Triplet-state benzophenone-sensitized photoreduction of bis(acetylacetonato)copper(II): the generation and stability of copper(I) complexes

Abstract

Triplet-state benzophenone rapidly sensitized the photoreduction of Cu(acac)2 in alcohols to give polymeric Cu(acac) as black precipitates. The binary complexes of Cu(acac) of polypyridines, polysulfide, olefins, acetylenes, and carbon monoxide could be generated in solution under an inert atmosphere when a ligand was present insitu during photoreduction or added after an appropriate photoreduction was completed. Except Cu(acac)—(PPh3)2, the Cu(acac) complexes of various ligands are sensitive to air oxidation, but show a wide range of reactivity towards disproportionation and photolysis. In the presence of terminal acetylenes, amorphous copper(I) acetylides were isolated in good yields.