Hydrogen bonding in 1,2-diazine–chloranilic acid (2/1) and 1,4-diazine–chloranilic acid (2/1) determined at 110 K

The crystal structures of the isomeric title compounds [systematic names: pyridazine–2,5-dichloro-3,6-dihydr­oxy-p-benzoquinone (2/1), (I), and pyrazine–2,5-dichloro-3,6-dihy­droxy-p-benzoquinone (2/1), (II)], 2C₄H₄N₂·C₆H₂Cl₂O₄, have been re­determined at 110 K. The H atom in the inter­molecular O...H...N hydrogen bond in each compound was revealed to be disordered; the relative occupancies at the O and N sites are 0.33 (3) and 0.67 (3), respectively, for (I), and 0.56 (4) and 0.44 (4) for (II). The formal charges of the chloranilic acid in (I) and (II) estimated from the occupancy factors are ca −1.3 and −0.8, respectively. The geometries of the centrosymmetric chloranilic acid molecule in (I) and (II) are compared with the neutral, monoanionic and dianionic forms of chloranilic acid optimized by density functional theory (DFT) at the B3LYP/6–311+G(3df,2p) level. The result implies that the chloranilic acid molecule in (I) is close to the monoanionic state, while that in (II) is between neutral and monoanionic, consistent with the result derived from the H-atom occupancies.

S1. Comment

The crystal structures of 1,2-diazine–chloranilic acid (2/1), (I), and 1,4-diazine–chloranilic acid (2/1), (II), have been determined at room temperature (Ishida & Kashino, 1999a,b). In each compound, the diazine and chloranilic acid molecules are connected by strong N···H···O hydrogen bonds [N···O = 2.582 (3) Å for (I) and 2.590 (4) Å for (II)] to afford a centrosymmetric 2:1 unit. In the hydrogen bond of (I), the H atom was found near the centre of N···O, while in (II), the H atom was located near the O-atom site with a fairly long O—H bond [O—H = 1.06 (5) Å]. From the positions of the H atoms and the large U_iso(H) values [U_iso(H) = 0.16 (1) Ų for (I) and 0.12 (1) Ų for (II)], disorder of the H atoms in the hydrogen bonds was suggested. Proton motion attributable to dynamically disordered H atoms in the hydrogen bonds was detected by ¹H NMR and ³⁵Cl NQR measurements for (I) (Nihei et al., 2000a) and (II) (Nihei et al., 2000b). The proton-transfer modes shown in Fig. 1 were proposed and the corresponding activation energies were estimated.

Interestingly, (I) showed an anomalous positive temperature coefficient of ³⁵Cl NQR resonance frequencies on heating in the range 77–170 K, which is cannot be explained by the conventional Bayer-type lattice motion (Bayer, 1951). On the other hand, (II) showed a normal negative temperature coefficient of ³⁵Cl NQR frequencies. The anomalous behaviour of (I) has been interpreted (Reference?) by population changes of chloranilate(2-) and hydrogen chloranilate(1-) ions with temperature. The population of 2- ions decreases on heating from 77 K, while that of 1- ions increases. In other words, the H atom in the N···H···O hydrogen bond migrates from the N-atom site to the O-atom site with increasing temperature. However, no crystallographic evidence has been obtained yet.

Recently, Suzuki et al. (2007) measured IR absorption spectra and dielectric responses [Of what?] over a wide temperature range. These authors observed O—H stretching and bending, C—O stretching and N—H stretching bands in IR spectra, and a broad maximum around 120 K in dielectric response. The first three IR bands were found to increase as the temperature was lowered, while the last band decreases. The authors therefore interpreted the broad maximum in dielectric response in terms of H-atom migration from N—H···O at 300 K to N···H—O below 90 K, which contradicts the interpretation from NQR.

In the present study, we collected single-crystal X-ray diffraction data at low temperature in order to clarify the hydrogen-bond states in both compounds. Wilson and co-workers have recently shown that high-quality X-ray diffraction data can be used to elucidate the relative site occupancies of the H atom in hydrogen-bond systems (Wilson & Goeta, 2004; Parkin et al., 2004). This prompted us to redetermine the crystal structures of the title compounds with relatively high-redundancy data at 110 K. The weak intermolecular interactions and crystal packing, which were unclear in the previous study at room temperature, are of additional interest.

The molecular structures of (I) and (II) are shown in Figs. 2 and 3, respectively. Although the structures are essentially the same as those at room temperature (Ishida & Kashino, 1999a,b), two disordered positions of the H atom in the hydrogen bond were clearly found in a difference Fourier map in each compound. The positional parameters and the occupancy factors were refined, with U_iso(H) = 1.2U_eq(N or O). The refined occupancy factors at the O and N sites are 0.33 (3) and 0.67 (3), respectively, for (I), and 0.56 (4) and 0.44 (4), respectively, for (II). The occupancies at the O and N sites as estimated from the peak heights in the difference Fourier maps are 0.35 (1) and 0.65 (1), respectively, for (I), and 0.58 (1) and 0.42 (1), respectively, for (II). Therefore, the formal charges of the chloranilic acids in (I) and (II) are ca -1.3 and -0.8, respectively.

A difference in the charge state between (I) and (II) was also found in the molecular geometries of chloranilic acid. In Table 3, the C—C, C—O and C—Cl bond lengths of chloranilic acid in (I) and (II) are given together with calculated values for the neutral molecule (0), monoanion (1-) and dianion (2-) of chloranilic acid. The calculation was carried out at the B3LYP/6-311+G(3df,2p) level of theory using the computer program GAUSSIAN98 (Frisch et al., 1998). Although the monoanion is non-centrosymmetric, the average structure of two states (B) and (C) shown in Fig. 1 is centrosymmetric, if a rapid exchange between these states is assumed. In Table 3, the bond lengths of the average structure of the 1- state are given. The geometries corresponding to the (B) state are given in footnote of Table 3. The C2—C3, C1—C3ⁱ, C1—O1 and C2—Cl1 bonds of (I) are longer than those of (II), while the C1—C2 and C3—O2 bonds of (I) are shorter than those of (II). The calculated data show that the former bond lengths increase in the order 0 state < 1- state < 2- state, while the latter bonds decrease in the order 0 state > 1- state > 2- state. This implies that the chloranilic acid in (I) has a more negative charge than that in (II). The geometries of chloranilic acid in (I) are close to the 1- state, while (II) has intermediate values between the 0 and 1- states, which are consistent with the formal charges estimated from the occupancy factors of the H atoms.

In the crystal structure of (I), the 1,2-diazine–chloranilic acid (2/1) unit is approximately planar, with a dihedral angle of 14.32 (5)° between the diazine ring and the chloranilic acid C1–C3/C1ⁱ–C3ⁱ plane [symmetry code (i) given in Table 1]. The (2/1) units are connected by C—H···O and C—H···N hydrogen bonds, forming a molecular sheet extending parallel to the (102) plane (Fig. 4). In (II), the (2/1) unit is considerably twisted, with a dihedral angle of 52.35 (6)° between the diazine and chloranilic acid planes. The units are linked by weak C—H···O hydrogen bonds (Table 2), forming a molecular sheet parallel to the (010) plane (Fig. 5). No C—H···N hydrogen bond exists in (II), but a Cl1···N2 short contact [3.1520 (15) Å] is observed in the sheet.

In this communication, we can clearly show the disordered states of the H atoms in both compounds. Although the relative occupancy factors evaluated for (I) imply a double-well hydrogen bond with a lower potential energy at the N site and support the interpretation from the NQR data, i.e. proton migration from the N site to the O site with increasing temperature, more detailed experiments are required to confirm it. Multi-temperature X-ray diffraction measurements with ¹⁴N NQR experiments are in progress for (I) to clarify the charge states of both chloranilic acid and 1,2-diazine.

Related literature

For related literature, see: Bayer (1951); Becke (1993); Frisch (1998); Ishida & Kashino (1999a, 1999b); Lee et al. (1988); Nihei et al. (2000a, 2000b); Parkin et al. (2004); Suzuki et al. (2007); Wilson & Goeta (2004).

S2. Experimental

Single crystals of (I) were obtained by slow evaporation from a methanol solution (100 ml) of chloranilic acid (0.197 g) and 1,2-diazine (0.155 g) at room temperature. Crystals of (II) were obtained by slow evaporation from an acetonitrile solution (150 ml) of chloranilic acid (0.209 g) and 1,4-diazine (0.165 g) at room temperature.

S3. Refinement

For both compounds, H atoms in the N···H···O hydrogen bonds were found to be disordered in difference Fourier maps. Since the site-occupancy factors and isotropic displacement parameters were strongly correlated, the positional parameters and occupancy factors were refined, with U_iso(H) = 1.2U_eq(N or O). The refined distances are given in Tables 1 and 2. Other H atoms were positioned geometrically (C—H = 0.95 Å) and treated as riding, with U_iso(H) = 1.2U_eq(C). The ab initio molecular calculations were performed using GAUSSIAN98 (Frisch et al., 1998) at the B3LYP/6-311+G(3df,2p) (Becke, 1993; Lee et al., 1988) level of theory. The full optimizations were carried out for chloranilic acid, the hydrogen chloranilate monoanion and the chloranilate dianion, and the resultant stable structures were confirmed by the vibrational analysis, which shows only real frequencies for the optimized structures.

Computing details

For both compounds, data collection: PROCESS-AUTO (Rigaku/MSC, 2004); cell refinement: PROCESS-AUTO (Rigaku/MSC, 2004); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2004) and PLATON (Spek, 2003).

Figures

	Fig. 1. Proton-transfer models proposed for (I) and the numbering scheme of the hydrogen chloranilate monoanion in (B) used for the DFT calculations.
	Fig. 2. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. [Symmetry code: (i) -x + 2, -y + 1, -z + 1.]
	Fig. 3. The molecular structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. [Symmetry code: (i) -x + 2, -y, -z + 1.]
	Fig. 4. A packing diagram for (I), showing a molecular sheet formed by C—H···N and C—H···O hydrogen bonds (dashed lines).
	Fig. 5. A partial packing diagram for (II), viewed approximately down the a axis, showing a molecular sheet formed by weak C—H···O hydrogen bonds (dashed lines). H atoms not involved in these hydrogen bonds have been omitted for clarity

(I) pyridazine–2,5-dichloro-3,6-dihydroxy-p-benzoquinone (2/1)

Crystal data

2C4H4N2·C6H2Cl2O4	F(000) = 376.00
Mr = 369.16	Dx = 1.721 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ybc	Cell parameters from 10589 reflections
a = 3.72940 (13) Å	θ = 3.0–30.0°
b = 20.0950 (5) Å	µ = 0.49 mm^−1
c = 9.6217 (2) Å	T = 110 K
β = 98.8484 (11)°	Platelet, brown
V = 712.49 (3) Å^3	0.35 × 0.25 × 0.10 mm
Z = 2

Data collection

Rigaku R-AXIS RAPIDII diffractometer	1883 reflections with I > 2σ(I)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.031
ω scans	θmax = 30.0°
Absorption correction: numerical (ABSCOR; Higashi, 1999)	h = −5→5
Tmin = 0.868, Tmax = 0.953	k = −28→27
11510 measured reflections	l = −13→13
2070 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.0498P)^2 + 0.2345P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.084	(Δ/σ)max = 0.001
S = 1.08	Δρmax = 0.57 e Å^−3
2070 reflections	Δρmin = −0.38 e Å^−3
116 parameters

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	Occ. (<1)
Cl1	0.57665 (7)	0.497315 (12)	0.18726 (3)	0.01488 (10)
O1	0.7134 (2)	0.61262 (4)	0.38189 (9)	0.01980 (19)
O2	0.9073 (2)	0.38215 (4)	0.35771 (9)	0.01699 (18)
H2	0.986 (14)	0.355 (3)	0.400 (5)	0.020*	0.33 (3)
N1	1.0509 (3)	0.26544 (5)	0.45609 (10)	0.01453 (19)
H1	1.026 (7)	0.3094 (13)	0.433 (3)	0.017*	0.67 (3)
N2	0.8690 (3)	0.22698 (5)	0.35476 (10)	0.01543 (19)
C1	0.8443 (3)	0.55961 (5)	0.43114 (11)	0.0131 (2)
C2	0.8084 (3)	0.49752 (5)	0.35832 (11)	0.0125 (2)
C3	0.9441 (3)	0.43858 (5)	0.41860 (11)	0.0129 (2)
C4	0.8811 (3)	0.16172 (5)	0.37715 (12)	0.0155 (2)
H4	0.7566	0.1334	0.3067	0.019*
C5	1.0691 (3)	0.13254 (5)	0.49997 (11)	0.0158 (2)
H5	1.0670	0.0857	0.5130	0.019*
C6	1.2561 (3)	0.17327 (5)	0.60076 (12)	0.0155 (2)
H6	1.3904	0.1558	0.6847	0.019*
C7	1.2395 (3)	0.24178 (5)	0.57394 (11)	0.0148 (2)
H7	1.3648	0.2717	0.6409	0.018*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.01827 (15)	0.01431 (14)	0.01023 (14)	0.00036 (8)	−0.00360 (10)	−0.00003 (8)
O1	0.0273 (4)	0.0126 (4)	0.0164 (4)	0.0038 (3)	−0.0063 (3)	0.0004 (3)
O2	0.0239 (4)	0.0114 (3)	0.0136 (4)	0.0017 (3)	−0.0040 (3)	−0.0013 (3)
N1	0.0165 (4)	0.0131 (4)	0.0130 (4)	0.0001 (3)	−0.0009 (3)	−0.0014 (3)
N2	0.0175 (4)	0.0154 (4)	0.0119 (4)	−0.0001 (3)	−0.0024 (3)	−0.0011 (3)
C1	0.0142 (4)	0.0128 (4)	0.0116 (4)	0.0000 (3)	−0.0006 (3)	0.0004 (4)
C2	0.0147 (5)	0.0127 (5)	0.0089 (5)	0.0006 (3)	−0.0021 (4)	0.0001 (3)
C3	0.0137 (4)	0.0134 (5)	0.0109 (4)	0.0008 (3)	−0.0005 (3)	0.0002 (4)
C4	0.0169 (5)	0.0143 (5)	0.0143 (5)	−0.0008 (4)	−0.0010 (4)	−0.0018 (4)
C5	0.0170 (5)	0.0133 (5)	0.0167 (5)	0.0004 (4)	0.0015 (4)	0.0015 (4)
C6	0.0165 (5)	0.0159 (5)	0.0134 (5)	0.0021 (4)	−0.0001 (4)	0.0017 (4)
C7	0.0161 (5)	0.0152 (5)	0.0120 (5)	0.0002 (4)	−0.0011 (4)	−0.0020 (4)

Geometric parameters (Å, º)

Cl1—C2	1.7374 (11)	C2—C3	1.3802 (14)
O1—C1	1.2355 (13)	C3—C1^i	1.5373 (15)
O2—C3	1.2740 (13)	C4—C5	1.4062 (15)
O2—H2	0.71 (6)	C4—H4	0.9500
N1—C7	1.3272 (13)	C5—C6	1.3741 (15)
N1—N2	1.3433 (12)	C5—H5	0.9500
N1—H1	0.91 (3)	C6—C7	1.4003 (15)
N2—C4	1.3285 (14)	C6—H6	0.9500
C1—C2	1.4270 (14)	C7—H7	0.9500
C1—C3^i	1.5373 (15)
C3—O2—H2	114 (4)	C2—C3—C1^i	118.48 (9)
C7—N1—N2	123.78 (9)	N2—C4—C5	123.23 (10)
C7—N1—H1	125.0 (15)	N2—C4—H4	118.4
N2—N1—H1	111.2 (15)	C5—C4—H4	118.4
C4—N2—N1	116.71 (9)	C6—C5—C4	118.56 (10)
O1—C1—C2	124.32 (10)	C6—C5—H5	120.7
O1—C1—C3^i	117.10 (9)	C4—C5—H5	120.7
C2—C1—C3^i	118.57 (8)	C5—C6—C7	116.88 (10)
C3—C2—C1	122.91 (10)	C5—C6—H6	121.6
C3—C2—Cl1	119.53 (8)	C7—C6—H6	121.6
C1—C2—Cl1	117.56 (8)	N1—C7—C6	120.82 (10)
O2—C3—C2	124.33 (10)	N1—C7—H7	119.6
O2—C3—C1^i	117.19 (9)	C6—C7—H7	119.6
C7—N1—N2—C4	0.55 (16)	C1—C2—C3—C1^i	−2.39 (18)
O1—C1—C2—C3	−177.01 (11)	Cl1—C2—C3—C1^i	178.62 (8)
C3^i—C1—C2—C3	2.39 (18)	N1—N2—C4—C5	0.57 (16)
O1—C1—C2—Cl1	2.01 (16)	N2—C4—C5—C6	−1.39 (18)
C3^i—C1—C2—Cl1	−178.60 (8)	C4—C5—C6—C7	1.06 (16)
C1—C2—C3—O2	177.89 (11)	N2—N1—C7—C6	−0.82 (17)
Cl1—C2—C3—O2	−1.10 (16)	C5—C6—C7—N1	−0.04 (16)

Symmetry code: (i) −x+2, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.71 (5)	2.32 (4)	2.6831 (11)	114 (4)
O2—H2···N1	0.71 (5)	1.89 (5)	2.5549 (12)	156 (5)
N1—H1···O1^i	0.91 (2)	2.46 (2)	2.9641 (12)	115.5 (17)
N1—H1···O2	0.91 (2)	1.66 (2)	2.5549 (12)	165 (2)
C4—H4···O1^ii	0.95	2.36	3.2251 (14)	152
C6—H6···O2^iii	0.95	2.47	3.3769 (14)	161
C7—H7···O1^i	0.95	2.35	2.9579 (13)	121
C7—H7···N2^iii	0.95	2.57	3.3548 (15)	141

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

(II) pyrazine–2,5-dichloro-3,6-dihydroxy-p-benzoquinone (2/1)

Crystal data

2C4H4N2·C6H2Cl2O4	F(000) = 376.00
Mr = 369.16	Dx = 1.660 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2yn	Cell parameters from 10588 reflections
a = 3.7530 (3) Å	θ = 3.8–30.1°
b = 18.3915 (14) Å	µ = 0.47 mm^−1
c = 10.7248 (8) Å	T = 110 K
β = 94.103 (3)°	Needle, brown
V = 738.36 (10) Å^3	0.40 × 0.18 × 0.10 mm
Z = 2

Data collection

Rigaku R-AXIS RAPIDII diffractometer	1929 reflections with I > 2σ(I)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.058
ω scans	θmax = 30.0°
Absorption correction: multi-scan (ABSCOR; Higashi, 1999)	h = −5→4
Tmin = 0.845, Tmax = 0.954	k = −25→25
14174 measured reflections	l = −15→15
2154 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.043	w = 1/[σ^2(Fo^2) + (0.0552P)^2 + 0.5664P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.108	(Δ/σ)max = 0.001
S = 1.04	Δρmax = 0.69 e Å^−3
2154 reflections	Δρmin = −0.25 e Å^−3
116 parameters

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	Occ. (<1)
Cl1	0.72803 (10)	0.122207 (19)	0.67675 (3)	0.01804 (12)
O1	1.1228 (3)	−0.01223 (6)	0.74702 (10)	0.0212 (3)
O2	0.6253 (4)	0.11712 (6)	0.39990 (11)	0.0207 (2)
H2	0.615 (12)	0.119 (2)	0.320 (5)	0.025*	0.56 (4)
N1	0.5479 (4)	0.14784 (8)	0.16695 (13)	0.0194 (3)
H1	0.571 (15)	0.135 (3)	0.232 (6)	0.023*	0.44 (4)
N2	0.4783 (4)	0.19578 (8)	−0.07878 (13)	0.0228 (3)
C1	1.0622 (4)	−0.00471 (8)	0.63385 (13)	0.0162 (3)
C2	0.8720 (4)	0.05662 (8)	0.57750 (13)	0.0156 (3)
C3	0.8045 (4)	0.06314 (8)	0.45154 (13)	0.0161 (3)
C4	0.6607 (5)	0.21367 (9)	0.13670 (15)	0.0210 (3)
H4	0.7651	0.2448	0.1999	0.025*
C5	0.6268 (5)	0.23740 (9)	0.01276 (16)	0.0221 (3)
H5	0.7117	0.2844	−0.0069	0.027*
C6	0.3643 (5)	0.12987 (9)	−0.04616 (15)	0.0212 (3)
H6	0.2557	0.0990	−0.1090	0.025*
C7	0.3998 (5)	0.10534 (9)	0.07613 (15)	0.0206 (3)
H7	0.3185	0.0581	0.0957	0.025*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0233 (2)	0.01832 (19)	0.01262 (18)	0.00128 (12)	0.00211 (13)	−0.00242 (11)
O1	0.0305 (6)	0.0221 (5)	0.0108 (5)	0.0030 (5)	0.0004 (4)	0.0004 (4)
O2	0.0302 (6)	0.0201 (5)	0.0117 (5)	0.0057 (4)	0.0008 (4)	0.0013 (4)
N1	0.0236 (7)	0.0218 (6)	0.0127 (6)	0.0037 (5)	0.0008 (5)	0.0009 (5)
N2	0.0292 (7)	0.0248 (7)	0.0145 (6)	0.0030 (6)	0.0015 (5)	0.0010 (5)
C1	0.0194 (7)	0.0172 (6)	0.0119 (6)	−0.0025 (5)	0.0008 (5)	−0.0008 (5)
C2	0.0194 (7)	0.0160 (6)	0.0114 (6)	−0.0004 (5)	0.0017 (5)	−0.0019 (5)
C3	0.0195 (7)	0.0164 (6)	0.0123 (6)	−0.0018 (5)	0.0013 (5)	−0.0006 (5)
C4	0.0253 (8)	0.0194 (7)	0.0180 (7)	0.0023 (6)	0.0000 (6)	−0.0021 (5)
C5	0.0275 (8)	0.0194 (7)	0.0196 (7)	0.0015 (6)	0.0029 (6)	0.0014 (6)
C6	0.0252 (8)	0.0243 (8)	0.0138 (7)	0.0007 (6)	−0.0005 (6)	−0.0017 (5)
C7	0.0241 (7)	0.0208 (7)	0.0166 (7)	−0.0002 (6)	0.0008 (6)	0.0008 (5)

Geometric parameters (Å, º)

Cl1—C2	1.7212 (15)	C1—C3^i	1.520 (2)
O1—C1	1.2266 (17)	C2—C3	1.3619 (19)
O2—C3	1.3004 (18)	C3—C1^i	1.520 (2)
O2—H2	0.86 (5)	C4—C5	1.396 (2)
N1—C4	1.330 (2)	C4—H4	0.9500
N1—C7	1.338 (2)	C5—H5	0.9500
N1—H1	0.74 (7)	C6—C7	1.384 (2)
N2—C5	1.335 (2)	C6—H6	0.9500
N2—C6	1.340 (2)	C7—H7	0.9500
C1—C2	1.444 (2)
C3—O2—H2	116 (3)	C2—C3—C1^i	119.31 (13)
C4—N1—C7	118.49 (15)	N1—C4—C5	120.51 (15)
C4—N1—H1	121 (4)	N1—C4—H4	119.7
C7—N1—H1	121 (4)	C5—C4—H4	119.7
C5—N2—C6	116.80 (14)	N2—C5—C4	121.72 (15)
O1—C1—C2	123.59 (14)	N2—C5—H5	119.1
O1—C1—C3^i	118.09 (13)	C4—C5—H5	119.1
C2—C1—C3^i	118.32 (12)	N2—C6—C7	122.09 (15)
C3—C2—C1	122.36 (13)	N2—C6—H6	119.0
C3—C2—Cl1	120.49 (12)	C7—C6—H6	119.0
C1—C2—Cl1	117.15 (11)	N1—C7—C6	120.39 (16)
O2—C3—C2	122.93 (14)	N1—C7—H7	119.8
O2—C3—C1^i	117.75 (13)	C6—C7—H7	119.8
O1—C1—C2—C3	−179.16 (15)	Cl1—C2—C3—C1^i	179.45 (11)
C3^i—C1—C2—C3	1.0 (2)	C7—N1—C4—C5	−0.4 (2)
O1—C1—C2—Cl1	0.4 (2)	C6—N2—C5—C4	−0.3 (3)
C3^i—C1—C2—Cl1	−179.45 (10)	N1—C4—C5—N2	0.7 (3)
C1—C2—C3—O2	178.12 (14)	C5—N2—C6—C7	−0.4 (2)
Cl1—C2—C3—O2	−1.4 (2)	C4—N1—C7—C6	−0.3 (2)
C1—C2—C3—C1^i	−1.0 (2)	N2—C6—C7—N1	0.8 (3)

Symmetry code: (i) −x+2, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.86 (5)	2.33 (5)	2.7038 (16)	107 (3)
O2—H2···N1	0.86 (5)	1.73 (5)	2.5576 (18)	163 (4)
N1—H1···O1^i	0.74 (6)	2.53 (5)	2.9044 (18)	113 (5)
N1—H1···O2	0.74 (6)	1.83 (6)	2.5576 (18)	171 (6)
C6—H6···O1^ii	0.95	2.59	3.505 (2)	162
C7—H7···O1^iii	0.95	2.59	3.303 (2)	132

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