Synthesis of a nanoscale Cu(ii)31-oxo-carboxylate cluster, and effect of Cu–oxo cluster size on visible-light absorption

Abstract

Cu₁₆–Cu₃₁ Cu(II)-oxo-carboxylate clusters are reported, including those with condensed 1.5 nm Cu–O cores supported exclusively by O-donor ligands. A size–colour correlation is observed due to a red-shift of the charge transfer absorption band on increasing size; hence these clusters sit between small molecules and (black) CuO nanostructures.