Controlled/"living'' radical polymerization. Atom transfer radical polymerization catalyzed by copper(I) and picolylamine complexes

Two picolyl structure based amines, the tridentate N,N-bis(2-pyridylmethyl)octylamine (BPMOA) and the tetradentate tris[(2-pyridyl)methyl]amine, have been successfully synthesized and employed as new ligands in the copper-mediated atom transfer radical polymerization (ATRP) of styrene, methyl acrylate, and methyl methacrylate. Polymerizations showed a linear increase in molecular weight with conversion and relatively low polydispersities throughout the reactions. Compared with the structurally related N,N,N ",N "-pentamethyldiethylenetriamine different kinetic behavior was observed when BPMOA was used as the ligand for the copper-mediated ATRP of methyl methacrylate. This is mainly attributed to the solubility difference of the catalyst in these systems. The ready availability of ligands based on the picolyl structure and their easily tunable solubilities as well as steric and electronic properties make them very attractive as new ligands in copper-mediated ATRP.