title: Copper-mediated controlled/"living" radical polymerization in polar solvents: insights into some relevant mechanistic aspects.
abstract: The field of transition-metal-mediated controlled/"living" radical polymerization (CLRP) has become the subject of intense discussion regarding the mechanism of this widely-used and versatile process. Most mechanistic analyses (atom transfer radical polymerization (ATRP) vs. single-electron transfer living radical polymerization (SET-LRP)) have been based on model experiments, which cannot correctly mimic the true reaction conditions. We present, for the first time, a determination of the [Cu(I)Br]/[L] (L=nitrogen-based chelating ligand) ratio and the extent of Cu(I)Br/L disproportionation during CLRP of methyl acrylate (MA) in dimethylsulfoxide (DMSO) with Cu(0) wire as a transition-metal catalyst source. The results suggest that Cu(0) acts as a supplemental activator and reducing agent of Cu(II)Br(2)/L to Cu(I)Br/L. More importantly, the Cu(I)Br/L species seem to be responsible for the activation of SET-LRP.
authors.affiliation: GE Power and Water; Water & Process Technologies, 4636 Somerton Road, Trevose, PA 19053, USA. tamaz.guliashvili@ge.com
authors.forename: Tamaz
authors.initials: T
authors.lastname: Guliashvili
authors.forename: Patrícia V
authors.initials: PV
authors.lastname: Mendonça
authors.forename: Arménio C
authors.initials: AC
authors.lastname: Serra
authors.forename: Anatoliy V
authors.initials: AV
authors.lastname: Popov
authors.forename: Jorge F J
authors.initials: JF
authors.lastname: Coelho