Kang Eun-Hye, Choi Tae-Lim
Department of Chemistry, Seoul National University, Seoul 151-747, Korea.
ACS Macro Lett. 2013 Sep 17;2(9):780-784. doi: 10.1021/mz400338p. Epub 2013 Aug 19.
We report the conformational change resulting from the coil-to-rod transition in conjugated polymers prepared by the cyclopolymerization of 1,6-heptadiyne derivatives (poly(cyclopentenylene-vinylene), PCPV). By aging a PCPV solution under various conditions, we observed dramatic changes in their absorption spectra (appearance of a 0-0 vibronic peak) and an increase in the Mark-Houwink-Sakurada shape parameter, thereby confirming the coil-to-rod transition of the polymer. Further studies using NMR spectroscopy and various control experiments demonstrated that the coil-to-rod transformation resulted from the -to- isomerization of the conjugated olefins by a radical mechanism.
我们报道了通过1,6-庚二炔衍生物（聚（环戊烯撑-亚乙烯基），PCPV）的环化聚合制备的共轭聚合物中由线圈到棒的转变引起的构象变化。通过在各种条件下老化PCPV溶液，我们观察到它们的吸收光谱发生了显著变化（出现0-0振动峰）以及马克-豪温克-樱田形状参数增加，从而证实了聚合物的线圈到棒的转变。使用核磁共振光谱和各种对照实验的进一步研究表明，线圈到棒的转变是由共轭烯烃通过自由基机制的 - 到 - 异构化引起的。
