Four salt phases of theophylline

The structures of two anhydrous salt phases of theophylline, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium tetra­fluoro­borate, C₇H₉N₄O₂⁺·BF₄⁻, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride, C₇H₉N₄O₂⁺·Cl⁻, are reported together with the structures of two monohydrate salt forms, namely 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium chloride monohydrate, C₇H₉N₄O₂⁺·Cl⁻·H₂O, and 1,3-dimethyl-2,6-dioxo-7H-purin-9-ium bromide monohydrate, C₇H₉N₄O₂⁺·Br⁻·H₂O. The monohydrate structures are mutually isostructural, with the cations and anions lying on crystallographic mirror planes (Z′ = ). The main inter­molecular inter­action motif is a hydrogen-bonding network in the same mirror plane. The tetra­fluoro­borate structure is based on planar hydrogen-bonded theopylline cation dimers; the anions inter­act with the dimers in a pendant fashion. The anhydrous chloride structure has Z′ = 2 and in contrast to the other species it does not form planar hydrogen-bonded constructs, instead one-dimensional chains of cations and anions propagate parallel to the crystallographic c direction. An earlier report claiming to describe an anhydrous structure of theophylline hydro­chloride is re-examined in light of these results. It is concluded that the earlier structure has been reported in the wrong space group and that it has been chemically misidentified.

S1. Introduction

Theophylline (1,3-di­methylxanthine) is a naturally occurring base that is chemically and structurally related to caffeine and theobromine. Its main medicinal use is in the treatment of asthma symptoms, but in the field of crystal science it is perhaps better known as the model active pharmaceutical ingredient (API) at the heart of many physical-form screening and prediction studies. Three polymorphs have been structurally described (Fucke et al., 2012), as have numerous organic cocrystal forms (see, for example, Fucke et al., 2012; Karki et al., 2007), as well as di­methyl sulfoxide (DMSO) and hydrate solvate forms (Cardin et al., 2007; Sun et al., 2002). The aqueous dissolution profile of theophylline and its transformation to theophylline hydrate has also received much attention (De Smidt et al., 1986; Rodriguez-Hornedo et al., 1992). Additionally, theophylline has been used as a ligand with d-block metals and several such complexes have been structurally characterized (for example, Abuhijleh et al., 2009; Griffith & Amma, 1979; Nolte et al., 2006). Despite this inter­est, only two structures of simple salt forms where theophyllline acts as a Brønsted base and hence occurs as a protonated cation are known. A perchlorate salt form has been described (Biradha et al., 2010) and, in a relatively early and film-based study that gave a poorly defined structure, an anhydrous hydro­chloride form has been described in the space group Pna2₁ (Koo et al., 1978). This latter form is especially inter­esting to the pharmaceutical community as hydro­chloride salts are the commonest salt form of basic APIs to be commercially exploited (Stahl & Wermuth, 2008). Herein, the structures of the tetra­fluoro­borate, (I), and hydrated bromide, (III), salts of theophylline are described, as are two new structures of theophylline hydro­chloride, an anhydrate, (IV), and a monohydrate, (II). The identity of the previously reported hydro­chloride structure is re-assessed in light of these results.

S2. Experimental

S2.1. Synthesis and crystallization

Large colourless crystals of (I), (II) and (III) were obtained using the following general scheme. Theophylline (approximately 0.5 g) was suspended in deionized water (10 ml). The appropriate concentrated acid (HBF₄, HCl or HBr) was added in sufficient volume to ensure dissolution of the theophylline. The solutions were filtered and left to evaporate. Crystals of (II) were recovered from solution after approximately 4 d, but crystals of (I) and (III) were only obtained after approximately two weeks. Buist et al. (2013) describe the method used for in situ generation of HCl by reaction of a alcohol solution of an active pharmaceutical ingredient (API) with acetyl chloride. Following this method with methanol and theophylline again gave crystals of (II), but with ethanol as the solvent, suitable colourless crystals of (IV) were deposited directly from the reaction mixture after 48 h.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms bound to C atoms were placed geometrically and refined in riding mode, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C) for Csp² groups, and C—H = 0.98 Å and U_iso(H) = 1.5U_eq(C) for methyl groups. H atoms bound to N atoms were positioned as found by difference syntheses; in (I) and (II), these atoms were refined freely; however, for (III) the N—H distances were restrained to 0.86 (1) Å and for (IV) the H atoms were restrained both to have N—H distances of 0.86 (2) Å and such that U_iso(H) = 1.2U_eq(N). In both hydrates, the H atoms of the water molecules were positioned as found by difference syntheses and were refined with restraints such that the O—H and H···H distances approximated 0.88 (1) and 1.33 (2) Å, respectively, and with U_iso(H) values set at 1.5U_eq(O).

S3. Results and discussion

The reaction of an aqueous slurry of theophylline with concentrated tetra­fluoro­boric acid gave the tetra­fluoro­borate salt of the protonated theophylline cation, (I) (Fig. 1). This structure has a unit cell that is isomorphous with that of the reported perchlorate salt (Biradha et al., 2010). Both the perchlorate and the tetra­fluoro­borate salt structures have the same hydrogen-bonding motif involving planar dimeric theophylline units forming a ten-membered ring (Fig. 2 and Table 2). A similar dimeric hydrogen-bonding motif is observed in the structure of theophylline hydrate (Sun et al., 2002). In tetra­fluoro­borate (I), the tetra­hedral counter-ion accepts a hydrogen bond from the second N—H group of the theophylline cation, and thus two anions lie pendant to the theophylline dimer. Note that only one of the four F atoms acts as a hydrogen-bond acceptor, though a second F atom does make a significantly short contact with π geometry through an inter­action with the central xanthine C—C bond [F4···C3 = 2.8704 (13) Å]. Again, a similar pendant inter­action occurs in the perchlorate structure, indicating that here similarities in the anions shape and general size outweigh any differences that might be expected due to their differing electronic natures. The molecular geometry of the cation in (I), as judged by a comparison of the bond lengths and angles, is also in good agreement with that described for the perchlorate salt. The same is true for the molecular geometries of all the other theophylline cations described herein (see Supporting information).

On reaction of theophylline with concentrated aqueous HCl or HBr, the monohydrates of theophylline hydro­chloride, (II) (Fig. 3), and theophylline hydro­bromide, (III) (Fig. 4), were obtained. The structures of (II) and (III) are essentially mutually isomorphous and isostructural and are thus described together. With the exception of the H atoms of the methyl groups, all the atoms of the cations of (II) and (III) lie on the mirror plane (Z' = 1/2) in the space group Pnma. The halide ions reside in the same plane, but modeling the water molecules in-plane gave models with elongated displacement ellipsoids for atom O1W. This effect was more pronounced for (III) than for (II). Thus, the water molecules are modeled as being displaced slightly out of plane, that is they are disordered about the mirror. Alternative refinement in the space group Pna2₁ gives similar models with disorder in the position of the water molecule. The higher-symmetry model is thus prefered. The hydrogen-bonded theophylline dimer observed for the structures with the tetra­hedral anions is not seen here. Instead, one N—H group donates a hydrogen bond to the halide anion, whilst the second N—H group donates a hydrogen bond to the water molecule. Both H atoms of the water molecule donate hydrogen bonds, one to the halide and one to atom O2 (Tables 3 and 4). These hydrogen bonds combine to form planar sheets parallel to the ac plane, but they also leave one C═O group of each theophylline that, in contradiction to predictions based on Etter's rules, does not act as a hydrogen-bond acceptor (Etter, 1990). The most significant inter­actions between adjacent sheets are the close contacts that result from the halides ions lying symmetrically between pairs of xanthine rings, see Fig. 5. For hydrated chloride salt (II), the shortest such contact is C3···Cl' [3.3979 (6) Å], whilst for hydrate bromide salt (III) the equivalent Br inter­action distance is 3.4307 (7) Å (symmetry code: -x+1/2, -y+1, z+1/2).

Rather than using aqueous HCl, HCl can be generated in situ by reaction of alcohols with acetyl chloride. This water-free method has been used recently to produce salt forms of weakly basic groups and to obtain nonhydrated forms of salts (Perumalla & Sun, 2012; Buist et al., 2013). Using this technique with theophylline and methanol led only to an alternative preparation of (II). However, with ethanol, an anhydrous phase of theophylline hydro­chloride (IV) was isolated and characterized (Fig. 6). The structure is pseudocentrosymmetric and a solution is possible in the higher-symmetry space group C2/c. However, refining with this higher symmetry leads to scrambling of the C═O and N—Me positions, with all C═O and N—Me distances lying between 1.32 and 1.34 Å, and the constituent atoms have poor displacement ellipsoid shapes. An ordered structure of (IV) is thus described in the space group Cc and consists of two crystallographically independent cation and anion pairs (Z' = 2), hereafter ions A and B. The N—H groups of the cations act as hydrogen-bond donors only to the chloride anions (Table 5). These inter­actions give parallel one-dimensional chains consisting of cation A and Cl2 and of cation B with Cl1. Both chains propagate parallel to the crystallographic c direction. Secondary inter­actions between chains of cation A and between chains of cation B take the form of stacking inter­actions between C₄N₂ rings. The shortest such C···C distances are 3.284 (8) and 2.285 (8) Å. The chains of cation A bind to the chains of cation B through C—H···Cl inter­actions involving the H atom of the imidazole rings (Table 5). This weak C—H donor is not used to form hydrogen bonds in hydrate (II), presumably because the water H atoms are available and are stronger donors. Unlike the other theopylline salt structures above, theophylline cations that are joined by hydrogen bonding are no longer coplanar, indeed neighbouring imidazole ring planes are now approximately perpendicular [89.8 (2) and 88.7 (2)°]. None of the C═O groups in chloride salt (IV) act as classical hydrogen-bond acceptors, all four form only relatively long inter­actions with methyl-group H atoms.

In 1978, Koo et al. reported a single-crystal structure which they described as anhydrous theophylline hydro­chloride [Cambridge Structural Database (CSD; Allen, 2002) refcode THEOPI (Koo et al., 1978)]. However, the unit cell given is not that of anhydrous chloride salt (IV), but instead matches that of the hydrated form (II). The earlier description was based on film data and is rather inaccurate, with an R factor > 12% and no H-atom positions reported. Although the structure is reported as having the space group Pna2₁, recovery of the atomic positions from the CSD shows that all reported atoms have z coordinates of 0.5. Comparing the structure of (II) with that of THEOPI shows that the cations and anions pack in aan almost manner, the only observable difference being that where the water molecules occur in (II) there is a void in THEOPI (Fig. 8). The diameter of the void is approximately 8.25 Å from N to Cl. Whilst one N—H group of the imidazole ring in THEOPI is in the correct position to form a hydrogen bond with the anion, the second N—H group is oriented towards the void. There is no suitable hydrogen-bond acceptor, such as would be expected for a formally partially positive H atom. Whilst it is possible to have hydrated and anhydrous phases of organic species that have somewhat similar unit cells, dehydration is typically accompanied by a shrinking of the void space previously occupied by water (see, for example, Shankland et al., 2001). The evidence outlined above points towards THEOPI having been wrongly described as an anhydrous phase in the space group Pna2₁. We believe that it should have been described as the Pnma monohydrate form (II).

Related literature

For related literature, see: Abuhijleh et al. (2009); Allen (2002); Biradha et al. (2010); Buist et al. (2013); Cardin et al. (2007); De Smidt, Fokkens, Grijseels & Crommelin (1986); Etter (1990); Fucke et al. (2012); Griffith & Amma (1979); Karki et al. (2007); Koo et al. (1978); Nolte et al. (2006); Perumalla & Sun (2012); Rodriguez-Hornedo, Lechuga-Ballesteros & Wu (1992); Shankland et al. (2001); Stahl & Wermuth (2008); Sun et al. (2002).

Computing details

For all compounds, data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008). Molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and X-SEED (Barbour, 2001) for (I), (II), (IV); ORTEP-3 for Windows (Farrugia, 2012) for (III). For all compounds, software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

Fig. 1. The ion-pair structure of (I), with non-H-atom ellipsoids drawn at the 50% probability level.

Fig. 2. The dimeric hydrogen-bonded fragment of (I), showing the pendant nature of the BF₄^- anions.

Fig. 3. The ion-pair structure of (II), with non-H-atom ellipsoids drawn at the 50% probability level.

Fig. 4. The ion-pair structure of (III), with non-H atom ellipsoids drawn at the 50% probability level.

Fig. 5. The structure of (II), viewed along the b axis, showing two hydrogen-bonded sheets parallel to the ac plane and the position of the anions with respect to the ring systems. The structure of (III) is similar.

Fig. 6. The ion-pair structure of (IV), with non-H-atom ellipsoids drawn at the 50% probability level.

Fig. 7. Packing diagram for (IV), showing parts of the one-dimensional chains that propagate parallel to the crystallographic c direction.

Fig. 8. Packing diagram produced from the atomic coordinates of CSD entry THEOPI (Koo et al., 1978). The void space has been highlighted.

(I) 1,3-Dimethyl-2,6-dioxo-7H-purin-9-ium tetrafluoroborate

Crystal data

C7H9N4O2^+·BF4^−	F(000) = 544
Mr = 267.99	Dx = 1.711 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7776 reflections
a = 13.0883 (4) Å	θ = 3.4–29.4°
b = 6.0413 (1) Å	µ = 0.17 mm^−1
c = 14.5542 (4) Å	T = 123 K
β = 115.306 (3)°	Block, colourless
V = 1040.37 (5) Å^3	0.30 × 0.12 × 0.10 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur E diffractometer	2705 independent reflections
Radiation source: fine-focus sealed tube	2366 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
ω scans	θmax = 29.5°, θmin = 3.4°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	h = −17→17
Tmin = 0.913, Tmax = 1.000	k = −7→8
14312 measured reflections	l = −19→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.082	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0316P)^2 + 0.5591P] where P = (Fo^2 + 2Fc^2)/3
2705 reflections	(Δ/σ)max < 0.001
173 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET) (compiled Aug 27 2010,11:50:40) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
F1	0.81186 (7)	0.15621 (14)	0.34517 (7)	0.0323 (2)
F2	0.86001 (7)	0.08252 (15)	0.51256 (6)	0.0339 (2)
F3	0.85378 (7)	−0.19548 (13)	0.40440 (6)	0.02707 (18)
F4	0.69139 (6)	−0.03528 (14)	0.39121 (6)	0.02790 (19)
O1	0.42131 (7)	0.24903 (15)	0.46997 (6)	0.02036 (19)
O2	0.33892 (8)	−0.26810 (15)	0.21988 (7)	0.0240 (2)
N1	0.55961 (8)	0.48102 (17)	0.37422 (7)	0.0169 (2)
N2	0.56503 (8)	0.34903 (17)	0.23748 (8)	0.0174 (2)
N3	0.38136 (8)	−0.00979 (16)	0.34439 (7)	0.01487 (19)
N4	0.44422 (8)	0.02592 (16)	0.21372 (7)	0.0160 (2)
C1	0.60316 (10)	0.5085 (2)	0.30823 (9)	0.0189 (2)
H1	0.6537	0.6236	0.3105	0.023*
C2	0.49099 (9)	0.29613 (19)	0.34591 (8)	0.0149 (2)
C3	0.49637 (9)	0.21386 (19)	0.26086 (8)	0.0146 (2)
C4	0.43007 (9)	0.18602 (19)	0.39354 (8)	0.0147 (2)
C5	0.38509 (9)	−0.09502 (19)	0.25639 (8)	0.0163 (2)
C6	0.31646 (10)	−0.1429 (2)	0.38539 (9)	0.0185 (2)
H6A	0.3229	−0.0773	0.4492	0.028*
H6B	0.3463	−0.2942	0.3980	0.028*
H6C	0.2368	−0.1460	0.3363	0.028*
C7	0.45279 (12)	−0.0565 (2)	0.12200 (9)	0.0238 (3)
H7A	0.4207	0.0532	0.0675	0.036*
H7B	0.4110	−0.1958	0.1003	0.036*
H7C	0.5324	−0.0816	0.1372	0.036*
B1	0.80447 (12)	0.0062 (2)	0.41456 (10)	0.0199 (3)
H1N	0.5721 (14)	0.569 (3)	0.4264 (13)	0.033 (4)*
H2N	0.5852 (14)	0.333 (3)	0.1866 (13)	0.033 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0403 (5)	0.0270 (4)	0.0402 (5)	0.0049 (4)	0.0275 (4)	0.0107 (4)
F2	0.0350 (4)	0.0393 (5)	0.0286 (4)	−0.0084 (4)	0.0148 (4)	−0.0115 (4)
F3	0.0370 (4)	0.0249 (4)	0.0289 (4)	0.0093 (3)	0.0233 (3)	0.0061 (3)
F4	0.0221 (4)	0.0308 (4)	0.0334 (4)	−0.0010 (3)	0.0144 (3)	−0.0003 (3)
O1	0.0239 (4)	0.0233 (4)	0.0176 (4)	−0.0045 (3)	0.0125 (3)	−0.0056 (3)
O2	0.0298 (5)	0.0190 (4)	0.0252 (4)	−0.0078 (4)	0.0135 (4)	−0.0075 (4)
N1	0.0187 (5)	0.0161 (5)	0.0169 (4)	−0.0031 (4)	0.0086 (4)	−0.0036 (4)
N2	0.0198 (5)	0.0185 (5)	0.0174 (5)	−0.0015 (4)	0.0113 (4)	−0.0013 (4)
N3	0.0149 (4)	0.0155 (5)	0.0155 (4)	−0.0011 (3)	0.0078 (4)	−0.0011 (4)
N4	0.0189 (5)	0.0160 (5)	0.0146 (4)	−0.0012 (4)	0.0086 (4)	−0.0032 (4)
C1	0.0194 (5)	0.0188 (6)	0.0199 (5)	−0.0032 (4)	0.0098 (4)	−0.0011 (4)
C2	0.0153 (5)	0.0149 (5)	0.0147 (5)	−0.0008 (4)	0.0066 (4)	−0.0019 (4)
C3	0.0141 (5)	0.0153 (5)	0.0146 (5)	0.0013 (4)	0.0064 (4)	0.0002 (4)
C4	0.0132 (5)	0.0156 (5)	0.0149 (5)	0.0007 (4)	0.0055 (4)	−0.0006 (4)
C5	0.0150 (5)	0.0164 (5)	0.0163 (5)	0.0010 (4)	0.0054 (4)	−0.0010 (4)
C6	0.0180 (5)	0.0178 (6)	0.0226 (6)	−0.0025 (4)	0.0115 (4)	0.0009 (4)
C7	0.0365 (7)	0.0216 (6)	0.0186 (5)	−0.0008 (5)	0.0166 (5)	−0.0054 (5)
B1	0.0219 (6)	0.0201 (6)	0.0221 (6)	0.0008 (5)	0.0135 (5)	0.0001 (5)

Geometric parameters (Å, º)

F1—B1	1.3908 (16)	N3—C6	1.4689 (14)
F2—B1	1.3744 (16)	N4—C3	1.3511 (15)
F3—B1	1.4158 (16)	N4—C5	1.3890 (15)
F4—B1	1.3925 (16)	N4—C7	1.4733 (14)
O1—C4	1.2266 (13)	C1—H1	0.9500
O2—C5	1.2110 (14)	C2—C3	1.3634 (15)
N1—C1	1.3203 (15)	C2—C4	1.4253 (15)
N1—C2	1.3812 (15)	C6—H6A	0.9800
N1—H1N	0.883 (18)	C6—H6B	0.9800
N2—C1	1.3412 (15)	C6—H6C	0.9800
N2—C3	1.3608 (14)	C7—H7A	0.9800
N2—H2N	0.892 (17)	C7—H7B	0.9800
N3—C4	1.3883 (14)	C7—H7C	0.9800
N3—C5	1.4005 (14)
C1—N1—C2	108.22 (10)	N3—C4—C2	112.09 (9)
C1—N1—H1N	124.8 (11)	O2—C5—N4	121.80 (10)
C2—N1—H1N	127.0 (11)	O2—C5—N3	120.86 (11)
C1—N2—C3	107.94 (10)	N4—C5—N3	117.35 (10)
C1—N2—H2N	124.9 (11)	N3—C6—H6A	109.5
C3—N2—H2N	127.1 (11)	N3—C6—H6B	109.5
C4—N3—C5	126.63 (9)	H6A—C6—H6B	109.5
C4—N3—C6	118.36 (9)	N3—C6—H6C	109.5
C5—N3—C6	114.99 (9)	H6A—C6—H6C	109.5
C3—N4—C5	118.17 (9)	H6B—C6—H6C	109.5
C3—N4—C7	121.77 (10)	N4—C7—H7A	109.5
C5—N4—C7	120.01 (10)	N4—C7—H7B	109.5
N1—C1—N2	109.47 (10)	H7A—C7—H7B	109.5
N1—C1—H1	125.3	N4—C7—H7C	109.5
N2—C1—H1	125.3	H7A—C7—H7C	109.5
C3—C2—N1	106.63 (10)	H7B—C7—H7C	109.5
C3—C2—C4	121.89 (10)	F2—B1—F1	111.40 (11)
N1—C2—C4	131.30 (10)	F2—B1—F4	110.43 (10)
N4—C3—N2	128.43 (10)	F1—B1—F4	109.67 (11)
N4—C3—C2	123.81 (10)	F2—B1—F3	109.55 (11)
N2—C3—C2	107.71 (10)	F1—B1—F3	107.97 (10)
O1—C4—N3	122.10 (10)	F4—B1—F3	107.71 (11)
O1—C4—C2	125.79 (11)
C2—N1—C1—N2	0.33 (14)	C6—N3—C4—O1	0.68 (16)
C3—N2—C1—N1	−1.05 (14)	C5—N3—C4—C2	−2.02 (15)
C1—N1—C2—C3	0.52 (13)	C6—N3—C4—C2	179.50 (10)
C1—N1—C2—C4	175.59 (12)	C3—C2—C4—O1	179.94 (11)
C5—N4—C3—N2	174.85 (11)	N1—C2—C4—O1	5.5 (2)
C7—N4—C3—N2	−2.56 (18)	C3—C2—C4—N3	1.18 (15)
C5—N4—C3—C2	−2.47 (16)	N1—C2—C4—N3	−173.26 (11)
C7—N4—C3—C2	−179.88 (11)	C3—N4—C5—O2	−177.95 (11)
C1—N2—C3—N4	−176.30 (11)	C7—N4—C5—O2	−0.49 (17)
C1—N2—C3—C2	1.36 (13)	C3—N4—C5—N3	1.61 (15)
N1—C2—C3—N4	176.65 (10)	C7—N4—C5—N3	179.07 (10)
C4—C2—C3—N4	1.01 (17)	C4—N3—C5—O2	−179.75 (11)
N1—C2—C3—N2	−1.15 (12)	C6—N3—C5—O2	−1.22 (15)
C4—C2—C3—N2	−176.79 (10)	C4—N3—C5—N4	0.69 (16)
C5—N3—C4—O1	179.16 (11)	C6—N3—C5—N4	179.22 (10)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^i	0.883 (18)	1.838 (18)	2.7165 (13)	172.7 (16)
N2—H2N···F3^ii	0.892 (17)	1.823 (18)	2.7094 (12)	172.2 (16)
N2—H2N···F1^ii	0.892 (17)	2.525 (17)	3.0239 (13)	115.9 (14)

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

(II) 1,3-Dimethyl-2,6-dioxo-7H-purin-9-ium chloride

Crystal data

C7H9N4O2^+·Cl^−·H2O	F(000) = 488
Mr = 234.65	Dx = 1.531 Mg m^−3
Orthorhombic, Pnma	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ac 2n	Cell parameters from 715 reflections
a = 13.8664 (7) Å	θ = 3.9–71.5°
b = 6.4623 (3) Å	µ = 3.33 mm^−1
c = 11.3634 (6) Å	T = 123 K
V = 1018.26 (9) Å^3	Fragment from plate, colourless
Z = 4	0.28 × 0.18 × 0.04 mm

Data collection

Oxford Diffraction Gemini S diffractometer	1090 independent reflections
Radiation source: fine-focus sealed tube	1077 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
ω scans	θmax = 73.0°, θmin = 7.5°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	h = −11→17
Tmin = 0.542, Tmax = 1.000	k = −7→7
3701 measured reflections	l = −11→14

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.081	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ^2(Fo^2) + (0.0478P)^2 + 0.3984P] where P = (Fo^2 + 2Fc^2)/3
1090 reflections	(Δ/σ)max < 0.001
106 parameters	Δρmax = 0.34 e Å^−3
3 restraints	Δρmin = −0.32 e Å^−3

Special details

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET) (compiled Aug 27 2010,11:50:40) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	Occ. (<1)
Cl1	0.23401 (3)	0.2500	0.03516 (4)	0.02111 (18)
O1	0.42178 (9)	0.2500	0.32625 (11)	0.0258 (3)
O2	0.36175 (11)	0.2500	0.72153 (12)	0.0331 (4)
N1	0.20282 (11)	0.2500	0.29566 (14)	0.0183 (3)
N2	0.10821 (11)	0.2500	0.44846 (14)	0.0193 (3)
N3	0.39025 (11)	0.2500	0.52517 (13)	0.0186 (3)
N4	0.23095 (11)	0.2500	0.60187 (14)	0.0184 (3)
C1	0.11223 (13)	0.2500	0.33042 (16)	0.0207 (4)
H1	0.0579	0.2500	0.2796	0.025*
C2	0.26060 (12)	0.2500	0.39409 (16)	0.0163 (4)
C3	0.20037 (13)	0.2500	0.48881 (16)	0.0165 (4)
C4	0.36339 (13)	0.2500	0.40650 (16)	0.0178 (4)
C5	0.32902 (14)	0.2500	0.62224 (16)	0.0213 (4)
C6	0.49388 (14)	0.2500	0.55447 (17)	0.0264 (4)
H6A	0.5319	0.2500	0.4817	0.040*
H6B	0.5093	0.1262	0.6006	0.040*	0.50
H6C	0.5093	0.3738	0.6006	0.040*	0.50
C7	0.16252 (15)	0.2500	0.70028 (17)	0.0279 (4)
H7A	0.1981	0.2500	0.7748	0.042*
H7B	0.1219	0.1262	0.6959	0.042*	0.50
H7C	0.1219	0.3738	0.6959	0.042*	0.50
O1W	−0.05899 (12)	0.258 (8)	0.55938 (16)	0.034 (2)	0.50
H1W	−0.080 (2)	0.233 (12)	0.6309 (14)	0.051*	0.50
H2W	−0.1110 (18)	0.226 (9)	0.519 (2)	0.051*	0.50
H1N	0.219 (2)	0.2500	0.219 (3)	0.041 (7)*
H2N	0.061 (2)	0.2500	0.488 (2)	0.030 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0230 (3)	0.0252 (3)	0.0151 (3)	0.000	0.00115 (14)	0.000
O1	0.0160 (6)	0.0414 (8)	0.0200 (7)	0.000	0.0031 (5)	0.000
O2	0.0301 (7)	0.0534 (9)	0.0157 (7)	0.000	−0.0051 (6)	0.000
N1	0.0176 (7)	0.0237 (8)	0.0137 (7)	0.000	−0.0008 (6)	0.000
N2	0.0136 (7)	0.0255 (8)	0.0188 (8)	0.000	0.0023 (6)	0.000
N3	0.0147 (7)	0.0238 (8)	0.0175 (8)	0.000	−0.0015 (6)	0.000
N4	0.0195 (8)	0.0233 (8)	0.0123 (7)	0.000	0.0028 (5)	0.000
C1	0.0168 (8)	0.0263 (9)	0.0191 (9)	0.000	−0.0022 (7)	0.000
C2	0.0168 (8)	0.0183 (8)	0.0139 (8)	0.000	0.0003 (6)	0.000
C3	0.0165 (8)	0.0167 (8)	0.0162 (8)	0.000	0.0007 (7)	0.000
C4	0.0167 (8)	0.0206 (8)	0.0160 (8)	0.000	−0.0015 (6)	0.000
C5	0.0229 (9)	0.0243 (9)	0.0166 (9)	0.000	−0.0021 (7)	0.000
C6	0.0166 (9)	0.0374 (11)	0.0252 (9)	0.000	−0.0058 (7)	0.000
C7	0.0246 (9)	0.0436 (12)	0.0156 (8)	0.000	0.0057 (7)	0.000
O1W	0.0180 (7)	0.061 (6)	0.0242 (8)	0.002 (4)	0.0063 (6)	0.007 (7)

Geometric parameters (Å, º)

O1—C4	1.220 (2)	N4—C7	1.467 (2)
O2—C5	1.216 (2)	C1—H1	0.9500
N1—C1	1.317 (2)	C2—C3	1.362 (2)
N1—C2	1.376 (2)	C2—C4	1.432 (2)
N1—H1N	0.90 (3)	C6—H6A	0.9800
N2—C1	1.342 (2)	C6—H6B	0.9800
N2—C3	1.358 (2)	C6—H6C	0.9800
N2—H2N	0.80 (3)	C7—H7A	0.9800
N3—C5	1.392 (2)	C7—H7B	0.9800
N3—C4	1.399 (2)	C7—H7C	0.9800
N3—C6	1.475 (2)	O1W—H1W	0.879 (10)
N4—C3	1.353 (2)	O1W—H2W	0.880 (10)
N4—C5	1.379 (2)
C1—N1—C2	108.15 (16)	N2—C3—C2	108.07 (16)
C1—N1—H1N	122.0 (19)	O1—C4—N3	122.96 (16)
C2—N1—H1N	129.8 (19)	O1—C4—C2	125.95 (17)
C1—N2—C3	107.36 (16)	N3—C4—C2	111.09 (15)
C1—N2—H2N	126.5 (19)	O2—C5—N4	121.57 (17)
C3—N2—H2N	126.1 (19)	O2—C5—N3	120.50 (17)
C5—N3—C4	126.97 (15)	N4—C5—N3	117.93 (16)
C5—N3—C6	114.54 (15)	N3—C6—H6A	109.5
C4—N3—C6	118.48 (15)	N3—C6—H6B	109.5
C3—N4—C5	117.92 (15)	H6A—C6—H6B	109.5
C3—N4—C7	121.42 (15)	N3—C6—H6C	109.5
C5—N4—C7	120.66 (15)	H6A—C6—H6C	109.5
N1—C1—N2	109.84 (16)	H6B—C6—H6C	109.5
N1—C1—H1	125.1	N4—C7—H7A	109.5
N2—C1—H1	125.1	N4—C7—H7B	109.5
C3—C2—N1	106.58 (16)	H7A—C7—H7B	109.5
C3—C2—C4	122.16 (16)	N4—C7—H7C	109.5
N1—C2—C4	131.27 (16)	H7A—C7—H7C	109.5
N4—C3—N2	128.01 (16)	H7B—C7—H7C	109.5
N4—C3—C2	123.92 (16)	H1W—O1W—H2W	99 (2)
C2—N1—C1—N2	0.0	C6—N3—C4—O1	0.0
C3—N2—C1—N1	0.0	C5—N3—C4—C2	0.0
C1—N1—C2—C3	0.0	C6—N3—C4—C2	180.0
C1—N1—C2—C4	180.0	C3—C2—C4—O1	180.0
C5—N4—C3—N2	180.0	N1—C2—C4—O1	0.0
C7—N4—C3—N2	0.0	C3—C2—C4—N3	0.0
C5—N4—C3—C2	0.0	N1—C2—C4—N3	180.0
C7—N4—C3—C2	180.0	C3—N4—C5—O2	180.0
C1—N2—C3—N4	180.0	C7—N4—C5—O2	0.0
C1—N2—C3—C2	0.0	C3—N4—C5—N3	0.0
N1—C2—C3—N4	180.0	C7—N4—C5—N3	180.0
C4—C2—C3—N4	0.0	C4—N3—C5—O2	180.0
N1—C2—C3—N2	0.0	C6—N3—C5—O2	0.0
C4—C2—C3—N2	180.0	C4—N3—C5—N4	0.0
C5—N3—C4—O1	180.0	C6—N3—C5—N4	180.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···Cl1	0.90 (3)	2.10 (3)	2.9915 (17)	171 (3)
N2—H2N···O1W	0.80 (3)	1.85 (3)	2.639 (3)	172 (3)
O1W—H1W···O2^i	0.88 (1)	1.86 (2)	2.722 (2)	165 (7)
O1W—H2W···Cl1^ii	0.88 (1)	2.24 (2)	3.065 (2)	156 (5)

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

(III) 1,3-Dimethyl-2,6-dioxo-7H-purin-9-ium chloride monohydrate

Crystal data

C7H9N4O2^+·Br^−·H2O	F(000) = 560
Mr = 279.11	Dx = 1.735 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 3572 reflections
a = 14.0120 (5) Å	θ = 2.9–29.9°
b = 6.6151 (3) Å	µ = 3.84 mm^−1
c = 11.5297 (4) Å	T = 123 K
V = 1068.70 (7) Å^3	Prism, colourless
Z = 4	0.22 × 0.12 × 0.08 mm

Data collection

Oxford Diffraction Xcalibur E diffractometer	1553 independent reflections
Radiation source: fine-focus sealed tube	1378 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
ω scans	θmax = 29.9°, θmin = 3.4°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	h = −18→18
Tmin = 0.943, Tmax = 1.000	k = −9→9
7635 measured reflections	l = −15→15

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.058	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0245P)^2 + 0.5427P] where P = (Fo^2 + 2Fc^2)/3
1553 reflections	(Δ/σ)max = 0.001
106 parameters	Δρmax = 0.36 e Å^−3
5 restraints	Δρmin = −0.48 e Å^−3

Special details

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET) (compiled Aug 27 2010,11:50:40) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	Occ. (<1)
Br1	0.238793 (17)	0.2500	0.030738 (19)	0.01977 (9)
O1	0.42192 (12)	0.2500	0.32740 (15)	0.0270 (4)
O2	0.36669 (15)	0.2500	0.71829 (16)	0.0376 (5)
N1	0.20447 (15)	0.2500	0.30119 (17)	0.0178 (4)
N2	0.11254 (14)	0.2500	0.45350 (17)	0.0187 (4)
N3	0.39277 (14)	0.2500	0.52399 (17)	0.0198 (4)
N4	0.23609 (14)	0.2500	0.60213 (17)	0.0187 (4)
C1	0.11501 (17)	0.2500	0.3368 (2)	0.0207 (5)
H1	0.0606	0.2500	0.2877	0.025*
C2	0.26338 (16)	0.2500	0.3970 (2)	0.0163 (5)
C3	0.20478 (17)	0.2500	0.4915 (2)	0.0159 (4)
C4	0.36473 (17)	0.2500	0.4072 (2)	0.0183 (5)
C5	0.33321 (18)	0.2500	0.6207 (2)	0.0214 (5)
C6	0.49547 (18)	0.2500	0.5505 (2)	0.0294 (6)
H6A	0.5320	0.2500	0.4780	0.044*
H6B	0.5114	0.1290	0.5956	0.044*	0.50
H6C	0.5114	0.3710	0.5956	0.044*	0.50
C7	0.16970 (19)	0.2500	0.6999 (2)	0.0277 (6)
H7A	0.2057	0.2500	0.7728	0.042*
H7B	0.1294	0.1290	0.6962	0.042*	0.50
H7C	0.1294	0.3710	0.6962	0.042*	0.50
O1W	−0.04826 (17)	0.221 (2)	0.5711 (2)	0.032 (3)	0.50
H1W	−0.094 (2)	0.286 (7)	0.535 (3)	0.048*	0.50
H2W	−0.057 (2)	0.280 (7)	0.6387 (19)	0.048*	0.50
H1N	0.225 (2)	0.2500	0.2308 (12)	0.036 (9)*
H2N	0.0595 (13)	0.2500	0.490 (2)	0.033 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02056 (13)	0.02542 (14)	0.01334 (12)	0.000	0.00125 (9)	0.000
O1	0.0164 (9)	0.0446 (12)	0.0198 (9)	0.000	0.0042 (7)	0.000
O2	0.0272 (11)	0.0694 (16)	0.0162 (9)	0.000	−0.0072 (8)	0.000
N1	0.0172 (10)	0.0250 (11)	0.0113 (9)	0.000	−0.0008 (8)	0.000
N2	0.0120 (9)	0.0293 (12)	0.0149 (9)	0.000	0.0020 (8)	0.000
N3	0.0125 (9)	0.0284 (12)	0.0183 (10)	0.000	−0.0023 (8)	0.000
N4	0.0167 (10)	0.0269 (11)	0.0125 (9)	0.000	0.0017 (8)	0.000
C1	0.0166 (12)	0.0277 (14)	0.0176 (11)	0.000	−0.0029 (9)	0.000
C2	0.0162 (11)	0.0204 (11)	0.0122 (10)	0.000	0.0011 (8)	0.000
C3	0.0148 (11)	0.0178 (11)	0.0150 (10)	0.000	−0.0005 (9)	0.000
C4	0.0178 (12)	0.0210 (12)	0.0161 (11)	0.000	−0.0010 (9)	0.000
C5	0.0202 (12)	0.0290 (14)	0.0152 (11)	0.000	−0.0016 (9)	0.000
C6	0.0152 (12)	0.0447 (18)	0.0284 (14)	0.000	−0.0056 (10)	0.000
C7	0.0232 (13)	0.0463 (17)	0.0136 (11)	0.000	0.0033 (9)	0.000
O1W	0.0173 (10)	0.058 (8)	0.0209 (10)	−0.0022 (18)	0.0038 (8)	−0.005 (2)

Geometric parameters (Å, º)

O1—C4	1.220 (3)	N4—C7	1.461 (3)
O2—C5	1.219 (3)	C1—H1	0.9500
N1—C1	1.319 (3)	C2—C3	1.364 (3)
N1—C2	1.379 (3)	C2—C4	1.425 (3)
N1—H1N	0.860 (10)	C6—H6A	0.9800
N2—C1	1.345 (3)	C6—H6B	0.9800
N2—C3	1.365 (3)	C6—H6C	0.9800
N2—H2N	0.855 (10)	C7—H7A	0.9800
N3—C5	1.393 (3)	C7—H7B	0.9800
N3—C4	1.403 (3)	C7—H7C	0.9800
N3—C6	1.471 (3)	O1W—H1W	0.882 (10)
N4—C3	1.349 (3)	O1W—H2W	0.880 (10)
N4—C5	1.378 (3)
C1—N1—C2	108.6 (2)	C2—C3—N2	108.3 (2)
C1—N1—H1N	127 (2)	O1—C4—N3	122.7 (2)
C2—N1—H1N	124 (2)	O1—C4—C2	126.4 (2)
C1—N2—C3	107.2 (2)	N3—C4—C2	111.0 (2)
C1—N2—H2N	121 (2)	O2—C5—N4	121.5 (2)
C3—N2—H2N	132 (2)	O2—C5—N3	120.6 (2)
C5—N3—C4	126.9 (2)	N4—C5—N3	117.9 (2)
C5—N3—C6	114.8 (2)	N3—C6—H6A	109.5
C4—N3—C6	118.3 (2)	N3—C6—H6B	109.5
C3—N4—C5	117.9 (2)	H6A—C6—H6B	109.5
C3—N4—C7	121.5 (2)	N3—C6—H6C	109.5
C5—N4—C7	120.6 (2)	H6A—C6—H6C	109.5
N1—C1—N2	109.6 (2)	H6B—C6—H6C	109.5
N1—C1—H1	125.2	N4—C7—H7A	109.5
N2—C1—H1	125.2	N4—C7—H7B	109.5
C3—C2—N1	106.2 (2)	H7A—C7—H7B	109.5
C3—C2—C4	122.3 (2)	N4—C7—H7C	109.5
N1—C2—C4	131.5 (2)	H7A—C7—H7C	109.5
N4—C3—C2	124.0 (2)	H7B—C7—H7C	109.5
N4—C3—N2	127.7 (2)	H1W—O1W—H2W	96 (2)
C2—N1—C1—N2	0.0	C6—N3—C4—O1	0.0
C3—N2—C1—N1	0.0	C5—N3—C4—C2	0.0
C1—N1—C2—C3	0.0	C6—N3—C4—C2	180.0
C1—N1—C2—C4	180.0	C3—C2—C4—O1	180.0
C5—N4—C3—C2	0.0	N1—C2—C4—O1	0.0
C7—N4—C3—C2	180.0	C3—C2—C4—N3	0.0
C5—N4—C3—N2	180.0	N1—C2—C4—N3	180.0
C7—N4—C3—N2	0.0	C3—N4—C5—O2	180.0
N1—C2—C3—N4	180.0	C7—N4—C5—O2	0.0
C4—C2—C3—N4	0.0	C3—N4—C5—N3	0.0
N1—C2—C3—N2	0.0	C7—N4—C5—N3	180.0
C4—C2—C3—N2	180.0	C4—N3—C5—O2	180.0
C1—N2—C3—N4	180.0	C6—N3—C5—O2	0.0
C1—N2—C3—C2	0.0	C4—N3—C5—N4	0.0
C5—N3—C4—O1	180.0	C6—N3—C5—N4	180.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···Br1	0.86 (1)	2.32 (1)	3.1551 (19)	166 (3)
N2—H2N···O1W	0.86 (1)	1.79 (1)	2.637 (3)	174 (1)
O1W—H2W···O2^i	0.88 (1)	1.97 (3)	2.712 (3)	140 (4)
O1W—H1W···Br1^ii	0.88 (1)	2.47 (3)	3.212 (3)	143 (4)

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

(IV) 1,3-Dimethyl-2,6-dioxo-7H-purin-9-ium bromide monohydrate

Crystal data

C7H9N4O2^+·Cl^−	F(000) = 896
Mr = 216.63	Dx = 1.598 Mg m^−3
Monoclinic, Cc	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: C -2yc	Cell parameters from 2617 reflections
a = 32.081 (3) Å	θ = 3.5–73.6°
b = 4.5028 (3) Å	µ = 3.63 mm^−1
c = 12.8256 (10) Å	T = 123 K
β = 103.524 (9)°	Rod, colourless
V = 1801.3 (3) Å^3	0.33 × 0.08 × 0.04 mm
Z = 8

Data collection

Oxford Diffraction Gemini S diffractometer	3230 independent reflections
Radiation source: fine-focus sealed tube	2966 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
ω scans	θmax = 73.8°, θmin = 5.7°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	h = −39→38
Tmin = 0.697, Tmax = 1.000	k = −3→5
6692 measured reflections	l = −15→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.048	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.130	w = 1/[σ^2(Fo^2) + (0.0677P)^2 + 2.7204P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max = 0.001
3230 reflections	Δρmax = 0.48 e Å^−3
270 parameters	Δρmin = −0.26 e Å^−3
6 restraints	Absolute structure: Flack (1983), 1431 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.28 (3)

Special details

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET) (compiled Aug 27 2010,11:50:40) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	0.45718 (3)	0.9707 (3)	0.79706 (7)	0.0269 (3)
Cl2	0.37986 (3)	0.9789 (3)	0.99217 (7)	0.0273 (3)
O1	0.77059 (13)	1.1342 (10)	0.4567 (3)	0.0353 (9)
O2	0.70844 (13)	0.4278 (11)	0.6295 (3)	0.0386 (10)
O3	0.56058 (13)	1.1302 (9)	0.5127 (3)	0.0333 (9)
O4	0.62989 (12)	0.6861 (9)	0.8257 (3)	0.0333 (9)
N1	0.84949 (14)	1.0771 (11)	0.6409 (4)	0.0255 (10)
H1N	0.8570 (17)	1.227 (8)	0.608 (4)	0.031*
N2	0.85034 (14)	0.7663 (10)	0.7711 (3)	0.0253 (10)
H2N	0.8583 (17)	0.649 (10)	0.826 (3)	0.030*
N3	0.73984 (14)	0.7781 (11)	0.5429 (4)	0.0282 (10)
N4	0.77748 (16)	0.5600 (10)	0.7066 (4)	0.0261 (10)
N5	0.48493 (14)	0.7281 (10)	0.5198 (3)	0.0257 (9)
H3N	0.4747 (17)	0.800 (11)	0.455 (2)	0.031*
N6	0.48836 (14)	0.4180 (11)	0.6518 (3)	0.0242 (9)
H4N	0.4791 (16)	0.317 (10)	0.700 (3)	0.029*
N7	0.59565 (15)	0.8915 (12)	0.6657 (4)	0.0271 (9)
N8	0.56160 (15)	0.5338 (10)	0.7531 (4)	0.0253 (11)
C1	0.87221 (18)	0.9721 (11)	0.7320 (5)	0.0243 (12)
H1	0.9004	1.0346	0.7655	0.029*
C2	0.81038 (17)	0.9267 (13)	0.6185 (4)	0.0243 (11)
C3	0.81109 (16)	0.7366 (12)	0.6999 (4)	0.0230 (10)
C4	0.77353 (18)	0.9665 (12)	0.5314 (4)	0.0245 (12)
C5	0.73991 (18)	0.5780 (14)	0.6249 (5)	0.0266 (11)
C6	0.70002 (18)	0.8011 (14)	0.4597 (4)	0.0349 (13)
H6A	0.6774	0.8837	0.4908	0.052*
H6B	0.6915	0.6033	0.4304	0.052*
H6C	0.7045	0.9314	0.4021	0.052*
C7	0.77826 (17)	0.3596 (12)	0.7959 (4)	0.0280 (10)
H7A	0.7664	0.4606	0.8501	0.042*
H7B	0.8079	0.3001	0.8276	0.042*
H7C	0.7611	0.1831	0.7701	0.042*
C8	0.4636 (2)	0.5198 (12)	0.5585 (5)	0.0275 (13)
H8	0.4355	0.4527	0.5260	0.033*
C9	0.52468 (16)	0.7610 (11)	0.5888 (4)	0.0219 (10)
C10	0.52639 (18)	0.5665 (12)	0.6721 (4)	0.0231 (11)
C11	0.55974 (19)	0.9490 (11)	0.5820 (5)	0.0239 (11)
C12	0.59735 (16)	0.7021 (12)	0.7535 (4)	0.0252 (10)
C13	0.6351 (2)	1.0532 (14)	0.6672 (5)	0.0339 (13)
H13A	0.6589	0.9122	0.6740	0.051*
H13B	0.6412	1.1901	0.7283	0.051*
H13C	0.6319	1.1659	0.6005	0.051*
C14	0.56211 (17)	0.3378 (13)	0.8448 (4)	0.0278 (11)
H14A	0.5428	0.1696	0.8216	0.042*
H14B	0.5526	0.4488	0.9007	0.042*
H14C	0.5913	0.2643	0.8734	0.042*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0303 (7)	0.0274 (6)	0.0232 (7)	−0.0055 (5)	0.0067 (5)	−0.0023 (5)
Cl2	0.0302 (7)	0.0294 (6)	0.0218 (6)	0.0045 (5)	0.0048 (5)	0.0013 (5)
O1	0.040 (2)	0.032 (2)	0.0298 (19)	−0.0018 (16)	0.0002 (15)	0.0048 (16)
O2	0.036 (2)	0.043 (2)	0.036 (2)	−0.0124 (18)	0.0075 (17)	−0.0027 (18)
O3	0.041 (2)	0.0287 (19)	0.0310 (18)	−0.0042 (16)	0.0107 (15)	0.0028 (15)
O4	0.0327 (17)	0.0333 (19)	0.0301 (19)	−0.0001 (15)	−0.0005 (14)	0.0047 (16)
N1	0.026 (2)	0.023 (2)	0.026 (2)	−0.0027 (19)	0.0049 (18)	−0.0002 (19)
N2	0.028 (2)	0.026 (2)	0.020 (2)	−0.0019 (18)	0.0021 (17)	0.0040 (18)
N3	0.028 (2)	0.029 (2)	0.025 (2)	−0.0011 (18)	0.0011 (17)	−0.0040 (17)
N4	0.029 (2)	0.025 (2)	0.024 (2)	0.0012 (19)	0.0063 (19)	0.0015 (19)
N5	0.025 (2)	0.025 (2)	0.024 (2)	0.0004 (18)	0.0004 (17)	0.0006 (18)
N6	0.028 (2)	0.024 (2)	0.020 (2)	0.001 (2)	0.0057 (18)	0.0029 (19)
N7	0.032 (2)	0.023 (2)	0.027 (2)	−0.0049 (18)	0.0088 (18)	−0.0031 (18)
N8	0.030 (3)	0.023 (2)	0.022 (3)	−0.0001 (17)	0.005 (2)	0.0020 (17)
C1	0.024 (3)	0.024 (3)	0.022 (3)	0.0011 (19)	0.000 (2)	−0.006 (2)
C2	0.024 (3)	0.027 (3)	0.022 (3)	0.002 (2)	0.005 (2)	−0.001 (2)
C3	0.027 (2)	0.019 (2)	0.022 (2)	0.0030 (19)	0.0036 (18)	−0.0011 (19)
C4	0.027 (3)	0.026 (3)	0.020 (3)	0.001 (2)	0.004 (2)	−0.003 (2)
C5	0.023 (2)	0.028 (2)	0.027 (3)	0.002 (2)	0.0027 (19)	−0.007 (2)
C6	0.034 (3)	0.037 (3)	0.029 (3)	0.005 (2)	−0.003 (2)	−0.007 (2)
C7	0.034 (3)	0.021 (2)	0.030 (2)	−0.0013 (19)	0.010 (2)	0.0015 (19)
C8	0.028 (3)	0.026 (3)	0.030 (3)	−0.0004 (19)	0.009 (3)	0.005 (2)
C9	0.024 (2)	0.017 (2)	0.024 (3)	−0.0007 (19)	0.0064 (19)	−0.0005 (19)
C10	0.029 (3)	0.017 (2)	0.024 (3)	−0.003 (2)	0.008 (2)	−0.003 (2)
C11	0.030 (3)	0.020 (2)	0.023 (3)	−0.004 (2)	0.009 (2)	−0.008 (2)
C12	0.026 (2)	0.022 (2)	0.028 (2)	0.0015 (19)	0.0059 (19)	0.002 (2)
C13	0.034 (3)	0.030 (3)	0.039 (3)	−0.007 (2)	0.010 (2)	0.000 (2)
C14	0.036 (2)	0.025 (3)	0.022 (2)	0.0017 (19)	0.0050 (19)	0.0010 (18)

Geometric parameters (Å, º)

O1—C4	1.205 (7)	N7—C12	1.404 (7)
O2—C5	1.228 (7)	N7—C13	1.458 (7)
O3—C11	1.211 (7)	N8—C10	1.352 (7)
O4—C12	1.225 (6)	N8—C12	1.373 (7)
N1—C1	1.313 (7)	N8—C14	1.468 (7)
N1—C2	1.395 (7)	C1—H1	0.9500
N1—H1N	0.86 (2)	C2—C3	1.346 (8)
N2—C1	1.329 (8)	C2—C4	1.436 (7)
N2—C3	1.379 (6)	C6—H6A	0.9800
N2—H2N	0.866 (19)	C6—H6B	0.9800
N3—C5	1.385 (7)	C6—H6C	0.9800
N3—C4	1.409 (8)	C7—H7A	0.9800
N3—C6	1.464 (6)	C7—H7B	0.9800
N4—C3	1.358 (7)	C7—H7C	0.9800
N4—C5	1.402 (8)	C8—H8	0.9500
N4—C7	1.454 (7)	C9—C10	1.373 (7)
N5—C8	1.324 (7)	C9—C11	1.427 (7)
N5—C9	1.380 (6)	C13—H13A	0.9800
N5—H3N	0.883 (19)	C13—H13B	0.9800
N6—C8	1.351 (7)	C13—H13C	0.9800
N6—C10	1.362 (7)	C14—H14A	0.9800
N6—H4N	0.872 (19)	C14—H14B	0.9800
N7—C11	1.403 (7)	C14—H14C	0.9800
C1—N1—C2	107.1 (5)	N3—C6—H6A	109.5
C1—N1—H1N	124 (4)	N3—C6—H6B	109.5
C2—N1—H1N	128 (4)	H6A—C6—H6B	109.5
C1—N2—C3	107.4 (4)	N3—C6—H6C	109.5
C1—N2—H2N	130 (4)	H6A—C6—H6C	109.5
C3—N2—H2N	122 (4)	H6B—C6—H6C	109.5
C5—N3—C4	127.3 (4)	N4—C7—H7A	109.5
C5—N3—C6	116.5 (5)	N4—C7—H7B	109.5
C4—N3—C6	116.2 (5)	H7A—C7—H7B	109.5
C3—N4—C5	118.4 (5)	N4—C7—H7C	109.5
C3—N4—C7	123.1 (5)	H7A—C7—H7C	109.5
C5—N4—C7	118.5 (5)	H7B—C7—H7C	109.5
C8—N5—C9	108.4 (5)	N5—C8—N6	108.9 (5)
C8—N5—H3N	120 (4)	N5—C8—H8	125.5
C9—N5—H3N	131 (4)	N6—C8—H8	125.5
C8—N6—C10	108.5 (5)	C10—C9—N5	107.1 (5)
C8—N6—H4N	125 (4)	C10—C9—C11	122.5 (5)
C10—N6—H4N	124 (4)	N5—C9—C11	130.4 (5)
C11—N7—C12	126.7 (5)	N8—C10—N6	130.1 (5)
C11—N7—C13	118.3 (5)	N8—C10—C9	122.8 (5)
C12—N7—C13	115.0 (5)	N6—C10—C9	107.0 (5)
C10—N8—C12	119.4 (5)	O3—C11—N7	122.0 (5)
C10—N8—C14	122.1 (5)	O3—C11—C9	126.7 (5)
C12—N8—C14	118.4 (4)	N7—C11—C9	111.2 (5)
N1—C1—N2	110.8 (5)	O4—C12—N8	122.3 (5)
N1—C1—H1	124.6	O4—C12—N7	120.6 (5)
N2—C1—H1	124.6	N8—C12—N7	117.1 (4)
C3—C2—N1	107.4 (5)	N7—C13—H13A	109.5
C3—C2—C4	123.0 (5)	N7—C13—H13B	109.5
N1—C2—C4	129.5 (5)	H13A—C13—H13B	109.5
C2—C3—N4	123.5 (5)	N7—C13—H13C	109.5
C2—C3—N2	107.4 (5)	H13A—C13—H13C	109.5
N4—C3—N2	129.1 (5)	H13B—C13—H13C	109.5
O1—C4—N3	122.7 (5)	N8—C14—H14A	109.5
O1—C4—C2	126.4 (6)	N8—C14—H14B	109.5
N3—C4—C2	110.8 (5)	H14A—C14—H14B	109.5
O2—C5—N3	122.6 (5)	N8—C14—H14C	109.5
O2—C5—N4	120.4 (5)	H14A—C14—H14C	109.5
N3—C5—N4	117.0 (5)	H14B—C14—H14C	109.5
C2—N1—C1—N2	−0.8 (6)	C9—N5—C8—N6	0.6 (6)
C3—N2—C1—N1	0.4 (6)	C10—N6—C8—N5	−0.1 (7)
C1—N1—C2—C3	0.9 (6)	C8—N5—C9—C10	−0.9 (6)
C1—N1—C2—C4	177.0 (6)	C8—N5—C9—C11	178.1 (6)
N1—C2—C3—N4	177.7 (5)	C12—N8—C10—N6	176.7 (6)
C4—C2—C3—N4	1.4 (9)	C14—N8—C10—N6	−7.4 (9)
N1—C2—C3—N2	−0.7 (6)	C12—N8—C10—C9	0.5 (8)
C4—C2—C3—N2	−177.1 (5)	C14—N8—C10—C9	176.4 (5)
C5—N4—C3—C2	−0.5 (8)	C8—N6—C10—N8	−177.2 (6)
C7—N4—C3—C2	−178.7 (5)	C8—N6—C10—C9	−0.4 (7)
C5—N4—C3—N2	177.5 (5)	N5—C9—C10—N8	177.8 (5)
C7—N4—C3—N2	−0.7 (9)	C11—C9—C10—N8	−1.3 (9)
C1—N2—C3—C2	0.2 (6)	N5—C9—C10—N6	0.8 (6)
C1—N2—C3—N4	−178.1 (6)	C11—C9—C10—N6	−178.3 (5)
C5—N3—C4—O1	179.9 (5)	C12—N7—C11—O3	175.4 (5)
C6—N3—C4—O1	−1.4 (8)	C13—N7—C11—O3	−1.0 (8)
C5—N3—C4—C2	0.3 (8)	C12—N7—C11—C9	−7.0 (8)
C6—N3—C4—C2	179.0 (4)	C13—N7—C11—C9	176.6 (5)
C3—C2—C4—O1	179.3 (6)	C10—C9—C11—O3	−178.4 (5)
N1—C2—C4—O1	3.8 (10)	N5—C9—C11—O3	2.7 (9)
C3—C2—C4—N3	−1.1 (8)	C10—C9—C11—N7	4.1 (7)
N1—C2—C4—N3	−176.7 (5)	N5—C9—C11—N7	−174.8 (5)
C4—N3—C5—O2	178.1 (6)	C10—N8—C12—O4	178.6 (5)
C6—N3—C5—O2	−0.7 (8)	C14—N8—C12—O4	2.6 (8)
C4—N3—C5—N4	0.4 (9)	C10—N8—C12—N7	−2.8 (8)
C6—N3—C5—N4	−178.3 (4)	C14—N8—C12—N7	−178.9 (5)
C3—N4—C5—O2	−178.0 (5)	C11—N7—C12—O4	−174.8 (5)
C7—N4—C5—O2	0.3 (8)	C13—N7—C12—O4	1.7 (8)
C3—N4—C5—N3	−0.3 (7)	C11—N7—C12—N8	6.6 (8)
C7—N4—C5—N3	178.0 (5)	C13—N7—C12—N8	−176.9 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···Cl2^i	0.86 (2)	2.23 (2)	3.074 (5)	164 (5)
N2—H2N···Cl2^ii	0.87 (2)	2.22 (2)	3.058 (4)	163 (5)
N5—H3N···Cl1^iii	0.88 (2)	2.22 (2)	3.099 (5)	171 (5)
N6—H4N···Cl1^iv	0.87 (2)	2.21 (2)	3.066 (5)	166 (5)
C1—H1···Cl1^v	0.95	2.64	3.479 (5)	147
C8—H8···Cl2^vi	0.95	2.61	3.452 (6)	149

Symmetry codes: (i) x+1/2, −y+5/2, z−1/2; (ii) x+1/2, y−1/2, z; (iii) x, −y+2, z−1/2; (iv) x, y−1, z; (v) x+1/2, y+1/2, z; (vi) x, −y+1, z−1/2.