2,3-Dimethyl-6-nitro-quinoxaline.

The asymmetric unit of the title quinoxaline compound, C(10)H(9)N(3)O(2), contains two crystallographically independent mol-ecules (A and B). The quinoxaline ring systems are essentially planar, with maximum deviations of 0.006 (1) and 0.017 (1) Å, respectively, for mol-ecules A and B. In mol-ecule A, the dihedral angle formed between the quinoxaline ring system and nitro group is 10.94 (3)° [6.31 (13)° for mol-ecule B]. In the crystal, mol-ecules are linked into chains propagating along [001]: one forms zigzag chains linked by C-H⋯O hydrogen bonds, whilst the other forms ladder-like chains by way of C-H⋯N and C-H⋯O hydrogen bonds. The packing is further consolidated by weak π-π inter-actions [range of centroid-centroid distances = 3.5895 (7)-3.6324 (7) Å].

Related literature

For general background to and applications of the title quinoxaline compound, see: Darabi et al. (2008 ▶). For the synthesis, see: Ajaikumar & Pandurangan (2009 ▶); Darabi et al. (2009 ▶). For related quinoxaline structures, see: Ghalib et al. (2010 ▶); Wozniak et al. (1993 ▶). For graph-set descriptions of hydrogen-bond ring motifs, see: Bernstein et al. (1995 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C10H9N3O2

M = 203.20

Monoclinic,

a = 7.1125 (7) Å

b = 22.490 (2) Å

c = 12.9596 (10) Å

β = 115.026 (4)°

V = 1878.4 (3) Å3

Z = 8

Mo Kα radiation

μ = 0.10 mm−1

T = 100 K

0.26 × 0.21 × 0.10 mm

Data collection

Bruker APEXII DUO CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.973, T max = 0.990

52279 measured reflections

7510 independent reflections

5559 reflections with I > 2σ(I)

R int = 0.043

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.136

S = 1.03

7510 reflections

275 parameters

H-atom parameters constrained

Δρmax = 0.55 e Å−3

Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810024463/hb5504sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810024463/hb5504Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C10H9N3O2	F(000) = 848
Mr = 203.20	Dx = 1.437 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9916 reflections
a = 7.1125 (7) Å	θ = 3.4–33.5°
b = 22.490 (2) Å	µ = 0.10 mm−1
c = 12.9596 (10) Å	T = 100 K
β = 115.026 (4)°	Block, brown
V = 1878.4 (3) Å3	0.26 × 0.21 × 0.10 mm
Z = 8

Bruker APEXII DUO CCD diffractometer	7510 independent reflections
Radiation source: fine-focus sealed tube	5559 reflections with I > 2σ(I)
graphite	Rint = 0.043
φ and ω scans	θmax = 33.8°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −10→11
Tmin = 0.973, Tmax = 0.990	k = −35→35
52279 measured reflections	l = −20→20

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.136	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.077P)2 + 0.2747P] where P = (Fo2 + 2Fc2)/3
7510 reflections	(Δ/σ)max = 0.001
275 parameters	Δρmax = 0.55 e Å−3
0 restraints	Δρmin = −0.20 e Å−3

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
O1A	0.42483 (15)	0.54231 (3)	0.13432 (7)	0.03320 (19)
O2A	0.40149 (14)	0.57864 (4)	0.28272 (7)	0.03070 (18)
N1A	0.46872 (13)	0.81176 (4)	0.03295 (7)	0.02043 (16)
N2A	0.50093 (12)	0.79631 (4)	0.25642 (7)	0.01853 (15)
N3A	0.41730 (13)	0.58434 (4)	0.19278 (7)	0.02205 (16)
C1A	0.49512 (15)	0.85691 (4)	0.10172 (8)	0.02068 (17)
C2A	0.45607 (13)	0.75638 (4)	0.07370 (8)	0.01702 (16)
C3A	0.42621 (14)	0.70659 (4)	0.00252 (8)	0.01940 (17)
H3A	0.4160	0.7116	−0.0709	0.023*
C4A	0.41210 (14)	0.65075 (4)	0.04132 (8)	0.01985 (17)
H4A	0.3915	0.6177	−0.0053	0.024*
C5A	0.42934 (14)	0.64452 (4)	0.15257 (8)	0.01822 (16)
C6A	0.45822 (14)	0.69133 (4)	0.22529 (8)	0.01792 (16)
H6A	0.4686	0.6855	0.2985	0.022*
C7A	0.47173 (13)	0.74866 (4)	0.18519 (7)	0.01652 (15)
C8A	0.51266 (14)	0.84900 (4)	0.21625 (8)	0.01909 (16)
C9A	0.54442 (18)	0.90164 (5)	0.29221 (9)	0.0257 (2)
H9A	0.5650	0.8884	0.3667	0.039*
H9B	0.4244	0.9269	0.2613	0.039*
H9C	0.6642	0.9234	0.2975	0.039*
C10A	0.5085 (2)	0.91790 (5)	0.05931 (10)	0.0309 (2)
H10A	0.4890	0.9156	−0.0186	0.046*
H10B	0.6425	0.9346	0.1049	0.046*
H10C	0.4027	0.9426	0.0643	0.046*
O1B	1.02498 (14)	0.88142 (4)	0.11899 (7)	0.03279 (18)
O2B	1.01367 (14)	0.86371 (3)	0.28010 (7)	0.03235 (18)
N1B	0.91353 (13)	0.60539 (4)	0.08423 (7)	0.02072 (15)
N2B	0.96057 (12)	0.64557 (4)	0.30076 (7)	0.01937 (15)
N3B	1.00834 (13)	0.84739 (4)	0.18868 (8)	0.02304 (17)
C1B	0.91658 (15)	0.56851 (4)	0.16330 (8)	0.02119 (17)
C2B	0.93380 (13)	0.66464 (4)	0.11081 (8)	0.01795 (16)
C3B	0.92863 (15)	0.70603 (4)	0.02753 (8)	0.02017 (17)
H3B	0.9091	0.6928	−0.0443	0.024*
C4B	0.95218 (14)	0.76554 (4)	0.05198 (8)	0.02043 (17)
H4B	0.9496	0.7930	−0.0022	0.025*
C5B	0.98036 (14)	0.78392 (4)	0.16108 (8)	0.01887 (16)
C6B	0.98399 (14)	0.74548 (4)	0.24403 (8)	0.01843 (16)
H6B	1.0023	0.7595	0.3152	0.022*
C7B	0.95944 (13)	0.68435 (4)	0.21894 (8)	0.01721 (16)
C8B	0.93904 (15)	0.58899 (4)	0.27364 (8)	0.02046 (17)
C9B	0.93881 (19)	0.54547 (5)	0.36108 (9)	0.0285 (2)
H9D	0.9554	0.5664	0.4289	0.043*
H9E	1.0512	0.5179	0.3786	0.043*
H9F	0.8097	0.5242	0.3318	0.043*
C10B	0.8977 (2)	0.50367 (5)	0.13618 (11)	0.0306 (2)
H10D	0.8890	0.4978	0.0609	0.046*
H10E	0.7747	0.4883	0.1399	0.046*
H10F	1.0171	0.4832	0.1903	0.046*

	U11	U22	U33	U12	U13	U23
O1A	0.0509 (5)	0.0197 (3)	0.0321 (4)	−0.0016 (3)	0.0206 (4)	−0.0041 (3)
O2A	0.0432 (5)	0.0283 (4)	0.0244 (4)	−0.0055 (3)	0.0179 (3)	0.0018 (3)
N1A	0.0232 (4)	0.0210 (4)	0.0172 (4)	0.0026 (3)	0.0086 (3)	0.0016 (3)
N2A	0.0196 (3)	0.0201 (3)	0.0165 (3)	0.0004 (3)	0.0082 (3)	−0.0012 (3)
N3A	0.0244 (4)	0.0203 (4)	0.0210 (4)	−0.0024 (3)	0.0092 (3)	−0.0006 (3)
C1A	0.0230 (4)	0.0203 (4)	0.0185 (4)	0.0031 (3)	0.0085 (3)	0.0016 (3)
C2A	0.0161 (4)	0.0199 (4)	0.0152 (4)	0.0017 (3)	0.0067 (3)	0.0005 (3)
C3A	0.0208 (4)	0.0232 (4)	0.0153 (4)	0.0006 (3)	0.0086 (3)	−0.0019 (3)
C4A	0.0204 (4)	0.0216 (4)	0.0182 (4)	−0.0013 (3)	0.0088 (3)	−0.0033 (3)
C5A	0.0174 (4)	0.0188 (4)	0.0187 (4)	−0.0010 (3)	0.0079 (3)	−0.0003 (3)
C6A	0.0175 (4)	0.0208 (4)	0.0157 (4)	−0.0001 (3)	0.0073 (3)	−0.0004 (3)
C7A	0.0149 (3)	0.0201 (4)	0.0145 (4)	0.0004 (3)	0.0061 (3)	−0.0010 (3)
C8A	0.0195 (4)	0.0202 (4)	0.0178 (4)	0.0013 (3)	0.0081 (3)	−0.0011 (3)
C9A	0.0338 (5)	0.0209 (4)	0.0239 (5)	−0.0006 (4)	0.0137 (4)	−0.0044 (4)
C10A	0.0488 (7)	0.0204 (4)	0.0243 (5)	0.0037 (4)	0.0162 (5)	0.0043 (4)
O1B	0.0440 (5)	0.0202 (3)	0.0365 (5)	−0.0034 (3)	0.0192 (4)	0.0045 (3)
O2B	0.0469 (5)	0.0206 (3)	0.0330 (4)	−0.0026 (3)	0.0203 (4)	−0.0061 (3)
N1B	0.0221 (4)	0.0186 (3)	0.0209 (4)	−0.0005 (3)	0.0085 (3)	−0.0020 (3)
N2B	0.0200 (3)	0.0183 (3)	0.0195 (4)	0.0003 (3)	0.0081 (3)	0.0010 (3)
N3B	0.0229 (4)	0.0176 (3)	0.0284 (4)	−0.0011 (3)	0.0106 (3)	−0.0001 (3)
C1B	0.0223 (4)	0.0171 (4)	0.0234 (4)	0.0008 (3)	0.0089 (3)	−0.0009 (3)
C2B	0.0159 (4)	0.0186 (4)	0.0187 (4)	−0.0005 (3)	0.0066 (3)	−0.0011 (3)
C3B	0.0208 (4)	0.0212 (4)	0.0188 (4)	−0.0017 (3)	0.0086 (3)	−0.0003 (3)
C4B	0.0194 (4)	0.0207 (4)	0.0213 (4)	−0.0007 (3)	0.0087 (3)	0.0018 (3)
C5B	0.0174 (4)	0.0160 (4)	0.0233 (4)	−0.0009 (3)	0.0087 (3)	−0.0006 (3)
C6B	0.0180 (4)	0.0181 (4)	0.0198 (4)	−0.0009 (3)	0.0085 (3)	−0.0017 (3)
C7B	0.0157 (3)	0.0173 (4)	0.0186 (4)	−0.0006 (3)	0.0072 (3)	−0.0010 (3)
C8B	0.0206 (4)	0.0190 (4)	0.0209 (4)	0.0009 (3)	0.0079 (3)	0.0014 (3)
C9B	0.0386 (6)	0.0209 (4)	0.0255 (5)	−0.0002 (4)	0.0131 (4)	0.0042 (4)
C10B	0.0433 (6)	0.0176 (4)	0.0334 (6)	−0.0009 (4)	0.0188 (5)	−0.0027 (4)

O1A—N3A	1.2267 (11)	O1B—N3B	1.2272 (11)
O2A—N3A	1.2242 (11)	O2B—N3B	1.2255 (12)
N1A—C1A	1.3111 (12)	N1B—C1B	1.3114 (12)
N1A—C2A	1.3705 (12)	N1B—C2B	1.3686 (12)
N2A—C8A	1.3111 (12)	N2B—C8B	1.3117 (12)
N2A—C7A	1.3717 (11)	N2B—C7B	1.3703 (12)
N3A—C5A	1.4658 (12)	N3B—C5B	1.4646 (12)
C1A—C8A	1.4469 (13)	C1B—C8B	1.4454 (14)
C1A—C10A	1.4956 (14)	C1B—C10B	1.4927 (14)
C2A—C3A	1.4087 (13)	C2B—C7B	1.4062 (13)
C2A—C7A	1.4121 (12)	C2B—C3B	1.4138 (13)
C3A—C4A	1.3722 (13)	C3B—C4B	1.3693 (13)
C3A—H3A	0.9300	C3B—H3B	0.9300
C4A—C5A	1.4014 (13)	C4B—C5B	1.4036 (13)
C4A—H4A	0.9300	C4B—H4B	0.9300
C5A—C6A	1.3691 (13)	C5B—C6B	1.3711 (13)
C6A—C7A	1.4086 (13)	C6B—C7B	1.4066 (12)
C6A—H6A	0.9300	C6B—H6B	0.9300
C8A—C9A	1.4944 (13)	C8B—C9B	1.4978 (14)
C9A—H9A	0.9600	C9B—H9D	0.9600
C9A—H9B	0.9600	C9B—H9E	0.9600
C9A—H9C	0.9600	C9B—H9F	0.9600
C10A—H10A	0.9600	C10B—H10D	0.9600
C10A—H10B	0.9600	C10B—H10E	0.9600
C10A—H10C	0.9600	C10B—H10F	0.9600
C1A—N1A—C2A	117.11 (8)	C1B—N1B—C2B	117.01 (8)
C8A—N2A—C7A	117.13 (8)	C8B—N2B—C7B	116.63 (8)
O2A—N3A—O1A	123.57 (9)	O2B—N3B—O1B	123.47 (9)
O2A—N3A—C5A	118.55 (8)	O2B—N3B—C5B	118.27 (8)
O1A—N3A—C5A	117.88 (8)	O1B—N3B—C5B	118.27 (9)
N1A—C1A—C8A	121.84 (9)	N1B—C1B—C8B	121.99 (9)
N1A—C1A—C10A	118.27 (8)	N1B—C1B—C10B	117.64 (9)
C8A—C1A—C10A	119.90 (9)	C8B—C1B—C10B	120.37 (9)
N1A—C2A—C3A	119.10 (8)	N1B—C2B—C7B	120.87 (8)
N1A—C2A—C7A	121.09 (8)	N1B—C2B—C3B	118.88 (8)
C3A—C2A—C7A	119.80 (8)	C7B—C2B—C3B	120.25 (8)
C4A—C3A—C2A	120.12 (8)	C4B—C3B—C2B	120.38 (9)
C4A—C3A—H3A	119.9	C4B—C3B—H3B	119.8
C2A—C3A—H3A	119.9	C2B—C3B—H3B	119.8
C3A—C4A—C5A	118.70 (8)	C3B—C4B—C5B	118.18 (9)
C3A—C4A—H4A	120.6	C3B—C4B—H4B	120.9
C5A—C4A—H4A	120.6	C5B—C4B—H4B	120.9
C6A—C5A—C4A	123.62 (8)	C6B—C5B—C4B	123.47 (9)
C6A—C5A—N3A	118.66 (8)	C6B—C5B—N3B	117.86 (8)
C4A—C5A—N3A	117.72 (8)	C4B—C5B—N3B	118.67 (8)
C5A—C6A—C7A	117.63 (8)	C5B—C6B—C7B	118.40 (9)
C5A—C6A—H6A	121.2	C5B—C6B—H6B	120.8
C7A—C6A—H6A	121.2	C7B—C6B—H6B	120.8
N2A—C7A—C6A	118.79 (8)	N2B—C7B—C2B	121.76 (8)
N2A—C7A—C2A	121.09 (8)	N2B—C7B—C6B	118.93 (8)
C6A—C7A—C2A	120.12 (8)	C2B—C7B—C6B	119.31 (8)
N2A—C8A—C1A	121.74 (8)	N2B—C8B—C1B	121.72 (9)
N2A—C8A—C9A	118.14 (8)	N2B—C8B—C9B	117.94 (9)
C1A—C8A—C9A	120.12 (8)	C1B—C8B—C9B	120.34 (9)
C8A—C9A—H9A	109.5	C8B—C9B—H9D	109.5
C8A—C9A—H9B	109.5	C8B—C9B—H9E	109.5
H9A—C9A—H9B	109.5	H9D—C9B—H9E	109.5
C8A—C9A—H9C	109.5	C8B—C9B—H9F	109.5
H9A—C9A—H9C	109.5	H9D—C9B—H9F	109.5
H9B—C9A—H9C	109.5	H9E—C9B—H9F	109.5
C1A—C10A—H10A	109.5	C1B—C10B—H10D	109.5
C1A—C10A—H10B	109.5	C1B—C10B—H10E	109.5
H10A—C10A—H10B	109.5	H10D—C10B—H10E	109.5
C1A—C10A—H10C	109.5	C1B—C10B—H10F	109.5
H10A—C10A—H10C	109.5	H10D—C10B—H10F	109.5
H10B—C10A—H10C	109.5	H10E—C10B—H10F	109.5
C2A—N1A—C1A—C8A	0.68 (14)	C2B—N1B—C1B—C8B	0.35 (14)
C2A—N1A—C1A—C10A	−179.74 (9)	C2B—N1B—C1B—C10B	−179.15 (9)
C1A—N1A—C2A—C3A	179.54 (9)	C1B—N1B—C2B—C7B	0.83 (13)
C1A—N1A—C2A—C7A	−0.23 (13)	C1B—N1B—C2B—C3B	−179.19 (9)
N1A—C2A—C3A—C4A	−179.69 (8)	N1B—C2B—C3B—C4B	−178.82 (9)
C7A—C2A—C3A—C4A	0.09 (13)	C7B—C2B—C3B—C4B	1.16 (14)
C2A—C3A—C4A—C5A	−0.42 (14)	C2B—C3B—C4B—C5B	−0.29 (14)
C3A—C4A—C5A—C6A	0.49 (14)	C3B—C4B—C5B—C6B	−0.49 (14)
C3A—C4A—C5A—N3A	−178.99 (8)	C3B—C4B—C5B—N3B	179.24 (8)
O2A—N3A—C5A—C6A	11.04 (13)	O2B—N3B—C5B—C6B	−6.86 (13)
O1A—N3A—C5A—C6A	−168.57 (9)	O1B—N3B—C5B—C6B	173.21 (9)
O2A—N3A—C5A—C4A	−169.46 (9)	O2B—N3B—C5B—C4B	173.39 (9)
O1A—N3A—C5A—C4A	10.93 (13)	O1B—N3B—C5B—C4B	−6.54 (13)
C4A—C5A—C6A—C7A	−0.20 (14)	C4B—C5B—C6B—C7B	0.38 (14)
N3A—C5A—C6A—C7A	179.27 (8)	N3B—C5B—C6B—C7B	−179.35 (8)
C8A—N2A—C7A—C6A	−179.96 (8)	C8B—N2B—C7B—C2B	0.80 (13)
C8A—N2A—C7A—C2A	0.28 (13)	C8B—N2B—C7B—C6B	−179.40 (8)
C5A—C6A—C7A—N2A	−179.91 (8)	N1B—C2B—C7B—N2B	−1.47 (13)
C5A—C6A—C7A—C2A	−0.15 (13)	C3B—C2B—C7B—N2B	178.54 (8)
N1A—C2A—C7A—N2A	−0.27 (13)	N1B—C2B—C7B—C6B	178.72 (8)
C3A—C2A—C7A—N2A	179.96 (8)	C3B—C2B—C7B—C6B	−1.26 (13)
N1A—C2A—C7A—C6A	179.98 (8)	C5B—C6B—C7B—N2B	−179.31 (8)
C3A—C2A—C7A—C6A	0.21 (13)	C5B—C6B—C7B—C2B	0.50 (13)
C7A—N2A—C8A—C1A	0.16 (13)	C7B—N2B—C8B—C1B	0.39 (13)
C7A—N2A—C8A—C9A	179.99 (8)	C7B—N2B—C8B—C9B	−179.77 (9)
N1A—C1A—C8A—N2A	−0.68 (15)	N1B—C1B—C8B—N2B	−1.02 (15)
C10A—C1A—C8A—N2A	179.74 (9)	C10B—C1B—C8B—N2B	178.47 (9)
N1A—C1A—C8A—C9A	179.49 (9)	N1B—C1B—C8B—C9B	179.14 (9)
C10A—C1A—C8A—C9A	−0.08 (14)	C10B—C1B—C8B—C9B	−1.37 (15)

D—H···A	D—H	H···A	D···A	D—H···A
C3A—H3A···N2Ai	0.93	2.56	3.4486 (14)	160
C9B—H9D···O1Bii	0.96	2.58	3.5380 (14)	176
C10A—H10A···O2Ai	0.96	2.38	3.3355 (15)	171

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3A—H3A⋯N2Ai	0.93	2.56	3.4486 (14)	160
C9B—H9D⋯O1Bii	0.96	2.58	3.5380 (14)	176
C10A—H10A⋯O2Ai	0.96	2.38	3.3355 (15)	171

Symmetry codes: (i) ; (ii) .