In-situ cryocrystallization of 1,2-dimethyl-3-nitro­benzene and 2,4-dimethyl-1-nitro­benzene

The crystal structures of 1,2-dimethyl-3-nitro­benzene, C₈H₉NO₂, and 2,4-dimethyl-1-nitro­benzene, C₈H₉NO₂, which are liquids at room temperature, have been obtained through in-situ cryocrystallization. Weak C—H...O and also π–π inter­actions are present in both crystal structures.

S1. Introduction

Obtaining the structures of compounds that are liquids at ambient temperature has gained increased inter­est over recent years. In-situ cryocrystallization at ambient pressure (Boese et al., 2003; Kirchner et al., 2010) or high-pressure crystallization at ambient temperature (Allan et al., 2002) are both suitable techniques for crystallizing liquids to obtain their crystal structures, although it is worth noting that sometimes the two method result in the formation of different polymorphs (McGregor et al., 2005; Gajda et al., 2006). Cryocrystallization techniques have been successfully used to obtain structures from a range of compounds that are liquids at ambient temperature including benzene, toluene and benzyl bromide (Nayak et al., 2010). The structures of 1,2-di­methyl-3-nitro­benzene, (I), and 2,4-di­methyl-1-nitro­benzene, (II), have been obtained using cryocrystallization techniques and are reported herein (Fig. 1).

S2. Experimental

S2.1. Synthesis and crystallization

(I) and (II) were purchased from Aldrich and used as supplied. Single crystals of both compounds were obtained in the following manner: thin-walled borosilicate glass capillaries (0.3 mm in diameter) were filled with each of the liquids and sealed. Compound (I) was crystallized from the pure liquid, while compound (II) was crystallized from a 1:1 mixture with acetone, this crystallization mode produced crystals of slightly better quality than those grown from the neat liquid. The capillaries were then mounted on the diffractometer using a modified mount (Yufit & Howard, 2005) which means that the capillary is aligned vertically in the N₂ flow of an Oxford Cryosystems cryostream. Compound (I) was cooled to just below its melting point of 280–282 K creating a polycrystalline sample which was then warmed to just above the melting point until only a few seed crystallites remained, this cooling and warming cycling was repeated until a single-crystal was obtained and diffraction data subsequently collected at 277 (2) K. Compound (II) also has a melting point of 280–282 K for the pure liquid but as a 1:1 mixture with acetone crystallization occurred at 248 K, the same method of using a warming and cooling cycle was employed to obtain a single crystal and diffraction data were subsequently recorded at 240 (2) K.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms were placed geometrically (aromatic C—H = 0.95 Å and methyl C—H = 0.98 Å) and refined using a riding model with the isotropic displacement parameters fixed at U_iso(H) = 1.2U_eq of the parent C atom for aromatic H atoms and U_iso(H) = 1.5U_eq(C) for methyl H atoms.

S3. Results and discussion

Compound (I) crystallized in the orthorhombic space group P2₁2₁2₁ with one molecule in the asymmetric unit (Fig. 2). In (I), the molecules form face-to-face stacks in the a-axis direction, that are separated by a centroid-to-centroid distance of 3.9338 (5) Å and an offset distance of 1.534 (5) Å, which indicates the presence of weak face-to-face aromatic π–π stacking inter­actions (Waller et al., 2006). The molecules in each stack are in the same orientation and related to those in adjacent stacks by 2₁ screw axes. Calculating planes through both the benzene ring and the NO₂ group shows that the NO₂ group is rotated out of the plane of the benzene ring by an angle of 46.75 (17)°. Short C—H···O contacts have been identified between the O atoms of the NO₂ group and aromatic H atoms on adjacent benzene rings (Fig. 3). The associated geometric parameters listed in Table 2 indicate the presence of weak C—H···O inter­actions (Taylor & Kennard, 1982; Thallapally et al., 2003). Together with π–π stacking inter­actions, these contacts create a three-dimensional framework.

Compound (II) crystallized in the monoclinic space group P2₁/c with one molecule in the asymmetric unit (Fig. 4). The crystal structure also displays weak face-to-tail aromatic π–π stacking inter­eactions, this time along the c axis, with centroid-to-centroid distances of 3.7729 (5) Å and offset distances of 1.3920 (6) and 1.4778 (5) Å to adjacent molecules above and below each molecule. The molecules in each stack are essentially parallel to each other, although related by a c-glide meaning that the NO₂ and methyl groups in adjacent molecules are not directly above/below themselves but related by the mirror of the glide. In this case, the NO₂ group lies in the plane of the benzene ring and again weak C—H···O inter­actions have been identified (Table 3), which form a three-dimensional hydrogen-bonding network (Fig. 5). It is worth noting that the structure obtained from the pure liquid using cryocrystallization was the same as that reported herein although the quality of the crystals were slightly better from the acetone mixture.

The Cambridge Structural Database (CSD, Version 5.34; Allen, 2002) was examined for structures, similar to those of (I) and (II), of benzene with an NO₂ substituent and the other 5 positions either being occupied by H atoms or relatively small substituents that were not or rings or long chains, e.g. OCH₃, OH, CO₂H. The structures were limited to those containing only C, H, N or O and with one molecule in the asymmetric unit. After removing duplicate structure determinations with the same cell, 207 structures were identified for examination. Taking face to face π–π stacking inter­actions as occurring when the centroid-to-centroid distance is <4.4 Å and the ring-plane-to-ring-plane angle is <30°, it was found that just under half (98) of the structures showed evidence of this type of π–π stacking inter­actions. The smallest centroid-to-centroid distances of 3.5 Å were observed in species such as 2-hy­droxy-5-methyl-3-nitro­aceto­phenone (Filarowski et al., 2006), and all of the ring-plane-to-ring-plane angles were <7.7°. Calculating planes through both the benzene ring and the NO₂ group for the structures with π–π stacking inter­actions showed a range of angles between the planes from 0–90°, approximately 32% of which were less than 5°. There was no significant correlation between the centroid-to-centroid distance and the twist of the NO₂ group (Fig. 6). A similar trend was observed in the complete dataset of 207 structures. Comparing the structures of (I) and (II) reported in this paper with those already in the CSD indicates that they are consistent with those structures already published.

The Hirshfeld surface fingerprint plots (Spackman & McKinnon, 2002) for (I) and (II) (Fig. 7) were calculated in CrystalExplorer (Wolff et al., 2012). Both compounds have a pointed feature around d_e/d_i 1.1–1.2 which is associated with short H···H contacts. In addition, the plot for (II) shows pointed features at d_e/d_i 1.4/1.1 and the reciprocal contact at 1.1/1.4 which correspond to the H···O contacts. These features are also present for compound (I) as the bright-green sections of the plot in this region; however, additional short H···H contacts in compound (I) make them less obvious. Examining the Hirshfeld surface plots (Fig. 8) the red colour indicates closer contacts, on the d_norm plot for (II) the red spots arise from the strongest of the C—H···O hydrogen bonds in the two compounds [C5—H5···O2(-x+1, y+1/2, -z+1/2)]. It is inter­esting to note that while weak C—H···O inter­actions were observed in both compounds along with π–π inter­actions, no evidence of C—H···π inter­actions have been identified although these were found to be important in the case of a number of benzene derivatives including benezene, toluene and benzyl bromide (Nayak et al., 2010).

In conclusion, the structures of (I) and (II), which are liquids at room temperature, have been determined by in-situ cryocrystallization. The structural features of both compounds are consistent with those of similar compounds previously observed in the literature, and all of the bond lengths and angles in these structures fall within the expected ranges. The Hirshfeld surface plots were relatively similar for the two compounds. Both of the structures show weak face to face/tail π–π stacking inter­actions and C—H···O inter­actions.

Related literature

For related literature, see: Allan et al. (2002); Allen (2002); Boese et al. (2003); Filarowski et al. (2006); Gajda et al. (2006); Kirchner et al. (2010); McGregor et al. (2005); Nayak et al. (2010); Spackman & McKinnon (2002); Taylor & Kennard (1982); Thallapally et al. (2003); Waller et al. (2006); Wolff et al. (2012); Yufit & Howard (2005).

Computing details

For both compounds, data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures

	Fig. 1. The crystal structure of (I), with displacement ellipsoids depicted at the 50% probability level.
	Fig. 2. Illustration of hydrogen bonding for (I).
	Fig. 3. The crystal structure of (II), with displacement ellipsoids depicted at the 50% probability level.
	Fig. 4. Illustration of hydrogen bonding for (II).
	Fig. 5. Scatterplot showing centroid–centroid distance versus twist angle calculated between a plane through NO2 plane and the benzene ring plane.
	Fig. 6. Hirshfeld surface fingerprint plots for (a) (I) and (b) (II).
	Fig. 7. Hirshfeld surface plots (de, di and dnorm) for (I) and (II). Red indicates close contacts and blue longer contacts, while green/white indicates contacts are neither particularly short or long.

(12-dimethyl-3-nitrobenzene) 1,2-Dimethyl-3-nitrobenzene

Crystal data

C8H9NO2	Dx = 1.289 Mg m^−3
Mr = 151.16	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 1048 reflections
a = 3.9338 (5) Å	θ = 2.9–25.7°
b = 14.022 (3) Å	µ = 0.09 mm^−1
c = 14.126 (3) Å	T = 277 K
V = 779.2 (3) Å^3	Block, colourless
Z = 4	0.4 × 0.3 × 0.3 mm
F(000) = 320

Data collection

Bruker SMART CCD 6000 area-detector diffractometer	744 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.029
Graphite monochromator	θmax = 26.4°, θmin = 2.1°
Detector resolution: 5.6 pixels mm^-1	h = −3→3
ω scans	k = −17→17
5395 measured reflections	l = −17→6
865 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.110	w = 1/[σ^2(Fo^2) + (0.0618P)^2 + 0.1023P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
865 reflections	Δρmax = 0.13 e Å^−3
102 parameters	Δρmin = −0.09 e Å^−3

Special details

Experimental. The data collection nominally covered a full sphere of reciprocal space by a combination of 2 sets of ω scans each set at different φ angles and each scan (5 s exposure) covering -0.300° degrees in ω. The crystal to detector distance was 4.85 cm.

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	0.2726 (8)	0.74176 (13)	0.72084 (14)	0.0978 (8)
O2	0.5030 (9)	0.63406 (15)	0.80610 (12)	0.1066 (11)
N1	0.4050 (7)	0.66406 (14)	0.73069 (14)	0.0677 (6)
C1	0.4585 (7)	0.60547 (14)	0.64549 (14)	0.0504 (6)
C2	0.3744 (7)	0.50913 (13)	0.64624 (14)	0.0485 (6)
C3	0.4354 (8)	0.45899 (14)	0.56239 (15)	0.0532 (6)
C4	0.5762 (8)	0.50585 (17)	0.48559 (15)	0.0646 (7)
H4	0.6218	0.4707	0.4295	0.077*
C5	0.6519 (9)	0.60098 (19)	0.48771 (17)	0.0684 (8)
H5	0.7465	0.6311	0.4335	0.082*
C6	0.5912 (8)	0.65258 (16)	0.56797 (16)	0.0611 (7)
H6	0.6388	0.7190	0.5704	0.073*
C7	0.2173 (8)	0.46018 (18)	0.73060 (17)	0.0671 (7)
H7A	0.3963	0.4301	0.7685	0.101*
H7B	0.0572	0.4113	0.7088	0.101*
H7C	0.0963	0.5072	0.7693	0.101*
C8	0.3480 (10)	0.35461 (16)	0.5539 (2)	0.0794 (9)
H8A	0.4189	0.3311	0.4916	0.119*
H8B	0.1021	0.3462	0.5611	0.119*
H8C	0.4665	0.3187	0.6034	0.119*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.132 (2)	0.0632 (10)	0.0985 (14)	0.0281 (13)	−0.0148 (17)	−0.0221 (10)
O2	0.169 (3)	0.0958 (14)	0.0550 (9)	0.0282 (17)	−0.0239 (15)	−0.0143 (9)
N1	0.0864 (17)	0.0540 (10)	0.0627 (11)	0.0089 (12)	−0.0100 (13)	−0.0102 (9)
C1	0.0557 (17)	0.0476 (10)	0.0480 (10)	0.0036 (11)	−0.0079 (10)	−0.0025 (9)
C2	0.0507 (16)	0.0460 (10)	0.0488 (10)	0.0064 (10)	−0.0052 (10)	0.0050 (8)
C3	0.0540 (17)	0.0485 (11)	0.0569 (11)	0.0096 (11)	−0.0130 (11)	−0.0039 (9)
C4	0.071 (2)	0.0753 (15)	0.0474 (11)	0.0159 (15)	−0.0040 (12)	−0.0044 (10)
C5	0.070 (2)	0.0813 (16)	0.0542 (12)	0.0042 (15)	0.0045 (12)	0.0188 (12)
C6	0.0652 (19)	0.0508 (11)	0.0674 (13)	−0.0005 (13)	−0.0058 (13)	0.0133 (10)
C7	0.072 (2)	0.0649 (13)	0.0649 (13)	0.0036 (14)	0.0071 (15)	0.0156 (11)
C8	0.089 (3)	0.0518 (12)	0.0977 (18)	0.0041 (15)	−0.0154 (18)	−0.0149 (13)

Geometric parameters (Å, º)

O1—N1	1.216 (3)	C4—C5	1.367 (3)
O2—N1	1.208 (3)	C5—H5	0.9500
N1—C1	1.472 (3)	C5—C6	1.366 (3)
C1—C2	1.391 (3)	C6—H6	0.9500
C1—C6	1.381 (3)	C7—H7A	0.9800
C2—C3	1.398 (3)	C7—H7B	0.9800
C2—C7	1.508 (3)	C7—H7C	0.9800
C3—C4	1.384 (3)	C8—H8A	0.9800
C3—C8	1.508 (3)	C8—H8B	0.9800
C4—H4	0.9500	C8—H8C	0.9800
O1—N1—C1	117.9 (2)	C6—C5—H5	120.1
O2—N1—O1	123.3 (2)	C1—C6—H6	121.0
O2—N1—C1	118.73 (19)	C5—C6—C1	118.1 (2)
C2—C1—N1	120.1 (2)	C5—C6—H6	121.0
C6—C1—N1	115.8 (2)	C2—C7—H7A	109.5
C6—C1—C2	124.1 (2)	C2—C7—H7B	109.5
C1—C2—C3	116.17 (19)	C2—C7—H7C	109.5
C1—C2—C7	123.1 (2)	H7A—C7—H7B	109.5
C3—C2—C7	120.73 (19)	H7A—C7—H7C	109.5
C2—C3—C8	121.1 (2)	H7B—C7—H7C	109.5
C4—C3—C2	119.61 (19)	C3—C8—H8A	109.5
C4—C3—C8	119.3 (2)	C3—C8—H8B	109.5
C3—C4—H4	118.9	C3—C8—H8C	109.5
C5—C4—C3	122.2 (2)	H8A—C8—H8B	109.5
C5—C4—H4	118.9	H8A—C8—H8C	109.5
C4—C5—H5	120.1	H8B—C8—H8C	109.5
C6—C5—C4	119.8 (2)
O1—N1—C1—C2	−134.4 (3)	C2—C1—C6—C5	−1.8 (4)
O1—N1—C1—C6	45.2 (4)	C2—C3—C4—C5	−1.6 (4)
O2—N1—C1—C2	47.7 (4)	C3—C4—C5—C6	0.6 (5)
O2—N1—C1—C6	−132.7 (3)	C4—C5—C6—C1	1.0 (4)
N1—C1—C2—C3	−179.7 (2)	C6—C1—C2—C3	0.8 (4)
N1—C1—C2—C7	1.9 (4)	C6—C1—C2—C7	−177.6 (3)
N1—C1—C6—C5	178.7 (2)	C7—C2—C3—C4	179.2 (3)
C1—C2—C3—C4	0.9 (4)	C7—C2—C3—C8	−0.4 (4)
C1—C2—C3—C8	−178.7 (3)	C8—C3—C4—C5	178.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O2^i	0.95	2.72	3.608 (3)	157
C5—H5···O1^ii	0.95	2.82	3.710 (3)	157

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

(24-dimethyl-1-nitrobenzene) 2,4-Dimethyl-1-nitrobenzene

Crystal data

C8H9NO2	F(000) = 320
Mr = 151.16	Dx = 1.311 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 259 reflections
a = 11.693 (4) Å	θ = 2.3–24.5°
b = 9.738 (3) Å	µ = 0.10 mm^−1
c = 7.018 (1) Å	T = 240 K
β = 106.54 (2)°	Block, colourless
V = 766.0 (4) Å^3	0.4 × 0.3 × 0.3 mm
Z = 4

Data collection

Bruker SMART CCD 6000 area-detector diffractometer	1319 independent reflections
Radiation source: fine-focus sealed tube	603 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.071
Detector resolution: 5.6 pixels mm^-1	θmax = 26.4°, θmin = 2.8°
ω scans	h = −14→14
Absorption correction: multi-scan (SADABS; Bruker ,2006)	k = −12→12
Tmin = 0.281, Tmax = 1.000	l = −6→6
4894 measured reflections

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)] = 0.077	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.265	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.1373P)^2] where P = (Fo^2 + 2Fc^2)/3
1319 reflections	(Δ/σ)max < 0.001
102 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

Experimental. The data collection nominally covered a full sphere of reciprocal space by a combination of 2 sets of ω scans each set at different φ angles and each scan (5 s exposure) covering -0.300° degrees in ω. The crystal to detector distance was 4.85 cm.

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.

Relatively low reflection count is a result of using of special attachment (see (Yufit & Howard 2005)), required for in situ growth of the crystal.

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

	x	y	z	Uiso*/Ueq
O1	0.8287 (3)	0.4693 (4)	0.5670 (6)	0.0963 (14)
O2	0.6397 (4)	0.4692 (4)	0.4495 (6)	0.0941 (14)
N1	0.7348 (4)	0.5290 (4)	0.5065 (6)	0.0595 (11)
C1	0.7338 (4)	0.6810 (4)	0.5029 (6)	0.0457 (10)
C2	0.8391 (3)	0.7559 (4)	0.5680 (6)	0.0459 (11)
C3	0.8255 (3)	0.8982 (4)	0.5585 (6)	0.0501 (11)
H3	0.8951	0.9531	0.6042	0.060*
C4	0.7169 (3)	0.9646 (4)	0.4866 (6)	0.0476 (11)
C5	0.6155 (4)	0.8839 (5)	0.4221 (6)	0.0542 (12)
H5	0.5397	0.9261	0.3713	0.065*
C6	0.6240 (4)	0.7436 (4)	0.4311 (6)	0.0505 (12)
H6	0.5540	0.6891	0.3877	0.061*
C7	0.9632 (4)	0.6996 (5)	0.6481 (8)	0.0699 (14)
H7A	0.9662	0.6382	0.7601	0.105*
H7B	1.0194	0.7755	0.6932	0.105*
H7C	0.9848	0.6483	0.5433	0.105*
C8	0.7098 (5)	1.1195 (5)	0.4804 (7)	0.0712 (14)
H8A	0.7655	1.1556	0.4116	0.107*
H8B	0.7309	1.1556	0.6164	0.107*
H8C	0.6284	1.1479	0.4094	0.107*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.096 (3)	0.049 (2)	0.151 (4)	0.0216 (19)	0.046 (2)	0.017 (2)
O2	0.100 (3)	0.053 (2)	0.115 (3)	−0.020 (2)	0.008 (2)	−0.006 (2)
N1	0.082 (3)	0.046 (2)	0.053 (3)	−0.001 (2)	0.0247 (19)	−0.0051 (18)
C1	0.060 (3)	0.037 (2)	0.040 (3)	0.0024 (19)	0.0141 (18)	−0.0015 (19)
C2	0.055 (3)	0.048 (3)	0.037 (3)	0.0037 (18)	0.0168 (19)	−0.0028 (18)
C3	0.053 (3)	0.045 (3)	0.051 (3)	−0.0024 (19)	0.0126 (19)	−0.004 (2)
C4	0.060 (3)	0.040 (2)	0.043 (3)	0.0028 (19)	0.0148 (18)	−0.0023 (19)
C5	0.053 (3)	0.055 (3)	0.051 (3)	0.013 (2)	0.0093 (19)	0.004 (2)
C6	0.051 (3)	0.058 (3)	0.041 (3)	−0.009 (2)	0.0123 (19)	−0.0104 (19)
C7	0.058 (3)	0.066 (3)	0.081 (4)	0.016 (2)	0.014 (2)	0.005 (2)
C8	0.091 (4)	0.043 (3)	0.081 (4)	0.009 (2)	0.028 (3)	0.000 (2)

Geometric parameters (Å, º)

O1—N1	1.207 (4)	C4—C8	1.511 (6)
O2—N1	1.218 (4)	C5—C6	1.370 (6)
N1—C1	1.481 (5)	C5—H5	0.9500
C1—C6	1.380 (5)	C6—H6	0.9500
C1—C2	1.391 (5)	C7—H7A	0.9800
C2—C3	1.394 (5)	C7—H7B	0.9800
C2—C7	1.503 (5)	C7—H7C	0.9800
C3—C4	1.386 (5)	C8—H8A	0.9800
C3—H3	0.9500	C8—H8B	0.9800
C4—C5	1.386 (6)	C8—H8C	0.9800
O1—N1—O2	122.6 (4)	C4—C5—H5	119.8
O1—N1—C1	119.3 (4)	C5—C6—C1	120.3 (4)
O2—N1—C1	118.0 (4)	C5—C6—H6	119.8
C6—C1—C2	122.2 (4)	C1—C6—H6	119.8
C6—C1—N1	116.7 (4)	C2—C7—H7A	109.5
C2—C1—N1	121.1 (4)	C2—C7—H7B	109.5
C1—C2—C3	115.3 (4)	H7A—C7—H7B	109.5
C1—C2—C7	127.0 (4)	C2—C7—H7C	109.5
C3—C2—C7	117.7 (4)	H7A—C7—H7C	109.5
C4—C3—C2	124.1 (4)	H7B—C7—H7C	109.5
C4—C3—H3	117.9	C4—C8—H8A	109.5
C2—C3—H3	117.9	C4—C8—H8B	109.5
C5—C4—C3	117.7 (4)	H8A—C8—H8B	109.5
C5—C4—C8	121.5 (4)	C4—C8—H8C	109.5
C3—C4—C8	120.9 (4)	H8A—C8—H8C	109.5
C6—C5—C4	120.4 (4)	H8B—C8—H8C	109.5
C6—C5—H5	119.8

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7B···O1^i	0.98	2.80	3.749 (6)	163
C7—H7C···O1^ii	0.98	2.76	3.606 (6)	145
C5—H5···O2^iii	0.95	2.64	3.459 (6)	145

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