二亞胺鋅錯合物在催化乳酸交酯的開環聚合中佔有一個很重要的角色,在先前的文獻中,焦點放在對稱型的二亞胺配位基,鮮少有不對稱型的二亞胺配位基。在本論文中,利用一系列不同的不對稱二亞胺配位基,旁邊具有一個吡啶取代基,合成出它們的鋅錯合物,並且藉由1H與13C光譜與X-ray單晶繞射鑑定。根據單晶結構分析可以發現這些二亞胺鋅錯合有單體(L2ZnEt (2), L4ZnEt (4), L2ZnCl (6), L4ZnCl (8))或二聚體([L1ZnEt]2 (1), [L3ZnEt]2 (3))的鍵結模式,利用這些二亞胺鋅錯合物進行L-乳酸交酯的開環聚合反應,有很好的催化效果。
The β-diketiminato zinc(II) complexes are important catalysts to the ring-opening polymerization of lactide (LA). Among these researches, most of catalysis design focus on the symmetric β-diketiminato ligand, however, there were less attention on the study of asymmetric β-diketiminato ligands. To explore the new type of asymmetric β-diketiminato ligands, we develop four N-aryl-N’-alkyl β-diketiminato ligands bearing a pendant pyridyl arm and their corresponding zinc(II) complexes. Eight zinc(II) complexes containing the tridentated asymmetric N-aryl-N’-alkyl β-diketiminato ligand have been synthesized, which were characterized by 1H and 13C NMR spectroscopy. The X-ray single-crystal diffraction results show the composition of these zinc complexes have two different forms, the monomer (L2ZnEt (2), L4ZnEt (4), L2ZnCl (6), L4ZnCl (8)) or dimer ([L1ZnEt]2 (1), [L3ZnEt]2 (3)). They show the high catalystic activity for the ring-opening polymerization of L-lactide.