(Z)-2-Phenyl-3-(2,2′:5′,2′′-terthio­phen-3′-yl)acrylonitrile

In the crystal structure of the title compound, C₂₁H₁₃NS₃, one of the terminal thio­phene rings is disordered in approximately a 3:1 ratio of components, and the disorder is of the flip type. The terthio­phene units are far from coplanarity, in contrast to terthio­phene itself. The conformation might be described, for the unit of greater occupancy, as quasi-cis [the S—C—C—S torsion angle is 41.1 (5)°] quasi-trans [the S—C—C—S torsion angle is −140.1 (4)°], and for the less-occupied part as quasi-cis–quasi-cis [35.7 (6)°]. The dihedral angle between the terminal ring planes is as high as 71.7 (2)°. The central C—C=C—C group is almost planar [maximum deviation of 0.027 (3) Å] and it is approximately equally twisted with respect to both the central thio­phene and the phenyl ring planes [26.5 (4) and 23.5 (7)°, respectively]. The crystal packing is determined by van der Waals inter­actions, and some weak C—H...N and C—H...π relatively short directional contacts.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.007 Å
• Disorder in main residue
• R factor = 0.066
• wR factor = 0.153
• Data-to-parameter ratio = 13.1

checkCIF/PLATON results

No syntax errors found



Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.149
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.15
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.25
PLAT301_ALERT_3_C Main Residue  Disorder .........................       7.00 Perc.
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          7
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C13    -   C14    ...       1.31 Ang.
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C17    -   C18    ...       1.42 Ang.

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......         51

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   8 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   6 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

S1. Comment

Oligo- and polythiophenes, potentially applicable as sollar cells, light-emitting diodes or NLO materials (Skotheim & Reynolds, 2007) are widely studied due to their good chemical stability in both oxidized and reduced states, and to relatively easy functionalization of the monomers whether thiophene, bithiophene, or terthiophene (for example: Roncali, 1999; Grant & Officer, 2005 and references therein).

Recently we have proposed an alternative approach to the formation of regioregular styryl-functionalized oligo- and polythiophenes (for example, Collis et al., 2003; Grant & Officer, 2005). We have demonstrated that the styryl functionality can control oligomer regioregularity and provides advantages in some applications. However styrylterthiophenes largely form dimers on oxidative polymerization as a result of "polaron trapping" (Clarke et al., 2007).

There is a flip-disorder of one of the terminal thiophene rings. The disorder is connected with two statistically distributed orientations of the thiophene sulfur atom. In practice that means that there are two molecules in which the thiophene rings are rotated by 180° approximately along the line that bisects the S—C—C angle. These two orientations are not equivalent, but they are distributed approximately in 3:1 proportion. The conformation of the molecule of greater occupancy might be described as quasi-trans-quasi-cis, while that of smaller occupancy is quasi-cis-quasi-cis. A disorder of this kind is often observed in the structures of simple thiophene and terthiophene derivatives with one substituent; for example in similar (E)-3'-(2-(4-cyanophenyl)ethenyl)-[2,2':5',2'']terthiophene (Collis et al., 2003) or in 3-(2-(anthracen-9-yl)ethenyl)-thiophene (Wagner et al., 2006).

The terthiophene rings are approximately planar (maximum deviation is 0.020 (6) Å), but the dihedral angles between their planes are large (for instance, between the terminal rings it is 71.7 (2)°). Also the planar (within 0.012 (3) Å) phenyl ring is inclined by 49.9 (2)° with respect to the central thiophene ring. In the crystal structure the van der Waals forces seem to determine the packing. Some weak specific C13—H13···N19ⁱ and C25—H25···π (Cg1ⁱⁱ) (Cg1 is the centroid of C11···C15 thiophene ring, symmetry codes as in Table 1) directional interactions also might be of some importance.

Related literature

Similar flip-type disorder was observed in other 3'-arylvinyl derivatives of terthiophene [without additional substituents at the vinyl group, e.g. Wagner et al. (2007)], or in simple thiophene derivatives (e.g. Sonar et al., 2004, 2005; Wagner et al., 2006). For related literature, see: Clarke et al. (2007); Collis et al. (2003); Grant & Officer (2005); Roncali (1999); Skotheim & Reynolds (2007).

S2. Refinement

Hydrogen atoms were placed at calculated positions and refined as 'riding model' with isotropic thermal parameters set at 1.2 (1.3 for methyl groups) times the U_eq values of appropriate carrier atoms. In the disordered part, the carbon atoms of the were constrained to have the same components of the displacement tensor as the sulfur atoms occupying the same site. Weak restraints were also applied to the geometry of disordered fragment.

Computing details

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. The molecular structure of (I), with displacement ellipsoids drawn at the 50% probability level for non H-atoms (Siemens, 1989)

(2Z)-2-Phenyl-3-(2,2':5',2''-terthiophen-3'-yl)acrylonitrile

Crystal data

C21H13NS3	F(000) = 776
Mr = 375.50	Dx = 1.432 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2212 reflections
a = 9.167 (1) Å	θ = 5–15°
b = 19.564 (2) Å	µ = 0.43 mm^−1
c = 10.424 (1) Å	T = 173 K
β = 111.30 (1)°	Block, yellow
V = 1741.8 (3) Å^3	0.26 × 0.2 × 0.16 mm
Z = 4

Data collection

Bruker P4 CCD diffractometer	1861 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.149
Graphite monochromator	θmax = 25.0°, θmin = 2.1°
ω scans	h = −10→10
10129 measured reflections	k = −23→22
3054 independent reflections	l = −11→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.153	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.05P)^2] where P = (Fo^2 + 2Fc^2)/3
3054 reflections	(Δ/σ)max < 0.001
233 parameters	Δρmax = 0.56 e Å^−3
51 restraints	Δρmin = −0.68 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	Occ. (<1)
S1	0.56931 (14)	0.14221 (6)	−0.00033 (13)	0.0210 (3)
C2	0.6725 (5)	0.0783 (2)	0.1084 (5)	0.0159 (11)
C3	0.7043 (6)	0.0252 (2)	0.0376 (5)	0.0183 (11)
C4	0.6420 (5)	0.0369 (2)	−0.1078 (5)	0.0178 (11)
H4	0.6522	0.0058	−0.1716	0.021*
C5	0.5666 (5)	0.0978 (2)	−0.1438 (5)	0.0185 (11)
C6	0.7141 (5)	0.0857 (2)	0.2557 (5)	0.0180 (11)
S7	0.58362 (16)	0.11909 (7)	0.32299 (13)	0.0260 (4)
C8	0.7152 (6)	0.1126 (3)	0.4875 (5)	0.0260 (13)
H8	0.6952	0.1262	0.5650	0.031*
C9	0.8511 (6)	0.0855 (3)	0.4913 (5)	0.0270 (13)
H9	0.9350	0.0775	0.5729	0.032*
C10	0.8555 (5)	0.0704 (2)	0.3611 (4)	0.0158 (11)
H10	0.9423	0.0524	0.3469	0.019*
C11	0.4806 (5)	0.1228 (2)	−0.2812 (5)	0.0201 (11)
S12	0.3782 (5)	0.06990 (10)	−0.4104 (3)	0.0205 (7)	0.725 (5)
C12	0.379 (5)	0.0865 (15)	−0.413 (3)	0.0205 (7)	0.275 (5)
H12	0.3736	0.0391	−0.4138	0.025*	0.275 (5)
C13	0.3084 (6)	0.1337 (3)	−0.5189 (6)	0.0325 (14)
H13	0.2411	0.1261	−0.6091	0.039*
C14	0.3516 (6)	0.1956 (3)	−0.4733 (5)	0.0314 (14)
H14	0.3198	0.2362	−0.5218	0.038*
C15	0.4584 (14)	0.1880 (5)	−0.3325 (10)	0.0231 (12)	0.725 (5)
H15	0.5091	0.2253	−0.2798	0.028*	0.725 (5)
S15	0.4713 (9)	0.2068 (2)	−0.3123 (6)	0.0231 (12)	0.275 (5)
C16	0.7830 (5)	−0.0363 (2)	0.1054 (5)	0.0192 (11)
H16	0.7778	−0.0452	0.1913	0.023*
C17	0.8621 (5)	−0.0818 (2)	0.0607 (5)	0.0171 (11)
C18	0.8859 (5)	−0.0716 (2)	−0.0653 (5)	0.0172 (11)
N19	0.9073 (5)	−0.0643 (2)	−0.1664 (4)	0.0265 (11)
C20	0.9287 (5)	−0.1459 (2)	0.1335 (5)	0.0175 (11)
C21	1.0512 (6)	−0.1787 (3)	0.1111 (5)	0.0223 (12)
H21	1.0948	−0.1594	0.0518	0.027*
C22	1.1089 (6)	−0.2397 (3)	0.1758 (5)	0.0266 (13)
H22	1.1898	−0.2618	0.1586	0.032*
C23	1.0471 (6)	−0.2681 (3)	0.2657 (5)	0.0260 (13)
H23	1.0861	−0.3092	0.3095	0.031*
C24	0.9279 (5)	−0.2354 (3)	0.2906 (5)	0.0238 (12)
H24	0.8860	−0.2544	0.3515	0.029*
C25	0.8696 (5)	−0.1743 (2)	0.2257 (5)	0.0196 (11)
H25	0.7898	−0.1521	0.2443	0.024*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0144 (7)	0.0187 (7)	0.0234 (7)	0.0031 (6)	−0.0008 (5)	−0.0007 (5)
C2	0.0102 (18)	0.0141 (18)	0.0197 (17)	0.0004 (15)	0.0008 (14)	0.0010 (14)
C3	0.0141 (19)	0.0172 (18)	0.0217 (18)	−0.0004 (15)	0.0043 (15)	−0.0006 (15)
C4	0.009 (3)	0.020 (3)	0.022 (3)	−0.003 (2)	0.002 (2)	−0.007 (2)
C5	0.010 (3)	0.023 (3)	0.018 (3)	−0.003 (2)	0.000 (2)	0.000 (2)
C6	0.018 (3)	0.011 (2)	0.022 (3)	0.000 (2)	0.003 (2)	0.001 (2)
S7	0.0199 (8)	0.0254 (7)	0.0299 (8)	−0.0009 (6)	0.0056 (6)	−0.0038 (6)
C8	0.031 (3)	0.027 (3)	0.017 (3)	−0.008 (3)	0.005 (2)	−0.007 (2)
C9	0.022 (3)	0.027 (3)	0.023 (3)	−0.008 (3)	−0.003 (2)	−0.001 (2)
C10	0.0124 (18)	0.0140 (17)	0.0192 (18)	−0.0028 (15)	0.0035 (14)	−0.0001 (14)
C11	0.0154 (19)	0.0203 (19)	0.0215 (18)	−0.0012 (16)	0.0032 (15)	−0.0036 (15)
S12	0.0168 (10)	0.0152 (15)	0.0226 (10)	−0.0020 (12)	−0.0010 (7)	0.0007 (9)
C12	0.0168 (10)	0.0152 (15)	0.0226 (10)	−0.0020 (12)	−0.0010 (7)	0.0007 (9)
C13	0.023 (3)	0.038 (4)	0.029 (3)	−0.006 (3)	0.001 (2)	0.000 (3)
C14	0.018 (3)	0.034 (3)	0.038 (3)	0.005 (3)	0.006 (3)	0.014 (3)
C15	0.0199 (16)	0.019 (2)	0.0227 (17)	−0.0020 (17)	−0.0010 (13)	−0.0084 (16)
S15	0.0199 (16)	0.019 (2)	0.0227 (17)	−0.0020 (17)	−0.0010 (13)	−0.0084 (16)
C16	0.011 (3)	0.021 (3)	0.021 (3)	−0.003 (2)	−0.001 (2)	−0.001 (2)
C17	0.0134 (18)	0.0159 (18)	0.0178 (17)	−0.0018 (15)	0.0006 (14)	−0.0025 (14)
C18	0.0126 (18)	0.0162 (18)	0.0193 (18)	0.0005 (15)	0.0016 (14)	−0.0022 (15)
N19	0.014 (2)	0.029 (3)	0.030 (3)	0.003 (2)	0.0006 (19)	−0.004 (2)
C20	0.0141 (18)	0.0163 (18)	0.0171 (17)	−0.0001 (16)	−0.0002 (14)	−0.0016 (15)
C21	0.015 (3)	0.024 (3)	0.026 (3)	−0.001 (2)	0.004 (2)	−0.002 (2)
C22	0.013 (3)	0.024 (3)	0.035 (3)	0.009 (3)	−0.001 (2)	−0.004 (2)
C23	0.017 (3)	0.021 (3)	0.031 (3)	0.008 (3)	−0.003 (2)	−0.001 (2)
C24	0.017 (3)	0.027 (3)	0.019 (3)	0.000 (3)	−0.003 (2)	0.000 (2)
C25	0.007 (3)	0.019 (3)	0.025 (3)	0.002 (2)	−0.003 (2)	−0.008 (2)

Geometric parameters (Å, º)

S1—C2	1.721 (5)	C12—H12	0.9300
S1—C5	1.722 (5)	C13—C14	1.309 (7)
C2—C3	1.366 (6)	C13—H13	0.9300
C2—C6	1.449 (6)	C14—C15	1.446 (11)
C3—C4	1.431 (6)	C14—S15	1.653 (5)
C3—C16	1.448 (6)	C14—H14	0.9300
C4—C5	1.360 (6)	C15—H15	0.9300
C4—H4	0.9300	C16—C17	1.335 (6)
C5—C11	1.447 (6)	C16—H16	0.9300
C6—C10	1.394 (6)	C17—C18	1.422 (6)
C6—S7	1.720 (5)	C17—C20	1.479 (6)
S7—C8	1.706 (5)	C18—N19	1.148 (5)
C8—C9	1.342 (7)	C20—C25	1.380 (6)
C8—H8	0.9300	C20—C21	1.384 (6)
C9—C10	1.404 (6)	C21—C22	1.378 (7)
C9—H9	0.9300	C21—H21	0.9300
C10—H10	0.9300	C22—C23	1.376 (7)
C11—C15	1.369 (10)	C22—H22	0.9300
C11—C12	1.53 (4)	C23—C24	1.370 (6)
C11—S15	1.670 (4)	C23—H23	0.9300
C11—S12	1.688 (5)	C24—C25	1.382 (7)
S12—C13	1.650 (6)	C24—H24	0.9300
C12—C13	1.402 (5)	C25—H25	0.9300
C2—S1—C5	92.1 (2)	C14—C13—H13	121.2
C3—C2—C6	128.5 (4)	C12—C13—H13	129.5
C3—C2—S1	111.7 (3)	S12—C13—H13	121.4
C6—C2—S1	119.8 (3)	C13—C14—C15	106.1 (6)
C2—C3—C4	111.7 (4)	C13—C14—S15	119.5 (4)
C2—C3—C16	122.3 (4)	C13—C14—H14	126.9
C4—C3—C16	125.9 (4)	C15—C14—H14	127.0
C5—C4—C3	113.5 (4)	S15—C14—H14	113.6
C5—C4—H4	123.3	C11—C15—C14	116.2 (7)
C3—C4—H4	123.2	C11—C15—H15	121.9
C4—C5—C11	127.5 (4)	C14—C15—H15	121.9
C4—C5—S1	110.9 (3)	C14—S15—C11	92.0 (3)
C11—C5—S1	121.3 (4)	C17—C16—C3	128.4 (5)
C10—C6—C2	128.7 (4)	C17—C16—H16	115.8
C10—C6—S7	110.2 (3)	C3—C16—H16	115.8
C2—C6—S7	121.0 (3)	C16—C17—C18	120.9 (4)
C8—S7—C6	92.2 (2)	C16—C17—C20	124.3 (4)
C9—C8—S7	111.6 (4)	C18—C17—C20	114.8 (4)
C9—C8—H8	124.2	N19—C18—C17	178.7 (5)
S7—C8—H8	124.2	C25—C20—C21	118.6 (5)
C8—C9—C10	114.1 (5)	C25—C20—C17	120.3 (4)
C8—C9—H9	123.0	C21—C20—C17	121.1 (4)
C10—C9—H9	123.0	C22—C21—C20	120.6 (5)
C6—C10—C9	111.8 (4)	C22—C21—H21	119.7
C6—C10—H10	124.1	C20—C21—H21	119.7
C9—C10—H10	124.1	C23—C22—C21	120.2 (5)
C15—C11—C5	130.7 (5)	C23—C22—H22	119.9
C5—C11—C12	132.0 (7)	C21—C22—H22	119.9
C5—C11—S15	119.7 (4)	C24—C23—C22	119.7 (5)
C12—C11—S15	108.1 (7)	C24—C23—H23	120.1
C15—C11—S12	107.4 (5)	C22—C23—H23	120.2
C5—C11—S12	121.8 (3)	C23—C24—C25	120.3 (5)
C13—S12—C11	92.7 (3)	C23—C24—H24	119.9
C13—C12—C11	111 (2)	C25—C24—H24	119.9
C13—C12—H12	130.0	C20—C25—C24	120.6 (5)
C11—C12—H12	119.0	C20—C25—H25	119.7
C14—C13—C12	109.3 (17)	C24—C25—H25	119.7
C14—C13—S12	117.4 (4)
C5—S1—C2—C3	0.3 (4)	C5—C11—S12—C13	175.6 (4)
C5—S1—C2—C6	−179.7 (4)	C5—C11—C12—C13	174.9 (13)
C6—C2—C3—C4	179.5 (4)	S15—C11—C12—C13	0 (3)
S1—C2—C3—C4	−0.5 (5)	C11—C12—C13—C14	0 (3)
C6—C2—C3—C16	3.2 (8)	C11—S12—C13—C14	0.2 (5)
S1—C2—C3—C16	−176.8 (4)	S12—C13—C14—C15	1.7 (8)
C2—C3—C4—C5	0.5 (6)	C12—C13—C14—S15	0 (2)
C16—C3—C4—C5	176.6 (4)	C5—C11—C15—C14	−173.9 (6)
C3—C4—C5—C11	−174.8 (4)	S15—C11—C15—C14	−168 (5)
C3—C4—C5—S1	−0.3 (5)	S12—C11—C15—C14	3.5 (11)
C2—S1—C5—C4	0.0 (4)	C13—C14—C15—C11	−3.4 (12)
C2—S1—C5—C11	174.9 (4)	C13—C14—S15—C11	−0.1 (7)
C3—C2—C6—C10	43.0 (8)	C15—C14—S15—C11	−7 (3)
S1—C2—C6—C10	−137.0 (4)	C5—C11—S15—C14	−175.7 (4)
C3—C2—C6—S7	−138.9 (4)	C12—C11—S15—C14	0 (2)
S1—C2—C6—S7	41.1 (5)	C2—C3—C16—C17	−158.0 (5)
C10—C6—S7—C8	0.0 (4)	C4—C3—C16—C17	26.3 (8)
C2—C6—S7—C8	−178.5 (4)	C3—C16—C17—C18	3.7 (8)
C6—S7—C8—C9	−0.8 (4)	C3—C16—C17—C20	−175.3 (4)
S7—C8—C9—C10	1.4 (6)	C16—C17—C20—C25	22.4 (7)
C2—C6—C10—C9	179.1 (5)	C18—C17—C20—C25	−156.6 (4)
S7—C6—C10—C9	0.8 (5)	C16—C17—C20—C21	−157.5 (5)
C8—C9—C10—C6	−1.5 (6)	C18—C17—C20—C21	23.4 (6)
C4—C5—C11—C15	−148.9 (9)	C25—C20—C21—C22	2.3 (7)
S1—C5—C11—C15	37.0 (10)	C17—C20—C21—C22	−177.7 (4)
C4—C5—C11—C12	35 (3)	C20—C21—C22—C23	−1.3 (7)
S1—C5—C11—C12	−139 (2)	C21—C22—C23—C24	0.0 (7)
C4—C5—C11—S15	−150.2 (6)	C22—C23—C24—C25	0.1 (7)
S1—C5—C11—S15	35.7 (6)	C21—C20—C25—C24	−2.2 (7)
C4—C5—C11—S12	34.0 (7)	C17—C20—C25—C24	177.9 (4)
S1—C5—C11—S12	−140.1 (4)	C23—C24—C25—C20	1.0 (7)
C15—C11—S12—C13	−2.1 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C13—H13···N19^i	0.93	2.54	3.435 (7)	161

Symmetry code: (i) −x+1, −y, −z−1.