2-{3-Cyano-5,5-dimethyl-4-[6-(pyrrol-i-din-1-yl)hexa-1,3,5-trien-yl]-2,5-dihydro-2-furylidene}malononitrile.

The title compound, C(20)H(20)N(4)O, is packed into a three-dimensional 'herringbone' matrix using two different types of attractive C-H⋯N(cyano) inter-actions. 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 = 332.40

Orthorhombic,

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[F 2 > 2σ(F 2)] = 0.048

wR(F 2) = 0.129

S = 0.98

3641 reflections

229 parameters

H-atom parameters constrained

Δρmax = 0.26 e Å−3

Δρmin = −0.27 e Å−3

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 ▶).

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

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

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

C20H20N4O	F(000) = 1408
Mr = 332.40	Dx = 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

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

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(Fo2) + (0.0633P)2] where P = (Fo2 + 2Fc2)/3
S = 0.98	(Δ/σ)max < 0.001
3641 reflections	Δρmax = 0.26 e Å−3
229 parameters	Δρmin = −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)

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.

	x	y	z	Uiso*/Ueq
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*

	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)

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)

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

?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—CTc	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)	—

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) ; (ii) .

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—CTc	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.