Hydrate frameworks involving the pyridazino[4,5-d]pyridazine unit as a multiple hydrogen-bond acceptor

1,4,5,8-Tetra­methyl­pyridazino[4,5-d]pyridazine trihydrate, C₁₀H₁₂N₄·3H₂O, (I), and 1,2,3,6,7,8-hexa­hydro­cinnolino[5,4,3-cde]cinnoline tetra­hydrate, C₁₂H₁₂N₄·4H₂O, (II), exhibit exceptional functionality of the condensed N₄-heteroaromatic frame as a symmetric acceptor of four hydrogen bonds [N...O = 2.843 (2)–2.8716 (10) Å]. Thus, all the N atoms of the electron-deficient and highly π-acidic polynitro­gen heterocycles function as lone-pair donors. In (I), all the mol­ecular components lie on or across special positions; the site symmetry is 2/m for the organic and m2m and m for the two water mol­ecules. In (II), the organic polycycle lies across a crystallographic inversion center. Both structures involve a hydrogen-bonded centrosymmetric water–pyridazine dimer as the basic supra­molecular unit, which is integrated into two-dimensional [in (I)] and three-dimensional [in (II)] hydrate frameworks by hydrogen bonding with the additional water mol­ecules [O...O = 2.744 (2)–2.8827 (19) Å]. The hydrate connectivity exists in the form of an (H₂O)₃ trimer in (I) and as a one-dimensional zigzag (H₂O)_n chain in (II).

S1. Comment

Heteroaromatic systems of diazines, triazines and 1,2,4,5-tetrazine provide multiple N-atom sites for sustaining coordination to metal centres and interacting with suitable hydrogen-bond donating groups. Both these types of interactions are applicable to the design of complex frameworks that could incorporate the azine module as an origin of the net connectivity. However, unlike the prototypal single N-atom donor pyridine (which is efficient either as a ligand in coordination chemistry or as acceptor of hydrogen bonding), the nitrogen-rich electron-deficient azines are very weak lone-pair donors and their potential for crystal design has scarcely been explored. Particularly, the multiple hydrogen-bond acceptor function is uncommon even for pyridazine, a relatively basic diazine, and has been observed only in the dihydrate of pyridazine-3,6-dicarboxylic acid (Sueur et al., 1987), in pyridazine-3,6-dimethanol (Abraham et al., 1988) and in the adduct with substituted silanol (Ruud et al., 1991), while the only precedent for multiple hydrogen bonding of tetrazine is self-complementary interactions in 3,6-diamino-1,2,4,5-tetrazine, with very long N—H···N separations of 3.09 Å (Krieger et al., 1987).

More efficient lone-pair-donating ability may be anticipated for polycyclic species combining several azine functions, as provided by pyridazino[4,5-d]pyridazines, a system of two d-edge sharing pyridazine cycles. Although annelation of an N-heteroaromatic ring decreases the energy of the LUMO by a similar degree as the introduction of an electron-withdrawing substituent (Haider, 1991), the condensed pyridazines retain relatively efficient donor properties and are well suited for preparation of coordination polymers (Gural'skiy et al., 2006; Solntsev et al., 2004). Even more rich and versatile applications for such a paradigmatic molecular building block may be found in the realm of hydrogen-bonded solids, and it is especially interesting to explore whether pyridazino[4,5-d]pyridazines are able to sustain multiple interactions for generation of hydrogen-bonded architecture. In this context, we have examined two closely related pyridazino[4,5-d]pyridazine representatives, which readily form hydrates, (I) and (II), and we report their structures here.

1,4,5,8-Tetramethylpyridazino[4,5-d]pyridazine crystallizes as the trihydrate (I). The composition of this solid was previously reported as (L).2H₂O on the basis of microanalysis data (Adembri et al., 1970). Each of the crystallographically independent molecules, namely one molecule of the condensed heterocycle and two water molecules, lie on or across special positions. The organic molecules lie across sites of 2/m symmetry, which implies that two atoms of the shared edge [C1—C1ⁱ; symmetry code: (i) x, -y + 1, -z)] are related by inversion and lie in the crystallographic mirror plane. The site symmetry of O2 is m2m, with the O and H atoms lying in a mirror plane and the pair of H atoms related by a mirror plane perpendicular to the first mirror plane. The second water molecule (O1) lies across a crystallographic mirror plane at x = 0. The asymmetric unit of 1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline tetrahydrate, (II), comprises two water molecules and a half-molecule of the organic component lying across a center of inversion.

The basic pattern of pyridazine–water interactions is similar for the two structures; the components complement each other as the double donors and acceptors of hydrogen bonding and afford centrosymmetric aqua–pyridazine dimers (Figs. 1 and 2). The corresponding N···O separations are similar [2.8716 (10) Å for (I), and 2.843 (2) and 2.870 (2) Å for (II); Tables 2 and 4]; they are characteristic for O—H···N hydrogen bonding and only slightly longer than the values for pyridazine interacting with the much more acidic 1,3-dihydroxy-1,1,3,3-tetraphenyldisiloxane [N···O = 2.751 (3) Å; Ruud et al., 1991]. The only precedent for the double hydrogen bonding of water molecules and pyridazine is pyridazine-3,6-dicarboxylic acid dihydrate (Sueur et al., 1987), with very comparable N···O separations [2.896 (3) Å]. In (I) and (II), each of the N atoms of the bicyclic frame accepts hydrogen bonding; such tetrafunctional behaviour of the pyridazino[4,5-d]pyridazine unit is an unprecedented feature, suggesting its significant σ-donor ability towards multiple electrophilic centers. The later is worth noting in view of similarity of pyridazino[4,5-d]pyridazines and 1,2,4,5-tetrazines. Both are very electron deficient (Haider, 1991) and commonly function rather as strong π-acids, sustaining very short interactions between the π-clouds and negatively polarized atoms (Gural'skiy et al., 2006).

Hydrogen-bonding interactions in (I) and (II) result in the same principal motif in the form of aqua–organic {(L)(H₂O)₂}_n ribbons, while the mode of further interconnection is sensitive to the molecular shape. In (I), neighboring ribbons (symmetry code: -x, -y + 1, z + 1/2) are linked by the remaining water molecules, forming pairs of equivalent hydrogen bonds [O2—H···O1 = 2.7881 (15) Å], into corrugated layers parallel to the ac plane (Fig. 3). Thus, the water–water linkage itself is very simple – it exists as a trimer (H₂O)₃. The entire hydrogen-bonded topology may be regarded as a planar (4,4)-net involving the aqua–pyridazine dimers as the four-connected net nodes and the organic frameworks and water molecules (O2) as the links. The layers are stacked in such a way that atom O2 forms contacts with four methyl groups from an adjacent layer. These C3—H3C···O2^iv [symmetry code: (iv) x + 1/2, y + 1/2, z] interactions reflect very weak, but directional, hydrogen bonding (Desiraju & Steiner, 1999), with a C—H···O angle of 175 (1)° (Fig. 4).

Considering the shape-complementary alignment of the components in (I) (Fig. 3), any further substitution into the organic framework will result in interference, and therefore substitution may be viewed as a tool for the modification of the pattern. This logic can be applied to the related structure of (II), which adopts a more complex three-dimensional framework (Figs. 5 and 6). The diaqua–organic ribbons are packed on top of one another (as depicted in Fig. 6 by molecules represented with filled and unfilled bonds), and these stacks are cross-linked by extended aqua chains running along the c direction. Within these chains, the typical hydrogen bonds O2—H4W···O2ⁱⁱⁱ [2.8827 (19) Å; symmetry code: (iii) x, -y + 1/2, z + 1/2] arrange the molecules into zigzag chains, similar to the one-dimensional hydrogen-bonded motif –OH···(OH)_n– in pentafluorophenol (Das et al., 2006), while a second O2H function provides bonding to atom O1 in the aqua–pyridazine dimer [O2—H3W···O1 = 2.744 (2) Å]. Therefore, the entire topology is best described as a uniform 3,4-heterocoordinated net (three-letter notation `tfc'; Bonneau et al., 2004), which includes O2 water molecules as three- and pyridazine–aqua dimers as four-connected nodes (in a 2:1 proportion).

For both compounds, the geometry of the organic molecules is consistent with the structure of unsubstituted pyridazino[4,5-d]pyridazine (Sabelli et al., 1969), and it is strongly suggestive of a significant contribution of the bis-azine (—C≐N—N≐C— [please check that correct symbol has been inserted]) resonance structure with relatively long pyridazine c and e bonds [C—C = 1.418 (3)–1.4413 (10) Å] and short C—N bonds [1.3137 (12)–1.315 (2) Å; Tables 1 and 3]. The latter are shorter than the C—N bonds [1.334 (7) Å] in the highly conjugated 1,2,4,5-tetrazine (Bertinotti et al., 1956). Distortion of the molecular frame in the structure of (I) and a certain elongation of the pyridazine d and c bonds [1.409 (2) and 1.4413 (10) Å] are influenced by an evident steric repulsion between methyl groups in peri-positions, as occurs for 1,4,5,8-tetramethylnaphthalene (Shiner et al., 1984). This steric interaction is reflected in the angles adopted by the methyl groups [N1—C2—C3 = 113.72 (8) and C1—C2—C3 = 125.47 (9)°] in order to avoid contacts between these groups that would otherwise be even shorter than the observed values [C3···C3ⁱⁱⁱ = 2.972 (2) Å; symmetry code: (iii) -x + 1, y, z]. At the same time, the presence of a methylene linker in (II) minimizes such intramolecular strains. Despite this strained geometry, the aromatic part in (I) retains a completely planar structure, unlike the appreciably twisted frame of octamethylnaphthalene (Sim, 1982). The latter possibility for decreasing the steric interactions could be especially relevant for µ₄-1,4,5,8-tetramethylpyridazino[4,5-d]pyridazine in the metal complexes, leading to a noncoplanar disposition of four metal ions.

In conclusion, the pyridazino[4,5-d]pyridazine tectons reveal a potential as fourfold acceptors of hydrogen bonding. The system suggests a new paradigm for polyfunctional building blocks, which may find wider applications for the development of multi-component hydrogen-bonded frameworks.

Related literature

For related literature, see: Abraham et al. (1988); Adembri et al. (1970); Bertinotti et al. (1956); Bonneau et al. (2004); Das et al. (2006); Desiraju & Steiner (1999); Gural'skiy, Solntsev, Krautscheid & Domasevitch (2006); Haider (1991); Krieger et al. (1987); Ruud et al. (1991); Sabelli et al. (1969); Sim (1982); Solntsev et al. (2004); Stille & Ertz (1964); Sueur et al. (1987).

S2. Experimental

1,4,5,8-Tetramethylpyridazino[4,5-d]pyridazine was synthesized from tetraacetylethylene using the method described by Adembri et al. (1970) and crystallized as a trihydrate, (I), from aqueous ethanol (95%). 1,2,3,6,7,8-Hexahydrocinnolino[5,4,3-cde]cinnoline was prepared by condensation of 1,3-cyclohexanedione and hydrazine (Stille & Ertz, 1964). Recrystallization of the compound from aqueous ethanol (95%) yielded an anhydrous material, while slow evaporation from the solution in aqueous methanol (90%) afforded the tetrahydrate (II).

S3. Refinement

For (I), all the H atoms were found in intermediate difference Fourier maps and were refined fully with isotropic displacement parameters [C—H = 0.960 (16)–0.986 (17) Å]. For (II), the methylene H atoms were treated as riding in geometrically idealized positions, with C—H distances of 0.97 Å and U_iso(H) values of 1.2U_eq(C). Water H atoms were located in difference maps and then their coordinates were fixed [with U_iso(H) = 1.5U_eq(O)], giving all O—H distances in the range 0.85–0.86 Å.

Computing details

Data collection: IPDS Software (Stoe & Cie, 2000) for (I); SMART-NT (Bruker, 1998) for (II). Cell refinement: IPDS Software (Stoe & Cie, 2000) for (I); SAINT-NT (Bruker, 1999) for (II). Data reduction: IPDS Software (Stoe & Cie, 2000) for (I); SAINT-NT (Bruker, 1999) for (II). For both compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Diamond (Brandenburg, 1999); software used to prepare material for publication: WinGX (Version 1.70.01; Farrugia, 1999).

Figures

	Fig. 1. The structure of (I), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Dashed lines indicate hydrogen bonds. [Symmetry codes: (i) x, -y + 1, -z; (ii) -x + 1, -y + 1, -z; (iii) -x + 1, y, z; (v) -x, y, z.]
	Fig. 2. The structure of (II), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 40% probability level and H atoms are shown as small spheres of arbitrary radii. Dashed lines indicate hydrogen bonds. [Symmetry codes: (i) -x + 1, -y + 1, -z + 2; (ii) x + 1, y, z - 1; (iv) -x + 2, -y + 1, -z + 1.]
	Fig. 3. A projection of the structure of (I) on to the ac plane, showing the principal hydrogen-bonding interactions as dashed lines, and showing the trimeric aqua ensembles (H2O)3 and diaqua–organic ribbons running along the a direction. N atoms are shaded grey. [Symmetry codes: (iii) -x + 1, y, z; (v) -x, y, z; (vi) -x, y, -z + 1/2.]
	Fig. 4. A projection of the structure of (I) on to the bc plane, showing the packing of hydrogen-bonded corrugated layers and directional C—H···O interactions that occur between the successive layers. Dashed lines indicate hydrogen bonds, N atoms are shaded grey and the O atoms are shown as crossed spheres. [Symmetry code: (iv) x + 1/2, y + 1/2, z.]
	Fig. 5. A fragment of the structure of (II), demonstrating the function of the organic molecules as symmetric acceptors of four hydrogen bonds (indicated as dashed lines) and the mode of their incorporation with the hydrate linkage. N atoms are shaded grey. [Symmetry code: (v) x - 1, y, z + 1.]
	Fig. 6. A packing diagram for the structure of (II), showing the mutual orientation of the diaqua–organic ribbons and one-dimensional (H2O)n chains, which results in a three-dimensional framework. Methylene H atoms have been omitted for clarity and N atoms are shaded grey. The molecules represented with filled and unfilled bonds correspond to two successive diaqua–organic ribbons. [Symmetry code: (iii) x, -y + 1/2, z + 1/2.]

(I) 1,4,5,8-Tetramethylpyridazino[4,5-d]pyridazine trihydrate

Crystal data

C10H12N4·3H2O	Dx = 1.331 Mg m^−3
Mr = 242.28	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Cmcm	Cell parameters from 4691 reflections
a = 9.8804 (8) Å	θ = 3.9–28.7°
b = 6.6540 (7) Å	µ = 0.10 mm^−1
c = 18.3908 (12) Å	T = 213 K
V = 1209.09 (18) Å^3	Elongated square prism, colourless
Z = 4	0.29 × 0.22 × 0.22 mm
F(000) = 520

Data collection

Stoe IPDS diffractometer	778 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.024
Graphite monochromator	θmax = 28.7°, θmin = 3.9°
ϕ oscillation scans	h = −13→13
4691 measured reflections	k = −8→8
828 independent reflections	l = −24→24

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)] = 0.040	Hydrogen site location: difference Fourier map
wR(F^2) = 0.109	All H-atom parameters refined
S = 1.13	w = 1/[σ^2(Fo^2) + (0.0585P)^2 + 0.5283P] where P = (Fo^2 + 2Fc^2)/3
828 reflections	(Δ/σ)max = 0.001
63 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

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.

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

	x	y	z	Uiso*/Ueq
O1	0.0000	0.4689 (2)	0.10868 (6)	0.0396 (4)
H1	0.0728 (19)	0.472 (3)	0.0813 (12)	0.056 (5)*
O2	0.0000	0.3172 (3)	0.2500	0.0556 (6)
H2	0.0000	0.398 (4)	0.2108 (14)	0.063 (8)*
N1	0.25746 (8)	0.48237 (13)	0.03641 (4)	0.0250 (3)
C1	0.5000	0.48161 (19)	0.03772 (7)	0.0204 (3)
C2	0.37060 (9)	0.46484 (14)	0.07340 (5)	0.0222 (3)
C3	0.34959 (11)	0.42778 (19)	0.15292 (5)	0.0302 (3)
H3A	0.2527 (17)	0.419 (2)	0.1626 (8)	0.042 (4)*
H3B	0.3901 (14)	0.304 (2)	0.1683 (8)	0.039 (4)*
H3C	0.3874 (15)	0.537 (2)	0.1828 (9)	0.044 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0213 (6)	0.0717 (9)	0.0259 (5)	0.000	0.000	0.0013 (5)
O2	0.0926 (17)	0.0399 (11)	0.0342 (9)	0.000	0.000	0.000
N1	0.0182 (4)	0.0313 (5)	0.0255 (5)	0.0002 (3)	0.0014 (3)	−0.0007 (3)
C1	0.0174 (6)	0.0214 (6)	0.0223 (6)	0.000	0.000	−0.0031 (5)
C2	0.0186 (4)	0.0237 (5)	0.0243 (5)	−0.0003 (3)	0.0020 (3)	−0.0023 (3)
C3	0.0228 (5)	0.0436 (6)	0.0242 (5)	0.0001 (4)	0.0036 (4)	0.0017 (4)

Geometric parameters (Å, º)

O1—H1	0.88 (2)	C1—C2	1.4413 (10)
O2—H2	0.90 (3)	C2—C3	1.4977 (14)
N1—C2	1.3137 (12)	C3—H3A	0.976 (17)
N1—N1^i	1.3596 (16)	C3—H3B	0.960 (16)
C1—C1^ii	1.409 (2)	C3—H3C	0.986 (17)
C2—N1—N1^i	121.69 (5)	C2—C3—H3A	108.9 (9)
C1^ii—C1—C2	117.50 (6)	C2—C3—H3B	111.8 (9)
C2—C1—C2^iii	125.00 (12)	H3A—C3—H3B	107.6 (13)
N1—C2—C1	120.81 (9)	C2—C3—H3C	111.7 (10)
N1—C2—C3	113.72 (8)	H3A—C3—H3C	108.4 (13)
C1—C2—C3	125.47 (9)	H3B—C3—H3C	108.2 (12)
N1^i—N1—C2—C1	−0.28 (17)	C2^iii—C1—C2—N1	179.95 (8)
N1^i—N1—C2—C3	179.58 (11)	C1^ii—C1—C2—C3	−179.50 (13)
C1^ii—C1—C2—N1	0.34 (19)	C2^iii—C1—C2—C3	0.1 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.88 (2)	2.00 (2)	2.8716 (10)	169 (2)
O2—H2···O1	0.90 (3)	1.94 (3)	2.7881 (15)	157 (2)
C3—H3C···O2^iv	0.986 (17)	2.50 (2)	3.480 (2)	175 (1)

Symmetry code: (iv) x+1/2, y+1/2, z.

(II) 1,2,3,6,7,8-Hexahydrocinnolino[5,4,3-cde]cinnoline tetrahydrate

Crystal data

C12H12N4·4H2O	F(000) = 304
Mr = 284.32	Dx = 1.342 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 6.6745 (14) Å	Cell parameters from 2866 reflections
b = 20.028 (4) Å	θ = 2.0–26.5°
c = 5.4860 (11) Å	µ = 0.10 mm^−1
β = 106.352 (3)°	T = 296 K
V = 703.7 (2) Å^3	Block, colourless
Z = 2	0.25 × 0.20 × 0.20 mm

Data collection

Siemens SMART CCD area-detector diffractometer	1438 independent reflections
Radiation source: sealed tube	911 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ω scans	θmax = 26.5°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.961, Tmax = 0.980	k = −19→24
2866 measured reflections	l = −6→6

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)] = 0.049	H-atom parameters constrained
wR(F^2) = 0.139	w = 1/[σ^2(Fo^2) + (0.0691P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
1438 reflections	Δρmax = 0.37 e Å^−3
92 parameters	Δρmin = −0.18 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: 0.047 (9)

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.

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

	x	y	z	Uiso*/Ueq
N1	0.2325 (3)	0.47121 (9)	1.2161 (3)	0.0490 (5)
N2	0.7139 (3)	0.46338 (9)	0.7227 (3)	0.0502 (5)
O1	0.8960 (2)	0.40798 (7)	0.3579 (3)	0.0592 (5)
H1W	0.8488	0.4276	0.4689	0.089*
H2W	0.9879	0.4340	0.3262	0.089*
O2	0.9521 (3)	0.27214 (8)	0.3838 (3)	0.0864 (7)
H3W	0.9292	0.3142	0.3802	0.130*
H4W	0.9492	0.2580	0.5307	0.130*
C1	0.5747 (3)	0.43288 (10)	0.8114 (3)	0.0419 (5)
C2	0.4729 (3)	0.46736 (9)	0.9692 (3)	0.0371 (5)
C3	0.3190 (3)	0.43741 (10)	1.0668 (3)	0.0407 (5)
C4	0.2558 (3)	0.36708 (11)	0.9983 (4)	0.0522 (6)
H4A	0.1351	0.3666	0.8502	0.063*
H4B	0.2162	0.3462	1.1374	0.063*
C5	0.4313 (4)	0.32744 (11)	0.9422 (4)	0.0584 (6)
H5A	0.3795	0.2836	0.8795	0.070*
H5B	0.5421	0.3213	1.0985	0.070*
C6	0.5203 (4)	0.36163 (10)	0.7467 (4)	0.0555 (6)
H6A	0.6444	0.3379	0.7365	0.067*
H6B	0.4185	0.3593	0.5811	0.067*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0519 (10)	0.0503 (12)	0.0534 (10)	−0.0042 (9)	0.0288 (9)	−0.0001 (8)
N2	0.0574 (11)	0.0513 (12)	0.0520 (10)	0.0032 (9)	0.0322 (9)	−0.0016 (8)
O1	0.0714 (10)	0.0514 (10)	0.0681 (9)	−0.0038 (7)	0.0414 (8)	−0.0068 (7)
O2	0.1399 (17)	0.0564 (12)	0.0691 (11)	0.0135 (10)	0.0396 (11)	−0.0010 (8)
C1	0.0487 (12)	0.0451 (13)	0.0367 (9)	0.0044 (9)	0.0198 (9)	0.0025 (8)
C2	0.0399 (10)	0.0409 (11)	0.0324 (9)	0.0045 (9)	0.0131 (8)	0.0029 (8)
C3	0.0407 (10)	0.0481 (12)	0.0362 (9)	−0.0011 (9)	0.0157 (8)	0.0017 (8)
C4	0.0586 (13)	0.0525 (14)	0.0496 (11)	−0.0118 (11)	0.0219 (10)	−0.0037 (10)
C5	0.0684 (15)	0.0474 (14)	0.0633 (13)	−0.0045 (11)	0.0247 (12)	−0.0028 (10)
C6	0.0741 (15)	0.0460 (14)	0.0544 (12)	0.0016 (11)	0.0311 (11)	−0.0075 (10)

Geometric parameters (Å, º)

N1—C3	1.315 (2)	C2—C3	1.418 (3)
N1—N2^i	1.374 (2)	C3—C4	1.488 (3)
N2—C1	1.315 (2)	C4—C5	1.517 (3)
O1—H1W	0.8561	C4—H4A	0.9700
O1—H2W	0.8588	C4—H4B	0.9700
O2—H3W	0.8548	C5—C6	1.527 (3)
O2—H4W	0.8593	C5—H5A	0.9700
C1—C2	1.421 (3)	C5—H5B	0.9700
C1—C6	1.491 (3)	C6—H6A	0.9700
C2—C2^i	1.373 (4)	C6—H6B	0.9700
C3—N1—N2^i	120.86 (16)	C3—C4—H4B	109.3
C1—N2—N1^i	121.00 (16)	C5—C4—H4B	109.3
H1W—O1—H2W	107	H4A—C4—H4B	108.0
H3W—O2—H4W	107	C4—C5—C6	112.54 (19)
N2—C1—C2	120.59 (19)	C4—C5—H5A	109.1
N2—C1—C6	120.44 (18)	C6—C5—H5A	109.1
C2—C1—C6	118.97 (18)	C4—C5—H5B	109.1
C2^i—C2—C3	118.6 (2)	C6—C5—H5B	109.1
C2^i—C2—C1	118.3 (2)	H5A—C5—H5B	107.8
C3—C2—C1	123.07 (18)	C1—C6—C5	112.26 (17)
N1—C3—C2	120.61 (18)	C1—C6—H6A	109.2
N1—C3—C4	120.10 (17)	C5—C6—H6A	109.2
C2—C3—C4	119.29 (17)	C1—C6—H6B	109.2
C3—C4—C5	111.51 (17)	C5—C6—H6B	109.2
C3—C4—H4A	109.3	H6A—C6—H6B	107.9
C5—C4—H4A	109.3
N1^i—N2—C1—C2	1.3 (3)	C1—C2—C3—N1	178.68 (16)
N1^i—N2—C1—C6	−179.09 (18)	C2^i—C2—C3—C4	179.0 (2)
N2—C1—C2—C2^i	−1.4 (3)	C1—C2—C3—C4	−1.4 (3)
C6—C1—C2—C2^i	178.9 (2)	N1—C3—C4—C5	−152.18 (18)
N2—C1—C2—C3	178.90 (17)	C2—C3—C4—C5	27.9 (2)
C6—C1—C2—C3	−0.7 (3)	C3—C4—C5—C6	−52.2 (2)
N2^i—N1—C3—C2	1.2 (3)	N2—C1—C6—C5	156.55 (17)
N2^i—N1—C3—C4	−178.74 (18)	C2—C1—C6—C5	−23.8 (3)
C2^i—C2—C3—N1	−1.0 (3)	C4—C5—C6—C1	50.4 (3)

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1W···N2	0.86	1.99	2.843 (2)	173
O1—H2W···N1^ii	0.86	2.04	2.870 (2)	164
O2—H3W···O1	0.85	1.89	2.744 (2)	175
O2—H4W···O2^iii	0.86	2.02	2.8827 (19)	178

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