Tripodal "click" ligands for copper-catalyzed ATRP

Abstract

A series of tris(R-methyltriazolylmethyl)amines [R = C6H 5 (1), 4-FC6H4 (2), 4-MeOC6H 4 (3), Fc (4)] were prepared and used as ligands for catalytic ATRP of methyl methacrylate (MMA). Despite a lower activity, the CuBr/4 catalyst promoted relatively well controlled polymerization compared to CuBr/1, as evidenced by narrower polydispersity indices. Meanwhile, no polymerization activity was observed with CuBr/2 and CuBr/3 under the catalytic conditions investigated. The CV measurements of CuBr2 complexes supported 1 and 4 in DMSO showed E1/2 values of -0.206 and -0.224 V, respectively, confirming the more electron-rich nature of CuBr/4. Although both CuBr/1 and CuBr/4 catalysts were only partially soluble in several organic solvents used, kinetic studies revealed a pseudo first order linear plot of ln[M] 0/[M]t versus time. Addition of CuBr2 into the polymerization systems led to a decrease in polymer polydispersities and the observed rate constants (kobs). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 Copyright © 2012 Wiley Periodicals, Inc.