Mechanisms of photo-induced degradation of polythiophene derivatives: re-examination of the role of singlet oxygen
Mechanisms of photo-induced degradation of polythiophene derivatives: re-examination of the role of singlet oxygen
复制标题
聚噻吩衍生物光致降解机制：重新审视单线态氧的作用
作者：
H. Ohta;H. Koizumi
研究了单线态氧 (1O2) 在聚(3-己基噻吩) (P3HT) 和聚(3-己氧基噻吩) (P3HOT) 光诱导降解中的作用。结果表明1O2对P3HT和P3HOT的降解有相当大的作用。 P3HT 在空气中的光照射导致 π 共轭减少。 P3HOT 也发生光诱导还原，并且比 P3HT 快得多。曼索等人。据报道，1O2 是在氧气存在下通过光照射 P3HT 生成的，尽管如此，1O2 并不是 P3HT 的主要光氧化降解中间体（Manceau 等人，Macromol Rapid Commun 29：1823–1827，2008）。然而，在我们的研究中，将固体 P3HT 和 P3HOT 暴露于化学生成的 1O2 会导致 ππ* 吸收降低。 P3HOT 的下降幅度远大于 P3HT。 P3HOT 的曝光显示了极化子的形成。 P3HT和P3HOT对于光照射和1O2的影响的差异将归因于它们的电离势的差异。
Roles of singlet oxygen (1O2) in photo-induced degradation of poly(3-hexylthiophene) (P3HT) and poly(3-hexyloxythiophene) (P3HOT) were examined. The results indicate that 1O2 has a considerable role in the degradation of P3HT and P3HOT. Photo-irradiation of P3HT in air resulted in the reduction of the π-conjugation. The photo-induced reduction also occurred for P3HOT, and it was much faster than that of P3HT. Manceau et al. have reported that 1O2 was generated by photo-irradiation of P3HT in the presence of oxygen and, nevertheless, 1O2 is not the principal photo-oxidative degradation intermediate of P3HT (Manceau et al., Macromol Rapid Commun 29:1823–1827, 2008). However, exposures of solid P3HT and P3HOT to chemically generated 1O2 provided decreases in the ππ*absorption in our study. The decrease for P3HOT was much larger than that for P3HT. The exposure of P3HOT showed the formation of polarons. The difference in P3HT and P3HOT for the effects of the photo-irradiation and of 1O2 will be ascribed to the difference in their ionization potentials.