Hyosun Lee
Kyungpook National University, Republic of Korea
Title: Catalytic study of late transition metal complexes in the polymerization of methyl methacrylate
Biography
Biography: Hyosun Lee
Abstract
We have prepared and screened cobalt(II), copper(II), zinc(II), palladium(II), and cadmium(II) complexes with several groups of a series of ligands, namely, N,N'-bidentate N-cycloalkyl 2-iminomethylpyridine (group LA), N,N’-bidentate derivatives of N-(pyridin-2-ylmethyl)aniline (group LB), N,N’,N-tridentate N,N-di(2-picolyl)cycloalkylamine (group LC), N,N’,X-tridentate N-substituted 2-iminomethylpyridine and 2-iminomethylquinoline (group LD), N,N'-bidentate N,N-bis[(1H-pyrazol-1-yl)methyl]amines (group LE), and N,N',N-tridentate N’-substituted N,N-bis[(1H-pyrazol-1-yl)methyl]amines (group LF). All these complexes were characterized by spectroscopic methods and X-ray crystallography and applied to catalytic polymerization of Methyl Methacrylate (MMA). Specifically, cobalt(II) and cadmium(II) complexes showed the highest catalytic activity for MMA polymerization in the presence of modified Methylaluminoxane (MMAO) when compared to the corresponding complexes with same ligand system and metal starting materials, such as [CoCl2•6H2O], [CuCl2•2H2O], [ZnCl2], [Pd(MeCN)2Cl2], and [CdBr2•4H2O]. Their activity were in the order of 105 (g PMMA)/(mol cat) h at 60°C and syndiotacticity of poly(methylmethacrylate) (PMMA), characterized by 1H NMR spectroscopy, was Ca 0.73.