Tripodal “click” ligands for copper‐catalyzed ATRP

A series of tris (R‐methyltriazolylmethyl)amines [R = C 6 H 5 ( 1 ), 4‐FC 6 H 4 ( 2 ), 4‐MeOC 6 H 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 CuBr 2 complexes supported 1 and 4 in DMSO showed E 1/2 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 CuBr 2 into the polymerization systems led to a decrease in polymer polydispersities and the observed rate constants ( k obs ). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013