Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan.
Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52062, Aachen, Germany.
Angew Chem Int Ed Engl. 2018 Feb 23;57(9):2492-2496. doi: 10.1002/anie.201709218. Epub 2018 Jan 17.
A new family of heterometallic catalysts based on trimetalated macrocyclic tris(salen) ligands and rare-earth metals was prepared and structurally characterized. The LaZn system containing anionic ligands such as acetate plays a critical role in catalyzing the alternating copolymerization of cyclohexene oxide (CHO) and CO with a high proportion of carbonate linkages. Among the lanthanide metals, the CeZn system exhibits high catalytic activity with a turnover frequency (TOF) of over 370 h . NMR analysis of the complex and end-group analysis of the polymer suggest that the acetate ligands are rapidly exchanged, not only among coordinated acetates, but also between coordinated acetates and added carboxylate anions. These unique properties make this the first example of telomerization for the copolymerization of CHO and CO .
一种基于三价金属化大环三（席夫碱）配体和稀土金属的新型杂金属催化剂被制备并进行了结构表征。含有乙酸盐等阴离子配体的 LaZn 体系在催化环氧化物（CHO）与 CO 的交替共聚反应中起着关键作用，生成了具有高碳酸酯键比例的共聚物。在镧系金属中，CeZn 体系具有较高的催化活性，其转化频率（TOF）超过 370 h。对配合物的 NMR 分析和聚合物的端基分析表明，乙酸盐配体不仅在配位的乙酸盐之间，而且在配位的乙酸盐和外加的羧酸盐阴离子之间迅速交换。这些独特的性质使得这是 CHO 和 CO 共聚的首例齐聚反应的例子。
