2-(3-Cyano-4-{7-[1-(2-hy­droxy­eth­yl)-3,3-dimethyl­indolin-2-yl­idene]hepta-1,3,5-trien­yl}-5,5-dimethyl-2,5-dihydro­furan-2-yl­idene)malononitrile

Graeme J Gainsford; M Delower H Bhuiyan; Andrew J Kay

doi:10.1107/S1600536811042036

. 2011 Oct 22;67(Pt 11):o3026. doi: 10.1107/S1600536811042036

2-(3-Cyano-4-{7-[1-(2-hydroxyethyl)-3,3-dimethylindolin-2-ylidene]hepta-1,3,5-trienyl}-5,5-dimethyl-2,5-dihydrofuran-2-ylidene)malononitrile

Graeme J Gainsford ^a,^*, M Delower H Bhuiyan ^a, Andrew J Kay ^a

PMCID: PMC3247422 PMID: 22220040

Abstract

The title compound, C₂₉H₂₈N₄O₂, excluding the hydroxyethyl and methyl groups, is slightly twisted from planarity so that the terminating indol-2-ylidene and furan-2-ylidene moiety planes subtend a dihedral angle of 6.27 (8)°. A small inwards fold in the polymethine atom chain is consistent with centrosymmetric dimer formation via O—H⋯N(cyano) hydrogen bonds. In the crystal, the molecules pack in layers approximately parallel to the (10 Inline graphic ) plane via pairs of O—H⋯N and C—H⋯N(cyano) interactions.

Related literature

For general background to NLO chromophores containing an indoline donor with a 2-(3-cyano-4,5,5-trimethyl-5H-furan-2-ylidene)-malontrile unit, see Gainsford et al. (2007 ▶, 2008 ▶, 2009 ▶). For closely related structures, see Bhuiyan et al. (2011 ▶). For hydrogen-motifs see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₉H₂₈N₄O₂
M _r = 464.55
Triclinic,
a = 9.3157 (4) Å
b = 10.5376 (4) Å
c = 13.4474 (6) Å
α = 101.338 (2)°
β = 100.087 (2)°
γ = 100.570 (2)°
V = 1241.42 (9) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 124 K
0.57 × 0.38 × 0.18 mm

Data collection

Nonius APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ▶) T _min = 0.642, T _max = 0.746
34665 measured reflections
7739 independent reflections
5982 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.130
S = 1.02
7739 reflections
323 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97, PLATON (Spek, 2009) ▶ and Mercury.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811042036/im2321sup1.cif

e-67-o3026-sup1.cif^{(32.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811042036/im2321Isup2.hkl

e-67-o3026-Isup2.hkl^{(378.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811042036/im2321Isup3.cml

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2O⋯N1ⁱ	0.87 (2)	2.14 (2)	2.993 (2)	166.8 (16)
C26—H26B⋯N2ⁱⁱ	0.99	2.44	3.254 (3)	139
C29—H29C⋯N1ⁱⁱⁱ	0.98	2.72	3.670 (2)	164

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

Acknowledgments

We thank Dr J. Wikaira of the University of Canterbury, New Zealand, for her assistance with the data collection.

supplementary crystallographic information

Comment

This report stems from our studies on new NLO chromophores containing an indoline donor with a well known moiety (2-(3-cyano-4,5,5-trimethyl-5H-furan-2-ylidene)-malontrile) (Gainsford et al., 2007, 2008, 2009). It presents the structural details which were referred to in a previous paper containing the synthesis and optical properties of the title compound (6 in Bhuiyan et al., 2011).

The asymmetric unit of the title compound (I) is shown in Figure 1. The furan-2-ylidene ring (C4–C7, O1) is planar while the component planar rings of the indol-2-ylidene are at 1.94 (6)° to each other similar to the 1.95 (11)° found for 2-(3-cyano-4-{5-[1-(2-hydroxy-ethyl)-3,3-dimethyl-1,3-dihydro-indol-2-ylidene] -penta-1,3-dienyl}-5,5-dimethyl-5H-furan-2-ylidene)-malononitrile (Bhuiyan et al., 2011). The indol-2-ylidene plane (N4, C16–C23) makes an angle of 6.27 (8)° to the plane through the polymethine chain atoms (C11–C15). At this point in the polymethine chain (C15) there is a small "fold" which allows the major hydrogen bond link which binds centrosymmetrically related molecules to form a dimer (Table 1, entry 1). So whereas the dihedral angle magnitudes along the polymethine chain are close to 180 ° (176–179 °), that for C14–C15–C16–C17 is 170.58 (10)°. Thus the plane formed by the C16, C17 & C18 atoms makes an angle of 6.819 (13) ° to the preceding polymethine chain plane atoms (C4–C15) and 0.03 (11)° to the mean indoline plane. With this twist/fold combination in the polymethine chain, the indoline and furan-2-ylidene ring planes subtend 6.27 (8)°. These minor deviations from planarity appear consistent with the cell packing (noted below), the electronically delocalized planar nature of the polymethine chain and the indoline ring substituents.

The molecules are packed into layers parallel to the (1,0,-1) plane via O–H···N1(cyano), motif R²₂(38), and C–H···N2(cyano), motif C(17) attractions (Bernstein et al., 1995). The nitrogen N1 can be considered to be a bifurcated acceptor via a weaker supportive (methyl)C –H···N1(cyano) interaction (Table 1, Fig 2).

Experimental

See details of compound 6 in Bhuiyan et al.(2011). Single crystals were grown by slow ether diffusion into a dichloromethane solution of the compound.