(E)-3-(2,3,4,5,6-Pentafluorostyryl)thiophene

The reaction of thiophene-3-carboxaldehyde and perfluorobenzyltriphenylphosphonium bromide in the presence of sodium hydride gave the title compound, C12H5F5S, in 70% yield. The thiophene and perfluorophenyl groups form a dihedral angle of 5.4 (2)°. The structure is characterized by a head-to-tail organization in a columnar arrangement due to π–π interactions between the thiophene and pentafluorophenyl rings with centroid–centroid distances in the range 3.698 (2)–3.802 (2) Å.

The reaction of thiophene-3-carboxaldehyde and perfluorobenzyltriphenylphosphonium bromide in the presence of sodium hydride gave the title compound, C 12 H 5 F 5 S, in 70% yield. The thiophene and perfluorophenyl groups form a dihedral angle of 5.4 (2) . The structure is characterized by a head-to-tail organization in a columnar arrangement due tointeractions between the thiophene and pentafluorophenyl rings with centroid-centroid distances in the range 3.698 (2)-3.802 (2) Å .

Related literature
For electronic materials with high conductivity due to complementary groups, see: Yamamoto et al. (2009) ;Hoeben et al. (2005). For a bottom-up approach to rational design of electronic materials, see: Lu & Lieber (2007). For thiophene derivatives used in solar cells or oLEDs, see: Osaka & McCullough (2008); Mishra et al. (2009). For the structure of 2,5-dibromo-3- (2,3,4,5,6-pentafluorostyryl) (Bruker, 2007); data reduction: SAINT; 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 Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009  The development of new electronic devices is currently performed through the engineering of organic electronic materials composed of π-conjugated polymers. The incorporation of unsaturated systems with complementary groups takes advantage of high electronic conductivity supplemented by a supramolecular organization at the nanoscale (Yamamoto et al., 2009, Hoeben et al., 2005. Therefore, the rational design of new building blocks has arisen as an essential pathway to fulfill the bottom-up approach (Lu & Lieber, 2007). As a preliminary milestone, we report the structure of (E)-3-(perfluorostyryl)thiophene (1), an intermediate aiming at the preparation of polythiophenes with self-complementary groups.
These thiophene derivatives could find applications in electronic devices with solar cell or organic light emitting diode (oLED) properties (Osaka & McCullough, 2008;Mishra et al., 2009). The structure of 1 is shown in Figure 1.
(E)-3-(perfluorostyryl)thiophene crystallizes in the space group P2 1 /c and exhibits an almost planar molecular geometry -a slight rotation of 5.4 (2)° between the L.S. planes of the thiophene and perfluorophenyl groups is observed. The π-π stacking between the aromatic rings arranges the unsaturated compound in alternating orientations within one column due to opposite dipole moments. The distance between the thiophene-perfluorophenyl centres for successive pairs is in the range 3.698 (2)-3.802 (2) Å.
The orientation of the double bonds of successive molecules in the columns is perpendicular, in contrast with 2,5dibromo-3-(perfluorostyryl)thiophene (Clément et al., 2010), where they are parallel, due to a different arrangement of the molecules with regard to the symmetry elements in the cell, although the space group is identical.
Neighboring columns in 1 are closely packed, with the molecules in neigboring columns shifted up or down by approximately half the intermolecular distance. Between columns, there are also short S-S contacts and 2 F-F interactions. For a list of short contacts, see the "Geometric parameters" table.

Refinement
All H-atoms were positioned geometrically and refined using a riding model with d(C-H) = 0.93 Å, U iso = 1.2U eq (C).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.