导电高聚物的EXAFS研究(Ⅱ)FeCl3掺杂的聚噻吩

EXAFS STUDY ON ELECTRICALLY CONDUCTIVE POLYMERS (Ⅱ) FeCl3-DOPED POLYTHIOPHENE

聚噻吩是一种共轭有机高聚物,其结构如图1所示。类似于聚乙炔,经电子受体掺杂后的聚噻吩,呈现出较高的电导率。为了阐明导电高聚物的电导机制,必须搞清掺杂后掺杂剂的化学结构和高分子链与掺杂剂之间的相互作用。前文我们报道了用扩展X射线吸收精细结构(EXAFS)谱对HPtCl·6HO掺杂聚乙炔的研究,本文报道对FeCl掺杂聚噻吩的研究结果。

Fe K absorption spectra of an electrically conductive polymer——FeCl-doped polythiophene and model compound [N(CH)][FeCl] were measured with a laboratory EXAFS system, which utilizes a high power rotating-anode X-ray generator (Rigaku model RU-1000) as a X-ray source. The analysis of observed EXAFS data shows that Fe atom is surrounded by four Cl atoms with Fe-Cl distance of 2.19. It is concluded that the dopant exists mainly in the form of FeCl. The result provides a direct structural information that strongly supports the proposition: the doping process is as follows 2FeCl+e→FeCl+ FeCl