Zhang Jiayu, Huang Wenshuang, Han Kailing, Song Guoyong, Hu Shaowei
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, People's Republic of China.
College of Chemistry, Beijing Normal University, No. 19, Xin-wai street, Beijing 100875, People's Republic of China.
Dalton Trans. 2022 Aug 16;51(32):12250-12257. doi: 10.1039/d2dt01389d.
A series of first-row early transition metal dialkyl complexes bearing pincer ligands [(POCOP)M(CHSiMe)] (POCOP: (2,6-(BuPO)-CH); 1-Sc: M = Sc; 1-Ti: M = Ti; 1-V: M = V) and [(PCP)M(CHSiMe)] (PCP: (2,6-(BuPCH)-CH); 2-Sc: M = Sc; 2-Ti: M = Ti) have been synthesized. These dialkyl complexes were characterized by single-crystal X-ray diffraction, NMR spectroscopy, and solution magnetic susceptibility (Evans method) analyses appropriately. All the complexes exhibited square pyramidal geometries with different extents of distortion. The activities of these complexes were further explored in styrene polymerization, in which combinations of scandium complexes (1-Sc or 2-Sc) with [PhC][B(CF)] were found to be active catalytic systems for highly syndiospecific (>99% ) polymerization of styrene. Meanwhile, the Ti(III) complexes 1-Ti and 2-Ti showed rather low activity in styrene polymerization, which stands in sharp contrast to those in previous reports involving Ti(III) catalysts bearing cyclopentadienyl derivative ligands.
一系列带有钳形配体的第一排早期过渡金属二烷基配合物[(POCOP)M(CHSiMe)]（POCOP：(2,6-(BuPO)-CH)；1-Sc：M = Sc；1-Ti：M = Ti；1-V：M = V）和[(PCP)M(CHSiMe)]（PCP：(2,6-(BuPCH)-CH)；2-Sc：M = Sc；2-Ti：M = Ti）已被合成。这些二烷基配合物通过单晶X射线衍射、核磁共振光谱和溶液磁化率（埃文斯法）分析进行了适当表征。所有配合物均呈现出不同程度畸变的四方锥几何构型。在苯乙烯聚合反应中进一步探索了这些配合物的活性，其中发现钪配合物（1-Sc或2-Sc）与[PhC][B(CF)]的组合是用于苯乙烯高度间同立构规整（>99%）聚合的活性催化体系。同时，Ti(III)配合物1-Ti和2-Ti在苯乙烯聚合反应中表现出相当低的活性，这与先前涉及带有环戊二烯基衍生物配体的Ti(III)催化剂的报道形成鲜明对比。
