ESR study and radical observation in transition metal-mediated polymerization: Unified view of atom transfer radical polymerization mechanism

Using an on-line electron spin resonance (ESR) technique, we studied the electron paramagnetic species of oxidized metal centers and carbon radicals in three representative catalyst/ligand systems of transition metal-mediated polymerization of methyl methacrylate. These systems were: (1) CuBr/Bpy, (2) RuCl2(PPh3)/Al(OiPr)3, and (3) CuBr/N-pentyl-2-pyridylmethanirnine. Ethylene glycol dimethacrylate was used as crosslinker to trigger the …