Iron-catalyzed living radical polymerization of acrylates: Iodide-based initiating systems and block and random copolymerizations

A half-metallocene iron iodide complex [Fe(Cp)I(CO)(2)] induced living radical polymerization of methyl acrylate (NLA,) in conjunction with an iodide initiator [(CH3)(2)C(CO(2)EtA)I, 1] and Al(Oi-Pr)(3) to give polymers of controlled molecular weights and narrow molecular weight distributions (M-w/M-n < 1.2). With the use of chloride and bromide initiators, the MWDs were broader, whereas the molecular weights were similarly controlled. Other acrylates such as n-butyl acrylate (nBA) and tert-butyl acrylate (tBA) can be polymerized with 1/Fe(Cp)I(CO)(2) in the presence of Ti(Oi-Pr)(4) and Al(Oi-Pr)(3), respectively, to give living polymers. The 1/Fe(Cp)I(CO)(2) initiating system is applicable for the synthesis of block and random copolymers of acrylates (MA, nBA, and tBA) and styrene of controlled molecular weights and narrow MWDs (M-w/M-n = 1.2-1.3). (C) 2002 Wiley Periodicals, Inc.