A dithienothiophene derivative as a long-wavelength photosensitizer for onium salt photoinitiated cationic polymerization
A dithienothiophene derivative as a long-wavelength photosensitizer for onium salt photoinitiated cationic polymerization
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DOI：
10.1021/ma800077k
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发表时间：
2008-05-27
期刊：
影响因子：
5.5
通讯作者：
Yagci, Yusuf
中科院分区：
文献类型：
--
作者：
Aydogan, Binnur;Gundogan, Ali Senol;Yagci, Yusuf
典型单体的光敏阳离子聚合，例如环己烯氧化物和3,4-环氧环己基-3',4'-环氧环己烯甲酸酯等环氧乙烷，乙烯基醚如正丁基乙烯基醚，以及其他乙烯基单体如苯乙烯和N-乙烯基咔唑的光敏阳离子聚合，通过使用 研究了二噻吩并噻吩衍生物。这些单体的阳离子聚合反应是在室温下，在二苯基碘鎓六氟磷酸盐 (Ph2I+PF6-) 存在下，在散装或 CH2Cl2 溶液中与 3,5-二苯基二噻吩并[3,2-b:2,3-d]噻吩 (DDT) 的 lambda > 350 nm 照射下引发的。从光学吸收、荧光和磷光光谱方面研究了 DDT 的光物理性质，以提供有助于确认引发机制有效性的信息。提出了一种涉及激基复合物的形成以及随后从激发的 DDT 到碘鎓离子的电子转移的机制。
The photosensitized cationic polymerization of typical monomers, e.g., of oxiranes such as cyclohexene oxide and 3,4-epoxycyclohexyl-3',4'-epoxycyclohexene carboxylate, of vinyl ethers such as n-butyl vinyl ether, and of other vinyl monomers such as styrene and N-vinylcarbazole by using a dithienothiophene derivative was studied. The cationic polymerization of these monomers was initiated at room temperature upon irradiation at lambda > 350 nm either in bulk or CH2Cl2 solutions with 3,5-diphenyldithieno[3,2-b:2,3-d]thiophene (DDT) in the presence of diphenyliodonium hexafluorophosphate (Ph2I+PF6-). Photophysical properties of DDT were studied in terms of optical absorption, fluorescence, and phosphorescence spectroscopy in order to provide information that would be useful in confirming the validity of the initiation mechanism. A mechanism involving formation of exciplex and subsequent electron transfer from excited DDT to iodonium ions is proposed.