2-(3-Chloro-1,2-dihydro-pyrazin-2-yl-idene)malononitrile.

In the crystal structure of the title compound, C(7)H(3)ClN(4), neighbouring mol-ecules are linked via pairs of N-H⋯N hydrogen bonds into inversion dimers, thereby forming an R(2) (2)(12) ring motif. With respective average deviations from planarity of 0.009 (1) and 0.006 (1) Å, the pyrazine skeleton and the malononitrile fragment are oriented at an angle of 6.0 (1)° with respect to each other. The mean planes of the pyrazine ring lie either parallel or are inclined at an angle of 68.5 (1)° in the crystal structure.

Related literature

For applications of this class of compounds, see: Daniel et al. (1947 ▶); Dutcher (1947 ▶, 1958 ▶); Matter et al. (2005 ▶); Kaliszan et al. (1985 ▶); Lampen & Jones (1946 ▶); Petrusewicz et al. (1993 ▶, 1995 ▶); White (1940 ▶); White & Hill (1943 ▶). For related structures, see: Vishweshwar et al. (2000 ▶); Wardell et al. (2006 ▶). For the synthesis, see: Pilarski & Foks (1981 ▶, 1982 ▶). For the analysis of inter­molecular inter­actions, see: Spek (2009 ▶).

Experimental

Crystal data

C7H3ClN4

M = 178.58

Monoclinic,

a = 5.7612 (2) Å

b = 8.1457 (2) Å

c = 16.2296 (5) Å

β = 94.116 (3)°

V = 759.67 (4) Å3

Z = 4

Mo Kα radiation

μ = 0.44 mm−1

T = 295 K

0.40 × 0.10 × 0.08 mm

Data collection

Oxford Diffraction Ruby CCD diffractometer

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T min = 0.946, T max = 0.967

6880 measured reflections

1335 independent reflections

1060 reflections with I > 2σ(I)

R int = 0.026

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.084

S = 1.10

1335 reflections

109 parameters

H-atom parameters constrained

Δρmax = 0.15 e Å−3

Δρmin = −0.19 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809006783/xu2486sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809006783/xu2486Isup2.hkl

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

C7H3ClN4	F(000) = 360
Mr = 178.58	Dx = 1.561 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1335 reflections
a = 5.7612 (2) Å	θ = 3.0–25.0°
b = 8.1457 (2) Å	µ = 0.44 mm−1
c = 16.2296 (5) Å	T = 295 K
β = 94.116 (3)°	Needle, orange
V = 759.67 (4) Å3	0.40 × 0.10 × 0.08 mm
Z = 4

Oxford Diffraction Ruby CCD diffractometer	1335 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1060 reflections with I > 2σ(I)
graphite	Rint = 0.026
Detector resolution: 10.4002 pixels mm-1	θmax = 25.0°, θmin = 3.6°
ω scans	h = −6→6
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)	k = −9→9
Tmin = 0.946, Tmax = 0.967	l = −18→19
6880 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.030	H-atom parameters constrained
wR(F2) = 0.084	w = 1/[σ2(Fo2) + (0.0481P)2 + 0.0305P] where P = (Fo2 + 2Fc2)/3
S = 1.10	(Δ/σ)max < 0.001
1335 reflections	Δρmax = 0.14 e Å−3
109 parameters	Δρmin = −0.19 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008)
Primary atom site location: structure-invariant direct methods

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 > 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.

	x	y	z	Uiso*/Ueq
N1	0.6636 (3)	0.11965 (16)	0.38343 (8)	0.0365 (4)
H1	0.7797	0.0722	0.4098	0.044*
C2	0.5179 (3)	0.20873 (19)	0.42756 (10)	0.0313 (4)
C3	0.3266 (3)	0.2760 (2)	0.37691 (10)	0.0373 (4)
N4	0.2971 (3)	0.25960 (19)	0.29792 (10)	0.0523 (5)
C5	0.4568 (4)	0.1719 (3)	0.25856 (12)	0.0611 (6)
H5	0.4395	0.1613	0.2014	0.073*
C6	0.6386 (4)	0.1004 (2)	0.30035 (11)	0.0508 (5)
H6	0.7452	0.0389	0.2730	0.061*
C7	0.5634 (3)	0.22285 (19)	0.51338 (9)	0.0327 (4)
C8	0.7584 (3)	0.13941 (19)	0.55144 (10)	0.0343 (4)
N9	0.9152 (3)	0.0691 (2)	0.58089 (9)	0.0467 (4)
C10	0.4414 (3)	0.3217 (2)	0.56834 (11)	0.0383 (4)
N11	0.3624 (3)	0.3981 (2)	0.61843 (11)	0.0568 (5)
Cl12	0.11485 (8)	0.38509 (6)	0.42290 (3)	0.0490 (2)

	U11	U22	U33	U12	U13	U23
N1	0.0352 (9)	0.0416 (8)	0.0323 (8)	0.0067 (7)	0.0001 (6)	0.0014 (6)
C2	0.0292 (9)	0.0286 (8)	0.0364 (9)	−0.0016 (7)	0.0034 (7)	0.0010 (7)
C3	0.0358 (10)	0.0344 (9)	0.0413 (10)	0.0015 (8)	−0.0009 (8)	0.0016 (7)
N4	0.0591 (12)	0.0544 (10)	0.0416 (9)	0.0133 (9)	−0.0099 (8)	−0.0002 (7)
C5	0.0793 (17)	0.0700 (14)	0.0324 (10)	0.0224 (13)	−0.0072 (11)	−0.0037 (9)
C6	0.0608 (14)	0.0565 (11)	0.0351 (10)	0.0137 (10)	0.0041 (9)	−0.0041 (8)
C7	0.0303 (10)	0.0330 (8)	0.0348 (9)	0.0012 (7)	0.0017 (7)	0.0013 (7)
C8	0.0379 (11)	0.0348 (9)	0.0302 (9)	−0.0012 (8)	0.0037 (8)	−0.0034 (7)
N9	0.0460 (11)	0.0536 (9)	0.0397 (9)	0.0108 (8)	−0.0029 (8)	−0.0034 (7)
C10	0.0341 (11)	0.0440 (10)	0.0366 (10)	0.0007 (8)	0.0016 (8)	0.0025 (8)
N11	0.0539 (11)	0.0717 (11)	0.0456 (10)	0.0135 (9)	0.0088 (8)	−0.0075 (8)
Cl12	0.0368 (3)	0.0530 (3)	0.0568 (3)	0.0114 (2)	0.0017 (2)	0.0011 (2)

N1—C2	1.353 (2)	C5—C6	1.339 (3)
N1—C6	1.355 (2)	C5—H5	0.9300
N1—H1	0.8600	C6—H6	0.9300
C2—C7	1.403 (2)	C7—C8	1.416 (2)
C2—C3	1.436 (2)	C7—C10	1.424 (2)
C3—N4	1.288 (2)	C8—N9	1.145 (2)
C3—Cl12	1.7219 (18)	C10—N11	1.144 (2)
N4—C5	1.360 (3)
C2—N1—C6	124.28 (15)	C6—C5—H5	119.3
C2—N1—H1	117.9	N4—C5—H5	119.3
C6—N1—H1	117.9	C5—C6—N1	118.50 (18)
N1—C2—C7	119.36 (15)	C5—C6—H6	120.8
N1—C2—C3	112.43 (15)	N1—C6—H6	120.8
C7—C2—C3	128.20 (16)	C2—C7—C8	118.66 (14)
N4—C3—C2	124.83 (17)	C2—C7—C10	127.03 (15)
N4—C3—Cl12	116.00 (14)	C8—C7—C10	114.20 (14)
C2—C3—Cl12	119.16 (13)	N9—C8—C7	178.40 (18)
C3—N4—C5	118.48 (16)	N11—C10—C7	172.83 (19)
C6—C5—N4	121.43 (18)
C6—N1—C2—C7	−178.76 (16)	C3—N4—C5—C6	1.5 (3)
C6—N1—C2—C3	2.4 (2)	N4—C5—C6—N1	−1.2 (3)
N1—C2—C3—N4	−2.1 (3)	C2—N1—C6—C5	−0.9 (3)
C7—C2—C3—N4	179.14 (17)	N1—C2—C7—C8	−1.6 (2)
N1—C2—C3—Cl12	176.92 (11)	C3—C2—C7—C8	177.09 (16)
C7—C2—C3—Cl12	−1.8 (3)	N1—C2—C7—C10	174.39 (16)
C2—C3—N4—C5	0.3 (3)	C3—C2—C7—C10	−6.9 (3)
Cl12—C3—N4—C5	−178.77 (15)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N9i	0.86	2.10	2.896 (2)	154

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N9i	0.86	2.10	2.896 (2)	154

Symmetry code: (i) .