Living radical polymerization of methyl methacrylate with a zerovalent nickel complex, Ni(PPh3)3.0.CO;2-K/asset/equation/tex2gif-stack-1.gif?v=1&t=h5ktnuch&s=24c22977ef1796234810faa9bf19062459dc8259" class="inlineGraphic">

✍ Scribed by Hiroko Uegaki; Masami Kamigaito; Mitsuo Sawamoto

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 184 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990801)37:15<3003::aid-pola33>3.0.co;2-k

✦ Synopsis

A zerovalent nickel complex, Ni(PPh 3 ) 4 , induced living radical polymerization of methyl methacrylate (MMA) in conjunction with an organic bromide as an initiator [R-Br: CCl 3 Br, (CH 3 ) 2 C(CO 2 Et)Br, (CH 3 ) 2 C(COPh)Br] in the presence of Al(Oi-Pr) 3 additive. The molecular weight distributions were narrow (M w /M n ϳ 1.2) throughout the reactions, and the number-average molecular weights (M n ) increased in direct proportion to monomer conversion. In contrast, the polymers obtained with CCl 4 in place of R-Br had broader MWDs (M w /M n Ͼ 2). The Al(Oi-Pr) 3 additive should be added for the smooth polymerizations of MMA to occur, similarly to those with a divalent nickel bromide, NiBr 2 (PPh 3 ) 2 . The Ni(PPh 3 ) 4 -mediated living polymerization apparently proceeds via the activation of the COBr bond from the initiators ROBr, assisted by the redox reaction of the complex between Ni(0) and Ni(I) species.