trans-1-Cyano-2-(2-methoxy­phenyl)-1-nitro­ethyl­ene

The title compound, C₁₀H₈N₂O₃, has been prepared by condensation of 2-methoxy­benz­aldehyde and nitro­aceto­nitrile in ethanol at room temperature. Its investigation has been undertaken as a part of search for new nonlinear optical compounds. The [pi]-conjugated mol­ecule is almost planar. Molecules in the crystal are packed in stacks with antiparallel molecular orientation and slightly alternating distances between mean molecular planes.

S1. Comment

Organic non-linear optical (NLO) crystals are attracting attention of chemists, physicists, optical and device scientists because of their superiority to the conventional inorganic crystals (see, for instance, Zyss, 1994). The present work is part of our project on synthesis, structure investigation and property evaluation of organic potential NLO compounds. Recently, we investigated a series of polarized molecules having a dicyanovinyl acceptor part and various donors connected by π-conjugated chains of different length. There are derivatives of 2-aryl-1,1-dicyanovinyl and 4-aryl-1,1-dicyano-1,3-butadiene (Antipin et al., 1997; Antipin, Clark et al., 1998; Antipin, Timofeeva et al., 1998; Timofeeva et al., 2000: Nesterov et al., 2000). We present herein a structural investigation of the title compound, (I), which molecules have another type of acceptor group.

The molecule of (I) is almost planar. The dihedral angle between o-methoxyphenyl and 1-cyanoethylene moieties is 1.90 (7)° and the dihedral angle between the 1-cyanoethylene moiety and the nitro group is 2.40 (6)°. The mean deviations from the least-squares plane passing through all non-H atoms in molecule (I) is 0.024 (3) Å. The 1-cyano-1-nitroethylene fragment in (I) is almost coplanar with the o-methoxyphenyl moiety despite the shortened intramolecular contact H6A···C9 of 2.472 Å (van der Waals radii sum is 2.87 Å; Rowland & Taylor, 1996). Planarity of this molecule indicates a significant level of π-conjugation in this system.

Bond lengths in molecule (I) do not differ significantly from those found in the other derivatives of 2-aryl-1,1-dicyanoethylene (Antipin, Clark et al., 1998) and are close to the standard bond lengths (Allen et al., 1987) in corresponding π-conjugated systems.

The H7A atom in (I) has a short non-bonded contact with the O atoms of methoxy and nitro groups: H7A···O1 2.236 Å and H7A···O2 2.309 Å (van der Waals radii sum is 2.68 Å; Rowland & Taylor, 1996).

The molecules in the crystal are packed in stacks along a, with antiparallel molecular orientation inside them. The interplanar distances in these stacks are slightly alternating, and are equal to 3.37 (7) and 3.41 (8) Å.

The title compound crystallizes in a centrosymmetric space group and therefore has no NLO properties (second harmonic generation) in the crystalline state.

S2. Experimental

The title compound was obtained by the reaction of 2-methoxybenzaldehyde (0.005 mol) with nitroacetonitrile (0.005 mol) in the presence of a catalytic amount of morpholine in 20 ml e thanol at room temperature (Mechkov & Demireva, 1985). Light-yellow crystals were obtained by isothermic evaporation from a solution in ethanol.

Computing details

Data collection: P3 (Siemens, 1989); cell refinement: P3; data reduction: SHELXL97 (Sheldrick, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

(I)

Crystal data

C10H8N2O3	F(000) = 424
Mr = 204.18	Dx = 1.398 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.1952 (13) Å	Cell parameters from 24 reflections
b = 17.356 (3) Å	θ = 10–11°
c = 8.3298 (16) Å	µ = 0.11 mm^−1
β = 111.148 (14)°	T = 298 K
V = 970.2 (3) Å^3	Prosm, light-yellow
Z = 4	0.45 × 0.30 × 0.25 mm

Data collection

Siemens P3/PC diffractometer	Rint = 0.021
Radiation source: fine-focus sealed tube	θmax = 29.1°, θmin = 2.4°
Graphite monochromator	h = 0→9
/q/2/q scans	k = 0→23
2776 measured reflections	l = −11→10
2592 independent reflections	2 standard reflections every 98 reflections
1664 reflections with I > 2σ(I)	intensity decay: 5%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.055	H-atom parameters constrained
wR(F^2) = 0.140	w = 1/[σ^2(Fo^2) + (0.0615P)^2 + 0.0957P] where P = (Fo^2 + 2Fc^2)/3
S = 1.11	(Δ/σ)max < 0.001
2592 reflections	Δρmax = 0.25 e Å^−3
137 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.049 (6)

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. All H atoms were positioned geometrically and thereafter refined using a riding model.

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

	x	y	z	Uiso*/Ueq
O1	0.8919 (2)	0.56821 (7)	0.29503 (14)	0.0682 (4)
O2	0.9569 (2)	0.33299 (7)	0.13498 (18)	0.0702 (4)
O3	0.8233 (2)	0.28651 (7)	−0.12090 (19)	0.0765 (4)
N1	0.8559 (2)	0.33904 (7)	−0.01625 (19)	0.0504 (4)
N2	0.5721 (4)	0.41135 (11)	−0.4071 (2)	0.0912 (6)
C1	0.7159 (2)	0.54977 (8)	0.00106 (18)	0.0384 (3)
C2	0.7712 (2)	0.59941 (9)	0.14553 (19)	0.0448 (4)
C3	0.7043 (3)	0.67504 (9)	0.1274 (2)	0.0552 (4)
H3A	0.7416	0.7077	0.2222	0.066*
C4	0.5825 (3)	0.70139 (9)	−0.0316 (2)	0.0571 (5)
H4A	0.5373	0.7520	−0.0432	0.069*
C5	0.5262 (3)	0.65395 (10)	−0.1742 (2)	0.0559 (4)
H5A	0.4434	0.6725	−0.2807	0.067*
C6	0.5930 (2)	0.57938 (9)	−0.15779 (19)	0.0466 (4)
H6A	0.5557	0.5478	−0.2545	0.056*
C7	0.7891 (2)	0.47199 (8)	0.02849 (18)	0.0388 (3)
H7A	0.8660	0.4602	0.1420	0.047*
C8	0.7650 (2)	0.41398 (8)	−0.08206 (18)	0.0409 (3)
C9	0.6585 (3)	0.41243 (10)	−0.2627 (2)	0.0563 (5)
C10	0.9523 (4)	0.61460 (13)	0.4490 (2)	0.0882 (7)
H10A	1.0374	0.5849	0.5444	0.132*
H10B	0.8365	0.6307	0.4717	0.132*
H10C	1.0231	0.6591	0.4334	0.132*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0923 (10)	0.0515 (7)	0.0395 (6)	0.0071 (7)	−0.0021 (6)	−0.0140 (5)
O2	0.0887 (10)	0.0487 (7)	0.0616 (8)	0.0145 (7)	0.0131 (7)	0.0105 (6)
O3	0.0994 (11)	0.0370 (7)	0.0875 (10)	0.0049 (6)	0.0269 (8)	−0.0164 (6)
N1	0.0582 (8)	0.0338 (7)	0.0595 (9)	0.0000 (6)	0.0216 (7)	0.0001 (6)
N2	0.1381 (17)	0.0702 (12)	0.0465 (9)	0.0079 (12)	0.0107 (10)	−0.0110 (8)
C1	0.0451 (8)	0.0313 (7)	0.0387 (7)	−0.0033 (6)	0.0151 (6)	−0.0013 (5)
C2	0.0534 (9)	0.0370 (8)	0.0412 (8)	−0.0027 (6)	0.0137 (7)	−0.0035 (6)
C3	0.0739 (11)	0.0355 (8)	0.0597 (10)	−0.0052 (8)	0.0283 (9)	−0.0110 (7)
C4	0.0780 (12)	0.0321 (8)	0.0692 (11)	0.0059 (7)	0.0362 (10)	0.0081 (7)
C5	0.0723 (11)	0.0438 (9)	0.0526 (10)	0.0092 (8)	0.0236 (8)	0.0145 (7)
C6	0.0611 (10)	0.0380 (8)	0.0387 (8)	0.0012 (7)	0.0156 (7)	0.0025 (6)
C7	0.0434 (8)	0.0345 (7)	0.0352 (7)	−0.0031 (6)	0.0103 (6)	−0.0010 (6)
C8	0.0487 (8)	0.0333 (7)	0.0397 (8)	−0.0016 (6)	0.0147 (6)	0.0000 (6)
C9	0.0784 (12)	0.0411 (9)	0.0453 (9)	0.0001 (8)	0.0175 (9)	−0.0088 (7)
C10	0.1118 (18)	0.0805 (15)	0.0474 (11)	0.0061 (13)	−0.0011 (11)	−0.0300 (10)

Geometric parameters (Å, º)

O1—C2	1.3483 (18)	C1—C7	1.437 (2)
O1—C10	1.442 (2)	C2—C3	1.388 (2)
O2—N1	1.2106 (18)	C3—C4	1.376 (3)
O3—N1	1.2242 (17)	C4—C5	1.380 (2)
N1—C8	1.4701 (19)	C5—C6	1.370 (2)
N2—C9	1.138 (2)	C7—C8	1.3328 (19)
C1—C6	1.397 (2)	C8—C9	1.421 (2)
C1—C2	1.4153 (19)
C2—O1—C10	118.95 (14)	C4—C3—C2	119.64 (15)
O2—N1—O3	124.41 (14)	C3—C4—C5	121.14 (15)
O2—N1—C8	118.96 (13)	C6—C5—C4	119.63 (16)
O3—N1—C8	116.63 (14)	C5—C6—C1	121.40 (15)
C6—C1—C2	117.98 (13)	C8—C7—C1	130.60 (14)
C6—C1—C7	124.51 (13)	C7—C8—C9	129.19 (15)
C2—C1—C7	117.51 (13)	C7—C8—N1	118.76 (13)
O1—C2—C3	124.26 (14)	C9—C8—N1	112.05 (13)
O1—C2—C1	115.52 (13)	N2—C9—C8	179.5 (2)
C3—C2—C1	120.22 (14)
C10—O1—C2—C3	2.1 (3)	C7—C1—C6—C5	179.04 (16)
C10—O1—C2—C1	−178.88 (18)	C6—C1—C7—C8	1.9 (3)
C6—C1—C2—O1	−179.18 (14)	C2—C1—C7—C8	−178.55 (16)
C7—C1—C2—O1	1.3 (2)	C1—C7—C8—C9	0.4 (3)
C6—C1—C2—C3	−0.1 (2)	C1—C7—C8—N1	−178.99 (14)
C7—C1—C2—C3	−179.64 (15)	O2—N1—C8—C7	−3.0 (2)
O1—C2—C3—C4	179.49 (16)	O3—N1—C8—C7	177.13 (15)
C1—C2—C3—C4	0.5 (3)	O2—N1—C8—C9	177.48 (16)
C2—C3—C4—C5	−0.3 (3)	O3—N1—C8—C9	−2.3 (2)
C3—C4—C5—C6	−0.2 (3)	C7—C8—C9—N2	−58 (25)
C4—C5—C6—C1	0.6 (3)	N1—C8—C9—N2	121 (25)
C2—C1—C6—C5	−0.5 (2)