Hiroko Uegaki, Yuzo Kotani, M. Kamigaito
Apr 21, 1997
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0
Influential Citations
190
Citations
Quality indicators
Journal
Macromolecules
Abstract
Nickel(II) bis(triphenylphosphine)halides [NiX2(PPh3)2; X = Cl, Br] were employed for possible living radical polymerization of methyl methacrylate (MMA) in conjunction with an organic halide as an initiator [R−X: CCl4, CCl3Br, and (CH3)2CBrCO2C2H5] in the presence of Al(OiPr)3 in benzene at 80 °C. The bromide-based initiating system [CCl3Br/NiBr2(PPh3)2] gave living polymers with narrow molecular weight distributions, whereas the chloride-based system [CCl4/NiCl2(PPh3)2] led to bimodal molecular weight distributions. The systems involving chloride and bromide [CCl4/NiBr2(PPh3)2 and CCl3Br/NiCl2(PPh3)2] failed to induce living polymerizations. The polymers obtained with (CH3)2CBrCO2C2H5/NiBr2(PPh3)2 were also living and possessed one initiator moiety at the α-end per polymer chain, which indicates the polymerization proceeds via the activation of the C−Br terminal by the nickel(II) bromide complex.