Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807041578/kp2126sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807041578/kp2126Isup2.hkl |
CCDC reference: 663691
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.004 Å
- R factor = 0.071
- wR factor = 0.235
- Data-to-parameter ratio = 19.6
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.97 PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.96 PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 2.13 PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ....... ? PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent ..... ? PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000) 3000 Deg. PLAT220_ALERT_2_C Large Non-Solvent C Ueq(max)/Ueq(min) ... 2.79 Ratio PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C3 PLAT371_ALERT_2_C Long C(sp2)-C(sp1) Bond C6 - C7 ... 1.44 Ang. PLAT371_ALERT_2_C Long C(sp2)-C(sp1) Bond C8 - C9 ... 1.43 Ang. PLAT371_ALERT_2_C Long C(sp2)-C(sp1) Bond C12 - C13 ... 1.43 Ang.
Alert level G PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 11 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 6 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The synthesis of the title compound was performed as described by Liu et al. (2006).
Colourless plate-like crystals of 4,4'-dicyano-(3,4-dibutyl-thienyl ethynyl) biphenyl were grown from ethanol /hexane mixture by slow evaporation of the solution.
Data collection: RAPID-AUTO (Rigaku, 2001); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Bruker, 1998); software used
to prepare material for publication: SHELXTL (Siemens, 1994).
By developing new techniques to fabricate miniature components, and to fit more components into each cm 2 of silicon, engineers have driven the speed and capabilities of computing at a predictably fast pace. But the reduction in size of components, and thus increase in speed, can only continue for some finite time. New processes are under development in order to extend the useful functionality of silicon integrated circuits (Carroll et al., 2002).
Linear, π-conjugated molecules have attracted great attention due to their potential in molecular scale electronic devices (Bloor, 1995; Bumm et al., 1996). Molecular wires typically consist of two electroactive functional groups linked by an extended π-electron network. Rainer E. Martin synthesized a series of monodisperse Me3Si -endcapped poly(triacetylene) oligomers (Martin et al., 1997; Martin et al., 1999). Here, the synthesis and crystal structures of 4,4'-dicyano- (3,4-dibutylthiophenylethynyl)biphenyl (I) are presented.
The molecular structure of the title compound (Fig. 1) is centrosymmetric. Thus, an asymmetric unit comprises a half on the molecule. The inversion centre is located in the middle of C3—C3i bond. The two phenyl rings and carbon triple bonds are coplanar. The torsion angle of C9—C8—C7—C6 is -165.6 (4)° whereas the diphenyl moiety is linear due to an inversion symmetry of the molecule. The crystal packing (Fig. 2) is dominated by van der Waals interactions.
For related literature, see: Bloor (1995); Bumm et al. (1996); Carroll & Gorman (2002); Liu et al. (2006); Martin et al. (1997, 1999).
Data collection: RAPID-AUTO (Rigaku, 2001); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Siemens, 1994 or Bruker, 1998) or XP (Bruker, 1998)?; software used to prepare material for publication: SHELXTL.
C42H44N2S2 | V = 922.3 (3) Å3 |
Mr = 640.91 | Z = 1 |
Triclinic, P1 | F(000) = 342 |
a = 8.1428 (16) Å | Dx = 1.154 Mg m−3 |
b = 9.1856 (18) Å | Mo Kα radiation, λ = 0.71073 Å |
c = 13.606 (3) Å | µ = 0.18 mm−1 |
α = 90.37 (3)° | T = 293 K |
β = 100.53 (3)° | Plate, colourless |
γ = 112.32 (3)° | 0.41 × 0.39 × 0.28 mm |
Rigaku R-AXIS RAPID IP diffractometer | 4080 independent reflections |
Radiation source: fine-focus sealed tube | 3287 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
Detector resolution: 0.76 pixels mm-1 | θmax = 27.5°, θmin = 1.5° |
Oscillation scans | h = −9→10 |
Absorption correction: empirical (using intensity measurements) (ABSCOR; Higashi, 1995) | k = −9→11 |
Tmin = 0.879, Tmax = 0.996 | l = −17→17 |
5834 measured reflections |
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)] = 0.071 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.235 | H-atom parameters constrained |
S = 1.01 | w = 1/[σ2(Fo2) + (0.1503P)2 + 0.3412P] where P = (Fo2 + 2Fc2)/3 |
4080 reflections | (Δ/σ)max < 0.001 |
208 parameters | Δρmax = 0.81 e Å−3 |
0 restraints | Δρmin = −0.38 e Å−3 |
C42H44N2S2 | γ = 112.32 (3)° |
Mr = 640.91 | V = 922.3 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.1428 (16) Å | Mo Kα radiation |
b = 9.1856 (18) Å | µ = 0.18 mm−1 |
c = 13.606 (3) Å | T = 293 K |
α = 90.37 (3)° | 0.41 × 0.39 × 0.28 mm |
β = 100.53 (3)° |
Rigaku R-AXIS RAPID IP diffractometer | 4080 independent reflections |
Absorption correction: empirical (using intensity measurements) (ABSCOR; Higashi, 1995) | 3287 reflections with I > 2σ(I) |
Tmin = 0.879, Tmax = 0.996 | Rint = 0.029 |
5834 measured reflections |
R[F2 > 2σ(F2)] = 0.071 | 0 restraints |
wR(F2) = 0.235 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.81 e Å−3 |
4080 reflections | Δρmin = −0.38 e Å−3 |
208 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. |
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. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.28848 (9) | 0.32421 (9) | 0.44787 (5) | 0.0608 (3) | |
C1 | 0.1734 (4) | 0.2078 (4) | 0.8390 (2) | 0.0766 (9) | |
H1A | 0.2773 | 0.2920 | 0.8308 | 0.092* | |
N1 | 0.4301 (5) | 0.4639 (4) | 0.2102 (3) | 0.1016 (11) | |
C2 | 0.1583 (4) | 0.1546 (4) | 0.9336 (2) | 0.0752 (9) | |
H2A | 0.2524 | 0.2049 | 0.9878 | 0.090* | |
C3 | 0.0075 (3) | 0.0290 (3) | 0.94934 (16) | 0.0469 (5) | |
C4 | −0.1306 (4) | −0.0409 (3) | 0.86606 (19) | 0.0639 (7) | |
H4A | −0.2353 | −0.1245 | 0.8740 | 0.077* | |
C5 | −0.1156 (4) | 0.0112 (3) | 0.77223 (19) | 0.0662 (7) | |
H5A | −0.2095 | −0.0393 | 0.7179 | 0.079* | |
C6 | 0.0349 (4) | 0.1361 (3) | 0.75692 (17) | 0.0533 (6) | |
C7 | 0.0492 (4) | 0.1910 (3) | 0.65898 (19) | 0.0574 (6) | |
C8 | 0.0589 (4) | 0.2360 (3) | 0.57725 (18) | 0.0556 (6) | |
C9 | 0.0843 (3) | 0.2910 (3) | 0.48107 (17) | 0.0506 (5) | |
C10 | −0.0335 (3) | 0.3280 (3) | 0.40904 (17) | 0.0492 (5) | |
C11 | 0.0437 (4) | 0.3854 (3) | 0.32413 (18) | 0.0534 (6) | |
C12 | 0.2171 (4) | 0.3890 (3) | 0.3356 (2) | 0.0589 (6) | |
C13 | 0.3348 (5) | 0.4322 (4) | 0.2656 (2) | 0.0717 (8) | |
C14 | −0.2209 (4) | 0.3068 (3) | 0.4213 (2) | 0.0589 (6) | |
H14A | −0.2454 | 0.3970 | 0.3970 | 0.071* | |
H14B | −0.2242 | 0.3058 | 0.4922 | 0.071* | |
C15 | −0.0488 (5) | 0.4360 (4) | 0.2334 (2) | 0.0686 (8) | |
H15A | 0.0366 | 0.5335 | 0.2151 | 0.082* | |
H15B | −0.1478 | 0.4583 | 0.2507 | 0.082* | |
C16 | −0.3690 (4) | 0.1584 (4) | 0.3671 (3) | 0.0848 (10) | |
H16A | −0.4820 | 0.1504 | 0.3849 | 0.102* | |
H16B | −0.3809 | 0.1699 | 0.2957 | 0.102* | |
C17 | −0.1229 (5) | 0.3166 (5) | 0.1432 (2) | 0.0803 (9) | |
H17A | −0.1959 | 0.2149 | 0.1632 | 0.096* | |
H17B | −0.0227 | 0.3054 | 0.1193 | 0.096* | |
C18 | −0.3470 (6) | 0.0111 (5) | 0.3857 (4) | 0.1018 (13) | |
H18A | −0.3299 | 0.0015 | 0.4574 | 0.122* | |
H18B | −0.2369 | 0.0170 | 0.3650 | 0.122* | |
C19 | −0.2385 (7) | 0.3634 (6) | 0.0574 (3) | 0.1009 (13) | |
H19A | −0.3402 | 0.3718 | 0.0810 | 0.121* | |
H19B | −0.1663 | 0.4668 | 0.0392 | 0.121* | |
C20 | −0.5024 (6) | −0.1393 (4) | 0.3335 (4) | 0.0994 (12) | |
H20A | −0.4765 | −0.2298 | 0.3532 | 0.149* | |
H20B | −0.5152 | −0.1357 | 0.2621 | 0.149* | |
H20C | −0.6130 | −0.1468 | 0.3526 | 0.149* | |
C21 | −0.3088 (8) | 0.2507 (7) | −0.0336 (3) | 0.1312 (19) | |
H21A | −0.3806 | 0.2867 | −0.0838 | 0.197* | |
H21B | −0.3823 | 0.1483 | −0.0167 | 0.197* | |
H21C | −0.2091 | 0.2443 | −0.0590 | 0.197* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0507 (4) | 0.0685 (5) | 0.0586 (4) | 0.0192 (3) | 0.0086 (3) | 0.0062 (3) |
C1 | 0.0565 (15) | 0.092 (2) | 0.0554 (15) | 0.0035 (15) | 0.0041 (12) | 0.0216 (14) |
N1 | 0.109 (3) | 0.090 (2) | 0.111 (2) | 0.0240 (19) | 0.067 (2) | 0.0237 (18) |
C2 | 0.0547 (14) | 0.092 (2) | 0.0499 (14) | 0.0031 (14) | −0.0033 (11) | 0.0171 (14) |
C3 | 0.0491 (12) | 0.0484 (12) | 0.0435 (11) | 0.0205 (10) | 0.0063 (9) | 0.0037 (9) |
C4 | 0.0622 (15) | 0.0614 (16) | 0.0479 (13) | 0.0051 (12) | 0.0037 (11) | 0.0033 (11) |
C5 | 0.0703 (17) | 0.0661 (16) | 0.0439 (13) | 0.0121 (13) | −0.0013 (11) | −0.0005 (11) |
C6 | 0.0623 (14) | 0.0603 (14) | 0.0433 (12) | 0.0305 (12) | 0.0100 (10) | 0.0085 (10) |
C7 | 0.0645 (15) | 0.0634 (15) | 0.0490 (13) | 0.0300 (13) | 0.0115 (11) | 0.0066 (11) |
C8 | 0.0613 (14) | 0.0601 (14) | 0.0454 (12) | 0.0242 (12) | 0.0089 (10) | 0.0054 (10) |
C9 | 0.0520 (12) | 0.0518 (12) | 0.0437 (11) | 0.0157 (10) | 0.0092 (9) | 0.0033 (9) |
C10 | 0.0549 (13) | 0.0455 (12) | 0.0443 (11) | 0.0168 (10) | 0.0086 (9) | 0.0014 (9) |
C11 | 0.0645 (14) | 0.0464 (12) | 0.0472 (12) | 0.0188 (11) | 0.0119 (10) | 0.0059 (9) |
C12 | 0.0639 (15) | 0.0546 (14) | 0.0547 (14) | 0.0160 (12) | 0.0189 (12) | 0.0096 (11) |
C13 | 0.0767 (19) | 0.0607 (16) | 0.0757 (19) | 0.0164 (14) | 0.0325 (16) | 0.0100 (13) |
C14 | 0.0606 (15) | 0.0583 (14) | 0.0621 (15) | 0.0266 (12) | 0.0149 (12) | 0.0025 (11) |
C15 | 0.094 (2) | 0.0677 (17) | 0.0520 (14) | 0.0403 (16) | 0.0142 (14) | 0.0149 (12) |
C16 | 0.0577 (17) | 0.082 (2) | 0.110 (3) | 0.0246 (16) | 0.0124 (17) | −0.0179 (19) |
C17 | 0.101 (2) | 0.092 (2) | 0.0537 (16) | 0.050 (2) | 0.0030 (15) | 0.0039 (15) |
C18 | 0.080 (2) | 0.074 (2) | 0.148 (4) | 0.028 (2) | 0.016 (2) | −0.006 (2) |
C19 | 0.122 (3) | 0.133 (4) | 0.064 (2) | 0.075 (3) | 0.001 (2) | 0.004 (2) |
C20 | 0.092 (3) | 0.067 (2) | 0.122 (3) | 0.0202 (19) | 0.004 (2) | −0.008 (2) |
C21 | 0.151 (5) | 0.169 (5) | 0.080 (3) | 0.087 (4) | −0.016 (3) | −0.010 (3) |
S1—C9 | 1.718 (3) | C14—H14A | 0.9700 |
S1—C12 | 1.725 (3) | C14—H14B | 0.9700 |
C1—C6 | 1.386 (4) | C15—C17 | 1.511 (4) |
C1—C2 | 1.389 (4) | C15—H15A | 0.9700 |
C1—H1A | 0.9300 | C15—H15B | 0.9700 |
N1—C13 | 1.140 (4) | C16—C18 | 1.448 (5) |
C2—C3 | 1.381 (4) | C16—H16A | 0.9700 |
C2—H2A | 0.9300 | C16—H16B | 0.9700 |
C3—C4 | 1.392 (4) | C17—C19 | 1.531 (5) |
C3—C3i | 1.490 (4) | C17—H17A | 0.9700 |
C4—C5 | 1.376 (4) | C17—H17B | 0.9700 |
C4—H4A | 0.9300 | C18—C20 | 1.532 (6) |
C5—C6 | 1.375 (4) | C18—H18A | 0.9700 |
C5—H5A | 0.9300 | C18—H18B | 0.9700 |
C6—C7 | 1.437 (3) | C19—C21 | 1.484 (6) |
C7—C8 | 1.195 (4) | C19—H19A | 0.9700 |
C8—C9 | 1.428 (3) | C19—H19B | 0.9700 |
C9—C10 | 1.380 (4) | C20—H20A | 0.9600 |
C10—C11 | 1.425 (3) | C20—H20B | 0.9600 |
C10—C14 | 1.504 (4) | C20—H20C | 0.9600 |
C11—C12 | 1.380 (4) | C21—H21A | 0.9600 |
C11—C15 | 1.497 (4) | C21—H21B | 0.9600 |
C12—C13 | 1.425 (4) | C21—H21C | 0.9600 |
C14—C16 | 1.506 (4) | ||
C9—S1—C12 | 90.36 (13) | C11—C15—H15A | 108.6 |
C6—C1—C2 | 120.4 (3) | C17—C15—H15A | 108.6 |
C6—C1—H1A | 119.8 | C11—C15—H15B | 108.6 |
C2—C1—H1A | 119.8 | C17—C15—H15B | 108.6 |
C3—C2—C1 | 121.9 (3) | H15A—C15—H15B | 107.6 |
C3—C2—H2A | 119.1 | C18—C16—C14 | 117.0 (3) |
C1—C2—H2A | 119.1 | C18—C16—H16A | 108.0 |
C2—C3—C4 | 116.9 (2) | C14—C16—H16A | 108.0 |
C2—C3—C3i | 121.7 (3) | C18—C16—H16B | 108.0 |
C4—C3—C3i | 121.4 (3) | C14—C16—H16B | 108.0 |
C5—C4—C3 | 121.4 (3) | H16A—C16—H16B | 107.3 |
C5—C4—H4A | 119.3 | C15—C17—C19 | 112.6 (3) |
C3—C4—H4A | 119.3 | C15—C17—H17A | 109.1 |
C6—C5—C4 | 121.5 (3) | C19—C17—H17A | 109.1 |
C6—C5—H5A | 119.2 | C15—C17—H17B | 109.1 |
C4—C5—H5A | 119.2 | C19—C17—H17B | 109.1 |
C5—C6—C1 | 117.9 (2) | H17A—C17—H17B | 107.8 |
C5—C6—C7 | 121.3 (2) | C16—C18—C20 | 116.4 (4) |
C1—C6—C7 | 120.8 (3) | C16—C18—H18A | 108.2 |
C8—C7—C6 | 179.2 (3) | C20—C18—H18A | 108.2 |
C7—C8—C9 | 175.7 (3) | C16—C18—H18B | 108.2 |
C10—C9—C8 | 128.5 (2) | C20—C18—H18B | 108.2 |
C10—C9—S1 | 113.10 (18) | H18A—C18—H18B | 107.4 |
C8—C9—S1 | 118.34 (19) | C21—C19—C17 | 114.0 (4) |
C9—C10—C11 | 112.0 (2) | C21—C19—H19A | 108.8 |
C9—C10—C14 | 122.5 (2) | C17—C19—H19A | 108.8 |
C11—C10—C14 | 125.5 (2) | C21—C19—H19B | 108.8 |
C12—C11—C10 | 111.3 (2) | C17—C19—H19B | 108.8 |
C12—C11—C15 | 123.5 (2) | H19A—C19—H19B | 107.7 |
C10—C11—C15 | 125.2 (3) | C18—C20—H20A | 109.5 |
C11—C12—C13 | 128.0 (3) | C18—C20—H20B | 109.5 |
C11—C12—S1 | 113.28 (19) | H20A—C20—H20B | 109.5 |
C13—C12—S1 | 118.7 (2) | C18—C20—H20C | 109.5 |
N1—C13—C12 | 178.3 (4) | H20A—C20—H20C | 109.5 |
C10—C14—C16 | 114.4 (2) | H20B—C20—H20C | 109.5 |
C10—C14—H14A | 108.7 | C19—C21—H21A | 109.5 |
C16—C14—H14A | 108.7 | C19—C21—H21B | 109.5 |
C10—C14—H14B | 108.7 | H21A—C21—H21B | 109.5 |
C16—C14—H14B | 108.7 | C19—C21—H21C | 109.5 |
H14A—C14—H14B | 107.6 | H21A—C21—H21C | 109.5 |
C11—C15—C17 | 114.6 (2) | H21B—C21—H21C | 109.5 |
C12—C11—C10—C9 | 0.1 (3) | C1—C2—C3—C4 | −0.9 (5) |
C12—S1—C9—C10 | 0.0 (3) | C5—C4—C3—C2 | 1.1 (6) |
C10—C11—C12—S1 | −0.1 (1) | C5—C6—C1—C2 | −0.4 (5) |
C11—C12—S1—C9 | 0.0 (5) | C12—C11—C15—C17 | 77.9 (4) |
C11—C10—C9—S1 | −0.1 (3) | C11—C15—C17—C19 | 172.0 (7) |
C11—C10—C9—C8 | 177.5 (5) | C15—C17—C19—C21 | 178.2 (5) |
C12—S1—C9—C8 | −177.8 (8) | C10—C11—C15—C17 | −102.1 (3) |
C7—C6—C5—C4 | −179.4 (1) | C11—C10—C14—C16 | 79.8 (7) |
C7—C6—C1—C2 | 179.6 (8) | C9—C10—C14—C16 | −99.4 (5) |
C6—C5—C4—C3 | −1.1 (5) | C10—C14—C16—C18 | 52.3 (7) |
C6—C1—C2—C3 | 0.5 (7) | C14—C16—C18—C20 | 177.5 (2) |
C4—C5—C6—C1 | 0.7 (2) | C4—C3—C3—C4 | 90.00 (3) |
Symmetry code: (i) −x, −y, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C42H44N2S2 |
Mr | 640.91 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.1428 (16), 9.1856 (18), 13.606 (3) |
α, β, γ (°) | 90.37 (3), 100.53 (3), 112.32 (3) |
V (Å3) | 922.3 (3) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 0.18 |
Crystal size (mm) | 0.41 × 0.39 × 0.28 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID IP |
Absorption correction | Empirical (using intensity measurements) (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.879, 0.996 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5834, 4080, 3287 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.071, 0.235, 1.01 |
No. of reflections | 4080 |
No. of parameters | 208 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.81, −0.38 |
Computer programs: RAPID-AUTO (Rigaku, 2001), RAPID-AUTO, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Siemens, 1994 or Bruker, 1998) or XP (Bruker, 1998)?, SHELXTL.
By developing new techniques to fabricate miniature components, and to fit more components into each cm 2 of silicon, engineers have driven the speed and capabilities of computing at a predictably fast pace. But the reduction in size of components, and thus increase in speed, can only continue for some finite time. New processes are under development in order to extend the useful functionality of silicon integrated circuits (Carroll et al., 2002).
Linear, π-conjugated molecules have attracted great attention due to their potential in molecular scale electronic devices (Bloor, 1995; Bumm et al., 1996). Molecular wires typically consist of two electroactive functional groups linked by an extended π-electron network. Rainer E. Martin synthesized a series of monodisperse Me3Si -endcapped poly(triacetylene) oligomers (Martin et al., 1997; Martin et al., 1999). Here, the synthesis and crystal structures of 4,4'-dicyano- (3,4-dibutylthiophenylethynyl)biphenyl (I) are presented.
The molecular structure of the title compound (Fig. 1) is centrosymmetric. Thus, an asymmetric unit comprises a half on the molecule. The inversion centre is located in the middle of C3—C3i bond. The two phenyl rings and carbon triple bonds are coplanar. The torsion angle of C9—C8—C7—C6 is -165.6 (4)° whereas the diphenyl moiety is linear due to an inversion symmetry of the molecule. The crystal packing (Fig. 2) is dominated by van der Waals interactions.