Treatment of N-aryl-2-methylquinolin-8-amines (L1âL3) with one equivalent AlMe3 or AlEt3 afforded dialkyl aluminum compounds (C1âC5), whereas the stoichiometric reaction of 2-((2-(1H-benzo[d]imidazol-2-yl)quinolin-8-ylimino)methyl)phenols (L4âL6) with either AlMe3 or AlEt3 produced monoalkyl aluminum compounds (C6âC10). All the organoaluminum compounds were characterized by 1H, 13C NMR and elemental analysis, and the molecular structures of representative compounds were confirmed by X-ray crystallography. With bidentate ligands, compounds C1 and C3 showed tetrahedron geometry around Al center, while compound C7 has a distorted square pyramidal geometry around Al center with the framework comprising the tetradentate ligand. The dialkyl aluminum compounds (C1âC5) performed high catalytic activities towards the ring opening polymerization (ROP) of ε-caprolactone (ε-CL), in parallel, the monoalkyl aluminum compounds (C6âC10) showed negative results for the polymerization of ε-CL. In the presence or absence of benzyl alcohol (BnOH), the four-coordination aluminum compounds (C1âC5) are both highly active towards the ring opening polymerization (ROP) of ε-caprolactone with resulting high conversation of ε-caprolactone and polymers with high molecular weight. In the presence of one equivalent of BnOH, polymerization of ε-caprolactone proceeded in a living manner and molecular weights of the obtained poly(ε-caprolactone)s could be precisely controlled by adapting the reaction conditions.
用一当量的 AlMe3 或 AlEt3 处理 N-芳基-
2-甲基喹啉-8-胺 (L1→L3) 得到二烷基
铝化合物 (C1→C5),而 2-((
2-(1H-苯并[d]咪唑-2-基)喹啉-8-亚
氨基)
甲基)
苯酚(L4→L6)与AlMe3或AlEt3生成单烷基
铝化合物(C6→C10)。所有
有机铝化合物均通过1H、13C NMR和元素分析进行了表征,并通过X射线晶体学证实了代表性化合物的分子结构。对于双齿
配体,化合物C1和C3在Al中心周围呈现四面体几何形状,而化合物C7在Al中心周围具有扭曲的方锥体几何形状,其框架包含四齿
配体。二烷基
铝化合物 (C1–C5) 对
ε-己内酯 (γ-CL) 的开环聚合 (ROP) 具有较高的催化活性,同时,单烷基
铝化合物 (C6–C10) 对γ-CL 的聚合。在存在或不存在
苯甲醇 (BnOH) 的情况下,四配位
铝化合物 (C1–C5) 对
ε-己内酯的开环聚合 (ROP) 均具有很高的活性,从而导致
ε-己内酯和
聚合物的高转化率具有高分子量。在一当量的 BnOH 存在下,
ε-己内酯的聚合反应以活泼的方式进行,并且通过调整反应条件可以精确控制所得聚(
ε-己内酯)的分子量。