trans-2,3-Bis(2,4,5-trimethyl-3-thien­yl)but-2-enedinitrile

Abstract

In title compound, C₁₈H₁₈N₂S₂, the dihedral angle between two thio­phene rings is 61.83 (8)°.

Related literature

For related structures, see: Munakata et al. (1996 ▶); Han et al. (2006 ▶).

Experimental

Crystal data

• C₁₈H₁₈N₂S₂

• M _r = 326.46

• Triclinic,

• a = 8.8368 (10) Å

• b = 9.1785 (10) Å

• c = 11.4160 (12) Å

• α = 85.271 (2)°

• β = 71.058 (2)°

• γ = 77.171 (2)°

• V = 853.88 (16) ų

• Z = 2

• Mo Kα radiation

• μ = 0.31 mm⁻¹

• T = 273 K

• 0.40 × 0.32 × 0.28 mm

Data collection

• Bruker SMART CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.886, T _max = 0.918

• 5025 measured reflections

• 3686 independent reflections

• 2264 reflections with I > 2σ(I)

• R _int = 0.020

Refinement

• R[F ² > 2σ(F ²)] = 0.058

• wR(F ²) = 0.175

• S = 1.06

• 3686 reflections

• 199 parameters

• H-atom parameters constrained

• Δρ_max = 0.28 e Å⁻³

• Δρ_min = −0.23 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1999 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

In the crystal structure of the title compound, two substituted thiophene rings are trans positioned with respect to the dicyano group. The ring skeleton of the molecule is not planar. This diarylethene with thiophene rings is prepared in an attempt to construct thermally irreversible photochromic systems. The dicyano group was selected to shift the absorption maxima of the dihydro-type isomers to longer wavelengths.

All bond lengths and angles in title compound are normal and good agreement with those previously reported. (Munakata, et al., 1996; Han et al., 2006). The dihedral angles between the two thiophene (S1/C12—C15 and S2/C1—C4) rings is 61.83 °. No classical hydrogen bonds were found, the crystal structure was mainly stabilized by Van der Waals forces.

Experimental

To 20 ml of 50% NaOH aqueous solution containing triethylbenzylammonium chloride (0.21 g, 0.0010 mol) was added a mixture of 2,3,5-trimethyl-4-(cyanomethyl)thiophene (16 g, 0.10 mol) and CCl4 (15 g, 0.10 mol) at 40 ° C. The solution was stirred for 1.5 h at 45 ° C. The reaction mixture was poured into water and the product was extracted with ether and chloroform. After the solvent was removed, the mixture of trans and cis forms was separated by column chlomatography on silica gel with light petroleum-CHCl3 (1: 1), collected the first yellow band, and then purified by recrystallization from a hexane-ether mixture. Single crystals suitable for X-ray measurements were obtained by recrystallization from methanol at room temperature for one week.

Refinement

H atoms bonded to C atoms were treated as riding atoms, with C—H distances of 0.96 Å and U_iso(H) values of 1.5U_eq(C).

Figures

Fig. 1.

View of the title compound (I), with displacement ellipsoids drawn at the 40% probability level.

Crystal data

C18H18N2S2	Z = 2
Mr = 326.46	F(000) = 344
Triclinic, P1	Dx = 1.270 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.8368 (10) Å	Cell parameters from 2501 reflections
b = 9.1785 (10) Å	θ = 2.3–25.1°
c = 11.4160 (12) Å	µ = 0.31 mm−1
α = 85.271 (2)°	T = 273 K
β = 71.058 (2)°	Block, yellow
γ = 77.171 (2)°	0.40 × 0.32 × 0.28 mm
V = 853.88 (16) Å3

Data collection

Bruker SMART CCD area-detector diffractometer	3686 independent reflections
Radiation source: fine-focus sealed tube	2264 reflections with I > 2σ(I)
graphite	Rint = 0.020
φ and ω scans	θmax = 27.5°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −11→9
Tmin = 0.886, Tmax = 0.918	k = −11→11
5025 measured reflections	l = −13→14

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.175	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0826P)2 + 0.1249P] where P = (Fo2 + 2Fc2)/3
3686 reflections	(Δ/σ)max < 0.001
199 parameters	Δρmax = 0.28 e Å−3
0 restraints	Δρmin = −0.23 e Å−3

Special details

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. 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 (Ų)

	x	y	z	Uiso*/Ueq
S1	0.36871 (11)	0.71963 (9)	0.60411 (8)	0.0553 (3)
S2	0.40282 (12)	−0.15478 (10)	0.92480 (9)	0.0616 (3)
C12	0.2777 (4)	0.4790 (3)	0.6886 (3)	0.0409 (7)
C2	0.2998 (4)	0.1229 (3)	0.8994 (3)	0.0428 (7)
C10	0.2760 (4)	0.3248 (3)	0.7386 (3)	0.0420 (7)
C15	0.1480 (4)	0.5656 (3)	0.6474 (2)	0.0410 (7)
C13	0.4056 (4)	0.5472 (4)	0.6719 (3)	0.0474 (8)
C8	0.2843 (4)	0.2788 (3)	0.8535 (3)	0.0438 (7)
C11	0.2615 (4)	0.2192 (4)	0.6591 (3)	0.0481 (8)
C14	0.1819 (4)	0.6995 (3)	0.5987 (3)	0.0459 (7)
C3	0.1900 (4)	0.0800 (3)	1.0143 (3)	0.0457 (7)
C1	0.4219 (4)	0.0072 (3)	0.8411 (3)	0.0481 (8)
C4	0.2314 (4)	−0.0692 (4)	1.0389 (3)	0.0527 (8)
C18	−0.0090 (4)	0.5183 (4)	0.6644 (3)	0.0556 (9)
H18A	−0.0777	0.5931	0.6298	0.083*
H18B	−0.0636	0.5061	0.7512	0.083*
H18C	0.0133	0.4252	0.6232	0.083*
N2	0.2477 (4)	0.1424 (3)	0.5914 (3)	0.0682 (9)
C9	0.2797 (5)	0.3908 (4)	0.9369 (3)	0.0543 (8)
C7	0.0454 (5)	0.1843 (4)	1.0961 (3)	0.0654 (10)
H7A	−0.0088	0.1304	1.1673	0.098*
H7B	−0.0292	0.2258	1.0509	0.098*
H7C	0.0816	0.2635	1.1223	0.098*
N1	0.2708 (5)	0.4759 (4)	1.0067 (3)	0.0814 (11)
C6	0.5626 (4)	0.0063 (4)	0.7253 (3)	0.0651 (10)
H6A	0.5563	0.1048	0.6892	0.098*
H6B	0.5588	−0.0623	0.6677	0.098*
H6C	0.6632	−0.0242	0.7444	0.098*
C17	0.0801 (5)	0.8252 (4)	0.5472 (3)	0.0655 (10)
H17A	−0.0200	0.7979	0.5506	0.098*
H17B	0.1395	0.8446	0.4628	0.098*
H17C	0.0558	0.9133	0.5953	0.098*
C16	0.5635 (4)	0.4920 (4)	0.6983 (4)	0.0648 (10)
H16A	0.5649	0.3945	0.7361	0.097*
H16B	0.5745	0.5595	0.7536	0.097*
H16C	0.6526	0.4866	0.6223	0.097*
C5	0.1468 (6)	−0.1591 (4)	1.1464 (3)	0.0789 (12)
H5A	0.0541	−0.0947	1.2009	0.118*
H5B	0.2214	−0.2043	1.1906	0.118*
H5C	0.1108	−0.2356	1.1164	0.118*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0595 (6)	0.0513 (5)	0.0576 (5)	−0.0242 (4)	−0.0145 (4)	0.0040 (4)
S2	0.0718 (6)	0.0429 (5)	0.0699 (6)	−0.0036 (4)	−0.0276 (5)	−0.0013 (4)
C12	0.0455 (17)	0.0419 (17)	0.0338 (15)	−0.0106 (14)	−0.0097 (13)	−0.0001 (12)
C2	0.0490 (18)	0.0417 (17)	0.0398 (16)	−0.0079 (14)	−0.0178 (14)	−0.0006 (13)
C10	0.0425 (17)	0.0417 (16)	0.0412 (16)	−0.0105 (13)	−0.0110 (13)	−0.0025 (13)
C15	0.0431 (17)	0.0462 (17)	0.0327 (15)	−0.0112 (14)	−0.0094 (13)	−0.0006 (13)
C13	0.0443 (18)	0.0493 (19)	0.0475 (17)	−0.0128 (15)	−0.0104 (14)	−0.0026 (14)
C8	0.0510 (18)	0.0394 (16)	0.0399 (16)	−0.0092 (14)	−0.0126 (14)	−0.0028 (13)
C11	0.055 (2)	0.0485 (19)	0.0433 (17)	−0.0162 (15)	−0.0156 (15)	0.0022 (15)
C14	0.0520 (19)	0.0447 (18)	0.0411 (16)	−0.0101 (15)	−0.0151 (14)	0.0010 (14)
C3	0.0533 (19)	0.0490 (18)	0.0367 (16)	−0.0127 (15)	−0.0153 (14)	−0.0003 (13)
C1	0.0486 (19)	0.0449 (18)	0.0508 (18)	−0.0058 (15)	−0.0169 (15)	−0.0058 (15)
C4	0.069 (2)	0.0485 (19)	0.0479 (18)	−0.0186 (17)	−0.0261 (16)	0.0059 (15)
C18	0.051 (2)	0.063 (2)	0.058 (2)	−0.0173 (17)	−0.0203 (16)	0.0035 (17)
N2	0.084 (2)	0.066 (2)	0.0641 (19)	−0.0231 (17)	−0.0289 (17)	−0.0100 (17)
C9	0.073 (2)	0.0437 (18)	0.0458 (18)	−0.0077 (17)	−0.0213 (17)	−0.0013 (15)
C7	0.072 (2)	0.065 (2)	0.051 (2)	−0.0134 (19)	−0.0064 (18)	−0.0075 (17)
N1	0.130 (3)	0.057 (2)	0.060 (2)	−0.019 (2)	−0.032 (2)	−0.0110 (17)
C6	0.050 (2)	0.064 (2)	0.070 (2)	−0.0069 (18)	−0.0050 (18)	−0.0098 (19)
C17	0.084 (3)	0.051 (2)	0.063 (2)	−0.0120 (19)	−0.029 (2)	0.0108 (17)
C16	0.050 (2)	0.069 (2)	0.081 (3)	−0.0162 (18)	−0.0243 (19)	−0.006 (2)
C5	0.117 (4)	0.067 (3)	0.060 (2)	−0.038 (2)	−0.031 (2)	0.017 (2)

Geometric parameters (Å, °)

S1—C13	1.716 (3)	C4—C5	1.503 (5)
S1—C14	1.723 (3)	C18—H18A	0.9600
S2—C1	1.711 (3)	C18—H18B	0.9600
S2—C4	1.723 (4)	C18—H18C	0.9600
C12—C13	1.364 (4)	C9—N1	1.133 (4)
C12—C15	1.432 (4)	C7—H7A	0.9600
C12—C10	1.483 (4)	C7—H7B	0.9600
C2—C1	1.370 (4)	C7—H7C	0.9600
C2—C3	1.441 (4)	C6—H6A	0.9600
C2—C8	1.476 (4)	C6—H6B	0.9600
C10—C8	1.364 (4)	C6—H6C	0.9600
C10—C11	1.433 (4)	C17—H17A	0.9600
C15—C14	1.361 (4)	C17—H17B	0.9600
C15—C18	1.493 (4)	C17—H17C	0.9600
C13—C16	1.492 (5)	C16—H16A	0.9600
C8—C9	1.443 (4)	C16—H16B	0.9600
C11—N2	1.140 (4)	C16—H16C	0.9600
C14—C17	1.502 (4)	C5—H5A	0.9600
C3—C4	1.367 (4)	C5—H5B	0.9600
C3—C7	1.500 (5)	C5—H5C	0.9600
C1—C6	1.491 (5)
C13—S1—C14	92.95 (15)	H18A—C18—H18B	109.5
C1—S2—C4	93.19 (15)	C15—C18—H18C	109.5
C13—C12—C15	114.4 (3)	H18A—C18—H18C	109.5
C13—C12—C10	123.2 (3)	H18B—C18—H18C	109.5
C15—C12—C10	122.3 (3)	N1—C9—C8	176.8 (4)
C1—C2—C3	113.7 (3)	C3—C7—H7A	109.5
C1—C2—C8	124.0 (3)	C3—C7—H7B	109.5
C3—C2—C8	122.3 (3)	H7A—C7—H7B	109.5
C8—C10—C11	118.9 (3)	C3—C7—H7C	109.5
C8—C10—C12	124.9 (3)	H7A—C7—H7C	109.5
C11—C10—C12	116.2 (2)	H7B—C7—H7C	109.5
C14—C15—C12	111.4 (3)	C1—C6—H6A	109.5
C14—C15—C18	124.7 (3)	C1—C6—H6B	109.5
C12—C15—C18	123.8 (3)	H6A—C6—H6B	109.5
C12—C13—C16	130.3 (3)	C1—C6—H6C	109.5
C12—C13—S1	109.8 (2)	H6A—C6—H6C	109.5
C16—C13—S1	119.8 (2)	H6B—C6—H6C	109.5
C10—C8—C9	117.8 (3)	C14—C17—H17A	109.5
C10—C8—C2	125.3 (3)	C14—C17—H17B	109.5
C9—C8—C2	116.9 (3)	H17A—C17—H17B	109.5
N2—C11—C10	175.8 (3)	C14—C17—H17C	109.5
C15—C14—C17	129.5 (3)	H17A—C17—H17C	109.5
C15—C14—S1	111.4 (2)	H17B—C17—H17C	109.5
C17—C14—S1	119.1 (3)	C13—C16—H16A	109.5
C4—C3—C2	111.6 (3)	C13—C16—H16B	109.5
C4—C3—C7	123.7 (3)	H16A—C16—H16B	109.5
C2—C3—C7	124.6 (3)	C13—C16—H16C	109.5
C2—C1—C6	130.3 (3)	H16A—C16—H16C	109.5
C2—C1—S2	110.3 (2)	H16B—C16—H16C	109.5
C6—C1—S2	119.4 (2)	C4—C5—H5A	109.5
C3—C4—C5	128.6 (3)	C4—C5—H5B	109.5
C3—C4—S2	111.2 (2)	H5A—C5—H5B	109.5
C5—C4—S2	120.2 (3)	C4—C5—H5C	109.5
C15—C18—H18A	109.5	H5A—C5—H5C	109.5
C15—C18—H18B	109.5	H5B—C5—H5C	109.5
C13—C12—C10—C8	61.6 (4)	C12—C15—C14—C17	−178.7 (3)
C15—C12—C10—C8	−121.9 (3)	C18—C15—C14—C17	−2.8 (5)
C13—C12—C10—C11	−119.5 (3)	C12—C15—C14—S1	−0.3 (3)
C15—C12—C10—C11	57.0 (4)	C18—C15—C14—S1	175.6 (2)
C13—C12—C15—C14	0.4 (4)	C13—S1—C14—C15	0.1 (2)
C10—C12—C15—C14	−176.3 (3)	C13—S1—C14—C17	178.7 (3)
C13—C12—C15—C18	−175.5 (3)	C1—C2—C3—C4	−0.9 (4)
C10—C12—C15—C18	7.7 (4)	C8—C2—C3—C4	−178.3 (3)
C15—C12—C13—C16	−177.6 (3)	C1—C2—C3—C7	−179.5 (3)
C10—C12—C13—C16	−0.9 (5)	C8—C2—C3—C7	3.1 (5)
C15—C12—C13—S1	−0.3 (3)	C3—C2—C1—C6	−176.8 (3)
C10—C12—C13—S1	176.4 (2)	C8—C2—C1—C6	0.6 (5)
C14—S1—C13—C12	0.1 (2)	C3—C2—C1—S2	0.6 (3)
C14—S1—C13—C16	177.7 (3)	C8—C2—C1—S2	177.9 (2)
C11—C10—C8—C9	−173.0 (3)	C4—S2—C1—C2	−0.1 (3)
C12—C10—C8—C9	5.9 (5)	C4—S2—C1—C6	177.6 (3)
C11—C10—C8—C2	7.8 (5)	C2—C3—C4—C5	−178.2 (3)
C12—C10—C8—C2	−173.3 (3)	C7—C3—C4—C5	0.4 (5)
C1—C2—C8—C10	55.5 (5)	C2—C3—C4—S2	0.8 (3)
C3—C2—C8—C10	−127.3 (3)	C7—C3—C4—S2	179.4 (3)
C1—C2—C8—C9	−123.7 (3)	C1—S2—C4—C3	−0.4 (3)
C3—C2—C8—C9	53.5 (4)	C1—S2—C4—C5	178.7 (3)
C8—C10—C11—N2	167 (5)	C10—C8—C9—N1	133 (7)
C12—C10—C11—N2	−12 (5)	C2—C8—C9—N1	−48 (7)