (2) GPa (100000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.29054 (18)	0.33488 (12)	0.3213 (4)	0.081 (2)
N4	0.3555 (7)	0.7502 (5)	0.4119 (14)	0.043 (8)
N5	0.3672 (7)	0.5948 (5)	0.4195 (14)	0.063 (8)
N3	0.4272 (6)	0.8393 (7)	0.5081 (12)	0.065 (8)
N2	0.3882 (9)	0.9773 (6)	0.462 (2)	0.079 (10)
N1	0.2949 (9)	0.9803 (6)	0.3498 (19)	0.068 (10)
C9	0.2762 (7)	0.8344 (6)	0.3160 (15)	0.054 (8)
C7	0.2015 (9)	0.6034 (7)	0.2076 (17)	0.054 (11)
H7	0.149998	0.547159	0.138065	0.064*
C6	0.2873 (8)	0.5314 (6)	0.3188 (15)	0.046 (9)
C8	0.1978 (7)	0.7586 (6)	0.2070 (17)	0.051 (8)
H8	0.144775	0.812038	0.136379	0.061*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0809 (9)	0.0409 (7)	0.120 (7)	−0.0014 (7)	0.0209 (17)	−0.0026 (13)
N4	0.049 (3)	0.046 (2)	0.03 (2)	−0.001 (2)	−0.007 (5)	−0.008 (5)
N5	0.052 (3)	0.046 (2)	0.09 (3)	0.003 (2)	−0.006 (6)	0.004 (5)
N3	0.077 (3)	0.069 (3)	0.05 (2)	−0.010 (3)	−0.014 (5)	−0.012 (6)
N2	0.078 (5)	0.055 (3)	0.10 (3)	−0.014 (3)	0.004 (9)	−0.016 (6)
N1	0.067 (5)	0.049 (3)	0.09 (3)	−0.001 (3)	0.012 (8)	−0.008 (5)
C9	0.048 (3)	0.044 (3)	0.07 (3)	0.008 (3)	0.001 (6)	−0.001 (7)
C7	0.059 (4)	0.067 (3)	0.03 (4)	−0.010 (3)	0.006 (8)	−0.008 (6)
C6	0.043 (3)	0.050 (3)	0.05 (3)	0.000 (3)	0.008 (9)	0.005 (6)
C8	0.056 (4)	0.069 (4)	0.03 (2)	0.007 (3)	−0.004 (7)	0.014 (6)

Geometric parameters (Å, º)

Cl1—C6	1.729 (6)	N1—C9	1.335 (9)
N4—N5	1.372 (6)	C9—C8	1.397 (17)
N4—N3	1.343 (14)	C7—H7	0.9300
N4—C9	1.338 (15)	C7—C6	1.420 (17)
N5—C6	1.286 (18)	C7—C8	1.365 (7)
N3—N2	1.330 (11)	C8—H8	0.9300
N2—N1	1.30 (3)
N3—N4—N5	121.2 (12)	C6—C7—H7	121.4
C9—N4—N5	128.1 (12)	C8—C7—H7	121.4
C9—N4—N3	110.7 (6)	C8—C7—C6	117.2 (13)
C6—N5—N4	111.2 (12)	N5—C6—Cl1	114.6 (9)
N2—N3—N4	101.7 (11)	N5—C6—C7	127.9 (8)
N1—N2—N3	115.2 (10)	C7—C6—Cl1	117.6 (9)
N2—N1—C9	104.5 (9)	C9—C8—H8	121.1
N4—C9—C8	117.8 (7)	C7—C8—C9	117.8 (12)
N1—C9—N4	107.9 (11)	C7—C8—H8	121.1
N1—C9—C8	134.2 (11)
N4—N5—C6—Cl1	−178.7 (6)	N3—N2—N1—C9	−2.5 (18)
N4—N5—C6—C7	2.3 (16)	N2—N1—C9—N4	1.6 (14)
N4—N3—N2—N1	2.2 (16)	N2—N1—C9—C8	−177.4 (13)
N4—C9—C8—C7	2.1 (13)	N1—C9—C8—C7	−178.9 (9)
N5—N4—N3—N2	179.4 (9)	C9—N4—N5—C6	−0.6 (16)
N5—N4—C9—N1	179.2 (9)	C9—N4—N3—N2	−1.0 (11)
N5—N4—C9—C8	−1.6 (15)	C6—C7—C8—C9	−0.7 (14)
N3—N4—N5—C6	178.9 (8)	C8—C7—C6—Cl1	179.3 (7)
N3—N4—C9—N1	−0.4 (11)	C8—C7—C6—N5	−1.7 (17)
N3—N4—C9—C8	178.8 (8)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_17GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.668 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1145 reflections
a = 6.9987 (3) Å	θ = 4.2–22.2°
b = 8.7740 (15) Å	µ = 0.53 mm^−1
c = 10.0863 (9) Å	T = 296 K
V = 619.37 (12) Å^3	Plate, colorless
Z = 4	0.37 × 0.27 × 0.16 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	666 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	519 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.1°, θmin = 4.2°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −8→8
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −7→7
Tmin = 0.387, Tmax = 1.000	l = −11→11
3715 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.037	w = 1/[σ^2(Fo^2) + (0.0432P)^2 + 0.1036P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.090	(Δ/σ)max < 0.001
S = 1.09	Δρmax = 0.17 e Å^−3
666 reflections	Δρmin = −0.13 e Å^−3
91 parameters	Absolute structure: Flack x determined using 181 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.39 (5)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.17 (2) GPa (170000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2920 (2)	0.3336 (3)	0.32339 (17)	0.0755 (10)
N4	0.3537 (8)	0.7494 (13)	0.4127 (5)	0.047 (3)
N5	0.3663 (7)	0.5973 (13)	0.4200 (5)	0.048 (2)
N3	0.4249 (7)	0.8405 (12)	0.5071 (5)	0.063 (3)
N2	0.3848 (10)	0.9793 (14)	0.4648 (8)	0.074 (3)
N1	0.2950 (8)	0.9840 (11)	0.3477 (6)	0.064 (3)
C9	0.2750 (8)	0.8358 (11)	0.3158 (5)	0.046 (3)
C7	0.2010 (10)	0.6046 (13)	0.2087 (6)	0.053 (3)
H7	0.148452	0.548371	0.139555	0.063*
C6	0.2873 (7)	0.5303 (11)	0.3180 (5)	0.042 (2)
C8	0.1965 (9)	0.7567 (12)	0.2066 (5)	0.055 (3)
H8	0.143226	0.809035	0.135421	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0761 (9)	0.055 (3)	0.0955 (14)	−0.0021 (14)	0.0249 (8)	−0.0035 (10)
N4	0.048 (2)	0.059 (11)	0.033 (4)	−0.002 (4)	0.001 (2)	−0.002 (3)
N5	0.055 (3)	0.043 (10)	0.046 (4)	0.004 (4)	0.001 (2)	0.004 (3)
N3	0.078 (3)	0.056 (12)	0.055 (4)	−0.008 (5)	−0.008 (2)	−0.012 (4)
N2	0.088 (4)	0.052 (14)	0.083 (6)	−0.019 (4)	0.010 (3)	−0.026 (4)
N1	0.065 (3)	0.067 (10)	0.060 (4)	−0.003 (4)	0.007 (3)	−0.017 (3)
C9	0.047 (2)	0.058 (13)	0.032 (4)	−0.003 (4)	0.003 (2)	0.004 (4)
C7	0.057 (3)	0.060 (11)	0.041 (5)	−0.008 (5)	−0.005 (3)	−0.006 (3)
C6	0.051 (3)	0.019 (9)	0.057 (4)	−0.003 (4)	0.013 (3)	0.001 (3)
C8	0.057 (3)	0.072 (12)	0.036 (5)	−0.001 (5)	−0.001 (3)	0.010 (3)

Geometric parameters (Å, º)

Cl1—C6	1.727 (9)	N1—C9	1.347 (11)
N4—N5	1.340 (8)	C9—C8	1.413 (10)
N4—N3	1.339 (11)	C7—H7	0.9300
N4—C9	1.354 (11)	C7—C6	1.416 (11)
N5—C6	1.308 (10)	C7—C8	1.336 (8)
N3—N2	1.320 (13)	C8—H8	0.9300
N2—N1	1.339 (9)
N5—N4—C9	128.6 (6)	C6—C7—H7	120.6
N3—N4—N5	122.1 (7)	C8—C7—H7	120.6
N3—N4—C9	109.3 (10)	C8—C7—C6	118.9 (6)
C6—N5—N4	112.2 (6)	N5—C6—Cl1	114.6 (7)
N2—N3—N4	104.0 (7)	N5—C6—C7	125.9 (10)
N3—N2—N1	114.4 (9)	C7—C6—Cl1	119.5 (6)
N2—N1—C9	103.3 (7)	C9—C8—H8	121.0
N4—C9—C8	116.5 (9)	C7—C8—C9	118.0 (6)
N1—C9—N4	109.0 (5)	C7—C8—H8	121.0
N1—C9—C8	134.5 (8)
N4—N5—C6—Cl1	−178.1 (4)	N3—N2—N1—C9	1.1 (7)
N4—N5—C6—C7	1.5 (9)	N2—N1—C9—N4	−0.6 (7)
N4—N3—N2—N1	−1.1 (7)	N2—N1—C9—C8	−179.0 (6)
N4—C9—C8—C7	1.8 (9)	N1—C9—C8—C7	−179.9 (7)
N5—N4—N3—N2	−179.9 (5)	C9—N4—N5—C6	−1.0 (10)
N5—N4—C9—N1	−179.4 (6)	C9—N4—N3—N2	0.7 (7)
N5—N4—C9—C8	−0.6 (10)	C6—C7—C8—C9	−1.3 (10)
N3—N4—N5—C6	179.8 (5)	C8—C7—C6—Cl1	179.2 (5)
N3—N4—C9—N1	−0.1 (7)	C8—C7—C6—N5	−0.4 (10)
N3—N4—C9—C8	178.7 (5)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_18GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.670 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 859 reflections
a = 7.005 (2) Å	θ = 3.5–23.4°
b = 8.7554 (18) Å	µ = 0.53 mm^−1
c = 10.086 (2) Å	T = 296 K
V = 618.6 (3) Å^3	Plate, colorless
Z = 4	0.38 × 0.26 × 0.14 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	961 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	410 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.313
Detector resolution: 16.1544 pixels mm^-1	θmax = 28.2°, θmin = 3.1°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −7→7
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −9→9
Tmin = 0.520, Tmax = 1.000	l = −12→12
3219 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.143	w = 1/[σ^2(Fo^2) + (0.2P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.430	(Δ/σ)max < 0.001
S = 1.16	Δρmax = 0.66 e Å^−3
961 reflections	Δρmin = −0.79 e Å^−3
91 parameters	Absolute structure: Classical Flack method preferred over Parsons because s.u. lower.
0 restraints	Absolute structure parameter: −0.3 (7)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.18 (2) GPa (180000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2916 (10)	0.3335 (6)	0.3239 (6)	0.091 (3)
N4	0.352 (3)	0.749 (2)	0.4127 (13)	0.072 (6)
N5	0.364 (3)	0.5955 (19)	0.4182 (15)	0.082 (6)
N3	0.421 (3)	0.840 (2)	0.5084 (13)	0.089 (6)
N2	0.380 (3)	0.978 (3)	0.4674 (18)	0.086 (6)
N1	0.295 (3)	0.984 (2)	0.3477 (16)	0.076 (5)
C9	0.274 (3)	0.831 (2)	0.3154 (14)	0.057 (5)
C7	0.207 (4)	0.605 (3)	0.2071 (17)	0.074 (6)
H7	0.164726	0.549814	0.134175	0.088*
C6	0.284 (3)	0.5309 (18)	0.3169 (15)	0.053 (4)
C8	0.195 (4)	0.756 (3)	0.2078 (15)	0.072 (6)
H8	0.136090	0.809662	0.139331	0.087*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.109 (6)	0.037 (4)	0.127 (4)	−0.003 (3)	0.024 (3)	−0.004 (2)
N4	0.096 (17)	0.063 (14)	0.058 (8)	0.001 (9)	0.017 (10)	−0.010 (7)
N5	0.13 (2)	0.028 (13)	0.083 (10)	−0.001 (9)	−0.006 (11)	0.006 (7)
N3	0.141 (19)	0.056 (16)	0.070 (10)	0.000 (11)	−0.012 (10)	−0.007 (10)
N2	0.078 (17)	0.078 (17)	0.100 (11)	−0.002 (9)	0.020 (10)	−0.022 (9)
N1	0.065 (15)	0.071 (14)	0.092 (9)	0.002 (10)	0.019 (11)	−0.008 (8)
C9	0.076 (17)	0.035 (13)	0.061 (9)	0.000 (9)	0.005 (9)	0.005 (7)
C7	0.09 (2)	0.068 (16)	0.059 (9)	0.004 (12)	−0.008 (11)	−0.005 (7)
C6	0.054 (14)	0.020 (11)	0.087 (10)	−0.004 (7)	0.016 (10)	−0.005 (7)
C8	0.090 (19)	0.075 (17)	0.051 (9)	0.010 (13)	−0.007 (12)	0.010 (7)

Geometric parameters (Å, º)

Cl1—C6	1.730 (16)	N1—C9	1.39 (2)
N4—N5	1.34 (2)	C9—C8	1.38 (3)
N4—N3	1.35 (2)	C7—H7	0.9300
N4—C9	1.33 (2)	C7—C6	1.39 (3)
N5—C6	1.29 (2)	C7—C8	1.33 (2)
N3—N2	1.30 (2)	C8—H8	0.9300
N2—N1	1.35 (2)
N5—N4—N3	122.9 (17)	C6—C7—H7	120.4
C9—N4—N5	126.6 (16)	C8—C7—H7	120.4
C9—N4—N3	110.5 (19)	C8—C7—C6	119.1 (16)
C6—N5—N4	112.1 (16)	N5—C6—Cl1	113.0 (14)
N2—N3—N4	104.1 (17)	N5—C6—C7	126.1 (17)
N3—N2—N1	114.9 (15)	C7—C6—Cl1	120.8 (14)
N2—N1—C9	102.4 (14)	C9—C8—H8	121.6
N4—C9—N1	108.0 (14)	C7—C8—C9	116.8 (18)
N4—C9—C8	118.9 (19)	C7—C8—H8	121.6
C8—C9—N1	133.1 (18)
N4—N5—C6—Cl1	−178.3 (14)	N3—N2—N1—C9	3 (2)
N4—N5—C6—C7	5 (3)	N2—N1—C9—N4	−2 (2)
N4—N3—N2—N1	−3 (3)	N2—N1—C9—C8	179 (2)
N4—C9—C8—C7	−2 (4)	N1—C9—C8—C7	177 (2)
N5—N4—N3—N2	−179.5 (17)	C9—N4—N5—C6	−2 (3)
N5—N4—C9—N1	−178.8 (19)	C9—N4—N3—N2	1 (3)
N5—N4—C9—C8	1 (4)	C6—C7—C8—C9	5 (4)
N3—N4—N5—C6	179 (2)	C8—C7—C6—Cl1	177 (2)
N3—N4—C9—N1	1 (2)	C8—C7—C6—N5	−7 (4)
N3—N4—C9—C8	−180 (2)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_20GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.674 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 802 reflections
a = 7.0156 (18) Å	θ = 3.1–19.8°
b = 8.7539 (8) Å	µ = 0.53 mm^−1
c = 10.0529 (13) Å	T = 296 K
V = 617.39 (19) Å^3	Plate, colorless
Z = 4	0.28 × 0.22 × 0.10 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	923 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	431 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.188
Detector resolution: 16.1544 pixels mm^-1	θmax = 28.6°, θmin = 3.1°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −6→6
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −11→11
Tmin = 0.491, Tmax = 1.000	l = −11→12
4557 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.062	w = 1/[σ^2(Fo^2) + (0.0207P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.123	(Δ/σ)max < 0.001
S = 1.00	Δρmax = 0.23 e Å^−3
923 reflections	Δρmin = −0.18 e Å^−3
91 parameters	Absolute structure: Flack x determined using 119 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: −0.1 (3)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.20 (2) GPa (200000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2913 (5)	0.3347 (2)	0.3215 (2)	0.0783 (13)
N4	0.3543 (17)	0.7480 (8)	0.4127 (8)	0.050 (4)
N5	0.3672 (16)	0.5962 (9)	0.4190 (7)	0.052 (3)
N3	0.4285 (13)	0.8417 (10)	0.5064 (6)	0.070 (3)
N2	0.3876 (19)	0.9804 (9)	0.4631 (10)	0.079 (5)
N1	0.2922 (18)	0.9827 (8)	0.3487 (8)	0.065 (4)
C9	0.2755 (15)	0.8332 (10)	0.3177 (8)	0.043 (3)
C7	0.201 (2)	0.6029 (10)	0.2088 (8)	0.063 (4)
H7	0.149029	0.545775	0.139895	0.075*
C6	0.2889 (18)	0.5305 (8)	0.3183 (11)	0.052 (4)
C8	0.1956 (19)	0.7558 (10)	0.2062 (9)	0.060 (4)
H8	0.142124	0.808787	0.135276	0.072*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.087 (4)	0.0470 (13)	0.101 (2)	−0.001 (2)	0.0258 (16)	0.0008 (15)
N4	0.051 (13)	0.050 (5)	0.048 (6)	−0.002 (5)	−0.001 (4)	0.001 (4)
N5	0.055 (11)	0.047 (5)	0.053 (6)	0.000 (5)	0.001 (4)	0.005 (4)
N3	0.081 (11)	0.077 (6)	0.053 (5)	−0.003 (7)	−0.013 (4)	−0.019 (6)
N2	0.089 (15)	0.053 (5)	0.096 (8)	−0.011 (6)	0.003 (6)	−0.019 (5)
N1	0.068 (13)	0.057 (5)	0.069 (7)	−0.001 (6)	−0.001 (5)	−0.005 (5)
C9	0.040 (11)	0.043 (5)	0.046 (5)	0.004 (7)	−0.001 (4)	0.000 (6)
C7	0.092 (15)	0.059 (5)	0.037 (7)	−0.005 (7)	−0.005 (5)	−0.006 (4)
C6	0.056 (13)	0.039 (5)	0.062 (7)	0.003 (6)	0.015 (6)	0.001 (5)
C8	0.068 (15)	0.073 (6)	0.040 (7)	0.002 (7)	0.000 (5)	0.009 (5)

Geometric parameters (Å, º)

Cl1—C6	1.715 (7)	N1—C9	1.351 (9)
N4—N5	1.333 (7)	C9—C8	1.424 (12)
N4—N3	1.354 (9)	C7—H7	0.9300
N4—C9	1.332 (10)	C7—C6	1.411 (12)
N5—C6	1.288 (12)	C7—C8	1.339 (9)
N3—N2	1.321 (9)	C8—H8	0.9300
N2—N1	1.331 (11)
N5—N4—N3	123.0 (9)	C6—C7—H7	120.8
C9—N4—N5	128.4 (9)	C8—C7—H7	120.8
C9—N4—N3	108.6 (7)	C8—C7—C6	118.5 (9)
C6—N5—N4	112.2 (8)	N5—C6—Cl1	115.3 (8)
N2—N3—N4	104.1 (7)	N5—C6—C7	126.8 (8)
N3—N2—N1	114.0 (7)	C7—C6—Cl1	117.9 (8)
N2—N1—C9	103.2 (7)	C9—C8—H8	121.7
N4—C9—N1	110.0 (8)	C7—C8—C9	116.6 (10)
N4—C9—C8	117.5 (8)	C7—C8—H8	121.7
N1—C9—C8	132.6 (9)
N4—N5—C6—Cl1	−177.7 (9)	N3—N2—N1—C9	−1.0 (13)
N4—N5—C6—C7	1.5 (19)	N2—N1—C9—N4	1.5 (12)
N4—N3—N2—N1	0.1 (14)	N2—N1—C9—C8	−177.3 (13)
N4—C9—C8—C7	2.0 (19)	N1—C9—C8—C7	−179.2 (12)
N5—N4—N3—N2	179.3 (11)	C9—N4—N5—C6	−1 (2)
N5—N4—C9—N1	−179.9 (12)	C9—N4—N3—N2	0.8 (13)
N5—N4—C9—C8	−1 (2)	C6—C7—C8—C9	−1 (2)
N3—N4—N5—C6	−179.0 (10)	C8—C7—C6—Cl1	178.8 (11)
N3—N4—C9—N1	−1.5 (13)	C8—C7—C6—N5	0 (2)
N3—N4—C9—C8	177.5 (9)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_30GPa_phase_alpha_xH2O)

Crystal data

C4H2ClN5	Dx = 1.700 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1343 reflections
a = 6.9235 (13) Å	θ = 4.2–22.3°
b = 8.7578 (5) Å	µ = 0.54 mm^−1
c = 10.0265 (11) Å	T = 296 K
V = 607.95 (14) Å^3	Plate, colorless
Z = 4	0.26 × 0.22 × 0.16 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	815 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	621 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.4°, θmin = 4.3°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −6→6
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −11→11
Tmin = 0.318, Tmax = 1.000	l = −11→11
3805 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.043	w = 1/[σ^2(Fo^2) + (0.0262P)^2 + 0.2376P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.081	(Δ/σ)max < 0.001
S = 1.08	Δρmax = 0.14 e Å^−3
815 reflections	Δρmin = −0.13 e Å^−3
91 parameters	Absolute structure: Flack x determined using 201 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
0 restraints	Absolute structure parameter: 0.16 (7)
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Data were collected at room temperature and pressure of 0.30 (2) GPa (300000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.2930 (3)	0.33337 (13)	0.32396 (16)	0.0680 (7)
N4	0.3534 (9)	0.7503 (4)	0.4126 (5)	0.0402 (17)
N5	0.3681 (9)	0.5960 (5)	0.4211 (5)	0.0504 (18)
N3	0.4245 (8)	0.8417 (5)	0.5086 (4)	0.0620 (17)
N2	0.3858 (11)	0.9800 (5)	0.4647 (6)	0.070 (2)
N1	0.2907 (11)	0.9822 (5)	0.3483 (6)	0.062 (2)
C9	0.2740 (9)	0.8339 (5)	0.3152 (5)	0.0408 (16)
C7	0.2020 (11)	0.6027 (6)	0.2094 (5)	0.049 (2)
H7	0.151171	0.545085	0.139791	0.059*
C6	0.2875 (11)	0.5300 (5)	0.3190 (6)	0.0438 (18)
C8	0.1937 (11)	0.7561 (6)	0.2052 (6)	0.050 (2)
H8	0.138187	0.807947	0.133834	0.060*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0723 (19)	0.0372 (6)	0.0945 (13)	−0.0008 (10)	0.0255 (9)	−0.0024 (8)
N4	0.036 (6)	0.043 (2)	0.042 (3)	−0.004 (2)	−0.004 (2)	0.001 (2)
N5	0.067 (6)	0.041 (2)	0.043 (3)	0.002 (3)	0.000 (2)	0.007 (2)
N3	0.076 (6)	0.063 (3)	0.047 (4)	−0.008 (4)	−0.010 (2)	−0.011 (3)
N2	0.084 (8)	0.053 (3)	0.073 (5)	−0.009 (3)	0.009 (3)	−0.016 (3)
N1	0.077 (7)	0.041 (2)	0.068 (4)	0.000 (3)	0.008 (3)	−0.004 (2)
C9	0.050 (6)	0.037 (2)	0.036 (3)	0.001 (3)	0.004 (2)	0.005 (3)
C7	0.053 (7)	0.054 (3)	0.040 (4)	−0.007 (3)	0.000 (3)	−0.011 (2)
C6	0.050 (7)	0.035 (2)	0.046 (4)	0.001 (3)	0.009 (3)	−0.001 (3)
C8	0.053 (8)	0.060 (3)	0.038 (4)	0.004 (3)	−0.004 (3)	0.008 (3)

Geometric parameters (Å, º)

Cl1—C6	1.723 (4)	N1—C9	1.346 (6)
N4—N5	1.358 (5)	C9—C8	1.411 (8)
N4—N3	1.346 (6)	C7—H7	0.9300
N4—C9	1.339 (6)	C7—C6	1.401 (8)
N5—C6	1.301 (7)	C7—C8	1.346 (6)
N3—N2	1.317 (6)	C8—H8	0.9300
N2—N1	1.340 (8)
N3—N4—N5	121.3 (5)	C6—C7—H7	120.1
C9—N4—N5	128.4 (5)	C8—C7—H7	120.1
C9—N4—N3	110.3 (4)	C8—C7—C6	119.7 (5)
C6—N5—N4	111.1 (5)	N5—C6—Cl1	114.3 (4)
N2—N3—N4	103.5 (5)	N5—C6—C7	126.6 (4)
N3—N2—N1	113.9 (4)	C7—C6—Cl1	119.1 (5)
N2—N1—C9	104.1 (5)	C9—C8—H8	121.9
N4—C9—N1	108.2 (5)	C7—C8—C9	116.1 (6)
N4—C9—C8	117.9 (4)	C7—C8—H8	121.9
N1—C9—C8	133.8 (5)
N4—N5—C6—Cl1	−178.2 (5)	N3—N2—N1—C9	−1.9 (8)
N4—N5—C6—C7	2.5 (11)	N2—N1—C9—N4	1.5 (8)
N4—N3—N2—N1	1.4 (8)	N2—N1—C9—C8	−178.6 (8)
N4—C9—C8—C7	1.0 (11)	N1—C9—C8—C7	−178.9 (7)
N5—N4—N3—N2	179.2 (6)	C9—N4—N5—C6	−1.5 (11)
N5—N4—C9—N1	179.7 (7)	C9—N4—N3—N2	−0.3 (7)
N5—N4—C9—C8	−0.1 (11)	C6—C7—C8—C9	−0.1 (12)
N3—N4—N5—C6	179.0 (6)	C8—C7—C6—Cl1	178.9 (6)
N3—N4—C9—N1	−0.8 (8)	C8—C7—C6—N5	−1.8 (13)
N3—N4—C9—C8	179.3 (6)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_54GPa_phase_alpha_prim_xH2O)

Crystal data

C4H2ClN5	Dx = 1.778 Mg m^−3
Mr = 155.56	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 734 reflections
a = 10.668 (2) Å	θ = 4.4–23.1°
b = 6.2042 (7) Å	µ = 0.57 mm^−1
c = 8.780 (4) Å	T = 296 K
V = 581.1 (3) Å^3	Plate, colorless
Z = 4	0.40 × 0.25 × 0.20 mm
F(000) = 312

Data collection

KM-4 CCD diffractometer	321 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	225 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.1°, θmin = 4.5°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −11→12
Absorption correction: multi-scan CrysAlisPro 1.171.40.67a (Rigaku Oxford Diffraction, 2019) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −7→7
Tmin = 0.710, Tmax = 1.000	l = −6→6
2992 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.094	w = 1/[σ^2(Fo^2) + (0.0468P)^2 + 0.1183P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
321 reflections	Δρmax = 0.16 e Å^−3
61 parameters	Δρmin = −0.13 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.54 GPa (540000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.61432 (15)	0.750000	0.9123 (3)	0.0670 (10)
C6	0.6267 (4)	0.750000	0.7208 (11)	0.037 (3)
C7	0.7478 (5)	0.750000	0.6485 (8)	0.053 (3)
H7	0.820363	0.750000	0.707122	0.063*
N6	0.5355 (4)	0.750000	0.4951 (10)	0.031 (3)
N1	0.6145 (5)	0.750000	0.2652 (9)	0.057 (3)
N5	0.5194 (4)	0.750000	0.6431 (8)	0.037 (2)
C8	0.7552 (5)	0.750000	0.4979 (10)	0.050 (3)
H8	0.832933	0.750000	0.449951	0.060*
N2	0.4922 (8)	0.750000	0.2641 (15)	0.063 (3)
N3	0.4373 (6)	0.750000	0.3954 (14)	0.063 (4)
C9	0.6447 (6)	0.750000	0.4118 (12)	0.054 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0895 (14)	0.0686 (8)	0.043 (3)	0.000	−0.0039 (8)	0.000
C6	0.067 (6)	0.038 (2)	0.006 (14)	0.000	0.001 (3)	0.000
C7	0.022 (4)	0.055 (2)	0.081 (13)	0.000	−0.008 (2)	0.000
N6	0.043 (4)	0.0382 (18)	0.011 (11)	0.000	−0.003 (3)	0.000
N1	0.078 (5)	0.054 (2)	0.040 (11)	0.000	−0.012 (4)	0.000
N5	0.038 (4)	0.0415 (18)	0.031 (9)	0.000	−0.002 (3)	0.000
C8	0.040 (5)	0.056 (2)	0.055 (11)	0.000	0.008 (3)	0.000
N2	0.080 (6)	0.053 (2)	0.057 (14)	0.000	−0.012 (4)	0.000
N3	0.044 (5)	0.048 (2)	0.097 (15)	0.000	−0.022 (3)	0.000
C9	0.032 (6)	0.038 (2)	0.092 (19)	0.000	0.001 (3)	0.000

Geometric parameters (Å, º)

Cl1—C6	1.687 (9)	N6—C9	1.375 (12)
C6—C7	1.440 (10)	N1—N2	1.305 (9)
C6—N5	1.332 (8)	N1—C9	1.327 (12)
C7—H7	0.9300	C8—H8	0.9300
C7—C8	1.324 (8)	C8—C9	1.401 (11)
N6—N5	1.310 (8)	N2—N3	1.293 (15)
N6—N3	1.366 (13)
C7—C6—Cl1	120.7 (5)	N6—N5—C6	113.3 (5)
N5—C6—Cl1	116.3 (5)	C7—C8—H8	120.4
N5—C6—C7	123.0 (8)	C7—C8—C9	119.2 (5)
C6—C7—H7	120.2	C9—C8—H8	120.4
C8—C7—C6	119.6 (5)	N3—N2—N1	116.5 (13)
C8—C7—H7	120.2	N2—N3—N6	102.9 (7)
N5—N6—N3	122.3 (7)	N6—C9—C8	115.2 (9)
N5—N6—C9	129.7 (5)	N1—C9—N6	108.1 (5)
N3—N6—C9	108.0 (9)	N1—C9—C8	136.7 (8)
N2—N1—C9	104.5 (7)
Cl1—C6—C7—C8	180.000 (2)	N5—N6—C9—C8	0.000 (2)
Cl1—C6—N5—N6	180.000 (1)	N2—N1—C9—N6	0.000 (1)
C6—C7—C8—C9	0.000 (2)	N2—N1—C9—C8	180.000 (1)
C7—C6—N5—N6	0.000 (1)	N3—N6—N5—C6	180.000 (1)
C7—C8—C9—N6	0.000 (2)	N3—N6—C9—N1	0.000 (1)
C7—C8—C9—N1	180.000 (1)	N3—N6—C9—C8	180.000 (1)
N1—N2—N3—N6	0.000 (2)	C9—N6—N5—C6	0.000 (2)
N5—C6—C7—C8	0.000 (2)	C9—N6—N3—N2	0.000 (2)
N5—N6—N3—N2	180.000 (1)	C9—N1—N2—N3	0.000 (1)
N5—N6—C9—N1	180.000 (1)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_17GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.766 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.878 (12) Å	Cell parameters from 734 reflections
b = 13.2446 (15) Å	θ = 3.9–21.9°
c = 5.7134 (11) Å	µ = 0.56 mm^−1
β = 101.14 (6)°	T = 296 K
V = 584.9 (9) Å^3	Plate, colorless
Z = 4	0.39 × 0.28 × 0.16 mm

Data collection

KM-4 CCD diffractometer	424 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	290 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.4°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −4→3
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −16→17
Tmin = 0.338, Tmax = 1.000	l = −7→7
3430 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.084	w = 1/[σ^2(Fo^2) + (0.0358P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max < 0.001
424 reflections	Δρmax = 0.10 e Å^−3
91 parameters	Δρmin = −0.11 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.17 (2) GPa (170000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0272 (7)	0.33900 (8)	0.8387 (3)	0.082 (3)
N4	0.563 (6)	0.3541 (4)	0.536 (3)	0.068 (19)
N5	0.693 (4)	0.3316 (3)	0.6974 (14)	0.031 (11)
N1	0.390 (4)	0.4160 (6)	0.2271 (14)	0.073 (14)
N3	0.398 (4)	0.3381 (5)	0.570 (3)	0.050 (15)
N2	0.292 (2)	0.3752 (3)	0.3821 (11)	0.067 (10)
C8	0.712 (3)	0.4242 (3)	0.2574 (17)	0.044 (11)
H8	0.715217	0.455216	0.112459	0.053*
C6	0.850 (3)	0.3573 (4)	0.636 (2)	0.049 (13)
C9	0.549 (6)	0.4002 (6)	0.322 (2)	0.062 (19)
C7	0.857 (3)	0.4010 (3)	0.4098 (10)	0.054 (13)
H7	0.964161	0.413346	0.368643	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.129 (10)	0.0651 (7)	0.0515 (10)	0.0042 (14)	0.017 (3)	0.0088 (7)
N4	0.13 (6)	0.034 (2)	0.044 (8)	0.003 (8)	0.040 (16)	0.002 (3)
N5	0.01 (4)	0.040 (2)	0.037 (4)	−0.006 (5)	−0.006 (10)	−0.001 (2)
N1	0.13 (4)	0.039 (3)	0.052 (5)	0.013 (5)	0.016 (12)	0.004 (3)
N3	0.05 (5)	0.050 (2)	0.051 (5)	−0.003 (6)	0.004 (15)	−0.005 (3)
N2	0.09 (3)	0.051 (2)	0.065 (4)	0.005 (5)	0.011 (10)	−0.007 (3)
C8	0.06 (3)	0.038 (2)	0.037 (4)	−0.003 (5)	0.021 (11)	0.001 (2)
C6	0.07 (4)	0.035 (2)	0.048 (6)	0.000 (6)	0.023 (14)	0.000 (2)
C9	0.12 (6)	0.027 (3)	0.039 (7)	0.014 (9)	0.027 (19)	0.003 (3)
C7	0.09 (4)	0.040 (2)	0.035 (4)	0.006 (5)	0.014 (10)	0.001 (2)

Geometric parameters (Å, º)

Cl1—C6	1.65 (2)	N3—N2	1.32 (3)
N4—N5	1.27 (6)	C8—H8	0.9300
N4—N3	1.37 (6)	C8—C9	1.44 (6)
N4—C9	1.351 (14)	C8—C7	1.34 (4)
N5—C6	1.39 (4)	C6—C7	1.426 (12)
N1—N2	1.39 (3)	C7—H7	0.9300
N1—C9	1.28 (6)
N5—N4—N3	121.0 (11)	N5—C6—Cl1	117.3 (10)
N5—N4—C9	133 (5)	N5—C6—C7	122 (3)
C9—N4—N3	106 (4)	C7—C6—Cl1	121.0 (19)
N4—N5—C6	112.8 (14)	N4—C9—C8	114 (4)
C9—N1—N2	106.3 (12)	N1—C9—N4	111 (4)
N2—N3—N4	107.0 (16)	N1—C9—C8	134.4 (13)
N3—N2—N1	108.9 (18)	C8—C7—C6	120 (2)
C9—C8—H8	120.7	C8—C7—H7	120.0
C7—C8—H8	120.7	C6—C7—H7	120.0
C7—C8—C9	118.6 (9)
Cl1—C6—C7—C8	−173.5 (4)	N3—N4—C9—C8	179.3 (5)
N4—N5—C6—Cl1	175.9 (3)	N2—N1—C9—N4	−2.0 (12)
N4—N5—C6—C7	−1.9 (7)	N2—N1—C9—C8	−178.9 (7)
N4—N3—N2—N1	−0.5 (6)	C9—N4—N5—C6	−2.3 (8)
N5—N4—N3—N2	175.5 (3)	C9—N4—N3—N2	−0.6 (7)
N5—N4—C9—N1	−173.7 (9)	C9—N1—N2—N3	1.6 (9)
N5—N4—C9—C8	3.8 (9)	C9—C8—C7—C6	−2.6 (7)
N5—C6—C7—C8	4.3 (6)	C7—C8—C9—N4	−0.9 (8)
N3—N4—N5—C6	−177.3 (4)	C7—C8—C9—N1	175.9 (11)
N3—N4—C9—N1	1.7 (11)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_20GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.775 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.885 (6) Å	Cell parameters from 1648 reflections
b = 13.2116 (6) Å	θ = 4.7–26.6°
c = 5.6949 (3) Å	µ = 0.57 mm^−1
β = 101.20 (2)°	T = 296 K
V = 582.0 (4) Å^3	Plate, colorless
Z = 4	0.28 × 0.26 × 0.23 mm

Data collection

KM-4 CCD diffractometer	361 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	310 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.4°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −2→2
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −16→17
Tmin = 0.394, Tmax = 1.000	l = −7→7
3466 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.021	H-atom parameters constrained
wR(F^2) = 0.051	w = 1/[σ^2(Fo^2) + (0.0299P)^2 + 0.0432P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
361 reflections	Δρmax = 0.07 e Å^−3
91 parameters	Δρmin = −0.06 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.20 (2) GPa (200000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0288 (3)	0.33898 (4)	0.84022 (13)	0.062 (2)
N4	0.556 (4)	0.3534 (3)	0.5363 (13)	0.041 (14)
N5	0.703 (2)	0.3316 (2)	0.7002 (5)	0.033 (8)
N1	0.388 (2)	0.4147 (3)	0.2274 (8)	0.047 (9)
N3	0.398 (3)	0.3372 (4)	0.5736 (17)	0.051 (14)
N2	0.2966 (14)	0.3751 (2)	0.3832 (8)	0.066 (9)
C8	0.704 (2)	0.4245 (2)	0.2549 (10)	0.039 (10)
H8	0.701587	0.455311	0.107460	0.047*
C6	0.843 (2)	0.3580 (2)	0.6325 (15)	0.058 (10)
C9	0.561 (4)	0.4008 (3)	0.3254 (8)	0.067 (17)
C7	0.8624 (18)	0.40180 (18)	0.4103 (5)	0.051 (11)
H7	0.969486	0.414336	0.370922	0.061*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.074 (6)	0.0632 (4)	0.0441 (4)	0.0034 (6)	0.0003 (11)	0.0082 (2)
N4	0.05 (4)	0.0330 (13)	0.036 (3)	−0.003 (4)	0.013 (9)	−0.0006 (14)
N5	0.02 (3)	0.0380 (12)	0.0292 (15)	0.003 (3)	−0.014 (7)	0.0022 (10)
N1	0.05 (3)	0.0421 (13)	0.046 (2)	0.002 (3)	−0.001 (5)	−0.0011 (14)
N3	0.05 (4)	0.0490 (17)	0.055 (4)	−0.004 (5)	0.020 (10)	−0.0020 (15)
N2	0.09 (3)	0.0487 (13)	0.0576 (19)	0.011 (4)	0.006 (6)	−0.0056 (13)
C8	0.05 (3)	0.0365 (12)	0.0247 (15)	0.004 (3)	−0.005 (6)	0.0035 (10)
C6	0.11 (3)	0.0301 (13)	0.038 (2)	−0.008 (4)	0.026 (7)	−0.0009 (12)
C9	0.14 (5)	0.0312 (14)	0.027 (3)	−0.004 (6)	0.019 (11)	0.0026 (18)
C7	0.07 (3)	0.0384 (11)	0.0349 (16)	−0.005 (4)	0.001 (4)	−0.0033 (11)

Geometric parameters (Å, º)

Cl1—C6	1.713 (15)	N3—N2	1.316 (18)
N4—N5	1.37 (4)	C8—H8	0.9300
N4—N3	1.32 (4)	C8—C9	1.31 (4)
N4—C9	1.362 (8)	C8—C7	1.417 (18)
N5—C6	1.28 (3)	C6—C7	1.426 (8)
N1—N2	1.353 (15)	C7—H7	0.9300
N1—C9	1.38 (4)
N3—N4—N5	123.9 (9)	N5—C6—Cl1	114.9 (8)
N3—N4—C9	114 (3)	N5—C6—C7	128.5 (16)
C9—N4—N5	122 (3)	C7—C6—Cl1	116.6 (11)
C6—N5—N4	113.8 (7)	N4—C9—N1	103 (3)
N2—N1—C9	107.0 (8)	C8—C9—N4	124 (3)
N4—N3—N2	104.4 (9)	C8—C9—N1	133.4 (5)
N3—N2—N1	111.7 (11)	C8—C7—C6	114.0 (13)
C9—C8—H8	121.1	C8—C7—H7	123.0
C9—C8—C7	117.9 (8)	C6—C7—H7	123.0
C7—C8—H8	121.1
Cl1—C6—C7—C8	−174.3 (2)	N3—N4—C9—C8	179.5 (4)
N4—N5—C6—Cl1	176.2 (3)	N2—N1—C9—N4	−0.2 (3)
N4—N5—C6—C7	−2.9 (5)	N2—N1—C9—C8	−179.4 (3)
N4—N3—N2—N1	0.0 (5)	C9—N4—N5—C6	−1.5 (5)
N5—N4—N3—N2	175.4 (2)	C9—N4—N3—N2	−0.1 (6)
N5—N4—C9—N1	−175.4 (4)	C9—N1—N2—N3	0.1 (4)
N5—N4—C9—C8	3.9 (6)	C9—C8—C7—C6	−2.1 (3)
N5—C6—C7—C8	4.7 (5)	C7—C8—C9—N4	−1.8 (5)
N3—N4—N5—C6	−176.7 (6)	C7—C8—C9—N1	177.3 (3)
N3—N4—C9—N1	0.2 (6)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_25GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.789 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.864 (4) Å	Cell parameters from 711 reflections
b = 13.1668 (6) Å	θ = 4.3–22.0°
c = 5.6843 (4) Å	µ = 0.57 mm^−1
β = 101.159 (16)°	T = 296 K
V = 577.5 (3) Å^3	Colourless, colourless
Z = 4	0.34 × 0.28 × 0.27 mm

Data collection

KM-4 CCD diffractometer	379 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	250 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.1°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −3→3
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −16→16
Tmin = 0.475, Tmax = 1.000	l = −6→7
3307 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.067	w = 1/[σ^2(Fo^2) + (0.0224P)^2 + 0.0843P] where P = (Fo^2 + 2Fc^2)/3
S = 1.16	(Δ/σ)max < 0.001
379 reflections	Δρmax = 0.10 e Å^−3
91 parameters	Δρmin = −0.10 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.25 (2) GPa 250000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0263 (9)	0.33933 (10)	0.8415 (3)	0.077 (4)
N4	0.559 (9)	0.3535 (6)	0.537 (4)	0.09 (4)
N5	0.694 (7)	0.3316 (5)	0.7005 (17)	0.05 (2)
N1	0.392 (6)	0.4159 (9)	0.2282 (19)	0.08 (2)
N3	0.402 (6)	0.3372 (7)	0.574 (4)	0.06 (2)
N2	0.297 (3)	0.3746 (4)	0.3847 (12)	0.075 (15)
C8	0.708 (5)	0.4246 (4)	0.256 (2)	0.045 (16)
H8	0.709793	0.455552	0.109945	0.055*
C6	0.847 (5)	0.3575 (6)	0.637 (3)	0.07 (2)
C9	0.547 (9)	0.4010 (8)	0.323 (3)	0.08 (3)
C7	0.860 (3)	0.4015 (5)	0.4085 (15)	0.04 (2)
H7	0.966977	0.413585	0.366676	0.048*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.121 (14)	0.0616 (7)	0.0497 (9)	0.0041 (18)	0.020 (3)	0.0077 (8)
N4	0.20 (11)	0.034 (3)	0.047 (10)	0.011 (13)	0.05 (2)	0.000 (4)
N5	0.06 (7)	0.042 (2)	0.032 (4)	−0.005 (9)	−0.011 (15)	−0.002 (3)
N1	0.15 (7)	0.041 (4)	0.055 (7)	0.008 (8)	0.023 (18)	0.000 (4)
N3	0.07 (7)	0.049 (3)	0.047 (8)	−0.004 (10)	0.005 (19)	−0.004 (4)
N2	0.12 (5)	0.047 (3)	0.061 (4)	0.010 (7)	0.017 (12)	−0.005 (3)
C8	0.07 (5)	0.039 (2)	0.029 (5)	0.012 (8)	0.016 (15)	0.000 (3)
C6	0.14 (7)	0.034 (3)	0.046 (8)	0.006 (10)	0.039 (19)	0.001 (3)
C9	0.18 (10)	0.029 (3)	0.045 (9)	0.011 (16)	0.07 (3)	0.004 (5)
C7	0.05 (6)	0.038 (3)	0.040 (6)	0.005 (9)	0.027 (14)	0.000 (3)

Geometric parameters (Å, º)

Cl1—C6	1.66 (4)	N3—N2	1.32 (4)
N4—N5	1.30 (9)	C8—H8	0.9300
N4—N3	1.31 (9)	C8—C9	1.43 (9)
N4—C9	1.355 (18)	C8—C7	1.37 (5)
N5—C6	1.37 (7)	C6—C7	1.44 (2)
N1—N2	1.38 (4)	C7—H7	0.9300
N1—C9	1.25 (10)
N5—N4—N3	121 (2)	N5—C6—Cl1	116.8 (16)
N5—N4—C9	131 (7)	N5—C6—C7	124 (4)
N3—N4—C9	108 (7)	C7—C6—Cl1	119 (3)
N4—N5—C6	113.2 (19)	N4—C9—C8	115 (6)
C9—N1—N2	105.1 (16)	N1—C9—N4	111 (6)
N4—N3—N2	106 (2)	N1—C9—C8	133.9 (16)
N3—N2—N1	110 (2)	C8—C7—C6	117 (3)
C9—C8—H8	120.1	C8—C7—H7	121.6
C7—C8—H8	120.1	C6—C7—H7	121.6
C7—C8—C9	119.9 (12)
Cl1—C6—C7—C8	−173.4 (6)	N3—N4—C9—C8	179.9 (8)
N4—N5—C6—Cl1	176.1 (5)	N2—N1—C9—N4	−1.1 (15)
N4—N5—C6—C7	−2.0 (9)	N2—N1—C9—C8	−179.9 (8)
N4—N3—N2—N1	−0.5 (9)	C9—N4—N5—C6	−3.3 (11)
N5—N4—N3—N2	175.1 (4)	C9—N4—N3—N2	−0.2 (11)
N5—N4—C9—N1	−173.8 (12)	C9—N1—N2—N3	1.0 (12)
N5—N4—C9—C8	5.2 (12)	C9—C8—C7—C6	−2.6 (9)
N5—C6—C7—C8	4.7 (9)	C7—C8—C9—N4	−1.7 (11)
N3—N4—N5—C6	−177.4 (9)	C7—C8—C9—N1	177.0 (13)
N3—N4—C9—N1	0.9 (15)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_33GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.808 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.824 (8) Å	Cell parameters from 822 reflections
b = 13.1476 (8) Å	θ = 3.1–22.1°
c = 5.6603 (6) Å	µ = 0.58 mm^−1
β = 101.05 (4)°	T = 296 K
V = 571.4 (6) Å^3	Plate, colourless
Z = 4	0.38 × 0.38 × 0.28 mm

Data collection

KM-4 CCD diffractometer	366 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	230 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.074
Detector resolution: 16.1544 pixels mm^-1	θmax = 27.9°, θmin = 3.1°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −3→3
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −17→17
Tmin = 0.769, Tmax = 1.000	l = −7→7
3822 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.060	H-atom parameters constrained
wR(F^2) = 0.177	w = 1/[σ^2(Fo^2) + (0.0673P)^2 + 1.1248P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
366 reflections	Δρmax = 0.22 e Å^−3
41 parameters	Δρmin = −0.29 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.33 (2) GPa (330000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0289 (12)	0.33956 (14)	0.8424 (5)	0.0582 (9)*
N4	0.549 (5)	0.3528 (4)	0.5375 (19)	0.0364 (18)*
N5	0.696 (5)	0.3320 (4)	0.7036 (19)	0.0384 (17)*
N1	0.389 (3)	0.4153 (5)	0.2290 (17)	0.050 (2)*
N3	0.396 (4)	0.3360 (5)	0.575 (2)	0.054 (2)*
N2	0.299 (3)	0.3742 (5)	0.3873 (16)	0.055 (2)*
C8	0.706 (3)	0.4251 (5)	0.2579 (17)	0.0368 (19)*
H8	0.708544	0.457206	0.112389	0.044*
C6	0.838 (5)	0.3573 (4)	0.6308 (19)	0.033 (2)*
C9	0.542 (6)	0.4008 (5)	0.322 (2)	0.035 (2)*
C7	0.856 (4)	0.4013 (4)	0.4093 (16)	0.035 (2)*
H7	0.964682	0.413124	0.369796	0.042*

Geometric parameters (Å, º)

Cl1—C6	1.74 (3)	N3—N2	1.28 (3)
N4—N5	1.37 (5)	C8—H8	0.9300
N4—N3	1.28 (5)	C8—C9	1.43 (5)
N4—C9	1.367 (13)	C8—C7	1.35 (4)
N5—C6	1.30 (5)	C6—C7	1.412 (11)
N1—N2	1.35 (2)	C7—H7	0.9300
N1—C9	1.22 (5)
N5—N4—C9	126 (4)	N5—C6—Cl1	114.8 (11)
N3—N4—N5	122.9 (9)	N5—C6—C7	128 (3)
N3—N4—C9	110 (3)	C7—C6—Cl1	117 (2)
C6—N5—N4	112.9 (8)	N4—C9—C8	116 (4)
C9—N1—N2	103.9 (14)	N1—C9—N4	109 (3)
N4—N3—N2	102.4 (13)	N1—C9—C8	134.8 (10)
N3—N2—N1	114 (2)	C8—C7—C6	116 (3)
C9—C8—H8	119.9	C8—C7—H7	122.2
C7—C8—H8	119.9	C6—C7—H7	122.2
C7—C8—C9	120.2 (9)
Cl1—C6—C7—C8	−172.8 (5)	N3—N4—C9—C8	179.4 (6)
N4—N5—C6—Cl1	176.3 (4)	N2—N1—C9—N4	−1.0 (9)
N4—N5—C6—C7	−0.3 (9)	N2—N1—C9—C8	−178.9 (8)
N4—N3—N2—N1	0.0 (8)	C9—N4—N5—C6	−4.1 (10)
N5—N4—N3—N2	174.4 (6)	C9—N4—N3—N2	−0.6 (8)
N5—N4—C9—N1	−173.7 (7)	C9—N1—N2—N3	0.7 (9)
N5—N4—C9—C8	4.6 (10)	C9—C8—C7—C6	−3.0 (9)
N5—C6—C7—C8	3.8 (10)	C7—C8—C9—N4	−0.6 (10)
N3—N4—N5—C6	−178.4 (7)	C7—C8—C9—N1	177.2 (9)
N3—N4—C9—N1	1.1 (10)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_40GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.826 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.824 (4) Å	Cell parameters from 1140 reflections
b = 13.0789 (6) Å	θ = 4.0–26.7°
c = 5.6290 (4) Å	µ = 0.58 mm^−1
β = 100.793 (19)°	T = 296 K
V = 565.8 (3) Å^3	Plate, colourless
Z = 4	0.38 × 0.28 × 0.27 mm

Data collection

KM-4 CCD diffractometer	433 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	345 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.3°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −4→4
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −16→16
Tmin = 0.434, Tmax = 1.000	l = −7→7
3186 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.062	H-atom parameters constrained
wR(F^2) = 0.158	w = 1/[σ^2(Fo^2) + (0.0594P)^2 + 1.5841P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
433 reflections	Δρmax = 0.39 e Å^−3
41 parameters	Δρmin = −0.45 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.40 (2) GPa (400000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0297 (6)	0.33986 (11)	0.8469 (3)	0.0498 (6)*
N4	0.553 (2)	0.3530 (3)	0.5387 (10)	0.0299 (12)*
N5	0.6971 (17)	0.3312 (3)	0.7051 (10)	0.0312 (11)*
N1	0.3853 (19)	0.4148 (4)	0.2297 (12)	0.0424 (16)*
N3	0.394 (2)	0.3356 (4)	0.5771 (11)	0.0425 (14)*
N2	0.2928 (17)	0.3733 (4)	0.3871 (11)	0.0457 (14)*
C8	0.7079 (18)	0.4256 (4)	0.2567 (11)	0.0303 (13)*
H8	0.711452	0.457264	0.109814	0.036*
C6	0.841 (2)	0.3577 (3)	0.6357 (11)	0.0282 (13)*
C9	0.546 (3)	0.4011 (4)	0.3234 (13)	0.0287 (14)*
C7	0.855 (2)	0.4019 (3)	0.4110 (11)	0.0322 (14)*
H7	0.963592	0.414222	0.371132	0.039*

Geometric parameters (Å, º)

Cl1—C6	1.730 (15)	N3—N2	1.302 (14)
N4—N5	1.356 (17)	C8—H8	0.9300
N4—N3	1.321 (19)	C8—C9	1.42 (2)
N4—C9	1.358 (8)	C8—C7	1.344 (19)
N5—C6	1.305 (18)	C6—C7	1.415 (8)
N1—N2	1.358 (12)	C7—H7	0.9300
N1—C9	1.28 (2)
N5—N4—C9	126.9 (14)	N5—C6—Cl1	115.6 (5)
N3—N4—N5	122.6 (6)	N5—C6—C7	126.4 (14)
N3—N4—C9	110.3 (15)	C7—C6—Cl1	118.0 (12)
C6—N5—N4	113.0 (5)	N4—C9—C8	117.0 (15)
C9—N1—N2	106.1 (8)	N1—C9—N4	107.5 (15)
N2—N3—N4	104.2 (7)	N1—C9—C8	135.5 (7)
N3—N2—N1	111.8 (12)	C8—C7—C6	118.0 (14)
C9—C8—H8	120.8	C8—C7—H7	121.0
C7—C8—H8	120.8	C6—C7—H7	121.0
C7—C8—C9	118.4 (6)
Cl1—C6—C7—C8	−173.2 (4)	N3—N4—C9—C8	179.7 (4)
N4—N5—C6—Cl1	176.0 (3)	N2—N1—C9—N4	−1.0 (6)
N4—N5—C6—C7	−1.9 (7)	N2—N1—C9—C8	−179.5 (5)
N4—N3—N2—N1	−0.4 (6)	C9—N4—N5—C6	−2.7 (7)
N5—N4—N3—N2	175.3 (4)	C9—N4—N3—N2	−0.3 (6)
N5—N4—C9—N1	−174.5 (5)	C9—N1—N2—N3	0.9 (6)
N5—N4—C9—C8	4.3 (7)	C9—C8—C7—C6	−2.6 (7)
N5—C6—C7—C8	4.6 (8)	C7—C8—C9—N4	−1.3 (7)
N3—N4—N5—C6	−177.5 (4)	C7—C8—C9—N1	177.1 (6)
N3—N4—C9—N1	0.9 (6)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_48GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.850 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.836 (2) Å	Cell parameters from 675 reflections
b = 12.9703 (12) Å	θ = 4.0–23.0°
c = 5.5885 (5) Å	µ = 0.59 mm^−1
β = 100.542 (16)°	T = 296 K
V = 558.43 (18) Å^3	Plate, colourless
Z = 4	0.34 × 0.30 × 0.26 mm

Data collection

KM-4 CCD diffractometer	359 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	240 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.2°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −3→3
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −16→16
Tmin = 0.544, Tmax = 1.000	l = −7→6
3109 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.054	H-atom parameters constrained
wR(F^2) = 0.112	w = 1/[σ^2(Fo^2) + (0.019P)^2 + 1.8498P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
359 reflections	Δρmax = 0.28 e Å^−3
41 parameters	Δρmin = −0.26 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.48 (2) GPa 480000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0317 (9)	0.34042 (14)	0.8507 (4)	0.0517 (7)*
N4	0.540 (4)	0.3516 (4)	0.5395 (15)	0.0326 (17)*
N5	0.707 (3)	0.3304 (4)	0.7138 (13)	0.0339 (15)*
N1	0.385 (3)	0.4144 (5)	0.2293 (14)	0.041 (2)*
N3	0.401 (3)	0.3344 (5)	0.5865 (16)	0.046 (2)*
N2	0.294 (3)	0.3729 (4)	0.3901 (14)	0.0491 (19)*
C8	0.710 (3)	0.4261 (5)	0.2584 (15)	0.0310 (18)*
H8	0.714611	0.458760	0.111546	0.037*
C6	0.830 (3)	0.3572 (4)	0.6333 (16)	0.0263 (18)*
C9	0.544 (5)	0.4009 (5)	0.3242 (18)	0.0291 (19)*
C7	0.853 (3)	0.4023 (4)	0.4091 (13)	0.0312 (19)*
H7	0.962580	0.413998	0.372121	0.037*

Geometric parameters (Å, º)

Cl1—C6	1.82 (3)	N3—N2	1.35 (2)
N4—N5	1.51 (4)	C8—H8	0.9300
N4—N3	1.19 (4)	C8—C9	1.45 (4)
N4—C9	1.369 (11)	C8—C7	1.31 (3)
N5—C6	1.19 (3)	C6—C7	1.424 (10)
N1—N2	1.354 (18)	C7—H7	0.9300
N1—C9	1.28 (4)
N3—N4—N5	123.1 (9)	N5—C6—Cl1	112.2 (10)
N3—N4—C9	117 (3)	N5—C6—C7	134 (2)
C9—N4—N5	120 (3)	C7—C6—Cl1	113.6 (18)
C6—N5—N4	111.8 (8)	N4—C9—C8	120 (3)
C9—N1—N2	105.2 (11)	N1—C9—N4	104 (3)
N4—N3—N2	101.9 (12)	N1—C9—C8	135.8 (9)
N3—N2—N1	111.5 (19)	C8—C7—C6	115 (2)
C9—C8—H8	120.5	C8—C7—H7	122.3
C7—C8—H8	120.5	C6—C7—H7	122.3
C7—C8—C9	119.0 (8)
Cl1—C6—C7—C8	−172.8 (5)	N3—N4—C9—C8	178.7 (6)
N4—N5—C6—Cl1	175.9 (4)	N2—N1—C9—N4	−0.1 (7)
N4—N5—C6—C7	−1.6 (10)	N2—N1—C9—C8	−178.9 (7)
N4—N3—N2—N1	−0.7 (7)	C9—N4—N5—C6	−2.9 (8)
N5—N4—N3—N2	175.1 (5)	C9—N4—N3—N2	0.6 (8)
N5—N4—C9—N1	−175.0 (6)	C9—N1—N2—N3	0.5 (7)
N5—N4—C9—C8	4.0 (9)	C9—C8—C7—C6	−3.0 (9)
N5—C6—C7—C8	4.7 (10)	C7—C8—C9—N4	−0.9 (9)
N3—N4—N5—C6	−177.2 (7)	C7—C8—C9—N1	177.8 (7)
N3—N4—C9—N1	−0.3 (9)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_55GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.865 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.808 (6) Å	Cell parameters from 1193 reflections
b = 12.9522 (8) Å	θ = 4.0–25.6°
c = 5.5722 (4) Å	µ = 0.59 mm^−1
β = 100.54 (2)°	T = 296 K
V = 554.0 (4) Å^3	Plate, colourless
Z = 4	0.35 × 0.25 × 0.14 mm

Data collection

KM-4 CCD diffractometer	367 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	308 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.2°, θmin = 4.0°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −2→2
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −15→16
Tmin = 0.453, Tmax = 1.000	l = −7→7
3241 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.022	H-atom parameters constrained
wR(F^2) = 0.048	w = 1/[σ^2(Fo^2) + (0.0229P)^2 + 0.0869P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
367 reflections	Δρmax = 0.08 e Å^−3
91 parameters	Δρmin = −0.08 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.55 (2) GPa 550000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0298 (3)	0.34049 (5)	0.85234 (12)	0.0418 (16)
N4	0.560 (3)	0.3523 (3)	0.5444 (12)	0.035 (13)
N5	0.6976 (18)	0.3299 (2)	0.7117 (6)	0.027 (7)
N1	0.3851 (18)	0.4143 (3)	0.2306 (8)	0.029 (8)
N3	0.397 (3)	0.3347 (4)	0.5820 (12)	0.028 (12)
N2	0.2924 (13)	0.3726 (2)	0.3897 (6)	0.047 (8)
C8	0.7050 (19)	0.4260 (3)	0.2559 (9)	0.026 (9)
H8	0.705002	0.458180	0.106683	0.031*
C6	0.8467 (19)	0.3572 (3)	0.6437 (10)	0.026 (9)
C9	0.554 (3)	0.4007 (3)	0.3268 (10)	0.030 (13)
C7	0.8610 (17)	0.40255 (17)	0.4123 (5)	0.030 (8)
H7	0.968583	0.415519	0.369373	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.035 (5)	0.0514 (4)	0.0355 (4)	0.0026 (7)	−0.0039 (9)	0.0053 (3)
N4	0.06 (4)	0.0240 (14)	0.029 (3)	−0.002 (4)	0.019 (7)	0.0014 (13)
N5	0.02 (2)	0.0290 (13)	0.0283 (17)	0.001 (3)	−0.001 (5)	0.0015 (10)
N1	0.01 (3)	0.0336 (14)	0.039 (2)	0.002 (4)	−0.002 (4)	−0.0004 (14)
N3	0.01 (4)	0.0357 (19)	0.039 (3)	0.003 (4)	0.003 (7)	−0.0013 (15)
N2	0.06 (2)	0.0358 (14)	0.0461 (18)	0.007 (4)	−0.003 (5)	−0.0059 (11)
C8	0.03 (3)	0.0252 (14)	0.0219 (18)	0.001 (3)	−0.003 (5)	0.0022 (11)
C6	0.02 (3)	0.0253 (16)	0.028 (2)	0.003 (4)	−0.008 (5)	−0.0027 (13)
C9	0.04 (4)	0.0216 (15)	0.025 (3)	−0.001 (5)	0.011 (9)	0.0016 (17)
C7	0.03 (2)	0.0282 (13)	0.0290 (16)	0.000 (4)	0.004 (4)	−0.0019 (10)

Geometric parameters (Å, º)

Cl1—C6	1.684 (12)	N3—N2	1.317 (15)
N4—N5	1.32 (3)	C8—H8	0.9300
N4—N3	1.35 (3)	C8—C9	1.35 (3)
N4—C9	1.358 (8)	C8—C7	1.396 (16)
N5—C6	1.34 (2)	C6—C7	1.439 (7)
N1—N2	1.355 (13)	C7—H7	0.9300
N1—C9	1.34 (3)
N5—N4—N3	121.6 (8)	N5—C6—Cl1	116.4 (5)
N5—N4—C9	128 (2)	N5—C6—C7	125.2 (12)
N3—N4—C9	110 (2)	C7—C6—Cl1	118.4 (10)
N4—N5—C6	112.4 (7)	N1—C9—N4	107 (2)
C9—N1—N2	106.9 (7)	N1—C9—C8	134.3 (7)
N2—N3—N4	105.8 (7)	C8—C9—N4	119 (2)
N3—N2—N1	110.9 (10)	C8—C7—C6	116.5 (11)
C9—C8—H8	120.9	C8—C7—H7	121.7
C9—C8—C7	118.3 (7)	C6—C7—H7	121.7
C7—C8—H8	120.9
Cl1—C6—C7—C8	−172.8 (2)	N3—N4—C9—C8	179.5 (4)
N4—N5—C6—Cl1	175.5 (3)	N2—N1—C9—N4	−0.9 (4)
N4—N5—C6—C7	−2.2 (5)	N2—N1—C9—C8	−179.3 (4)
N4—N3—N2—N1	−0.2 (6)	C9—N4—N5—C6	−2.5 (5)
N5—N4—N3—N2	175.3 (2)	C9—N4—N3—N2	−0.3 (7)
N5—N4—C9—N1	−174.5 (4)	C9—N1—N2—N3	0.7 (4)
N5—N4—C9—C8	4.2 (7)	C9—C8—C7—C6	−2.8 (4)
N5—C6—C7—C8	4.8 (5)	C7—C8—C9—N4	−1.1 (5)
N3—N4—N5—C6	−177.3 (7)	C7—C8—C9—N1	177.3 (3)
N3—N4—C9—N1	0.8 (6)

6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C4H2N5Cl1@0_80GPa_phase_beta)

Crystal data

C4H2ClN5	F(000) = 312
Mr = 155.56	Dx = 1.945 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.756 (5) Å	Cell parameters from 1202 reflections
b = 12.7163 (5) Å	θ = 4.1–26.0°
c = 5.4680 (3) Å	µ = 0.62 mm^−1
β = 100.006 (18)°	T = 296 K
V = 531.1 (3) Å^3	Plate, colourless
Z = 4	0.24 × 0.22 × 0.22 mm

Data collection

KM-4 CCD diffractometer	355 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Mo) X-ray Source	306 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
Detector resolution: 16.2413 pixels mm^-1	θmax = 27.0°, θmin = 4.1°
HP ω scans – for more details see: A. Budzianowski, A. Katrusiak in High–Pressure Crystallography (Eds.: A. Katrusiak, P. F. McMillan), Dordrecht: Kluwer Acad. Publ., 2004 pp.157–168	h = −2→2
Absorption correction: multi-scan CrysAlisPro 1.171.39.46 (Rigaku Oxford Diffraction, 2018) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	k = −15→16
Tmin = 0.535, Tmax = 1.000	l = −6→6
2908 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.054	H-atom parameters constrained
wR(F^2) = 0.133	w = 1/[σ^2(Fo^2) + (0.0513P)^2 + 1.5556P] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max < 0.001
355 reflections	Δρmax = 0.37 e Å^−3
41 parameters	Δρmin = −0.44 e Å^−3
0 restraints

Special details

Experimental. Data were collected at room temperature and pressure of 0.80 (2) GPa 800000 kPa) with the crystal obtained by the in-situ high-pressure crystallization technique. Pressure was determined by monitoring the shift of the ruby R1-fluorescence line.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	1.0312 (6)	0.34163 (10)	0.8608 (3)	0.0364 (6)*
N4	0.553 (2)	0.3507 (3)	0.5508 (9)	0.0209 (12)*
N5	0.6944 (19)	0.3293 (3)	0.7196 (8)	0.0216 (11)*
N1	0.383 (2)	0.4142 (3)	0.2324 (10)	0.0303 (14)*
N3	0.392 (2)	0.3322 (4)	0.5901 (11)	0.0332 (14)*
N2	0.2904 (19)	0.3708 (4)	0.3966 (9)	0.0341 (14)*
C8	0.705 (2)	0.4269 (4)	0.2560 (10)	0.0209 (13)*
H8	0.707514	0.459507	0.104428	0.025*
C6	0.844 (2)	0.3569 (4)	0.6483 (10)	0.0200 (12)*
C9	0.543 (3)	0.4008 (4)	0.3279 (12)	0.0193 (13)*
C7	0.857 (2)	0.4034 (3)	0.4126 (9)	0.0225 (13)*
H7	0.965471	0.417025	0.368229	0.027*

Geometric parameters (Å, º)

Cl1—C6	1.703 (15)	N3—N2	1.299 (14)
N4—N5	1.333 (18)	C8—H8	0.9300
N4—N3	1.33 (2)	C8—C9	1.42 (3)
N4—C9	1.366 (8)	C8—C7	1.37 (2)
N5—C6	1.34 (2)	C6—C7	1.437 (8)
N1—N2	1.362 (14)	C7—H7	0.9300
N1—C9	1.27 (2)
N5—N4—C9	128.8 (17)	N5—C6—Cl1	116.8 (5)
N3—N4—N5	122.5 (7)	N5—C6—C7	124.7 (14)
N3—N4—C9	108.5 (15)	C7—C6—Cl1	118.4 (13)
N4—N5—C6	113.4 (7)	N4—C9—C8	116.0 (16)
C9—N1—N2	105.3 (8)	N1—C9—N4	109.4 (16)
N2—N3—N4	104.8 (9)	N1—C9—C8	134.6 (7)
N3—N2—N1	112.1 (14)	C8—C7—C6	117.8 (14)
C9—C8—H8	120.5	C8—C7—H7	121.1
C7—C8—H8	120.5	C6—C7—H7	121.1
C7—C8—C9	119.1 (6)
Cl1—C6—C7—C8	−172.2 (4)	N3—N4—C9—C8	180.0 (5)
N4—N5—C6—Cl1	175.3 (3)	N2—N1—C9—N4	−0.6 (6)
N4—N5—C6—C7	−1.1 (8)	N2—N1—C9—C8	−179.8 (6)
N4—N3—N2—N1	−0.1 (6)	C9—N4—N5—C6	−3.9 (8)
N5—N4—N3—N2	174.8 (4)	C9—N4—N3—N2	−0.3 (6)
N5—N4—C9—N1	−174.0 (5)	C9—N1—N2—N3	0.5 (6)
N5—N4—C9—C8	5.3 (8)	C9—C8—C7—C6	−2.5 (7)
N5—C6—C7—C8	4.1 (8)	C7—C8—C9—N4	−1.6 (7)
N3—N4—N5—C6	−177.9 (5)	C7—C8—C9—N1	177.5 (6)
N3—N4—C9—N1	0.6 (6)