Synthesis and characterisation of 1,2-difluoro-1,2-bis(5-trimethylsilyl-2-thienyl)ethenes. A new family of conjugated monomers for oxidative polymerisation
作者:Luca Albertin、Chiara Bertarelli、Maria C. Gallazzi、Stefano V. Meille、Silvia C. Capelli
DOI:10.1039/b203589h
日期:2002.10.1
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. 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.
描述了一系列(E)-1,2-二氟-1,2-二(2-噻吩基)乙烯(DFDTEs)的合成,采用低温反应将2-锂噻吩与四氟乙烯(TFE)反应。也阐明了导致更高聚合物形成的机制的可能解释,并提出使用TMS作为保护基团以防止这一现象。所有化合物均经过彻底表征,其E构型通过振动光谱学得以证明。一个代表性系统在120 K下的晶体结构证实了其基本的平面性,并表明π-电子存在显著的去局域化。氟原子参与了与硫原子和氢原子的短程分子内及分子间相互作用,显然稳定了平面的分子排列。