Atom Transfer Radical Polymerization Enabled by Sonochemically Labile Cu-carbonate Species WangZhenhua LorandiFrancesca FantinMarco WangZongyu YanJiajun WangZhanhua XiaHesheng MatyjaszewskiKrzysztof 2019 Atom transfer radical polymerization (ATRP) has been previously mediated by ultrasound using a low concentration of copper complex in water (sono-ATRP) or by addition of piezoelectric materials in organic solvents (mechano-ATRP). However, these procedures proceeded slowly and yielded polymers contaminated by new chains initiated by hydroxyl radicals or by residual piezoelectrics. Unexpectedly, in the presence of sodium carbonate, rapid sono-ATRP of methyl acrylate in DMSO was achieved (80% conversion in <2 h) with excellent control of molecular weights and low dispersities (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.2). The <i>in situ</i> formed Cu<sup>II</sup>/L-CO<sub>3</sub> complex in the the presence of ultrasound generated Cu<sup>I</sup>/L species as activators for ATRP and carbonate radical anions. The latter were scavenged by DMSO that was oxidized to dimethyl sulfone. This simple and robust process employs low-intensity ultrasound, air-stable Cu<sup>II</sup>/L catalysts, and carbonate or bicarbonate salts (washing soda or baking soda) to prepare well-defined polyacrylates.