5-(4-Cyano-5-dicyano­methyl­ene-2,2-dimethyl-2,5-dihydro-3-fur­yl)-3-(1-methyl-1,4-dihydro­pyridin-4-yl­idene)pent-4-enyl 3,5-bis­(benz­yloxy)benzoate acetonitrile 0.25-solvate: a synchrotron radiation study

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

doi:10.1107/S1600536809050430

. 2009 Nov 28;65(Pt 12):o3261–o3262. doi: 10.1107/S1600536809050430

5-(4-Cyano-5-dicyanomethylene-2,2-dimethyl-2,5-dihydro-3-furyl)-3-(1-methyl-1,4-dihydropyridin-4-ylidene)pent-4-enyl 3,5-bis(benzyloxy)benzoate acetonitrile 0.25-solvate: a synchrotron radiation study

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

PMCID: PMC2972047 PMID: 21578957

Abstract

The title compound, C₄₂H₃₆N₄O₅·0.25CH₃CN, crystallizes with a partial twofold disordered (1/4) acetonitrile solvent of crystallization. The linking atoms to the 3,5-bis(benzyloxy)benzoic acid are disordered between two conformations in the ratio 0.780 (6):0.220 (6). In the crystal, the molecules pack using mainly C—H⋯N(cyano) interactions coupled with weak C—H⋯O(ether) interactions and C—H⋯π interactions. A brief comparison is made between a conventional and this synchrotron data collection.

Related literature

For general background, see Kay et al. (2004 ▶); Marder et al. (1993 ▶). For related structures, see: Kay et al. (2008 ▶), Gainsford et al. (2007 ▶, 2008 ▶); Kim et al. (2007 ▶) For synthetic data, see: Clarke et al. (2009 ▶). For details of the PX1 beamline, see: McPhillips et al. (2002 ▶). graphic file with name e-65-o3261-scheme1.jpg

Experimental

Crystal data

C₄₂H₃₆N₄O₅·0.25C₂H₃N
M _r = 687.01
Monoclinic,
a = 29.374 (6) Å
b = 15.825 (3) Å
c = 16.317 (3) Å
β = 108.61 (3)°
V = 7188 (3) Å³
Z = 8
Synchrotron radiation
λ = 0.77300 Å
μ = 0.08 mm⁻¹
T = 100 K
0.26 × 0.08 × 0.04 mm

Data collection

ADSC Quantum 210r CCD diffractometer
38733 measured reflections
5381 independent reflections
4076 reflections with I > 2σ(I)
R _int = 0.098
θ_max = 26.0°

Refinement

R[F ² > 2σ(F ²)] = 0.060
wR(F ²) = 0.167
S = 1.04
5381 reflections
482 parameters
H-atom parameters constrained
Δρ_max = 0.91 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: ADSC Quantum 210r software (ADSC, 2009 ▶); cell refinement: XDS (Kabsch, 1993 ▶); data reduction: XDS, locally modified software and XPREP (Bruker, 2001 ▶); 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809050430/sj2693sup1.cif

e-65-o3261-sup1.cif^{(32.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809050430/sj2693Isup2.hkl

e-65-o3261-Isup2.hkl^{(258.3KB, hkl)}

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
C9—H9A⋯N1ⁱ	0.98	2.59	3.529 (4)	161
C9—H9B⋯N3ⁱⁱ	0.98	2.59	3.497 (5)	153
C16—H16⋯N1ⁱⁱⁱ	0.95	2.51	3.406 (4)	156
C17—H17⋯N2^iv	0.95	2.51	3.380 (4)	152
C19—H19C⋯N2^iv	0.98	2.50	3.340 (4)	143
C26—H26⋯O5^v	0.95	2.51	3.398 (4)	155
C8—H8B⋯Cg1^vi	0.98	2.54	3.515 (3)	171

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) . Cg1 is the centroid of the C30–C35 ring.

Table 2. Interplanar angles and SIGP values for the planar entities (Å, °).

Plane	P1	P2	P3	P4	P5	SIGP^a
P1		14.59 (10)	18.77 (7)	31.92 (12)	64.58 (13)	0.025 (3)
P2	14.59 (10)		4.90 (9)	18.33 (13)	75.25 (15)	0.033 (3)
P3	18.77 (7)	4.90 (9)		13.48 (11)	80.11 (12)	0.026 (3)
P4^b	31.92 (12)	18.33 (13)	13.48 (11)		86.94 (16)	0.004 (3)

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Notes: P1 = C1–C12,N1–N3,O1; P2 = C12–C19,N4; P3 = C22–C30,O3–O4; P4 = C29–C35; P5 = C37–C42. (a) Inline graphic (Spek, 2009 ▶); (b) SIGP for plane C37–C42 is 0.014 (3) Å.

Acknowledgments

The structural study was supported by the New Zealand Synchrotron Group and the Australian Synchrotron, Victoria, Australia. We thank Drs Adams, Huyton and Williamson of the Australian Synchrotron for their assistance and the New Zealand Foundation for Research, Science and Technology and New Zealand Pharmaceuticals Ltd for financial support. The diffraction data was collected on the PX1 beamline (McPhillips et al., 2002 ▶) at the Australian Synchrotron, Victoria, Australia. The views expressed herein are those of the authors and are not necessarily those of the owner or operator of the Australian Synchrotron. We thank Professor Ward T. Robinson and Dr J. Wikaira of the University of Canterbury for their assistance with the conventional data collection.

supplementary crystallographic information

Comment

The title compound (I) was synthesized as part of a continuing research programme involving the development of organic nonlinear optical (NLO) chromophores. Due to the highly polar nature of these compounds they have a strong tendency to aggregate, a phenomenon that often leads to a reduction in the macroscopic nonlinearity. We have previously reported the crystallographic parameters for two chromophores containing a quinolinylidene donor coupled to a cyanodicyanomethylidenedihydrofuran (CDFP) electron acceptor group (Gainsford et al., 2008). In both instances an examination of the unit cell packing showed plane to plane stacking of the chromophores via the interaction of the donor end of one molecule with the acceptor end of another. This is clear evidence for potentially deleterious H-aggregation occurring between the compounds. However, it has been reported that the introduction of bulky substituents near the centre of NLO chromophores leads to a significant reduction in the observed aggregation (Kim et al., 2007). Consequently we were interested to make modifications to the core structure of our compounds to see whether the introduction of a bulky 3,5-bis(benzyloxy) benzoate group would lead to any change in the unit cell packing. We report here on the structural properties of a chromophore containing a pyridinylidene donor, CDFP acceptor and bulky side group. While a direct comparison between the compounds studied earlier (Gainsford et al., 2008) and one also containing a quinolinylidene donor would be preferable, this wasn't feasible from synthetic viewpoint. An initial report based on the earlier conventional data collection has been given (Kay et al., 2008).

The asymmetric unit of crystals of (I) contains one independent copy of the molecule and a partial (1/4) acetonitrile molecule disordered around a twofold symmetry site (Figure 1). The linking atoms to the 3,5-bis-benzyloxy-benzoic acid (C20,C21,O2) are disordered over two conformations with refined occupancies of 0.780:0.220 (6). The CDFP ring (atoms C4/C5/O1/C6/C7) and the cyano groups appended to C2 are coplanar (Table 2). The geometric parameters are consistent with the localized electron configuration shown in the scheme with ony subtle differences to the closely related quinoline molecules (NAJKUT & NOJLAA, Gainsford et al., 2008); the similarity is reflected in the bond length alternation (Marder et al., 1993) BLA values of -0.042 (here) and -0.015 & -0.042 respectively. The interplanar angles (Table 2) show the overall moleculear non-planarity of the adjacent planar entities.

The molecular packing is provided by mainly C–H···N(cyano) interactions but also a C–H···O interaction with one benzolyoxy oxygen and C—H ···π crosslinks (Figure 2). Two adjacent molecules are linked through the methyl hydrogen atoms (entries 1 & 2, Table 1) and extended into layers parallel to the (3,0,1) plane via the H16, H17 & H19C (entries 3,4 & 5) and the C–H···O5 (entry 6) interactions. These layers are crosslinked via methyl H8B interaction with phenyl ring C30—C35 (entry 7, Table 1; Figure 2).

An opportunity arose to recollect data on the Australian synchrotron, which is the data presented here. The conventional laboratory results are quite similar but that data did not support refinement of the partial acetonitrile solvent molecule. There were about 2.5 times more observed data in the synchrotron data set (collected in 5% of the conventional time) giving smaller su (by ~70%) values, but overall both datasets gave similar agreement factors. Given the overall agreement data statistics (see exptl_refinement) and the different crystal used, further comparison seems unwarranted.

Experimental

The title compound was synthesized by a published procedure (Clarke et al., 2009). Black crystals suitable for X-ray structure determination were grown in acetonitrile by slow evaporation of the solvent at room temperature.