Chromium complexes supported by phenanthrene-imine derivative ligands: synthesis, characterization and catalysis on isoprene cis-1,4 polymerization
作者:Bo Gao、Xuyang Luo、Wei Gao、Long Huang、Si-meng Gao、Xiaoming Liu、Qiaolin Wu、Ying Mu
DOI:10.1039/c2dt11365a
日期:——
Reactions of CrCl2(THF)2 with N-aryl-9,10-iminophenanthraquinone in CH2Cl2 give the monoimine chromium complexes ArIPQCrCl2(THF)2 (1, Ar = 2,6-Me2C6H3; 2, Ar = 2,6-Et2C6H3; 3, Ar = 2,6-iPr2C6H3). Molecular structures of 1 and 3 were revealed to be monomeric with the chromium atoms in distorted octahedral geometries. Similar reactions of CrCl2(THF)2 with N,N-bis(arylimino)phenanthrene ligands afford the diimine complexes Ar1,Ar2BIPCrCl(μ-Cl)3Cr(THF)Ar1,Ar2BIP (4, Ar1 = Ar2 = 2,6-Me2C6H3; 5, Ar1 = Ar2 = 2,6-Et2C6H3; 6, Ar1 = Ar2 = 2,6-iPr2C6H3; 7, Ar1 = 2,6-Me2C6H3, Ar2 = 2,6-iPr2C6H3). The X-ray diffraction analysis shows that 4, 5, and 7 are chlorine-bridged dimers with each chromium atom in a distorted octahedral geometry. Upon activation with MAO, all these complexes exhibit good catalytic activities for isoprene polymerization affording polyisoprene with predominantly a cis-1,4 unit.
在 CH2Cl2 中,CrCl2(THF)2 与 N-芳基-9,10-亚氨基蒽醌反应生成单亚胺铬络合物 ArIPQCrCl2(THF)2(1,Ar = 2,6-Me2C6H3;2,Ar = 2,6-Et2C6H3;3,Ar = 2,6-iPr2C6H3)。1 和 3 的分子结构被揭示为单体,铬原子呈扭曲的八面体几何结构。CrCl2(THF)2 与 N,N-双(芳基亚氨基)菲配体的类似反应产生了二亚胺配合物 Ar1,Ar2BIPCrCl(μ-Cl)3Cr(THF)Ar1,Ar2BIP(4,Ar1 = Ar2 = 2,6-Me2C6H3;5,Ar1 = Ar2 = 2,6-Me2C6H3;6,Ar1 = Ar2 = 2,6-Me2C6H3);5,Ar1 = Ar2 = 2,6-Et2C6H3;6,Ar1 = Ar2 = 2,6-iPr2C6H3;7,Ar1 = 2,6-Me2C6H3,Ar2 = 2,6-iPr2C6H3)。X 射线衍射分析表明,4、5 和 7 是氯桥二聚体,每个铬原子都呈扭曲的八面体几何形状。在 MAO 的活化作用下,所有这些配合物在异戊二烯聚合过程中都表现出良好的催化活性,生成的聚异戊二烯主要具有顺式-1,4 单元。