New insights into the mechanism of activation of atom transfer radical polymerization by Cu(I) complexes

The kinetics of activation of RX by a Cu-I complex has been investigated in MeCN both in the absence and presence of halide ions. The system Cu-I/L/X- (L = Me6TREN) is mainly composed of (CuL+)-L-I, (XCuL)-L-I and (CuX2-)-X-I, but only (CuL+)-L-I is found to be an active catalyst reacting with RX.