Trimethylsilyl‐substituted triazole‐based ligand for copper‐mediated single‐electron transfer living radical polymerization of methyl methacrylate

The tripodal ‘click’ compound tris(4‐trimethylsilylmethyl‐1,2,3‐triazolylmethyl)amine (TTTA) was prepared and investigated as a ligand for copper‐catalysed single‐electron transfer living radical polymerization of methyl methacrylate (MMA). Bulk polymerizations catalysed by Cu⁰/CuBr₂/TTTA with a molar ratio of [MMA]₀/[ethyl‐2‐bromoisobutyrate]₀/[CuBr₂]₀/[TTTA]₀ = 200:2:1:1 and a 1.0 × 1.0 cm² Cu⁰ sheet were fast and well controlled (76% conversion with M_w/M_n = 1.19 after 3.5 h). Greater amounts of added air generally gave slower polymerizations although M_w/M_n remained low (<1.3) even when the polymerization was carried out under aerobic conditions. Decreasing initial concentrations of the Cu⁰/CuBr₂/TTTA catalyst system or polymerization temperatures also resulted in slower polymerizations and yielded polymers with broader dispersity. Kinetic studies in the temperature range 40–90 °C revealed an apparent activation energy of 22.6 kJ mol^?1. © 2014 Society of Chemical Industry