Lanthanide Complexes Supported by a Trizinc Crown Ether as Catalysts for Alternating Copolymerization of Epoxide and CO<sub>2</sub>
: Telomerization Controlled by Carboxylate Anions
作者:Haruki Nagae、Ryota Aoki、Shin-nosuke Akutagawa、Julian Kleemann、Risa Tagawa、Tobias Schindler、Gyeongshin Choi、Thomas P. Spaniol、Hayato Tsurugi、Jun Okuda、Kazushi Mashima
DOI:10.1002/anie.201709218
日期:2018.2.23
A new family of heterometallic catalysts based on trimetalated macrocyclic tris(salen) ligands and rare‐earth metals was prepared and structurally characterized. The LaZn3 system containing anionic ligands such as acetate plays a critical role in catalyzing the alternating copolymerization of cyclohexene oxide (CHO) and CO2 with a high proportion of carbonate linkages. Among the lanthanide metals,
基于三金属化的大环三(salen)配体和稀土金属制备了新的杂金属催化剂家族,并对其结构进行了表征。包含阴离子配体(如乙酸盐)的LaZn 3系统在催化环己烯氧化物(CHO)和具有高比例碳酸盐键的CO 2交替共聚中起关键作用。在镧系金属中,CeZn 3体系表现出高催化活性,周转频率(TOF)超过370 h -1。聚合物的复杂和端基分析的NMR分析表明,不仅在配位的乙酸酯之间,而且在配位的乙酸酯和添加的羧酸根阴离子之间,乙酸酯配体都可以快速交换。这些独特的特性使它成为CHO和CO 2共聚的端粒化的第一个例子。