Hydro­gen-bonding patterns in two structural isomers of 3,6-bis(2-chloro­phenyl)-1,4-di­hydro-1,2,4,5-tetrazine

Two structural isomers, 3,6-bis(2-chloro­phenyl)-1,4-di­hydro-1,2,4,5-tetrazine, (I), and 3,5-bis(2-chloro­phenyl)-4-amino-1H-1,2,4-triazole, (II), both C₁₄H₁₀Cl₂N₄, form chain-like structures in the solid state, stabilized by N-H...N and N-H...Cl hydrogen bonds. A contribution from weak interactions to the strong hydrogen-bond network is observed in both structures. The secondary graph sets for intermolecular hydrogen bonds [(11) for (I) and (12) for (II)] indicate the similarity between the networks.

S1. Comment

The compound of general formulae C₂H₂N₄(C₆H₄Cl)₂ crystallizes as 3,6-bis(2-chlorophenyl)-1,4-dihydro-1,2,4,5-tetrazine, (I), in the form of yellow–orange needles. It undergoes irreversible isomerization above 353 K in acidic water solution, forming the structural isomer 3,5-bis (2-chlorophenyl)-4-amino-1,2,4-triazol, (II).

X-ray structure determination revealed that isomer (I) crystallizes in the monoclinic space group C2/c, while isomer (II) crystallizes in the orthorhombic space group Pbca. The molecular structures of (I) and (II), with the atom-numbering schemes, are shown in Figs. 1 and 2, respectively.

Since both molecules retain potential strong proton-donor groups [–NH in (I) and –NH₂ in (II)] and proton acceptors (N and Cl atoms) we undertook a detailed analysis of the hydrogen-bonded networks. Analysis of intra- and intermolecular contacts occurring in crystalline isomers indicated that, in both cases, the weaker –CH donor groups are also important in the formation of the hydrogen-bonded network (Taylor & Kennard, 1982; Desiraju & Steiner, 1999). To attempt a consistent characterization of the differences and similarities of the solid-state structures of the studied compounds, we have used the Etter (1990, 1991) graph-set descriptors.

The molecule of (I) consists of a six-membered central tetrazine ring and two chlorophenyl rings. As a twofold axis passes through the centre of the tetrazine ring, the molecule exhibits crystallographic C₂ point-group symmetry, so the chlorophenyl rings are symmetry equivalent. The central ring is folded along the N1—N1ⁱ vector and exhibits a boat conformation [puckering parameters Q = 0.513 (2)°, θ = 90.0 (2)° and ϕ = 175.7 (2)°; Cremer & Pople, 1975]. An analysis of structures deposited in the Cambridge Structural Database (Version 5.24 of April 2003; Allen, 2002) showed that a boat conformation is observed for all structurally characterized tetrazine derivatives. The chlorophenyl rings are twisted to one another with a dihedral angle of 77.94 (7)°. The Cl atoms lie on the same side of the C10—N2—C10ⁱ—N2ⁱ plane [symmetry code: (i) −x, y, 1/2 − z]. Atoms N1 and N1ⁱ lie above this plane, and atoms H1 and H1ⁱ are located in equatorial positions. Such an arrangement enables the formation of a pair of strong intermolecular N—H···N hydrogen bonds between centrosymmetrically related neighbouring molecules [H···N = 2.29 (2) Å, N···N = 3.052 (2) Å and N—H···N = 145 (2)°; hydrogen-bond motif R₂²(6) (Bernstein et al., 1995); motif a in Fig.3], leading to the formation of an infinite C(4)[R₂²(6)] chain of rings along the c axis.

The molecule of (II) consists of a five-membered (heterocyclic) aromatic triazole ring and two chlorophenyl rings (Ph1 and Ph2). The main difference from the molecule of (I) is the asymmetry of the molecule of (II), which is a result of the postions of the H atoms of the –NH₂ amine group. They lie on the same side of the quasi-mirror plane that passes through the amine N atom and the ring N—N bond, and is perpendicular to the ring plane. Excluding these H atoms, the molecule displays almost C_m point-group symmetry. The main reason for the asymmetry of the molecule is the strong N4—H4B···N2ⁱ intermolecular hydrogen bond [H···N = 2.19 (3) Å, N···N = 3.016 (3) Å and N—H···N 154 (2)°]. The observed infinite zigzag C(5) chain (motif a in Fig. 4) is formed by molecules related by a b-glide plane. As atoms H4A and H4B are both directed towards ring Ph1, the formation of an intramolecular hydrogen bond between the N4—H4A donor group and atom Cl1 is observed. The proton–acceptor distance is 2.66 (3) Å and the N4—H4A···Cl1 angle is 137 (2)°. The corresponding graph-set descriptor is S(7) (motif b in Fig. 4). This interaction is also evidenced by the significantly different thermal parameters of atoms Cl1 and Cl2, the U_eq values being 0.0503 (2) and 0.0908 (3), respectively. The dihedral angles between the triazole plane and the planes of the chlorophenyl rings Ph1 and Ph2 are 60.06 (7) and 65.21 (8)°, respectively. The larger value for ring Ph2 is a consequence of the repulsion between atoms Cl2 and N4 [Cl2···N4 = 3.378 (3) Å].

The observed one-dimensional assemblies formed by strong hydrogen bonding are enforced by weaker intermolecular interactions. C—H···Cl contacts are observed along the main chains, between the chlorophenyl rings of adjacent molecules. The H···Cl distances [2.83 (3) Å in (I) and 2.85 (2) Å in (II)] typify relatively strong C—H···Cl bonding (Taylor & Kennard, 1982). The assigned graph-set descriptors are C(5) for both compounds (motif b in Fig. 3 and motif c in Fig. 4). Motifs a, b and c constitute primary graph sets given as N₁ = C(5) C(4)[R₂²(6)] [for (I)] and N₁= C(5)S(7) C(5) [for (II)] (Etter, et al., 1990). The first-level graph sets are different because of the presence of symmetry-equivalent atoms in (I) and intramolecular hydrogen bonding in (II). Secondary graph sets for intermolecular bonding are N₂(ab) = R₂²(11) [(I)] and N₂(ac) = R₂²(12) [(II)], indicating the similarity of the main structural features.

Detailed analysis of the molecular packing shows that the main chains form close-packed structures. In the case of (II), the zigzag chains are connected together via C24—H24···N4^v and C13—H13···N2^vi weak hydrogen bonds, with motifs R₂²(16) and C(6), respectively. There is no evidence of weak hydrogen bonding between the chains of (I), but by analogy to the crystal structure of (II), the long C3—H3···N1^iv contact [H···N = 2.98 (3) Å] can be regarded as an atractive interaction. The same graph-set descriptor, C(6), is applicable.

S2. Experimental

Compound (I) was prepared using a modification of the procedure described by Brooker et al. (1987), by reacting bis-(α,2-dichlorobenzilidene)hydrazine and hydrazine hydrate at low temperature. Crystals suitable for X-ray diffraction were crystallized from ethanol, precipitating in the form of yellow–orange needles (m.p. 482–483 K). Compound (I) was dissolved in an acidic water solution and heated to above 353 K, giving the structural isomer (II). The isomerization reaction is irreversible. Well shaped crystals of (II), in the form of colourless prisms (m.p. 441–442 K), were obtained from ethanol. Detailed descriptions of the products and synthesis routes are given elsewhere (Włostowski & Olszewski, 2003).

S3. Refinement

Since the absorption coefficients of both compounds were comparatively high, a numerical correction (Gaussian integration) based on a well defined crystal shape was applied using SHELX76 (Sheldrick, 1976). For both compounds, H atoms were found from a difference Fourier map and their positional and isotropic displacement parameters were refined.

Computing details

For both compounds, data collection: P3/P4-PC Software (Siemens, 1991). Cell refinement: P3/P4-PC Software for (I); P3/P4-PC for (II). For both compounds, data reduction: XDISK (Siemens, 1991); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).

Figures

	Fig. 1. The molecule of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level·[Symmetry code: (i) −x, y, 1/2 − z.]
	Fig. 2. The molecule of (II), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. A map of the hydrogen-bond patterns in the main structural feature of (I). Hydrogen bonds are shown as dashed and dotted lines. For motif a, a full description of the pattern is C(4)[R2^2(6)] (Bernstein et al., 1995). The two motifs together constitute the first-order hydrogen-bonded network described as N1 = C(5) C(4)[R2^2(6)].
	Fig. 4. A map of the hydrogen-bond patterns in the main structural feature of (II). Hygrogen bonds are shown as dashed and dotted lines. The three motifs together constitute the first-order hydrogen-bonded network described as N1 = C(5)S(7) C(5).

(I) 3,6-bis(2-chlorophenyl)-1,4-dihydro-1,2,4,5-tetrazine

Crystal data

C14H10Cl2N4	F(000) = 624
Mr = 305.16	Dx = 1.495 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 30 reflections
a = 16.0020 (12) Å	θ = 7.7–16.4°
b = 9.4123 (8) Å	µ = 0.47 mm^−1
c = 10.5752 (7) Å	T = 293 K
β = 121.664 (5)°	Needle, yellow–orange
V = 1355.69 (18) Å^3	0.62 × 0.09 × 0.09 mm
Z = 4

Data collection

Siemens, P3 diffractometer	996 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.014
Graphite monochromator	θmax = 25.0°, θmin = 2.6°
profile data from ω–2θ scans	h = −18→18
Absorption correction: gaussian SHELX76 (Sheldrick, 1976)	k = −11→11
Tmin = 0.936, Tmax = 0.960	l = −12→12
2496 measured reflections	1 standard reflections every 70 reflections
1203 independent reflections	intensity decay: 1.8%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	All H-atom parameters refined
wR(F^2) = 0.099	w = 1/[σ^2(Fo^2) + (0.0452P)^2 + 1.4393P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
1203 reflections	Δρmax = 0.39 e Å^−3
112 parameters	Δρmin = −0.43 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0047 (12)

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Cl1	0.16401 (5)	0.74870 (6)	0.21918 (8)	0.0646 (3)
N1	0.04530 (12)	0.4499 (2)	0.18150 (18)	0.0376 (4)
N2	0.05456 (12)	0.49908 (19)	0.40415 (17)	0.0372 (4)
C1	0.20247 (14)	0.5248 (2)	0.4027 (2)	0.0359 (5)
C2	0.24122 (16)	0.6321 (2)	0.3587 (2)	0.0439 (5)
C3	0.3429 (2)	0.6493 (3)	0.4296 (3)	0.0618 (8)
C4	0.4044 (2)	0.5597 (4)	0.5428 (3)	0.0646 (8)
C5	0.36748 (18)	0.4549 (3)	0.5887 (3)	0.0589 (7)
C6	0.26745 (15)	0.4384 (3)	0.5202 (2)	0.0434 (5)
C10	0.09617 (14)	0.4949 (2)	0.3295 (2)	0.0334 (5)
H1	0.0749 (15)	0.470 (2)	0.134 (2)	0.036 (5)*
H3	0.362 (2)	0.720 (3)	0.398 (3)	0.072 (9)*
H4	0.475 (2)	0.568 (4)	0.593 (3)	0.094 (10)*
H5	0.412 (2)	0.391 (3)	0.670 (3)	0.078 (9)*
H6	0.2407 (16)	0.363 (3)	0.552 (2)	0.049 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0958 (6)	0.0467 (4)	0.0745 (5)	0.0089 (3)	0.0608 (4)	0.0122 (3)
N1	0.0339 (9)	0.0530 (11)	0.0309 (9)	0.0034 (8)	0.0204 (8)	−0.0022 (8)
N2	0.0340 (9)	0.0513 (10)	0.0298 (8)	−0.0032 (7)	0.0191 (7)	0.0000 (7)
C1	0.0388 (11)	0.0407 (11)	0.0350 (10)	−0.0041 (9)	0.0242 (9)	−0.0080 (8)
C2	0.0558 (13)	0.0434 (12)	0.0480 (12)	−0.0080 (10)	0.0380 (11)	−0.0100 (10)
C3	0.0720 (18)	0.0631 (16)	0.0756 (18)	−0.0309 (15)	0.0560 (16)	−0.0241 (15)
C4	0.0409 (14)	0.091 (2)	0.0577 (16)	−0.0135 (14)	0.0232 (13)	−0.0206 (15)
C5	0.0424 (13)	0.0792 (19)	0.0461 (13)	−0.0030 (13)	0.0172 (11)	−0.0095 (13)
C6	0.0378 (12)	0.0531 (14)	0.0372 (11)	−0.0024 (10)	0.0181 (10)	−0.0040 (10)
C10	0.0370 (11)	0.0366 (10)	0.0309 (10)	−0.0004 (8)	0.0208 (9)	0.0004 (8)

Geometric parameters (Å, º)

Cl1—C2	1.730 (2)	C2—C3	1.399 (3)
N1—C10	1.398 (2)	C3—C4	1.369 (4)
N1—N2^i	1.438 (2)	C3—H3	0.87 (3)
N1—H1	0.88 (2)	C4—C5	1.363 (4)
N2—C10	1.273 (2)	C4—H4	0.97 (3)
N2—N1^i	1.438 (2)	C5—C6	1.376 (3)
C10—C1	1.480 (3)	C5—H5	0.98 (3)
C1—C2	1.388 (3)	C6—H6	0.98 (2)
C1—C6	1.389 (3)
C10—N1—N2^i	114.14 (15)	C4—C3—C2	119.8 (3)
C10—N1—H1	114.1 (14)	C4—C3—H3	125 (2)
N2^i—N1—H1	109.0 (13)	C2—C3—H3	115 (2)
C10—N2—N1^i	111.68 (16)	C5—C4—C3	120.7 (2)
N2—C10—N1	121.13 (18)	C5—C4—H4	117 (2)
N2—C10—C1	120.07 (17)	C3—C4—H4	122 (2)
N1—C10—C1	118.55 (16)	C4—C5—C6	119.7 (3)
C2—C1—C6	118.02 (19)	C4—C5—H5	120.6 (17)
C2—C1—C10	123.78 (19)	C6—C5—H5	119.7 (17)
C6—C1—C10	118.17 (18)	C5—C6—C1	121.5 (2)
C1—C2—C3	120.2 (2)	C5—C6—H6	120.0 (13)
C1—C2—Cl1	120.20 (17)	C1—C6—H6	118.4 (13)
C3—C2—Cl1	119.56 (19)
N1^i—N2—C10—N1	1.4 (3)	C6—C1—C2—Cl1	−176.82 (16)
N1^i—N2—C10—C1	−172.72 (17)	C10—C1—C2—Cl1	4.8 (3)
N2^i—N1—C10—N2	39.8 (2)	C1—C2—C3—C4	0.0 (4)
N2^i—N1—C10—C1	−146.05 (18)	Cl1—C2—C3—C4	178.2 (2)
N2—C10—C1—C2	−121.8 (2)	C2—C3—C4—C5	−0.9 (4)
N1—C10—C1—C2	63.9 (3)	C3—C4—C5—C6	0.2 (4)
N2—C10—C1—C6	59.8 (3)	C4—C5—C6—C1	1.2 (4)
N1—C10—C1—C6	−114.4 (2)	C2—C1—C6—C5	−2.0 (3)
C6—C1—C2—C3	1.3 (3)	C10—C1—C6—C5	176.5 (2)
C10—C1—C2—C3	−177.05 (19)

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N2^ii	0.88 (2)	2.29 (2)	3.052 (2)	145 (2)
C6—H6···Cl1^iii	0.98 (2)	2.83 (2)	3.732 (2)	154 (2)

Symmetry codes: (ii) x, −y+1, z−1/2; (iii) x, −y+1, z+1/2.

(II) 3,5-bis(2-chlorophenyl)-4-amino-1H-1,2,4-triazole

Crystal data

C14H10Cl2N4	F(000) = 1248
Mr = 305.16	Dx = 1.458 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 29 reflections
a = 12.3382 (14) Å	θ = 4.1–10.3°
b = 8.6777 (9) Å	µ = 0.46 mm^−1
c = 25.968 (4) Å	T = 293 K
V = 2780.3 (6) Å^3	Prism, colourless
Z = 8	0.49 × 0.18 × 0.12 mm

Data collection

Siemens, P3 diffractometer	1662 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 25.1°, θmin = 2.3°
profile data from ω–2θ scans	h = 0→14
Absorption correction: gaussian SHELX76 (Sheldrick, 1976)	k = 0→10
Tmin = 0.913, Tmax = 0.952	l = −30→0
2461 measured reflections	2 standard reflections every 70 reflections
2461 independent reflections	intensity decay: 0.0%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	All H-atom parameters refined
wR(F^2) = 0.098	w = 1/[σ^2(Fo^2) + (0.0497P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
2461 reflections	Δρmax = 0.22 e Å^−3
222 parameters	Δρmin = −0.23 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0016 (4)

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Cl1	0.50422 (5)	0.13786 (7)	0.26922 (2)	0.0503 (2)
Cl2	0.48752 (7)	0.13503 (11)	0.43241 (3)	0.0908 (3)
N1	0.78855 (15)	0.2046 (2)	0.38776 (7)	0.0518 (6)
N2	0.79746 (15)	0.1982 (2)	0.33424 (7)	0.0473 (5)
N3	0.65026 (13)	0.3238 (2)	0.35401 (6)	0.0343 (4)
N4	0.55912 (17)	0.4213 (3)	0.35109 (8)	0.0416 (5)
C1	0.71345 (16)	0.2705 (2)	0.31492 (8)	0.0362 (5)
C2	0.69952 (17)	0.2803 (2)	0.39847 (8)	0.0396 (5)
C11	0.69218 (16)	0.2990 (2)	0.26003 (8)	0.0350 (5)
C12	0.59812 (17)	0.2490 (2)	0.23554 (8)	0.0367 (5)
C13	0.5780 (2)	0.2813 (3)	0.18424 (9)	0.0462 (6)
C14	0.6538 (2)	0.3637 (3)	0.15663 (9)	0.0515 (7)
C15	0.7480 (2)	0.4125 (3)	0.17992 (9)	0.0564 (7)
C16	0.76670 (19)	0.3809 (3)	0.23107 (9)	0.0454 (6)
C21	0.65961 (19)	0.3180 (3)	0.45040 (8)	0.0432 (6)
C22	0.5635 (2)	0.2598 (3)	0.46946 (9)	0.0535 (7)
C23	0.5276 (3)	0.2992 (4)	0.51846 (12)	0.0696 (9)
C24	0.5879 (3)	0.3959 (4)	0.54759 (11)	0.0777 (11)
C25	0.6840 (3)	0.4539 (4)	0.53002 (11)	0.0760 (9)
C26	0.7199 (2)	0.4152 (3)	0.48162 (10)	0.0587 (7)
H4A	0.512 (2)	0.375 (3)	0.3340 (10)	0.065 (9)*
H4B	0.586 (2)	0.508 (3)	0.3383 (10)	0.071 (10)*
H13	0.5124 (18)	0.251 (3)	0.1703 (9)	0.047 (7)*
H14	0.6408 (19)	0.383 (3)	0.1202 (10)	0.064 (8)*
H15	0.800 (2)	0.471 (3)	0.1614 (10)	0.070 (8)*
H16	0.8318 (18)	0.414 (2)	0.2493 (8)	0.045 (6)*
H23	0.460 (2)	0.262 (3)	0.5265 (11)	0.077 (10)*
H24	0.561 (2)	0.425 (3)	0.5811 (12)	0.086 (10)*
H25	0.730 (2)	0.529 (4)	0.5505 (12)	0.096 (11)*
H26	0.789 (2)	0.454 (3)	0.4679 (10)	0.064 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0436 (3)	0.0512 (4)	0.0561 (4)	−0.0137 (3)	0.0032 (3)	−0.0011 (3)
Cl2	0.0859 (6)	0.0964 (6)	0.0902 (6)	−0.0431 (5)	0.0163 (5)	−0.0045 (5)
N1	0.0455 (12)	0.0693 (14)	0.0407 (12)	0.0152 (11)	−0.0017 (9)	0.0066 (10)
N2	0.0387 (11)	0.0658 (13)	0.0375 (11)	0.0138 (10)	0.0020 (8)	0.0034 (10)
N3	0.0303 (9)	0.0368 (10)	0.0356 (10)	0.0053 (8)	−0.0002 (8)	0.0008 (8)
N4	0.0341 (11)	0.0426 (12)	0.0482 (12)	0.0070 (10)	−0.0028 (10)	−0.0031 (11)
C1	0.0311 (11)	0.0391 (13)	0.0384 (12)	0.0000 (10)	0.0030 (9)	0.0001 (10)
C2	0.0370 (12)	0.0451 (13)	0.0367 (13)	0.0033 (10)	−0.0009 (10)	0.0035 (11)
C11	0.0335 (11)	0.0344 (11)	0.0371 (13)	0.0044 (10)	0.0010 (10)	−0.0034 (10)
C12	0.0377 (12)	0.0291 (11)	0.0435 (13)	0.0004 (9)	0.0029 (11)	−0.0021 (10)
C13	0.0477 (14)	0.0474 (15)	0.0433 (14)	0.0014 (12)	−0.0081 (12)	−0.0040 (12)
C14	0.0642 (17)	0.0547 (16)	0.0357 (13)	0.0010 (14)	−0.0017 (12)	0.0034 (12)
C15	0.0608 (16)	0.0624 (18)	0.0461 (14)	−0.0128 (14)	0.0098 (14)	0.0090 (13)
C16	0.0376 (13)	0.0527 (15)	0.0458 (12)	−0.0081 (12)	0.0040 (11)	0.0002 (12)
C21	0.0476 (14)	0.0454 (14)	0.0364 (13)	0.0096 (12)	−0.0002 (11)	0.0049 (11)
C22	0.0579 (16)	0.0561 (17)	0.0464 (15)	0.0051 (13)	0.0071 (12)	0.0101 (12)
C23	0.074 (2)	0.084 (2)	0.0504 (18)	0.0169 (19)	0.0204 (16)	0.0230 (17)
C24	0.107 (3)	0.090 (3)	0.0355 (17)	0.038 (2)	0.0059 (18)	0.0045 (17)
C25	0.096 (2)	0.088 (2)	0.0443 (18)	0.012 (2)	−0.0170 (18)	−0.0105 (17)
C26	0.0573 (17)	0.074 (2)	0.0444 (15)	0.0060 (16)	−0.0094 (13)	0.0007 (14)

Geometric parameters (Å, º)

Cl1—C12	1.743 (2)	C14—C15	1.376 (4)
Cl2—C22	1.725 (3)	C14—H14	0.97 (3)
N1—C2	1.310 (3)	C15—C16	1.376 (3)
N1—N2	1.395 (3)	C15—H15	0.95 (3)
N2—C1	1.311 (3)	C16—H16	0.98 (2)
N3—C2	1.358 (2)	C2—C21	1.473 (3)
N3—C1	1.361 (3)	C21—C22	1.381 (3)
N3—N4	1.410 (2)	C21—C26	1.387 (3)
N4—H4A	0.83 (3)	C22—C23	1.390 (4)
N4—H4B	0.88 (3)	C23—C24	1.352 (5)
C1—C11	1.470 (3)	C23—H23	0.92 (3)
C11—C16	1.384 (3)	C24—C25	1.367 (5)
C11—C12	1.393 (3)	C24—H24	0.96 (3)
C12—C13	1.384 (3)	C25—C26	1.374 (4)
C13—C14	1.379 (4)	C25—H25	1.02 (3)
C13—H13	0.93 (2)	C26—H26	0.98 (3)
C2—N1—N2	107.30 (18)	C14—C15—H15	120.6 (16)
C1—N2—N1	107.46 (17)	C15—C16—C11	121.0 (2)
C2—N3—C1	106.45 (17)	C15—C16—H16	123.2 (13)
C2—N3—N4	124.73 (17)	C11—C16—H16	115.8 (13)
C1—N3—N4	128.39 (17)	N1—C2—N3	109.53 (18)
N3—N4—H4A	107.3 (18)	N1—C2—C21	125.9 (2)
N3—N4—H4B	103.6 (17)	N3—C2—C21	124.55 (19)
H4A—N4—H4B	118 (2)	C22—C21—C26	118.3 (2)
N2—C1—N3	109.26 (19)	C22—C21—C2	122.3 (2)
N2—C1—C11	126.33 (19)	C26—C21—C2	119.4 (2)
N3—C1—C11	124.31 (18)	C21—C22—C23	120.8 (3)
C16—C11—C12	117.74 (19)	C21—C22—Cl2	119.75 (19)
C16—C11—C1	119.6 (2)	C23—C22—Cl2	119.5 (2)
C12—C11—C1	122.62 (19)	C24—C23—C22	119.3 (3)
C13—C12—C11	121.7 (2)	C24—C23—H23	126.2 (18)
C13—C12—Cl1	118.42 (18)	C22—C23—H23	114.2 (19)
C11—C12—Cl1	119.81 (16)	C23—C24—C25	121.3 (3)
C14—C13—C12	119.0 (2)	C23—C24—H24	118.9 (19)
C14—C13—H13	122.6 (15)	C25—C24—H24	119.9 (19)
C12—C13—H13	118.3 (15)	C24—C25—C26	119.7 (3)
C15—C14—C13	120.2 (2)	C24—C25—H25	123.2 (17)
C15—C14—H14	120.8 (15)	C26—C25—H25	117.0 (18)
C13—C14—H14	118.9 (15)	C25—C26—C21	120.7 (3)
C14—C15—C16	120.3 (2)	C25—C26—H26	121.7 (16)
C16—C15—H15	119.0 (16)	C21—C26—H26	117.6 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4B···N2^i	0.88 (3)	2.19 (3)	3.016 (3)	154 (2)
N4—H4B···N1^i	0.88 (3)	2.64 (3)	3.238 (3)	126 (2)
N4—H4A···Cl1	0.83 (3)	2.66 (3)	3.321 (2)	137 (2)
C16—H16···Cl1^i	0.98 (2)	2.85 (2)	3.734 (2)	151 (2)
C24—H24···N4^ii	0.96 (3)	2.66 (3)	3.567 (4)	157 (2)
C13—H13···N2^iii	0.93 (2)	2.69 (2)	3.568 (3)	158 (2)

Symmetry codes: (i) −x+3/2, y+1/2, z; (ii) −x+1, −y+1, −z+1; (iii) x−1/2, y, −z+1/2.