Synthesis and characterisation of 1,2-difluoro-1,2-bis(5-trimethylsilyl-2-thienyl)ethenes. A new family of conjugated monomers for oxidative polymerisation

Abstract

The synthesis of a series of (E )-1,2-difluoro-1,2-bis(2-thienyl)ethenes (DFDTEs) by low temperature reaction of 2-lithiothiophenes with tetrafluoroethene (TFE) is described. A possible explanation of the mechanism leading to the formation of higher oligomers is also elucidated together with the use of TMS as protecting group to prevent it. All compounds are thoroughly characterised and their E – configuration proved by vibrational spectroscopy.\ud The crystal structure at 120 K of a representative system evidences its essential planarity and suggests significant delocalisation of π-electrons. Fluorine atoms are involved both in short intra- and intermolecular interactions with sulfur atoms and hydrogen atoms, apparently stabilising the planar molecular arrangement

A new low band gap dithienylene-fluorovinylene electrochromic polymer: an intriguing effect of silyl substitution on the polymerisation reaction

“…3(a)) in AN with 0.2 M TBAP and 0.2 M TBAFB. In both cases, after a flow of about 1 faraday mol 21 , a very low current was reached. UV-Vis spectra before, during and after electrolysis of one of these solutions are shown in Fig.…”

“…Further details on the synthesis and the X-ray structure of DTSMO are given elsewhere. 21 The spectroscopic characterisation of the monomers ( 1 H, 13 C and 19 F NMR; chemical shifts are given in ppm, J values in Hz) are reported below.…”

Catalytic and highly enantioselective Friedel–Crafts type reactions of heteroaromatic compounds with trifluoropyruvate and glyoxylate by a dicationic palladium complex

“…PdCl 2 [(S)-BINAP] was synthesized according to the literature procedure. 18 Heteroarylsilanes 4a, 19 11b, 20 11c, 21 11g, 22 11h, 23 11k, 24 vinylsilane 7, 25 and dienylsilane 9 26 were also synthesized according to the literature procedures.…”

Synthesis, structure and cytotoxic activity of new 1‐[5‐organylsilyl(germyl)‐2‐furyl (thienyl)]nitroethenes

“…A search of the Cambridge Structural Database (CSD, Version 5.31, November 2009) indicates that there is only 1 entry containing 2‐vinyl‐5‐silylthiophene derivative. This is structure of ( E )‐1,2‐difluoro‐1,2‐bis(2‐methoxy‐5‐trimethylsilyl‐2‐thienyl)ethane,20 where the molecule is also characterized by planar conformation.…”