2-{3-Cyano-5,5-dimethyl-4-[6-(pyrrol­i­din-1-yl)hexa-1,3,5-trien­yl]-2,5-dihydro-2-furylidene}malononitrile

Gainsford, G.J.; Bhuiyan, M.D.H.; Kay, A.J.

doi:10.1107/S1600536808028110

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 64| Part 10| October 2008| Pages o2036-o2037

doi:10.1107/S1600536808028110

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2-{3-Cyano-5,5-dimethyl-4-[6-(pyrrolidin-1-yl)hexa-1,3,5-trienyl]-2,5-dihydro-2-furylidene}malononitrile

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

^aIndustrial Research Limited, PO Box 31-310, Lower Hutt, New Zealand
^*Correspondence e-mail: g.gainsford@irl.cri.nz

(Received 17 July 2008; accepted 3 September 2008; online 27 September 2008)

The title compound, C₂₀H₂₀N₄O, is packed into a three-dimensional `herringbone' matrix using two different types of attractive C—H⋯N(cyano) interactions. The bond-length alternation, caused by delocalization of charge between the donor N atoms and the cyano acceptor groups, is compared with related compounds.

Related literature

For general background, see: Kay et al. (2004 ). For related literature, see: Gainsford et al. (2007 , 2008a ,b ); Marder et al. (1993 ); Li et al. (2005 ). For a similar herringbone structure, see: Desiraju & Gavezzotti (1989 ).

Experimental

Crystal data

C₂₀H₂₀N₄O
M_r = 332.40
Orthorhombic, P b c a
a = 12.6766 (13) Å
b = 11.7603 (13) Å
c = 24.164 (3) Å
V = 3602.4 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 116 (2) K
0.32 × 0.25 × 0.07 mm

Data collection

Bruker Nonius APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.494, T_max = 1.0 (expected range = 0.491–0.995)
20272 measured reflections
3641 independent reflections
2078 reflections with I > 2σ(I)
R_int = 0.081

Refinement

R[F² > 2σ(F²)] = 0.048
wR(F²) = 0.129
S = 0.98
3641 reflections
229 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯N3ⁱ	0.95	2.49	3.379 (3)	156
C17—H17A⋯N1ⁱⁱ	0.99	2.61	3.402 (3)	137
C20—H20B⋯N2ⁱⁱ	0.99	2.56	3.316 (3)	133
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ ; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Table 2
Selected bond lengths and angles (Å,°) in the title compound and related compounds

Compound (I) is the title compound, (II) is the closely related buta-1,3-dienyl equivalent (Gainsford et al., 2008c), (III) is the piperidin-1-yl equivalent of (II) (Gainsford et al., 2008b) and (IV) is the starting acceptor molecule 2-dicyanomethylene-4,5,5-trimethyl-2,5-dihydro-furan-3-carbonitrile (Li et al., 2005)

	(I)	(II)^a	(III)^b	(IV)
C2—C6	1.388 (3)	1.388 (5)	1.389 (6)	1.359 (4)
C6—C7	1.401 (3)	1.412 (5)	1.390 (5)	1.445 (4)
C4—C7	1.417 (3)	1.402 (5)	1.426 (6)	1.343 (4)
C4—C11	1.374 (3)	1.405 (5)	1.366 (5)	1.472 (4)
C11—C12	1.410 (3)	1.397 (5)	1.402 (6)	—
C12—C13	1.369 (3)	1.384 (5)	1.381 (5)	—
C13—C14	1.407 (3)	1.397 (5)	1.396 (6)	—
C14—C15	1.369 (3)	—	—	—
C15—C16	1.404 (3)	—	—	—
N4—CT^c	1.306 (2)	1.317 (4)	1.315 (5)	—
C6—O1	1.351 (2)	1.341 (4)	1.360 (4)	1.333 (3)
C5—O1	1.486 (2)	1.482 (4)	1.489 (8)	1.481 (4)
C4—C7—C6	109.84 (18)	108.7 (3)	109.7 (4)	109.4 (2)
C7—C6—C2	132.3 (2)	131.7 (3)	133.7 (4)	131.3 (3)
C11—C4—C7	126.6 (2)	125.2 (3)	126.6 (4)	128.6 (3)
C4—C11—C12—C13	179.6 (2)	−177.4 (4)	178.1 (4)	—
Notes: (a) Larger s.u. values reflect crystal quality; (b) Average of two independent molecules; (c) CT is the terminal atom of the polyene chain.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); 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 PLATON (Spek, 2003 ); software used to prepare material for publication: SHELXL97, PLATON and Mercury (Macrae et al., 2006 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808028110/ng2475sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808028110/ng2475Isup2.hkl

checkCIF report

Comment top

We have previously reported on the synthesis of a number of high figure of merit chromophores for nonlinear optics (Kay et al., 2004), and the X-ray crystallographic and structural properties of crucial dye precursors used [Gainsford et al., 2007; Gainsford et al., 2008a (hereafter III); Gainsford et al., 2008b (hereafter II)]. We report here the crystallographic data of another molecule derived from a chromophore precursor and summarize the structural details of this and closely related compounds.

The asymmetric unit contents of the title compound (I) is shown in Fig. 1. The molecule possesses approximately planar geometry with a major tilt between the pendant planar dicyanomethylene groups (N1,N2,C1–C3) and the "CDFP" 5-membered ring plane (O1, C4—C7) of 11.56 (14)°. The polyene chain atoms (C4,C11–C16), which are coplanar with r.m.s. deviations of 0.026 (2) Å, make an angle of 2.07 (15)° to the "CDFP" ring plane. The pyrrolidin-1-yl ring adopts an envelope configuration with C19 the flap atom at 0.551 (2) Å out of plane (Spek, 2003).

Selected geometrical values for (I), the closely related buta-1,3-dienyl equivalent (II) (Gainsford et al., 2008c), the piperidin-1-yl equivalent of II (III) (Gainsford et al., 2008b) and the starting acceptor molecule 2-dicyanomethylene-4,5,5-trimethyl-2,5-dihydro-furan-3-carbonitrile (IV) (Li et al., 2005) are collected in Table 2. Delocalization is apparent through the polyene chain and CDFP fragment (e.g. compare C4—C7 & C4—C11 bond lengths). Bond length alternation (BLA) calculations (Marder et al., 1993) confirm the similarities of (I) to (II) & (III) with values of -0.027 (I), 0.005 (II) and -0.027 (III) Å compared with the value of 0.108Å in (IV). The similar values for (I) & (III) also confirm the equivalent donor strengths of the pyrolidine & piperidine N-donors.

The molecules are arranged in planes (Fig. 2) with the well known "herringbone" motif (Desiraju & Gavezzotti, 1989). The polyene C—H attractive interactions with adjacent cyano nitrogen atom N3 (principally entry 1, Table 1), commonly observed for these molecules (Gainsford et al., 2008a), link adjacent molecules which lie parallel to each other and the 0,1,-2 plane. The other two main methylene H···N (cyano) interactions (entries 3 & 4, Table 2) link to the other (herringbone) planes which are parallel to the 0,1,2 plane.

Related literature top

For general background, see: Kay et al. (2004). For related literature, see: Gainsford et al. (2007, 2008a,b); Marder et al. (1993); Li et al. (2005). For a similar herringbone structure, see: Desiraju & Gavezzotti (1989).

Experimental top

To a solution of 5.8 mmole of {4-(4-Acetanilido-trans,trans-1,3,5-hexatrienyl) -3-cyano-5,5-dimethyl-2(5H)-furanylidene}propanedinitrile (Compound 11c, Kay et al., 2004) in 30 ml of ethanol was added an equimolar quantity of pyrrolidine. The solution was refluxed 1 h, cooled and the product collected by filtration and washed with ethanol. λ_max 645 nm (pyridine); 630 nm (DMF) log₁₀ε 5.11. Final crystallization was from dichloromethane.

Computing details top

Data collection: APEX2 (Bruker,2005); cell refinement: APEX2 (Bruker,2005); data reduction: SAINT (Bruker, 2005); 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 PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003) and Mercury (Macrae et al., 2006).

Figures top

	Fig. 1. Molecular structure of the asymmetric unit (Farrugia, 1997); displacement ellipsoids are shown at the 50% probability level.
	Fig. 2. Partial packing diagram of the cell (I) (Mercury; Macrae et al., 2006) viewed approximately down the a axis. Only H atoms involved in selected C—H···N hydrogen bonds (dashed lines) are shown. Atom labels indicate the three main interactions (see text & Table 1). Colours: Nitrogen, blue; Oxygen, red; Carbon, black.

2-{3-Cyano-5,5-dimethyl-4-[6-(pyrrolidin-1-yl)hexa-1,3,5-trienyl]-2,5-dihydro- 2-furylidene}malononitrile top

Crystal data top

C₂₀H₂₀N₄O	F(000) = 1408
M_r = 332.40	D_x = 1.226 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 6328 reflections
a = 12.6766 (13) Å	θ = 2.5–25.0°
b = 11.7603 (13) Å	µ = 0.08 mm⁻¹
c = 24.164 (3) Å	T = 116 K
V = 3602.4 (7) Å³	Plate, brown
Z = 8	0.32 × 0.25 × 0.07 mm

Data collection top

Bruker Nonius APEXII CCD area-detector diffractometer	3641 independent reflections
Radiation source: fine-focus sealed tube	2078 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.081
Detector resolution: 8.192 pixels mm^-1	θ_max = 26.4°, θ_min = 3.4°
ϕ and ω scans	h = −10→15
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −14→14
T_min = 0.494, T_max = 1.0	l = −30→27
20272 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.048	H-atom parameters constrained
wR(F²) = 0.129	w = 1/[σ²(F_o²) + (0.0633P)²] where P = (F_o² + 2F_c²)/3
S = 0.98	(Δ/σ)_max < 0.001
3641 reflections	Δρ_max = 0.26 e Å⁻³
229 parameters	Δρ_min = −0.27 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0124 (13)

Crystal data top

C₂₀H₂₀N₄O	V = 3602.4 (7) Å³
M_r = 332.40	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 12.6766 (13) Å	µ = 0.08 mm⁻¹
b = 11.7603 (13) Å	T = 116 K
c = 24.164 (3) Å	0.32 × 0.25 × 0.07 mm

Data collection top

Bruker Nonius APEXII CCD area-detector diffractometer	3641 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2078 reflections with I > 2σ(I)
T_min = 0.494, T_max = 1.0	R_int = 0.081
20272 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.048	0 restraints
wR(F²) = 0.129	H-atom parameters constrained
S = 0.98	Δρ_max = 0.26 e Å⁻³
3641 reflections	Δρ_min = −0.27 e Å⁻³
229 parameters

Special details top

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. An extinction parameter was refined. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.18457 (11)	0.09182 (12)	0.41943 (5)	0.0312 (4)
N1	−0.10627 (17)	−0.09427 (19)	0.33366 (8)	0.0476 (6)
N2	0.24246 (16)	−0.08511 (17)	0.31039 (8)	0.0447 (5)
N3	−0.18623 (16)	0.14659 (16)	0.40666 (7)	0.0371 (5)
N4	0.07598 (13)	0.73470 (14)	0.71061 (6)	0.0276 (4)
C1	−0.02458 (19)	−0.05836 (19)	0.34560 (8)	0.0331 (6)
C2	0.07610 (17)	−0.01503 (19)	0.36100 (8)	0.0289 (5)
C3	0.16705 (19)	−0.05488 (19)	0.33319 (8)	0.0331 (6)
C4	0.06334 (17)	0.20694 (18)	0.46776 (7)	0.0262 (5)
C5	0.17947 (17)	0.17853 (18)	0.46411 (7)	0.0272 (5)
C6	0.08595 (16)	0.06720 (18)	0.40190 (8)	0.0271 (5)
C7	0.01165 (16)	0.13485 (17)	0.42942 (8)	0.0258 (5)
C8	0.24674 (17)	0.27708 (18)	0.44398 (8)	0.0330 (5)
H8A	0.3161	0.2487	0.4326	0.049*
H8B	0.2554	0.3324	0.4740	0.049*
H8C	0.2121	0.3137	0.4124	0.049*
C9	0.22067 (17)	0.11865 (18)	0.51558 (8)	0.0321 (5)
H9A	0.1729	0.0564	0.5255	0.048*
H9B	0.2245	0.1730	0.5463	0.048*
H9C	0.2912	0.0880	0.5082	0.048*
C10	−0.09674 (19)	0.13888 (18)	0.41677 (8)	0.0274 (5)
C11	0.01687 (17)	0.28779 (18)	0.50081 (8)	0.0294 (5)
H11	−0.0572	0.2970	0.4971	0.035*
C12	0.06770 (18)	0.35851 (18)	0.53967 (8)	0.0292 (5)
H12	0.1418	0.3493	0.5437	0.035*
C13	0.02036 (17)	0.43921 (18)	0.57211 (8)	0.0290 (5)
H13	−0.0539	0.4490	0.5698	0.035*
C14	0.07818 (17)	0.50812 (18)	0.60878 (7)	0.0277 (5)
H14	0.1523	0.4964	0.6100	0.033*
C15	0.03820 (17)	0.59043 (18)	0.64288 (8)	0.0284 (5)
H15	−0.0358	0.6031	0.6443	0.034*
C16	0.10612 (18)	0.65628 (18)	0.67577 (8)	0.0282 (5)
H16	0.1797	0.6427	0.6724	0.034*
C17	−0.03553 (16)	0.75976 (18)	0.72429 (8)	0.0305 (5)
H17A	−0.0717	0.6910	0.7383	0.037*
H17B	−0.0739	0.7882	0.6914	0.037*
C18	−0.02940 (18)	0.85123 (19)	0.76908 (9)	0.0363 (6)
H18A	−0.0828	0.8376	0.7982	0.044*
H18B	−0.0410	0.9277	0.7531	0.044*
C19	0.08212 (17)	0.84082 (19)	0.79260 (8)	0.0358 (6)
H19A	0.1061	0.9139	0.8086	0.043*
H19B	0.0855	0.7813	0.8215	0.043*
C20	0.14812 (18)	0.80835 (18)	0.74275 (8)	0.0340 (6)
H20A	0.1689	0.8764	0.7212	0.041*
H20B	0.2124	0.7665	0.7540	0.041*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0281 (9)	0.0392 (9)	0.0264 (7)	0.0026 (7)	−0.0026 (6)	−0.0084 (6)
N1	0.0432 (14)	0.0531 (14)	0.0466 (12)	−0.0001 (11)	−0.0019 (10)	−0.0186 (11)
N2	0.0464 (14)	0.0491 (13)	0.0385 (11)	0.0012 (11)	0.0056 (10)	−0.0111 (10)
N3	0.0351 (13)	0.0421 (13)	0.0342 (10)	−0.0013 (9)	0.0022 (9)	−0.0045 (9)
N4	0.0303 (11)	0.0320 (10)	0.0205 (8)	−0.0010 (8)	0.0004 (7)	−0.0002 (8)
C1	0.0395 (15)	0.0351 (14)	0.0248 (11)	0.0029 (11)	−0.0006 (10)	−0.0078 (10)
C2	0.0336 (13)	0.0321 (13)	0.0209 (10)	0.0020 (10)	−0.0007 (9)	−0.0024 (9)
C3	0.0420 (16)	0.0339 (13)	0.0235 (11)	−0.0008 (11)	−0.0009 (10)	−0.0051 (10)
C4	0.0301 (13)	0.0298 (12)	0.0189 (10)	−0.0005 (10)	0.0019 (9)	0.0018 (9)
C5	0.0296 (13)	0.0311 (12)	0.0209 (10)	−0.0003 (10)	−0.0004 (9)	−0.0043 (9)
C6	0.0302 (13)	0.0322 (13)	0.0190 (10)	−0.0019 (10)	−0.0025 (9)	0.0019 (9)
C7	0.0266 (13)	0.0306 (13)	0.0201 (10)	0.0006 (9)	−0.0002 (9)	−0.0015 (9)
C8	0.0336 (13)	0.0380 (13)	0.0272 (11)	−0.0014 (11)	0.0024 (10)	0.0029 (10)
C9	0.0370 (14)	0.0325 (13)	0.0267 (11)	0.0030 (10)	−0.0020 (10)	0.0019 (10)
C10	0.0343 (15)	0.0283 (13)	0.0197 (10)	−0.0018 (10)	0.0042 (10)	−0.0035 (9)
C11	0.0291 (13)	0.0382 (14)	0.0211 (10)	0.0005 (10)	−0.0004 (9)	−0.0017 (10)
C12	0.0308 (13)	0.0356 (13)	0.0212 (10)	−0.0004 (10)	0.0017 (9)	0.0004 (9)
C13	0.0328 (13)	0.0339 (13)	0.0204 (10)	0.0013 (10)	0.0011 (9)	−0.0007 (9)
C14	0.0337 (13)	0.0308 (12)	0.0186 (10)	−0.0008 (10)	0.0022 (9)	0.0030 (9)
C15	0.0336 (13)	0.0327 (13)	0.0190 (10)	0.0002 (10)	0.0015 (9)	0.0008 (9)
C16	0.0341 (13)	0.0303 (12)	0.0200 (10)	0.0023 (10)	0.0048 (9)	0.0029 (9)
C17	0.0330 (14)	0.0359 (13)	0.0225 (10)	0.0031 (10)	0.0002 (9)	−0.0008 (9)
C18	0.0490 (16)	0.0341 (13)	0.0258 (11)	0.0033 (11)	−0.0010 (11)	−0.0045 (10)
C19	0.0451 (16)	0.0352 (13)	0.0270 (11)	0.0002 (11)	−0.0043 (10)	−0.0071 (10)
C20	0.0440 (15)	0.0324 (13)	0.0257 (11)	−0.0062 (11)	−0.0058 (10)	−0.0020 (10)

Geometric parameters (Å, º) top

O1—C6	1.351 (2)	C9—H9C	0.9800
O1—C5	1.486 (2)	C11—C12	1.410 (3)
N1—C1	1.155 (3)	C11—H11	0.9500
N2—C3	1.159 (3)	C12—C13	1.369 (3)
N3—C10	1.164 (3)	C12—H12	0.9500
N4—C16	1.306 (2)	C13—C14	1.407 (3)
N4—C20	1.480 (3)	C13—H13	0.9500
N4—C17	1.481 (3)	C14—C15	1.369 (3)
C1—C2	1.424 (3)	C14—H14	0.9500
C2—C6	1.388 (3)	C15—C16	1.404 (3)
C2—C3	1.414 (3)	C15—H15	0.9500
C4—C11	1.374 (3)	C16—H16	0.9500
C4—C7	1.417 (3)	C17—C18	1.528 (3)
C4—C5	1.512 (3)	C17—H17A	0.9900
C5—C8	1.519 (3)	C17—H17B	0.9900
C5—C9	1.522 (3)	C18—C19	1.529 (3)
C6—C7	1.401 (3)	C18—H18A	0.9900
C7—C10	1.408 (3)	C18—H18B	0.9900
C8—H8A	0.9800	C19—C20	1.516 (3)
C8—H8B	0.9800	C19—H19A	0.9900
C8—H8C	0.9800	C19—H19B	0.9900
C9—H9A	0.9800	C20—H20A	0.9900
C9—H9B	0.9800	C20—H20B	0.9900

C6—O1—C5	109.54 (15)	C13—C12—C11	126.1 (2)
C16—N4—C20	124.81 (18)	C13—C12—H12	116.9
C16—N4—C17	124.30 (17)	C11—C12—H12	116.9
C20—N4—C17	110.87 (16)	C12—C13—C14	122.1 (2)
N1—C1—C2	179.2 (2)	C12—C13—H13	118.9
C6—C2—C3	119.7 (2)	C14—C13—H13	118.9
C6—C2—C1	121.06 (19)	C15—C14—C13	126.4 (2)
C3—C2—C1	119.22 (19)	C15—C14—H14	116.8
N2—C3—C2	178.5 (2)	C13—C14—H14	116.8
C11—C4—C7	126.6 (2)	C14—C15—C16	120.2 (2)
C11—C4—C5	127.16 (18)	C14—C15—H15	119.9
C7—C4—C5	106.25 (17)	C16—C15—H15	119.9
O1—C5—C4	103.67 (15)	N4—C16—C15	125.1 (2)
O1—C5—C8	105.46 (15)	N4—C16—H16	117.5
C4—C5—C8	113.37 (17)	C15—C16—H16	117.5
O1—C5—C9	105.15 (16)	N4—C17—C18	104.45 (16)
C4—C5—C9	112.87 (16)	N4—C17—H17A	110.9
C8—C5—C9	114.97 (17)	C18—C17—H17A	110.9
O1—C6—C2	117.11 (18)	N4—C17—H17B	110.9
O1—C6—C7	110.58 (17)	C18—C17—H17B	110.9
C2—C6—C7	132.3 (2)	H17A—C17—H17B	108.9
C6—C7—C10	124.89 (18)	C17—C18—C19	104.71 (17)
C6—C7—C4	109.84 (18)	C17—C18—H18A	110.8
C10—C7—C4	124.96 (18)	C19—C18—H18A	110.8
C5—C8—H8A	109.5	C17—C18—H18B	110.8
C5—C8—H8B	109.5	C19—C18—H18B	110.8
H8A—C8—H8B	109.5	H18A—C18—H18B	108.9
C5—C8—H8C	109.5	C20—C19—C18	103.61 (17)
H8A—C8—H8C	109.5	C20—C19—H19A	111.0
H8B—C8—H8C	109.5	C18—C19—H19A	111.0
C5—C9—H9A	109.5	C20—C19—H19B	111.0
C5—C9—H9B	109.5	C18—C19—H19B	111.0
H9A—C9—H9B	109.5	H19A—C19—H19B	109.0
C5—C9—H9C	109.5	N4—C20—C19	102.91 (17)
H9A—C9—H9C	109.5	N4—C20—H20A	111.2
H9B—C9—H9C	109.5	C19—C20—H20A	111.2
N3—C10—C7	177.4 (2)	N4—C20—H20B	111.2
C4—C11—C12	126.8 (2)	C19—C20—H20B	111.2
C4—C11—H11	116.6	H20A—C20—H20B	109.1
C12—C11—H11	116.6

C6—O1—C5—C4	−3.51 (19)	C5—C4—C7—C6	−1.4 (2)
C6—O1—C5—C8	−122.90 (17)	C11—C4—C7—C10	3.6 (3)
C6—O1—C5—C9	115.19 (17)	C5—C4—C7—C10	−175.33 (18)
C11—C4—C5—O1	−176.05 (18)	C7—C4—C11—C12	178.9 (2)
C7—C4—C5—O1	2.9 (2)	C5—C4—C11—C12	−2.4 (3)
C11—C4—C5—C8	−62.2 (3)	C4—C11—C12—C13	179.6 (2)
C7—C4—C5—C8	116.70 (18)	C11—C12—C13—C14	−178.23 (19)
C11—C4—C5—C9	70.7 (3)	C12—C13—C14—C15	−179.8 (2)
C7—C4—C5—C9	−110.35 (18)	C13—C14—C15—C16	−177.29 (19)
C5—O1—C6—C2	−178.33 (17)	C20—N4—C16—C15	−176.28 (19)
C5—O1—C6—C7	2.8 (2)	C17—N4—C16—C15	5.4 (3)
C3—C2—C6—O1	−10.6 (3)	C14—C15—C16—N4	−178.18 (19)
C1—C2—C6—O1	170.85 (18)	C16—N4—C17—C18	176.39 (18)
C3—C2—C6—C7	168.0 (2)	C20—N4—C17—C18	−2.2 (2)
C1—C2—C6—C7	−10.6 (3)	N4—C17—C18—C19	−20.2 (2)
O1—C6—C7—C10	173.07 (18)	C17—C18—C19—C20	34.8 (2)
C2—C6—C7—C10	−5.5 (4)	C16—N4—C20—C19	−154.84 (18)
O1—C6—C7—C4	−0.9 (2)	C17—N4—C20—C19	23.7 (2)
C2—C6—C7—C4	−179.5 (2)	C18—C19—C20—N4	−35.4 (2)
C11—C4—C7—C6	177.55 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···N3ⁱ	0.95	2.49	3.379 (3)	156
C17—H17A···N1ⁱⁱ	0.99	2.61	3.402 (3)	137
C20—H20B···N2ⁱⁱ	0.99	2.56	3.316 (3)	133

Symmetry codes: (i) x+1/2, −y+1/2, −z+1; (ii) x, −y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula	C₂₀H₂₀N₄O
M_r	332.40
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	116
a, b, c (Å)	12.6766 (13), 11.7603 (13), 24.164 (3)
V (Å³)	3602.4 (7)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.32 × 0.25 × 0.07

Data collection
Diffractometer	Bruker Nonius APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.494, 1.0
No. of measured, independent and observed [I > 2σ(I)] reflections	20272, 3641, 2078
R_int	0.081
(sin θ/λ)_max (Å⁻¹)	0.626

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.129, 0.98
No. of reflections	3641
No. of parameters	229
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.27

Computer programs: APEX2 (Bruker,2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2003), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003) and Mercury (Macrae et al., 2006).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···N3ⁱ	0.95	2.49	3.379 (3)	156
C17—H17A···N1ⁱⁱ	0.99	2.61	3.402 (3)	137
C20—H20B···N2ⁱⁱ	0.99	2.56	3.316 (3)	133

Symmetry codes: (i) x+1/2, −y+1/2, −z+1; (ii) x, −y+1/2, z+1/2.

Selected bond lengths and angles (Å,°) in the title compound and related compounds top

?s	(I)	(II)^a	(III)^b	(IV)
C2—C6	1.388 (3)	1.388 (5)	1.389 (6)	1.359 (4)
C6—C7	1.401 (3)	1.412 (5)	1.390 (5)	1.445 (4)
C4—C7	1.417 (3)	1.402 (5)	1.426 (6)	1.343 (4)
C4—C11	1.374 (3)	1.405 (5)	1.366 (5)	1.472 (4)
C11—C12	1.410 (3)	1.397 (5)	1.402 (6)	—
C12—C13	1.369 (3)	1.384 (5)	1.381 (5)	—
C13—C14	1.407 (3)	1.397 (5)	1.396 (6)	—
C14—C15	1.369 (3)	—	—	—
C15—C16	1.404 (3)	—	—	—
N4—CT^c	1.306 (2)	1.317 (4)	1.315 (5)	—
C6—O1	1.351 (2)	1.341 (4)	1.360 (4)	1.333 (3)
C5—O1	1.486 (2)	1.482 (4)	1.489 (8)	1.481 (4)
C4—C7—C6	109.84 (18)	108.7 (3)	109.7 (4)	109.4 (2)
C7—C6—C2	132.3 (2)	131.7 (3)	133.7 (4)	131.3 (3)
C11—C4—C7	126.6 (2)	125.2 (3)	126.6 (4)	128.6 (3)
C4—C11—C12—C13	179.6 (2)	-177.4 (4)	178.1 (4)	—

Notes: (a) Larger s.u. values reflect crystal quality; (b) Average of two independent molecules; (c) CT is the terminal atom of the polyene chain.

Acknowledgements

We thank Dr J. Wikaira and Dr C. Fitchett of the University of Canterbury, New Zealand, for their assistance with the data collection.

References

Bruker (2005). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Desiraju, G. R. & Gavezzotti, A. (1989). J. Chem. Soc. Chem. Commun. pp. 621–623. CrossRef Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Gainsford, G. J., Bhuiyan, M. D. H. & Kay, A. J. (2007). Acta Cryst. C63, o633–o637. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Gainsford, G. J., Bhuiyan, M. D. H., Kay, A. J. & Spek, A. L. (2008a). Acta Cryst. E64, o503. Web of Science CSD CrossRef IUCr Journals Google Scholar
Gainsford, G. J., Bhuiyan, M. D. H., Kay, A. J. & Robinson, W. T. (2008b). Acta Cryst. E64, o1715. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kay, A. J., Woolhouse, A. D., Zhao, Y. & Clays, K. (2004). J. Mater. Chem. 14, 1321–1330. Web of Science CrossRef CAS Google Scholar
Li, S.-Y., Song, Y.-Y., You, Z.-L., Wen, Y.-W. & Qin, J.-G. (2005). Acta Cryst. E61, o2093–o2095. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Marder, S. R., Perry, J. W., Tiemann, B. G., Gorman, C. B., Gilmour, S., Biddle, S. L. & Bourhill, G. (1993). J. Am. Chem. Soc. 115, 2524–2526. CSD CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar

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