Visible Light-Induced Thiol-Ene Reaction: A New Strategy to Prepare A,omega-Dithiol and A,omega-Divinyl Telechelic Polythiolether Oligomers
Visible Light-Induced Thiol-Ene Reaction: A New Strategy to Prepare A,omega-Dithiol and A,omega-Divinyl Telechelic Polythiolether Oligomers
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可见光诱导硫醇-烯反应：制备 α,omega-二硫醇和 α,omega-二乙烯基遥爪聚硫醇醚低聚物的新策略
DOI：
10.1002/pola.27906
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Yang Wantai
中科院分区：
文献类型：
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作者：
Ma Wenchao;Chen Dong;Liu Lianying;Ma Yuhong;Wang Li;Zhao Changwen;Yang Wantai
在afac-Ir（ppy）3光氧化还原催化剂的存在下，通过可见光诱导的硫醇-烯化学反应制备了α，ω-二硫醇和α，ω-二乙烯基线型遥爪聚硫醚低聚物。通过改变1，4-苯二甲硫醇（BDMT）与二甘醇二乙烯基醚（DEGVE）的单体摩尔比，成功合成了具有明确端基和可控分子量的聚硫醚低聚物。1H NMR和MALDI-TOF MS分析表明，所制备的聚硫醚具有高端基保真度，这进一步得到了带有α，ω-二硫醇和α，ω-二乙烯基的聚硫醚的成功加聚的支持。例如，用α，ω-二硫醇-（Mn= 1900 g mol-1，PDI = 1.25）和α，ω-二乙烯基封端的（Mn= 2000 g mol-1，PDI = 1.29）聚硫醚作为大分子单体，所得聚硫醚的分子量高达7700 g mol-1，PDI为1.67。通过与N-（1-芘基）马来酰亚胺的加成反应进一步证实了末端巯基的反应性。紫外-维斯光谱和荧光光谱研究表明，fac-Ir（ppy）3与BDMT发生氧化还原猝灭反应，生成巯基自由基。根据这些结果，提出了光氧化还原催化剂催化硫醇-烯反应的机理。© 2015威利期刊公司. J.波利姆科学，A部分：聚合物Chem.2016，54，740-749
A new strategy is developed to prepare both α,ω‐dithiol and α,ω‐divinyl linear telechelic polythiolether oligomers by visible light induced thiol‐ene chemistry in the presence of afac‐Ir(ppy)3photoredox catalyst. Polythiolether oligomers of well‐defined end groups and controlled molecular weights have been successfully synthesized at varying monomer molar ratios of 1,4‐benzenedimethanethiol (BDMT) to diethylene glycol divinyl ether (DEGVE).1H NMR and MALDI‐TOF MS analyses demonstrate that as‐prepared polythiolethers possess high end‐group fidelity, which is further supported by the successful polyaddition of polythiolethers bearing α,ω‐dithiol and α,ω‐divinyl groups. For example, with the α,ω‐dithiol‐ (Mn= 1900 g mol−1, PDI = 1.25) and α,ω‐divinyl‐terminated (Mn= 2000 g mol−1, PDI = 1.29) polythiolethers as macromonomers, the molecular weight of resulting polythiolether is up to 7700 g mol−1with PDI as 1.67. The reactivity of the terminal thiol group is further confirmed by the addition reaction withN‐(1‐pyrenyl)maleimide. UV‐vis spectra and fluorescene measurements suggest thatfac‐Ir(ppy)3undergo a redox quenching process reacted with BDMT to generate thiyl free radicals. With these results, the mechanism of the thiol‐ene reaction catalyzed by photoredox catalyst is proposed. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2016,54, 740–749