Living radical polymerization of N,N-dimethylacrylamide with RuCl2(PPh3)3-based initiating systems

N,N-Dimethylacrylamide (DMAA) was radically polymerized with RuCl2(PPh3)(3) in conjunction with an alkyl halide (R-X; X = Br, Cl) as an initiator in the presence of Al(Oi-Pr)(3) in toluene at 60-80 degrees C, where the polymerizations were much faster than that of methacrylates. Specifically with bromides as initiators [CCl3Br, CH3CH(CONMe2)Br, (CH3)(2)C(CONMe2)Br, and (CH3)(2)C(CO2Et)Br], the Ru(II) complex induced living radical polymerization of DMAA to give polymers with controlled molecular weights and relatively narrow molecular weight distributions ((M) over bar(W)/(M) over bar(n) similar to 1.6). Similar living polymerizations were also possible for N,N-diethylacrylamide. H-1 NMR analysis of the obtained polymers showed that the polymerization proceeds via activation of the C-Br terminal originating from the bromide initiators by the ruthenium complex.