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organic compounds
1-(4-{[(1,3,3-Trimethylindolin-2-ylidene)methyl]diazenyl}phenyl)ethanone
aCallaghan Innovation Research Limited, PO Box 31-310, Lower Hutt, New Zealand
*Correspondence e-mail: graeme.gainsford@callaghaninnovation.govt.nz
The title compound, C20H21N3O, has crystallographic mirror symmetry with all non-H atoms apart from the methyl C atom of the CMe2 group lying on the mirror plane. Molecules are linked into planar sheets parallel to (010) by phenyl–azo C—H⋯N and phenyl–ethanone C—H⋯O interactions. Methyl C—H⋯π interactions provide crosslinking between the planes.
Related literature
For general background to NLO chromophores, see: Dalton et al. (2011); Marder et al. (1994
); Cheng et al. (1991
); Mashraqui et al. (2004
); Moylan et al. (1993
); Zhang et al. (1997
); Prim et al. (1994
). For related structures, see: Odabasoglu et al. (2005
); Simunek et al. (2003
); Bhuiyan et al. (2011
); Ashraf et al. (2013
). For analysis of the structures, see: Spek (2009
); Bernstein et al. (1995
). For a description of the Cambridge Structural Database, see: Allen (2002
).
Experimental
Crystal data
|
|
Data collection: CrysAlis PRO (Agilent, 2013); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008
); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2012
); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012
) and Mercury (Macrae et al., 2006
); software used to prepare material for publication: SHELXL2012, PLATON (Spek, 2009
) and Mercury.
Supporting information
10.1107/S1600536813024124/tk5249sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813024124/tk5249Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813024124/tk5249Isup3.cml
4-Aminacetophenone (1.35 g, 10 mmol) was added to concentrated sulfuric acid (10 ml) and the reaction mixture cooled to 0–5 °C. A solution of sodium nitrite (824 mg, 12 mmol) in water (5 ml) was added slowly and the reaction stirred at 0–5 °C for 30 min. To this, was added a solution of 1,3,3-trimethyl 2-methyleneindole (1.56 g, 9 mmol) in acetic acid (20 ml); the resultant mixture was stirred for an additional 2 h and then poured into water and neutralized with aqueous sodium carbonate. The resulting oil was extracted with dichloromethane, dried (MgSO4) and concentrated under reduced pressure. The crude material was purified by δ: 1.71 (6H, s, 2x CH3), 2.58 (3H, s, CO—CH3), 3.43 (3H, s, N—CH3), 7.05–7.12 (1H, m, ArH), 7.19 (1H, d, J 5.0 Hz, ArH), 7.30–7.35 (1H, m, ArH), 7.45 (1H, d J 5.0 Hz, ArH), 7.51 (1H, s, CH), 7.63 (2H, d, J 5.0 Hz, ArH), 8.02 (2H, d, J 10.0 Hz, ArH). 13C NMR (125 MHz, DMSO-d6) δ: 26.6, 28.5, 29.8, 48.0, 108.9, 120.4, 120.8, 122.0, 122.4, 127.9, 128.1, 129.6, 134.4, 138.4, 139.8, 143.8, 156.9, 164.8, 168.0, 196.8.
(silica gel, dichloromethane: hexanes 1:1) to afford the final compound (1.89 g, 66%) as a bright-red-yellow solid. X-ray quality red crystals were grown by slow evaporation of a solution of the chromophore in a chloroform and methanol mixture (1:1). M.pt: XXX K. 1H NMR (500 MHz, DMSO-d6)All H atoms except those on C11 & C20 bound to carbon were constrained to their expected geometries (C—H 0.95–0.98 Å). The methyl-H atoms bound to atoms on the mirror plane were located on difference Fourier maps and their positions refined. All methyl- and phenyl-H atoms were refined with Uiso 1.5 & 1.2 times, respectively, that of the Ueq of their parent atom.
Data collection: CrysAlis PRO (Agilent, 2013); cell
CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis PRO (Agilent, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2012); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2012), PLATON (Spek, 2009) and Mercury (Macrae et al., 2006).C20H21N3O | F(000) = 680 |
Mr = 319.40 | Dx = 1.283 Mg m−3 |
Monoclinic, C2/m | Cu Kα radiation, λ = 1.5418 Å |
a = 14.8688 (2) Å | Cell parameters from 4498 reflections |
b = 6.89500 (12) Å | θ = 5.5–73.9° |
c = 16.3546 (3) Å | µ = 0.64 mm−1 |
β = 99.5834 (16)° | T = 120 K |
V = 1653.27 (5) Å3 | Block, red |
Z = 4 | 0.19 × 0.15 × 0.09 mm |
Agilent SuperNova (Dual, Cu at zero, Atlas) diffractometer | 1803 independent reflections |
Radiation source: SuperNova (Cu) X-ray Source | 1634 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.026 |
Detector resolution: 10.6501 pixels mm-1 | θmax = 73.8°, θmin = 2.7° |
ω scans | h = −17→18 |
Absorption correction: gaussian (CrysAlis PRO; Agilent, 2013) | k = −8→8 |
Tmin = 0.804, Tmax = 1.000 | l = −20→19 |
9379 measured reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.036 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.098 | w = 1/[σ2(Fo2) + (0.0502P)2 + 0.9765P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
1803 reflections | Δρmax = 0.27 e Å−3 |
153 parameters | Δρmin = −0.21 e Å−3 |
C20H21N3O | V = 1653.27 (5) Å3 |
Mr = 319.40 | Z = 4 |
Monoclinic, C2/m | Cu Kα radiation |
a = 14.8688 (2) Å | µ = 0.64 mm−1 |
b = 6.89500 (12) Å | T = 120 K |
c = 16.3546 (3) Å | 0.19 × 0.15 × 0.09 mm |
β = 99.5834 (16)° |
Agilent SuperNova (Dual, Cu at zero, Atlas) diffractometer | 1803 independent reflections |
Absorption correction: gaussian (CrysAlis PRO; Agilent, 2013) | 1634 reflections with I > 2σ(I) |
Tmin = 0.804, Tmax = 1.000 | Rint = 0.026 |
9379 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.098 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.27 e Å−3 |
1803 reflections | Δρmin = −0.21 e Å−3 |
153 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.93789 (7) | 0.0000 | 0.21729 (7) | 0.0256 (3) | |
N1 | 0.24599 (8) | 0.0000 | 0.25969 (8) | 0.0192 (3) | |
N2 | 0.46957 (8) | 0.0000 | 0.19967 (7) | 0.0186 (3) | |
N3 | 0.50012 (8) | 0.0000 | 0.13053 (8) | 0.0204 (3) | |
C1 | 0.22453 (9) | 0.0000 | 0.34038 (9) | 0.0187 (3) | |
C2 | 0.13956 (10) | 0.0000 | 0.36490 (10) | 0.0227 (3) | |
H2 | 0.0848 | 0.0000 | 0.3256 | 0.027* | |
C3 | 0.13841 (11) | 0.0000 | 0.44990 (11) | 0.0255 (3) | |
H3 | 0.0814 | 0.0000 | 0.4690 | 0.031* | |
C4 | 0.21825 (11) | 0.0000 | 0.50739 (10) | 0.0245 (3) | |
H4 | 0.2153 | 0.0000 | 0.5650 | 0.029* | |
C5 | 0.30291 (10) | 0.0000 | 0.48133 (9) | 0.0216 (3) | |
H5 | 0.3577 | 0.0000 | 0.5206 | 0.026* | |
C6 | 0.30564 (9) | 0.0000 | 0.39733 (9) | 0.0185 (3) | |
C7 | 0.38604 (9) | 0.0000 | 0.35149 (9) | 0.0177 (3) | |
C8 | 0.44476 (7) | 0.18267 (16) | 0.37151 (6) | 0.0217 (2) | |
H8A | 0.4685 | 0.1868 | 0.4311 | 0.033* | |
H8B | 0.4075 | 0.2981 | 0.3557 | 0.033* | |
H8C | 0.4958 | 0.1796 | 0.3405 | 0.033* | |
C10 | 0.33759 (9) | 0.0000 | 0.26123 (9) | 0.0176 (3) | |
C11 | 0.17867 (10) | 0.0000 | 0.18420 (10) | 0.0232 (3) | |
H11A | 0.1863 (9) | 0.114 (2) | 0.1498 (9) | 0.035* | |
H11B | 0.1170 (14) | 0.0000 | 0.1982 (13) | 0.035* | |
C12 | 0.37724 (10) | 0.0000 | 0.19120 (9) | 0.0191 (3) | |
H12 | 0.3407 | 0.0000 | 0.1377 | 0.023* | |
C13 | 0.59616 (10) | 0.0000 | 0.14061 (9) | 0.0188 (3) | |
C14 | 0.63291 (10) | 0.0000 | 0.06719 (9) | 0.0215 (3) | |
H14 | 0.5933 | 0.0000 | 0.0152 | 0.026* | |
C15 | 0.72657 (10) | 0.0000 | 0.06964 (9) | 0.0222 (3) | |
H15 | 0.7505 | 0.0000 | 0.0193 | 0.027* | |
C16 | 0.78629 (10) | 0.0000 | 0.14535 (9) | 0.0196 (3) | |
C17 | 0.74891 (10) | 0.0000 | 0.21879 (9) | 0.0201 (3) | |
H17 | 0.7886 | 0.0000 | 0.2707 | 0.024* | |
C18 | 0.65596 (10) | 0.0000 | 0.21732 (9) | 0.0208 (3) | |
H18 | 0.6322 | 0.0000 | 0.2678 | 0.025* | |
C19 | 0.88757 (10) | 0.0000 | 0.15055 (10) | 0.0214 (3) | |
C20 | 0.92658 (11) | 0.0000 | 0.07131 (11) | 0.0316 (4) | |
H20A | 0.9913 (16) | 0.0000 | 0.0818 (15) | 0.047* | |
H20B | 0.9057 (10) | 0.113 (2) | 0.0369 (10) | 0.047* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0193 (5) | 0.0339 (6) | 0.0220 (6) | 0.000 | −0.0014 (4) | 0.000 |
N1 | 0.0140 (6) | 0.0235 (6) | 0.0189 (6) | 0.000 | −0.0007 (5) | 0.000 |
N2 | 0.0185 (6) | 0.0208 (6) | 0.0164 (6) | 0.000 | 0.0026 (5) | 0.000 |
N3 | 0.0186 (6) | 0.0259 (6) | 0.0160 (6) | 0.000 | 0.0010 (5) | 0.000 |
C1 | 0.0176 (7) | 0.0177 (7) | 0.0205 (7) | 0.000 | 0.0024 (6) | 0.000 |
C2 | 0.0164 (7) | 0.0220 (7) | 0.0295 (8) | 0.000 | 0.0036 (6) | 0.000 |
C3 | 0.0216 (7) | 0.0235 (7) | 0.0338 (9) | 0.000 | 0.0115 (6) | 0.000 |
C4 | 0.0301 (8) | 0.0229 (7) | 0.0223 (8) | 0.000 | 0.0100 (6) | 0.000 |
C5 | 0.0225 (7) | 0.0219 (7) | 0.0201 (7) | 0.000 | 0.0029 (6) | 0.000 |
C6 | 0.0173 (7) | 0.0176 (7) | 0.0206 (7) | 0.000 | 0.0031 (5) | 0.000 |
C7 | 0.0150 (6) | 0.0227 (7) | 0.0146 (7) | 0.000 | 0.0000 (5) | 0.000 |
C8 | 0.0196 (5) | 0.0265 (5) | 0.0180 (5) | −0.0039 (4) | 0.0002 (4) | −0.0018 (4) |
C10 | 0.0155 (6) | 0.0179 (7) | 0.0179 (7) | 0.000 | −0.0014 (5) | 0.000 |
C11 | 0.0167 (7) | 0.0286 (8) | 0.0217 (8) | 0.000 | −0.0038 (6) | 0.000 |
C12 | 0.0171 (7) | 0.0231 (7) | 0.0156 (7) | 0.000 | −0.0017 (5) | 0.000 |
C13 | 0.0176 (7) | 0.0198 (7) | 0.0184 (7) | 0.000 | 0.0012 (5) | 0.000 |
C14 | 0.0204 (7) | 0.0281 (8) | 0.0146 (7) | 0.000 | −0.0012 (5) | 0.000 |
C15 | 0.0216 (7) | 0.0289 (8) | 0.0162 (7) | 0.000 | 0.0035 (6) | 0.000 |
C16 | 0.0188 (7) | 0.0204 (7) | 0.0189 (7) | 0.000 | 0.0011 (5) | 0.000 |
C17 | 0.0204 (7) | 0.0227 (7) | 0.0154 (7) | 0.000 | −0.0019 (5) | 0.000 |
C18 | 0.0216 (7) | 0.0255 (7) | 0.0152 (7) | 0.000 | 0.0026 (6) | 0.000 |
C19 | 0.0203 (7) | 0.0216 (7) | 0.0218 (8) | 0.000 | 0.0018 (6) | 0.000 |
C20 | 0.0187 (7) | 0.0527 (11) | 0.0234 (8) | 0.000 | 0.0037 (6) | 0.000 |
O1—C19 | 1.2163 (19) | C8—H8A | 0.9800 |
N1—C10 | 1.3580 (18) | C8—H8B | 0.9800 |
N1—C1 | 1.4084 (19) | C8—H8C | 0.9800 |
N1—C11 | 1.4541 (19) | C10—C12 | 1.373 (2) |
N2—N3 | 1.2868 (18) | C11—H11A | 0.983 (15) |
N2—C12 | 1.3567 (18) | C11—H11B | 0.98 (2) |
N3—C13 | 1.4101 (18) | C12—H12 | 0.9500 |
C1—C2 | 1.388 (2) | C13—C14 | 1.400 (2) |
C1—C6 | 1.396 (2) | C13—C18 | 1.412 (2) |
C2—C3 | 1.393 (2) | C14—C15 | 1.386 (2) |
C2—H2 | 0.9500 | C14—H14 | 0.9500 |
C3—C4 | 1.386 (2) | C15—C16 | 1.398 (2) |
C3—H3 | 0.9500 | C15—H15 | 0.9500 |
C4—C5 | 1.395 (2) | C16—C17 | 1.405 (2) |
C4—H4 | 0.9500 | C16—C19 | 1.494 (2) |
C5—C6 | 1.381 (2) | C17—C18 | 1.378 (2) |
C5—H5 | 0.9500 | C17—H17 | 0.9500 |
C6—C7 | 1.5132 (19) | C18—H18 | 0.9500 |
C7—C10 | 1.5310 (19) | C19—C20 | 1.505 (2) |
C7—C8i | 1.5365 (13) | C20—H20A | 0.95 (2) |
C7—C8 | 1.5365 (13) | C20—H20B | 0.983 (17) |
C10—N1—C1 | 111.44 (12) | H8B—C8—H8C | 109.5 |
C10—N1—C11 | 124.21 (13) | N1—C10—C12 | 123.59 (13) |
C1—N1—C11 | 124.35 (12) | N1—C10—C7 | 109.11 (12) |
N3—N2—C12 | 114.17 (12) | C12—C10—C7 | 127.30 (13) |
N2—N3—C13 | 113.32 (12) | N1—C11—H11A | 110.9 (8) |
C2—C1—C6 | 122.29 (14) | N1—C11—H11B | 109.8 (12) |
C2—C1—N1 | 129.04 (14) | H11A—C11—H11B | 109.6 (10) |
C6—C1—N1 | 108.67 (12) | N2—C12—C10 | 118.86 (13) |
C1—C2—C3 | 116.83 (14) | N2—C12—H12 | 120.6 |
C1—C2—H2 | 121.6 | C10—C12—H12 | 120.6 |
C3—C2—H2 | 121.6 | C14—C13—N3 | 115.60 (13) |
C4—C3—C2 | 121.70 (14) | C14—C13—C18 | 118.97 (13) |
C4—C3—H3 | 119.2 | N3—C13—C18 | 125.43 (13) |
C2—C3—H3 | 119.2 | C15—C14—C13 | 120.59 (13) |
C3—C4—C5 | 120.48 (14) | C15—C14—H14 | 119.7 |
C3—C4—H4 | 119.8 | C13—C14—H14 | 119.7 |
C5—C4—H4 | 119.8 | C14—C15—C16 | 120.81 (14) |
C6—C5—C4 | 118.79 (14) | C14—C15—H15 | 119.6 |
C6—C5—H5 | 120.6 | C16—C15—H15 | 119.6 |
C4—C5—H5 | 120.6 | C15—C16—C17 | 118.28 (13) |
C5—C6—C1 | 119.91 (13) | C15—C16—C19 | 122.40 (13) |
C5—C6—C7 | 130.49 (13) | C17—C16—C19 | 119.33 (13) |
C1—C6—C7 | 109.60 (13) | C18—C17—C16 | 121.56 (13) |
C6—C7—C10 | 101.19 (11) | C18—C17—H17 | 119.2 |
C6—C7—C8i | 111.23 (8) | C16—C17—H17 | 119.2 |
C10—C7—C8i | 111.41 (8) | C17—C18—C13 | 119.79 (14) |
C6—C7—C8 | 111.24 (8) | C17—C18—H18 | 120.1 |
C10—C7—C8 | 111.41 (8) | C13—C18—H18 | 120.1 |
C8i—C7—C8 | 110.12 (12) | O1—C19—C16 | 120.98 (14) |
C7—C8—H8A | 109.5 | O1—C19—C20 | 120.33 (14) |
C7—C8—H8B | 109.5 | C16—C19—C20 | 118.70 (13) |
H8A—C8—H8B | 109.5 | C19—C20—H20A | 111.7 (14) |
C7—C8—H8C | 109.5 | C19—C20—H20B | 111.3 (9) |
H8A—C8—H8C | 109.5 | H20A—C20—H20B | 108.5 (12) |
C12—N2—N3—C13 | 180.0 | C6—C7—C10—N1 | 0.000 (1) |
C10—N1—C1—C2 | 180.000 (1) | C8i—C7—C10—N1 | 118.30 (8) |
C11—N1—C1—C2 | 0.000 (1) | C8—C7—C10—N1 | −118.30 (8) |
C10—N1—C1—C6 | 0.000 (1) | C6—C7—C10—C12 | 180.000 (1) |
C11—N1—C1—C6 | 180.000 (1) | C8i—C7—C10—C12 | −61.70 (8) |
C6—C1—C2—C3 | 0.000 (1) | C8—C7—C10—C12 | 61.70 (8) |
N1—C1—C2—C3 | 180.000 (1) | N3—N2—C12—C10 | 180.000 (1) |
C1—C2—C3—C4 | 0.000 (1) | N1—C10—C12—N2 | 180.000 (1) |
C2—C3—C4—C5 | 0.000 (1) | C7—C10—C12—N2 | 0.000 (1) |
C3—C4—C5—C6 | 0.000 (1) | N2—N3—C13—C14 | 180.0 |
C4—C5—C6—C1 | 0.000 (1) | N2—N3—C13—C18 | 0.000 (1) |
C4—C5—C6—C7 | 180.000 (1) | N3—C13—C14—C15 | 180.0 |
C2—C1—C6—C5 | 0.000 (1) | C18—C13—C14—C15 | 0.000 (1) |
N1—C1—C6—C5 | 180.000 (1) | C13—C14—C15—C16 | 0.0 |
C2—C1—C6—C7 | 180.000 (1) | C14—C15—C16—C17 | 0.000 (1) |
N1—C1—C6—C7 | 0.000 (1) | C14—C15—C16—C19 | 180.0 |
C5—C6—C7—C10 | 180.000 (1) | C15—C16—C17—C18 | 0.000 (1) |
C1—C6—C7—C10 | 0.000 (1) | C19—C16—C17—C18 | 180.000 (1) |
C5—C6—C7—C8i | 61.57 (8) | C16—C17—C18—C13 | 0.000 (1) |
C1—C6—C7—C8i | −118.43 (8) | C14—C13—C18—C17 | 0.000 (1) |
C5—C6—C7—C8 | −61.58 (8) | N3—C13—C18—C17 | 180.000 (1) |
C1—C6—C7—C8 | 118.42 (8) | C15—C16—C19—O1 | 180.0 |
C1—N1—C10—C12 | 180.000 (1) | C17—C16—C19—O1 | 0.000 (1) |
C11—N1—C10—C12 | 0.000 (1) | C15—C16—C19—C20 | 0.000 (1) |
C1—N1—C10—C7 | 0.000 (1) | C17—C16—C19—C20 | 180.0 |
C11—N1—C10—C7 | 180.000 (1) |
Symmetry code: (i) x, −y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1ii | 0.95 | 2.57 | 3.5227 (19) | 179 |
C14—H14···N3iii | 0.95 | 2.55 | 3.4985 (19) | 175 |
C11—H11A···Cg3iv | 0.981 (15) | 2.665 (14) | 3.5230 (4) | 145.8 (11) |
Symmetry codes: (ii) x−1, y, z; (iii) −x+1, y, −z; (iv) −x−1, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1i | 0.95 | 2.57 | 3.5227 (19) | 179 |
C14—H14···N3ii | 0.95 | 2.55 | 3.4985 (19) | 175 |
C11—H11A···Cg3iii | 0.981 (15) | 2.665 (14) | 3.5230 (4) | 145.8 (11) |
Symmetry codes: (i) x−1, y, z; (ii) −x+1, y, −z; (iii) −x−1, −y, −z. |
Acknowledgements
We thank Dr Matthew Colson of the University of Canterbury for the data collection.
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The synthesis of organic non-linear optical (NLO) molecules continue to be of research interest due to their potential use in optical communications, information storage, optical switching and photonic imaging and sensing (Dalton et al., 2011). Dipolar donor-π-acceptor (D-π-A) type chromophores are commonly connected via olefins (Marder et al., 1994), acetylenes (Cheng et al., 1991), oxadiazole systems (Mashraqui et al., 2004) and azo groups (Moylan et al., 1993). However, despite the vast range of possibilities, there are some strategies for designing effective NLO materials that consistently give good results, including the incorporation of azo linkers into the conjugated interconnect. Consequently, a number of such D-azo-A systems have been investigated, with many azo-containing systems showing improved non-linear optical performance and thermal stability (Zhang et al., 1997) when compared to the olefinic analogues.
Furthermore, over the past two decades, azobenzene/azoheterocycle containing polymers have been the subject of intensive research in optical switching, and digital and holographic storage applications (Prim et al., 1994). Thus, they represent a useful class of compound to study as they hold promise for applications beyond just non-linear optics. Hence, there is a need to synthesize new organic NLO materials with azo linkers and study their structural, physical, thermal and optical properties. We have recently reported a range of NLO materials containing an azo linker (Ashraf et al., 2013).
The asymmetric unit contains the title compound which lies on a crystallographic mirror plane (Fig. 1). The planarity of structures containing an azo linkage and indeed, the N–N bond length, varies considerably depending on the bound ring systems (Allen, 2002; CSD Version 5.34, with May 2013 updates). For example in LAQYAE (Odabasoglu et al., 2005) the dihedral angles of the pendant phenyl rings being 0.31 (12) and 26.74 (14)° for the two independent molecules with N–N lengths of 1.158 (4) and 1.247 (3) Å, respectively. The closest related structure with appended phenyl and alkene chain is ULEGAT (Simunek et al., 2003) with a comparable N—N length of 1.282 (2) Å, and dihedral angle 0.4 (2)°. The quality of the crystal packing & consequent diffraction data confirms that the methyl hydrogen atoms based on the in-plane carbon C11 are ordered unlike the disorder model required for the related compound 2-{3-[2-(1,3,3-trimethyl-1,3-dihydroindol-2-ylidene)propenyl] -5H-furan-2-ylidene}malonitrile (Bhuiyan et al., 2011), hereafter FATN, which also crystallized in space group C2/m.
The planar molecules in the title compound form sheets utilizing two interactions in a similar way although with different interactions to those in FATN. Here, the phenyl(C14)–H14···N3(azo) interaction provides one of the in-plane links making the common R22(8) motif (Bernstein et al., 1995) parallel to ethene(C)—H···N3(cyano) R22(16) interaction in FATN, aligned around a two fold axis of symmetry (Fig. 2). Likewise, a second in-plane interaction here occurs between phenyl(C2)—H and the ketone oxygen O1 described by the C(14) motif whilst in FATN a (dichloromethane)C–Cl···N(cyano) interaction performs the same role. A methylC–H···O(ketone) interaction is also found in the ULEGAT crystal packing. The planar (0 1 0) sheets are then cross-linked by two (symmetric) methyl(C11)–H11A···π(phenyl) interactions as shown in Fig. 2.