Zhong Yi, Li Min, Deng Meng, Gong Mingliang, Xie Hongzhen, Luo Yunjie
School of Materials Science and Chemical Engineering, Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Ningbo University, Ningbo 315211, P. R. China.
Dalton Trans. 2021 Jan 7;50(1):346-354. doi: 10.1039/d0dt03680c. Epub 2020 Dec 14.
Redox-controlled polymerization is one of the new and efficient strategies to precisely construct the microstructures of polymeric materials, and thus has received increasing attention in the chemical community. Salt metathesis of ScCl with 1 equiv. of Fc(1-CH)Li (where Fc = ferrocenyl group), followed by the addition of 2 equiv. of LiCHCHNMe-o in THF at room temperature gave the ferrocenyl functionalized half-sandwich scandium bis(o-dimethylaminobenzyl) complex [Fc(1-CH)]Sc(CHCHNMe-o) (1) in 89% isolated yield. This complex was characterized by elemental analysis, FT-IR spectroscopy, NMR spectroscopy and single-crystal X-ray diffraction. Treatment of 1 with 1 equiv. of [PhC][B(CF)] in THF generated the THF-coordinated cationic half-sandwich scandium mono(o-dimethylaminobenzyl) complex {[Fc(1-CH)]Sc(CHCHNMe-o)}{[B(CF)]} (2-THF). Switching in situ between the oxidized and reduced forms of active THF-free species (originally generated from 1/[PhC][B(CF)] in situ) resulted in the redox-controlled syndio-specific polymerization of styrene.
氧化还原控制的聚合反应是精确构建聚合物材料微观结构的新型高效策略之一，因此在化学界受到越来越多的关注。将ScCl与1当量的Fc(1-CH)Li（其中Fc = 二茂铁基）进行盐复分解反应，然后在室温下于四氢呋喃中加入2当量的LiCHCHNMe-o，得到二茂铁基官能化的半夹心钪双(邻二甲基氨基苄基)配合物[Fc(1-CH)]Sc(CHCHNMe-o)（1），分离产率为89%。该配合物通过元素分析、傅里叶变换红外光谱、核磁共振光谱和单晶X射线衍射进行表征。在四氢呋喃中用1当量的[PhC][B(CF)]处理1，生成四氢呋喃配位的阳离子半夹心钪单(邻二甲基氨基苄基)配合物{[Fc(1-CH)]Sc(CHCHNMe-o)}{[B(CF)]}（2-THF）。活性无四氢呋喃物种（最初由1/[PhC][B(CF)]原位生成）的氧化态和还原态之间的原位切换导致苯乙烯的氧化还原控制间同立构聚合反应。
