Calcium complexes containing oxalamidinate ligands as catalysts for ε-caprolactone polymerization
作者:Tzu-Lun Huang、Chi-Tien Chen
DOI:10.1039/c2dt32300a
日期:——
A series of calcium complexes containing oxalamidinate ligands is described. Reactions of oxalamidinate ligand precursors, [PhNCNH(CH2)2OMe}âCNH(CH2)2OMe}NPh] (1), [PhNCNH(CH2)2NMe2}âCNH(CH2)2NMe2}NPh] (2), [PhTriMeNCNH(CH2)2OMe}âCNH(CH2)2OMe}NPhTriMe] (3), [PhTriMeNCNH(CH2)2SMe}âCNH(CH2)2SMe}NPhTriMe] (4), [PhTriMeNCNHCH2Py}âCNHCH2Py}NPhTriMe] (5), with two molar equivalents of Ca[N(SiMe3)2]2(THF)2 gave calcium oxalamidinate complexes, [CaN(SiMe3)2}(THF)(PhN)CN(CH2)2OMe}â]2 (6), [CaN(SiMe3)2}(THF)(PhN)CN(CH2)2NMe2}â]2 (7), [CaN(SiMe3)2}(THF)(PhTriMeN)CN(CH2)2OMe}â]2 (8), [CaN(SiMe3)2}(THF)(PhTriMeN)CN(CH2)2SMe}â]2 (9), [CaN(SiMe3)2}(THF)(PhTriMeN)CNCH2Py}â]2 (10), respectively. The molecular structure of complex 7 was further characterized by the single crystal X-ray diffraction technique. The catalytic activities of complexes 6â10 toward the ring opening polymerization of ε-caprolactone were studied. Complex 8 exhibited excellent activity for the polymerization of ε-caprolactone with controlled molecular weights and polydispersities.
一系列含有草酰胺配体的钙配合物被报道。草酰胺配体前体[PhNCNH(CH2)2OMe}–CNH(CH2)2OMe}NPh] (1)、[PhNCNH(CH2)2NMe2}–CNH(CH2)2NMe2}NPh] (2)、[PhTriMeNCNH(CH2)2OMe}–CNH(CH2)2OMe}NPhTriMe] (3)、[PhTriMeNCNH(CH2)2SMe}–CNH(CH2)2SMe}NPhTriMe] (4)、[PhTriMeNCNHCH2Py}–CNHCH2Py}NPhTriMe] (5)与两摩尔当量的Ca[N(SiMe3)2]2(THF)2反应,分别得到了草酰胺配体的钙配合物[CaN(SiMe3)2}(THF)(PhN)CN(CH2)2OMe}–]2 (6)、[CaN(SiMe3)2}(THF)(PhN)CN(CH2)2NMe2}–]2 (7)、[CaN(SiMe3)2}(THF)(PhTriMeN)CN(CH2)2OMe}–]2 (8)、[CaN(SiMe3)2}(THF)(PhTriMeN)CN(CH2)2SMe}–]2 (9)、[CaN(SiMe3)2}(THF)(PhTriMeN)CNCH2Py}–]2 (10)。配合物7的分子结构通过单晶X射线衍射技术进一步表征。研究了配合物6–10对于ε-己内酯开环聚合的催化活性。配合物8在ε-己内酯聚合中表现出优异的活性,具有可控的分子量和多分散性。