作者:Jolanta Ejfler、Michał Kobyłka、Lucjan B. Jerzykiewicz、Piotr Sobota
DOI:10.1039/b503134f
日期:——
Two monomeric, six-coordinated magnesium complexes with bulky aminophenolate ligands [(Htbpoa)2Mg]
(1) and [(Htbpca)2Mg(THF)2]
(2), where Htbpoa =
N-[methyl(2-hydroxy-3,5-di-tert-butylphenyl)]-N-methyl-N-methyl-1,3-dioxolaneamine and Htbpca =
N-[methyl(2-hydroxy-3,5-di-tert-butylphenyl)]-N-methyl-N-cyclohexylamine have been prepared, characterized and employed as initiators for lactide polymerization. The crystal structure of the homoleptic compound 1 has been determined and shows that the six-coordinate magnesium atom in 1 is surrounded by two tridendate tbpoa ligands. In the solution, however, complex 1 exists in equilibrium with a five-coordinate species 1a having one oxolane fragment dangling. The tbpoa and tbpca ligands in 1 and 2 play a dual role, as the ancillary ligand stabilizing the monomeric magnesium species and as the initiating polymerization group.
两个单体、六配位镁配合物,具有庞大的氨基酚盐配体 [(Htbpoa)2Mg]
(1) 和 [(Htbpca)2Mg(THF)2]
(2), 其中 Htbpoa =
N-[甲基(2-羟基-3,5-二叔丁基苯基)]-N-甲基-N-甲基-1,3-二氧戊环胺和Htbpca =
N-[甲基(2-羟基-3,5-二叔丁基苯基)]-N-甲基-N-环己胺已被制备、表征并用作丙交酯聚合的引发剂。均配化合物1的晶体结构已被确定,并表明1中的六配位镁原子被两个三齿tbpoa配体包围。然而,在该溶液中,配合物 1 与具有一个悬挂的四氢呋喃片段的五配位物质 1a 处于平衡状态。 1和2中的tbpoa和tbpca配体发挥双重作用,作为稳定单体镁物质的辅助配体和作为引发聚合基团。