Abstract: PtL_Ⅲ absorption spectra of an electrically conductive polymer——H_2PtCl_6· 6H_2O-doped polyacetylene and the model compound K_2PtCl_6 were measured with a laboratory EXAFS system, which utilizes a high power rotating-anode X-ray gene- rator (Rigaku model RU-1000) as an X-ray source.The Fourier transforms of k~3-weighted EXAFS oscillations of sample and thc model compound are shown in Fig.3. The prominent peak in the Fourier transform for H_2PtCl_6·6H_2O-doped polyaeetylene can be attributed to the Cl atoms surrounding Pt atom. The curvefitting analysis for the first shell shows two types of neighboring Cl atoms with Pt-Cl distances of 0.2329 nm and 0.2277 nm, respectively.
According to the results from use of the theoretical and empircal methods, it is concluded that the dopant anion in polyacetylene film is PtCl_6~(2-). The result provides a direct structural information that supports the proposition: the following reaction accompanied by electron transfer from (CH)_x chains to platinum salt:
2H_2PtCl_6+2e~-→PtCl_6~(2-)+PtCl_2+4HCl