现场拉曼光谱研究聚吡咯的去质子化和氧化降解

利用电化学现场拉曼光谱结合循环伏安法，研究了中性和碱性溶液中聚吡咯（ＰＰＹ）膜的行为及其结构．结果表明，氧化态ＰＰＹ中吡咯环Ｎ原子上的Ｈ失去发生去质子化，形成一种醌式结构．由于该醌式结构的出现使ＰＰＹ的Ｃ＝Ｃ伸缩振动峰发生分裂，且因该醌式结构不能被进一步氧化，以致ｐＨ值增大，去质子化程度提高，ＰＰＹ变得较难被氧化，而使其可逆性也受到一定程度的破坏，在ｐＨ＝１３的强碱性溶液中，ＰＰＹ膜在正于ＯＶ的电位区间内发生降解，该降解过程可能涉及到ＰＰＹ的吡咯环单元结构的破坏．

Studies of In-situ Raman Spectroscopy on Deprotonation and Degeneration of PPY Films

By combining the in-situ Raman spectroscopic technique with the normalelectrochemical measurements ,the behavior and structure of PPY films in neutral or basic solutionswere studied.The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated inthese solutions ,resulting the formation of the quinoid structure. It makes the C=C stretching vibrationbonds of PPY split.Because this quinoid structure can′t be further oxidized ,the PPY becomes moredifficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree ofdeprotonation of PPY. In the strong basic solution ( pH=13),the PPY film is degenerated in thepotential region more positive than O V. The degeneration may be related to the damage of the pyrrolering structure of PPY.