2-[3-((Z)-2-{4-[Bis(2-chloro­eth­yl)amino]­phen­yl}ethen­yl)-5,5-dimethyl­cyclo­hex-2-en-1-yl­idene]propane­dinitrile

Li Liu; Ying Shao; Jie-Ping Shi; Hong-Wen Hu; Guo-Yuan Lu

doi:10.1107/S1600536810051068

. 2010 Dec 15;67(Pt 1):o124. doi: 10.1107/S1600536810051068

2-[3-((Z)-2-{4-[Bis(2-chloroethyl)amino]phenyl}ethenyl)-5,5-dimethylcyclohex-2-en-1-ylidene]propanedinitrile

Li Liu ^a, Ying Shao ^b, Jie-Ping Shi ^a, Hong-Wen Hu ^a, Guo-Yuan Lu ^a,^*

PMCID: PMC3050295 PMID: 21522635

Abstract

The highly conjugated title compound, C₂₃H₂₅Cl₂N₃, is nearly planar (the mean deviation from the plane being 0.049 Å), except for the –C(CH₃)₂ group on the cyclohexene ring and the two CH₂Cl groups. The cyclohexene ring has an envelope configuration. In the crystal, the packing is stabilized by C—H⋯Cl interactions and C—H⋯π interactions involving the benzene ring.

Related literature

The title compound was prepared by the Knoevenagel reaction, see: Bai et al. (2006 ▶); Samyn et al. (2001 ▶). It is an intermediate for the preparation of non-linear optical materials, see: Kwon et al. (2006 ▶); Shu et al. (1998 ▶); Chun et al. (2001 ▶); Zheng et al. (2000 ▶). For a related structure, see Kolev et al. (2005 ▶).

Experimental

Crystal data

C₂₃H₂₅Cl₂N₃
M _r = 414.36
Triclinic,
a = 9.106 (7) Å
b = 10.819 (9) Å
c = 13.325 (4) Å
α = 70.052 (6)°
β = 70.02 (1)°
γ = 65.11 (1)°
V = 1088.8 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 295 K
0.25 × 0.20 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.926, T _max = 0.955
5376 measured reflections
3695 independent reflections
3130 reflections with I > 2σ(I)
R _int = 0.108

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.149
S = 1.08
3695 reflections
253 parameters
H-atom parameters constrained
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.45 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810051068/fl2317sup1.cif

e-67-0o124-sup1.cif^{(21.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810051068/fl2317Isup2.hkl

e-67-0o124-Isup2.hkl^{(181.1KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C11–C16 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C18—H18B⋯Cl1Bⁱ	0.97	2.91	3.822 (2)	158
C4—H4A⋯Cg1ⁱⁱ	0.97	2.55	3.459 (2)	156

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported by the National Natural Science Foundation of China (research grant No. 20774039).

supplementary crystallographic information

Comment

The title compound, (I), was prepared by the Knoevenagel reaction (Bai et al., 2006; Samyn et al., 2001). With a donor-π-acceptor (D-π-A) structure, it is one of the important intermediates used in nonlinear optical materials (Kwon et al., 2006; Shu et al., 1998; Chun et al., 2001; Zheng et al., 2000). We now report the structure (I) (Fig. 1). The C—N1 bond length is shorter than a normal single C—N bond (1.47–1.50 Å) and longer than a double C=N bond distance (1.34–1.38 Å) which is due to the p-π conjugation in the phenyl amine group. Because of the extended conjugation, almost all atoms in the molecule are roughly coplanar, except for the C(CH₃)₂ and CH₂Cl groups. The cyclohexene ring adopts an envelope configuration due to its ring tension, with atom C3 deviating by 0.635 (2) Å from the mean plane through the remaining atoms. The CH₂Cl groups are on opposite sides of the plane, the N—C—C—Cl torsion angles are 64.5 (2)° for Cl1—C18—C17—N1 and 173.0 (1)° for Cl2—C20—C19—N1. The structure of a related compound having a diphenyl group instead of the chloroethyl moiety has been reported (Kolev et al., 2005). In the crystal structure of (I), no hydrogen bonding is found. The crystal packing is stabilized by C—H···Cl interactions and C—H···π interactions involving the benzene ring (Table 1, Fig. 2). For the C—H···π interactions, the relevant distances and angles are: C···Cg^[i] = 3.459 (4) Å, H···Cg^[i] =2.548 (2)Å and C—H···Cg^[i]= 156 (1)° [symmetry code: (i) 2 - x, 2 - y, 1 - z].

Experimental

To a solution of 4-(bis(2-chloroethyl)amino)benzaldehyde (1.0 g, 4.1 mmol) in 10 ml anhydrous DMF, 2-(3,5,5-trimethylcyclohex-2-enylidene)malononitrile (0.93 g, 5.0 mmol), 0.5 ml acetic acid, 1 ml piperidine were added, respectively. The reaction mixture was stirred for 2 days at room temperature. Then, the mixture was poured into 50 ml of water and filtered. The resulting solid was purified by column chromatography (petroleum ether/acetic ester, 5:1). Red product 0.24 g was obtained. Yield: 14.2%. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of the eluate.