| Abstract: | Well defined Pd(II) catalysts of the type (N′N)Pd(CH3)(Solv.)+ B(Arf)4- (Arf = −3, 5-(CF3)2C6H3) have been prepared for living alternating copolymerizations of olefins with CO. This talk will focus on the mechanistic details of chain growth as elucidated by 1H and 13C NMR spectroscopy, model studies of key migratory insertion steps and synthesis and properties of various copolymers and block copolymers based on styrenes, CH2=CHC6H4X X = p-C(CH3)3, p-OC(O)CH3, p-OC(O)C-t-Bu), p-NHC(O)(C-t-Bu)]. Use of the catalysts based on the C2 symmetric, homochiral ligand 2, 2'-bis2-4(S)-(Alkyl)-1, 3-oxazolinyl]]propane Alkyl = CH3, CH(CH3)2] produces a copolymer, 1, with a highly isotactic microstructure and high optical activity in contrast to achiral ligands such as 1,10-phenanthroline which produce copolymers with predominantly syndiotactic microstructure. |
