Bis(acyl)phosphine Oxides as Stoichiometric Photo-Reductants for Copper Nanoparticle Synthesis: Efficiency and Kinetics

Abstract

Bis(acyl)phospine oxide (BAPO) photo-initiators show excellent properties in photo-induced radical polymerization. Furthermore, in aqueous or alcoholic solutions, the primary phosphorus-centred radical forms a solvent adduct, which acts as a reductant for metal cations. Here, we present the mechanism, stoichiometry and kinetics of this reduction process. Moreover, we address the controlled production of copper nanoparticles. This is accomplished using optical spectroscopy in conjunction with in-depth kinetic analysis. This study opens the door for the application of BAPOs as a light-activated reducing agents, allowing a facile, mild and controlled generation of metal nanoparticles and of metal/polymer nanocomposites.