Kermagoret Anthony, Nakamura Yasuyuki, Bourguignon Maxime, Detrembleur Christophe, Jérôme Christine, Yamago Shigeru, Debuigne Antoine
Center for Education and Research on Macromolecules (CERM), Department of Chemistry, University of Liège (ULg), Sart-Tilman, B6a, 4000 Liège, Belgium.
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
ACS Macro Lett. 2014 Jan 21;3(1):114-118. doi: 10.1021/mz400635h. Epub 2014 Jan 6.
Cobalt-mediated radical polymerization (CMRP) and tellurium-mediated radical polymerization (TERP) were combined for the first time, offering new perspectives in the precision design of macromolecular structures. In particular, the present work highlights the benefits of this strategy for the synthesis of novel poly(vinyl acetate)-based block copolymers. A range of well-defined poly(vinyl acetate)s (PVAc) were first produced via CMRP using the bis(acetylacetonato)cobalt(II) complex (Co(acac)) as a regulating agent. Substitution of a methyltellanyl moiety for Co(acac) at the ω-chain end of the precursor was then achieved upon treatment with dimethylditelluride. In contrast to the PVAc prepared by TERP, the ones produced by sequential CMRP and Co/Te exchange reaction almost exclusively consist of regular head-to-tail-TeMe chain-end species that can be activated by TERP. Ultimately, a series of monomers problematic in Co(acac)-mediated radical polymerization including -isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl acrylate (ADAME), -butyl acrylate (BA), isoprene (IP), and vinylimidazole (NVIm) were polymerized by TERP from the PVAc-TeMe macroinitiators leading to novel diblock copolymers that cannot be made by each technique used separately.
首次将钴介导的自由基聚合（CMRP）和碲介导的自由基聚合（TERP）相结合，为大分子结构的精确设计提供了新的视角。特别是，本工作突出了该策略在合成新型聚醋酸乙烯酯基嵌段共聚物方面的优势。首先通过使用双（乙酰丙酮基）钴（II）配合物（Co(acac)）作为调节剂的CMRP制备了一系列结构明确的聚醋酸乙烯酯（PVAc）。在用二甲基二碲化物处理后，在前体的ω链端用甲基碲基部分取代Co(acac)。与通过TERP制备的PVAc相比，通过顺序CMRP和Co/Te交换反应制备的PVAc几乎完全由可被TERP活化的规则头对尾-TeMe链端物种组成。最终，通过TERP从PVAc-TeMe大分子引发剂聚合了一系列在Co(acac)介导的自由基聚合中存在问题的单体，包括N-异丙基丙烯酰胺（NIPAM）、丙烯酸2-（二甲氨基）乙酯（ADAME）、丙烯酸丁酯（BA）、异戊二烯（IP）和乙烯基咪唑（NVIm），得到了单独使用每种技术无法制备的新型二嵌段共聚物。
