2,3-Di­methyl­quinoxaline–di­methyl­glyoxime (1/1)

The title compound, C₁₀H₁₀N₂·C₄H₈N₂O₂, consists of hydrogen-bonded 2,3-di­methyl­quinoxaline and di­methyl­glyoxime mol­ecules. Both di­methyl­glyoximes are located on an inversion centre and there are two half-mol­ecules in the asymmetric unit. The di­methyl­glyoxime mol­ecules are linked about inversion centres to the 2,3-di­methyl­quinoxaline moiety by O—H...N hydrogen bonds (O...N 2.898 and 2.805 Å) to form polymeric chains.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.046
• wR factor = 0.133
• Data-to-parameter ratio = 14.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



PLAT_726  Alert A H...A   Calc    13.00(2), Rep     2.04510, Dev.     10.95 Ang.
                     H1   -N2      1.555   1.546

PLAT_727  Alert A D...A   Calc   12.230(3), Rep     2.89770, Dev.      9.33 Ang.
                     O1   -N2      1.555   1.546

PLAT_728  Alert A D-H..A  Calc    24.9(16), Rep      176.30, Dev.    151.40 Deg.
                     O1   -H1   -N2      1.555   1.555   1.546


 Alert Level C:



PLAT_745  Alert C D-H     Calc     0.85(2), Rep     0.85390 ....    Missing s.u.
                     O1   -H1      1.555   1.555

PLAT_745  Alert C D-H     Calc     0.81(2), Rep     0.81800 ....    Missing s.u.
                     O2   -H2      1.555   1.555

PLAT_746  Alert C H...A   Calc     2.00(2), Rep     1.99170 ....    Missing s.u.
                     H2   -N3      1.555   1.555

PLAT_747  Alert C D...A   Calc    2.805(2), Rep     2.80530 ....    Missing s.u.
                     O2   -N3      1.555   1.555

PLAT_748  Alert C D-H..A  Calc      173(2), Rep      172.85 ....    Missing s.u.
                     O2   -H2   -N3      1.555   1.555   1.555


 3 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 5 Alert Level C = Please check

---

S1. Comment

Intermolecular hydrogen bonding has received considerable attention among the directional non-covalent intermolecular interactions (Etter et al., 1990), which combines moderate strength and directionality (Karle et al., 1996) in designing the compounds to form supramolecular structures.

Oxime (–C═N—OH) groups possess stronger hydrogen-bonding capabilities than alcohols, phenols and carboxylic acids (Marsman et al., 1999). The hydrogen-bond systems in the crystals of oximes have been analysed and a correlation between a pattern of hydrogen bonding and N—O bond lengths is suggested (Bertolasi et al., 1982). The configurational and/or conformational isomers of glyoxime derivatives (dioximes) have also been analysed (Chertanova et al., 1994).

Oxime/oximato metal complexes have been investigated actively since the beginning of the last century of the millennium (Kukushkin & Pombeiro, 1999). In general, oxime and dioxime derivatives are very important compounds in chemical industry and medicine. Dimethylglyoxime is actually the first selective organic reagent applied in the analysis of metals (Tshugaeff, 1905).

Crystals of dimethylglyoxime were reported by McCrone (1949) to be triclinic and its structure was undertaken by Merritt & Lanterman (1952). A neutron diffraction refinement of the crystal structure of the dimethylgluoxime clarified the existence of the O—H (classical structure) bonding rather than N—H (zwitterion structure) (Hamilton, 1961).

Quinoxaline derivatives are very useful compounds with well known biological activities (Cheeseman & Werstiuk, 1978; Sato, 1996). Some of the quinoxaline derivatives act as in vitro anticancer compounds (Corona et al., 1998).

The structure of 2,3-dimethylquinoxaline was reported by Wozniak et al., (1990) to be monoclinic. The crystal structures containing 2,3-disubstituted derivatives of quinoxaline have aroused considerable interest because of the repulsions between the neighbouring substituents (Visser et al., 1968; Visser & Vos, 1971; Lipkovski et al., 1985; Krigier et al., 1985).

The crystal structure determination of the title molecule, (I), was carried out in order to understand the strength of the hydrogen-bonding capabilities of the oxime groups having the classical (–C═N—O—H) structures. As shown in Fig. 1, the title compound, (I), consists of hydrogen-bonded 2,3-dimethylquinoxaline and dimethylglyoxime moieties. Both dimethylglyoximes are located on an inversion centre and there are two half-molecules in the asymmetric unit.

The bond lengths and angles of the 2,3-dimethylquinoxaline moiety are in accordance with the reported values (Wozniak et al., 1990).

In the dimethylglyoxime moieties, the O—N, C═N, C—C bond lengths and C═N—O bond angles are larger, while the O—H, C—C' bonds and N—O—H, C—C═N, C'-C═N angles are smaller than the corresponding ones, reported in dimethylglyoxime (Hamilton, 1961) (Table 2). A comparison of the bond lengths and angles of the dimethylgluoxime moieties in the title compound, (I), with the corresponding ones in dimethylglyoxime, (II) (Hamilton, 1961), nickel dimethylglyoxime, (III) (Godkycki & Rundle, 1953), copper dimethylglyoxime, (IV) (Frasson et al., 1959) and acetoxime, (V) (Bierlein & Lingafelter, 1951), are given in Table 2.

As can be seen from the packing diagram (Fig. 2), there are intermolecular hydrogen bonds between the hydroxy H atoms of the dimethylglyoxime and N atoms of the 2,3-dimethylquinoxaline moieties (Table 3). The intermolecular hydrogen bonds are highly effective in forming the polymeric chains. Dipole-dipole and van der Waals interactions are also effective in the molecular packing.

An examination of the deviations from the least-squares planes through the individual rings shows that rings A (C5—C10) and B (C5/N2/C3/C11/N3/C10) are nearly planar with maximum deviations for the C5 [-0.007 (2) Å] and C5 [0.016 (2) Å] atoms, respectively.

S2. Experimental

The title compound, (I), was prepared from a mixture of 2,3-butaneidone monoxime (2.02 g, 20.0 mmol), o-phenylendiamine (1.08 g, 10.0 mmol) and Na₂SO₄ (2.84 g, 20.0 mmol) in ethanol (30 ml). The mixture was heated at 343 K for 6 h. The solution was filtered and allowed to stand overnight in a refrigerator. The resulting precipitate was filtered and then recrystallized from 1,4-dioxane.

S3. Refinement

The oxime H atoms were located from a difference map and refined isotropically; the positions of the remaining H atoms were calculated geometrically at distances of 0.93 (CH) and 0.96 Å (CH₃) from the corresponding C atoms, and a riding model was used during the refinement process. The H atoms of the C2 and C13 methyl groups are disordered.

Computing details

Data collection: MolEN (Fair, 1990); cell refinement: MolEN; data reduction: MolEN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: MolEN.

Figures

	Fig. 1. An ORTEPII (Johnson, 1976) drawing of the title molecule with the atom-numbering scheme. The displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The packing diagram for (I). Hydrogen bonds are shown as dotted lines.

(I)

Crystal data

C10H10N2·C4H8N2O2	Z = 2
Mr = 274.32	F(000) = 292
Triclinic, P1	Dx = 1.283 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.9814 (10) Å	Cell parameters from 25 reflections
b = 8.2719 (10) Å	θ = 10–11°
c = 12.168 (3) Å	µ = 0.09 mm^−1
α = 91.779 (18)°	T = 294 K
β = 106.668 (14)°	Rod-shaped, yellow
γ = 111.018 (10)°	0.30 × 0.25 × 0.20 mm
V = 710.3 (2) Å^3

Data collection

Enraf-Nonius CAD-4 diffractometer	2244 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 26.3°, θmin = 2.7°
ω/2θ scans	h = 0→9
Absorption correction: ψ scan (Fair, 1990)	k = −10→9
Tmin = 0.974, Tmax = 0.982	l = −15→14
2884 measured reflections	3 standard reflections every 120 min
2884 independent reflections	intensity decay: 1%

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.133	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0745P)^2 + 0.0913P] where P = (Fo^2 + 2Fc^2)/3
2884 reflections	(Δ/σ)max < 0.001
193 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.23 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.

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)
C1	0.41475 (19)	−0.03235 (18)	0.44813 (11)	0.0359 (3)
C3	0.27915 (19)	0.05366 (18)	−0.04196 (12)	0.0337 (3)
C5	0.53352 (19)	0.26909 (18)	0.09310 (12)	0.0343 (3)
C10	0.6008 (2)	0.34364 (18)	0.00366 (12)	0.0347 (3)
C11	0.3451 (2)	0.13324 (19)	−0.13348 (12)	0.0366 (3)
C14	0.5746 (2)	0.51620 (19)	−0.44390 (12)	0.0414 (4)
N1	0.43691 (17)	0.03273 (16)	0.35668 (10)	0.0403 (3)
N2	0.37163 (16)	0.12052 (15)	0.06745 (10)	0.0351 (3)
N3	0.50272 (17)	0.27221 (16)	−0.10997 (10)	0.0384 (3)
N4	0.5232 (2)	0.42225 (18)	−0.36865 (11)	0.0480 (3)
O1	0.27003 (15)	−0.03360 (16)	0.26142 (9)	0.0512 (3)
O2	0.67083 (19)	0.45902 (19)	−0.26459 (11)	0.0635 (4)
C2	0.2332 (2)	−0.1654 (2)	0.45309 (14)	0.0538 (5)
H2A	0.1363	−0.1868	0.3798	0.081*	0.50
H2B	0.1968	−0.1226	0.5130	0.081*	0.50
H2C	0.2498	−0.2724	0.4696	0.081*	0.50
H2D	0.2523	−0.2011	0.5285	0.081*	0.50
H2E	0.1918	−0.2653	0.3953	0.081*	0.50
H2F	0.1388	−0.1154	0.4387	0.081*	0.50
C4	0.1028 (2)	−0.10884 (19)	−0.07081 (14)	0.0443 (4)
H4A	0.0866	−0.1514	−0.0005	0.066*
H4B	0.1132	−0.1967	−0.1189	0.066*
H4C	−0.0044	−0.0826	−0.1116	0.066*
C6	0.6350 (2)	0.3473 (2)	0.20883 (13)	0.0439 (4)
H6	0.5904	0.3009	0.2683	0.053*
C7	0.7989 (2)	0.4915 (2)	0.23377 (14)	0.0503 (4)
H7	0.8660	0.5425	0.3106	0.060*
C8	0.8679 (2)	0.5643 (2)	0.14522 (15)	0.0495 (4)
H8	0.9809	0.6618	0.1639	0.059*
C9	0.7705 (2)	0.4932 (2)	0.03228 (14)	0.0440 (4)
H9	0.8159	0.5431	−0.0261	0.053*
C12	0.2337 (2)	0.0600 (2)	−0.25797 (13)	0.0520 (4)
H12A	0.2928	0.1336	−0.3067	0.078*
H12B	0.1071	0.0554	−0.2732	0.078*
H12C	0.2298	−0.0559	−0.2739	0.078*
C13	0.7696 (3)	0.6519 (2)	−0.42280 (16)	0.0601 (5)
H13A	0.8442	0.6635	−0.3434	0.090*	0.50
H13B	0.7613	0.7623	−0.4386	0.090*	0.50
H13C	0.8280	0.6170	−0.4729	0.090*	0.50
H13D	0.7781	0.6984	−0.4932	0.090*	0.50
H13E	0.8611	0.5995	−0.3980	0.090*	0.50
H13F	0.7943	0.7448	−0.3637	0.090*	0.50
H1	0.303 (3)	0.009 (3)	0.2045 (19)	0.071 (6)*
H2	0.619 (3)	0.397 (3)	−0.224 (2)	0.081 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0342 (7)	0.0367 (7)	0.0343 (7)	0.0081 (6)	0.0137 (6)	0.0092 (6)
C3	0.0320 (7)	0.0355 (7)	0.0373 (7)	0.0151 (6)	0.0134 (6)	0.0086 (6)
C5	0.0334 (7)	0.0351 (7)	0.0365 (7)	0.0131 (6)	0.0136 (6)	0.0109 (6)
C10	0.0353 (7)	0.0358 (7)	0.0368 (7)	0.0145 (6)	0.0149 (6)	0.0139 (6)
C11	0.0369 (7)	0.0406 (8)	0.0363 (8)	0.0176 (6)	0.0135 (6)	0.0101 (6)
C14	0.0463 (9)	0.0417 (8)	0.0389 (8)	0.0135 (7)	0.0213 (7)	0.0129 (6)
N1	0.0352 (6)	0.0453 (7)	0.0337 (6)	0.0079 (5)	0.0103 (5)	0.0108 (5)
N2	0.0338 (6)	0.0364 (6)	0.0367 (6)	0.0114 (5)	0.0159 (5)	0.0121 (5)
N3	0.0391 (7)	0.0437 (7)	0.0356 (7)	0.0157 (6)	0.0162 (5)	0.0141 (5)
N4	0.0506 (8)	0.0569 (8)	0.0367 (7)	0.0165 (6)	0.0188 (6)	0.0171 (6)
O1	0.0396 (6)	0.0650 (7)	0.0332 (6)	0.0050 (5)	0.0071 (5)	0.0153 (5)
O2	0.0572 (8)	0.0833 (9)	0.0411 (7)	0.0148 (7)	0.0164 (6)	0.0293 (6)
C2	0.0382 (8)	0.0633 (10)	0.0411 (9)	−0.0015 (7)	0.0113 (7)	0.0172 (7)
C4	0.0377 (8)	0.0417 (8)	0.0493 (9)	0.0091 (7)	0.0158 (7)	0.0057 (7)
C6	0.0466 (9)	0.0458 (8)	0.0364 (8)	0.0113 (7)	0.0168 (7)	0.0109 (6)
C7	0.0489 (9)	0.0466 (9)	0.0402 (8)	0.0067 (7)	0.0073 (7)	0.0018 (7)
C8	0.0401 (8)	0.0393 (8)	0.0572 (10)	0.0028 (7)	0.0141 (7)	0.0090 (7)
C9	0.0401 (8)	0.0419 (8)	0.0491 (9)	0.0098 (7)	0.0199 (7)	0.0169 (7)
C12	0.0539 (10)	0.0612 (10)	0.0348 (8)	0.0166 (8)	0.0122 (7)	0.0065 (7)
C13	0.0506 (10)	0.0640 (11)	0.0518 (10)	0.0051 (9)	0.0163 (8)	0.0210 (8)

Geometric parameters (Å, º)

C1—N1	1.2811 (18)	C2—H2D	0.9600
C1—C1^i	1.477 (3)	C2—H2E	0.9600
C1—C2	1.491 (2)	C2—H2F	0.9600
C3—N2	1.3119 (18)	C4—H4A	0.9600
C3—C11	1.4434 (19)	C4—H4B	0.9600
C3—C4	1.497 (2)	C4—H4C	0.9600
C5—N2	1.3723 (18)	C6—C7	1.363 (2)
C5—C6	1.404 (2)	C6—H6	0.9300
C5—C10	1.4114 (19)	C7—C8	1.403 (2)
C10—N3	1.3676 (19)	C7—H7	0.9300
C10—C9	1.410 (2)	C8—C9	1.359 (2)
C11—N3	1.3123 (19)	C8—H8	0.9300
C11—C12	1.495 (2)	C9—H9	0.9300
C14—N4	1.2813 (19)	C12—H12A	0.9600
C14—C14^ii	1.473 (3)	C12—H12B	0.9600
C14—C13	1.499 (2)	C12—H12C	0.9600
N1—O1	1.4033 (16)	C13—H13A	0.9600
N4—O2	1.3956 (18)	C13—H13B	0.9600
O1—H1	0.85 (2)	C13—H13C	0.9600
O2—H2	0.82 (2)	C13—H13D	0.9600
C2—H2A	0.9600	C13—H13E	0.9600
C2—H2B	0.9600	C13—H13F	0.9600
C2—H2C	0.9600
N1—C1—C1^i	115.18 (15)	C3—C4—H4A	109.5
N1—C1—C2	124.09 (13)	C3—C4—H4B	109.5
C1^i—C1—C2	120.73 (15)	H4A—C4—H4B	109.5
N2—C3—C11	121.25 (12)	C3—C4—H4C	109.5
N2—C3—C4	118.64 (12)	H4A—C4—H4C	109.5
C11—C3—C4	120.12 (13)	H4B—C4—H4C	109.5
N2—C5—C6	120.23 (12)	C7—C6—C5	119.83 (14)
N2—C5—C10	120.40 (13)	C7—C6—H6	120.1
C6—C5—C10	119.37 (13)	C5—C6—H6	120.1
N3—C10—C9	119.98 (13)	C6—C7—C8	120.96 (15)
N3—C10—C5	120.59 (13)	C6—C7—H7	119.5
C9—C10—C5	119.43 (13)	C8—C7—H7	119.5
N3—C11—C3	121.11 (13)	C9—C8—C7	120.41 (14)
N3—C11—C12	118.26 (13)	C9—C8—H8	119.8
C3—C11—C12	120.63 (13)	C7—C8—H8	119.8
N4—C14—C14^ii	115.03 (17)	C8—C9—C10	119.99 (14)
N4—C14—C13	124.25 (15)	C8—C9—H9	120.0
C14^ii—C14—C13	120.72 (16)	C10—C9—H9	120.0
C1—N1—O1	112.39 (12)	C11—C12—H12A	109.5
C3—N2—C5	118.23 (11)	C11—C12—H12B	109.5
C11—N3—C10	118.35 (12)	H12A—C12—H12B	109.5
C14—N4—O2	112.15 (13)	C11—C12—H12C	109.5
N1—O1—H1	104.5 (14)	H12A—C12—H12C	109.5
N4—O2—H2	102.4 (16)	H12B—C12—H12C	109.5
C1—C2—H2A	109.5	C14—C13—H13A	109.5
C1—C2—H2B	109.5	C14—C13—H13B	109.5
H2A—C2—H2B	109.5	H13A—C13—H13B	109.5
C1—C2—H2C	109.5	C14—C13—H13C	109.5
H2A—C2—H2C	109.5	H13A—C13—H13C	109.5
H2B—C2—H2C	109.5	H13B—C13—H13C	109.5
C1—C2—H2D	109.5	C14—C13—H13D	109.5
H2A—C2—H2D	141.1	H13A—C13—H13D	141.1
H2B—C2—H2D	56.3	H13B—C13—H13D	56.3
H2C—C2—H2D	56.3	H13C—C13—H13D	56.3
C1—C2—H2E	109.5	C14—C13—H13E	109.5
H2A—C2—H2E	56.3	H13A—C13—H13E	56.3
H2B—C2—H2E	141.1	H13B—C13—H13E	141.1
H2C—C2—H2E	56.3	H13C—C13—H13E	56.3
H2D—C2—H2E	109.5	H13D—C13—H13E	109.5
C1—C2—H2F	109.5	C14—C13—H13F	109.5
H2A—C2—H2F	56.3	H13A—C13—H13F	56.3
H2B—C2—H2F	56.3	H13B—C13—H13F	56.3
H2C—C2—H2F	141.1	H13C—C13—H13F	141.1
H2D—C2—H2F	109.5	H13D—C13—H13F	109.5
H2E—C2—H2F	109.5	H13E—C13—H13F	109.5
N2—C5—C10—N3	2.0 (2)	C3—C11—N3—C10	−2.0 (2)
C6—C5—C10—N3	−178.67 (13)	C12—C11—N3—C10	177.37 (13)
N2—C5—C10—C9	−178.06 (13)	C9—C10—N3—C11	−179.87 (13)
C6—C5—C10—C9	1.3 (2)	C5—C10—N3—C11	0.1 (2)
N2—C3—C11—N3	2.0 (2)	C14^ii—C14—N4—O2	179.87 (16)
C4—C3—C11—N3	−177.63 (13)	C13—C14—N4—O2	−0.8 (2)
N2—C3—C11—C12	−177.35 (14)	N2—C5—C6—C7	177.88 (14)
C4—C3—C11—C12	3.0 (2)	C10—C5—C6—C7	−1.5 (2)
C1^i—C1—N1—O1	−179.87 (14)	C5—C6—C7—C8	0.4 (3)
C2—C1—N1—O1	0.8 (2)	C6—C7—C8—C9	0.9 (3)
C11—C3—N2—C5	0.1 (2)	C7—C8—C9—C10	−1.1 (3)
C4—C3—N2—C5	179.73 (12)	N3—C10—C9—C8	179.93 (14)
C6—C5—N2—C3	178.68 (13)	C5—C10—C9—C8	0.0 (2)
C10—C5—N2—C3	−2.0 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N2^iii	0.8539	2.0451	2.8977	176.30
O2—H2···N3	0.8180	1.9917	2.8053	172.85

Symmetry code: (iii) x, y−1, z+1.