Abstract
This study describes the synthesis of zinc(II) carboxylate complexes with the pyrazolylethylamine ligands and the application of these complexes as catalysts for the copolymerization reaction of carbon dioxide (CO2) and cyclohexene oxide (CHO) to form polycarbonates.
A series of pyrazolyl-based ligands, 2-(3,5-dimethyl-1H-pyrazol-1-yl)ethanamine (L1), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethanamine) (L2), 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethan-amine (L3), 2-(3-phenyl-5-(trifluoromethyl)-1H-pyrazol-1-yl)ethanamine (L4) were synthesized according to the literature which involves N sp3 alkylation of the appropriate pyrazole with 2-bromoethylamine hydrobromide. These ligands were reacted with zinc(II) acetate and benzoates to form bidentate complexes, [(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethan-amine)Zn(OAc)2] (1), [(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO)2] (2), [(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO(NO2)2] (3), [(2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethanamine)(Zn(OAc)2] (4), [(2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO)2] (5), [(2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)-ethanamine)-Zn(C6H5COO(NO2)2] (6), [(2-(3,5-diphenyl-1H-pyrazol-1-yl)ethanamine)Zn(OAc)2] (7), [(2-(3,5-diphenyl-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO)2] (8), [(2-(3,5-diphenyl-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO(NO2)2] (9), [(2-(5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)ethanamine)Zn(OAc)2] (10), [(2-(5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO)2] (11), [(2-(5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)ethanamine)Zn(C6H5COO(NO2)2] (12)...
M.Sc.