Covalent Association of a Ruthenium-Based Chromophore and a Copper Catalyst: A Synergy for Sulfides Photo-oxidation

The development of catalytic systems for the oxidation of organic substrates using renewable sources such as water and dioxygen remains challenging. In this paper we report the synthesis and full characterization of a new dyad combining a ruthenium(II)-based chromophore and a bio-inspired copper(II) pre-catalyst. In particular, photo-induced electron transfer from the photosensitized Ru-II subunit toward the Cu-II center is highlighted. The photogenerated Cu-I moiety proves to be catalytically efficient for sulfides oxidation by O-3(2) in the presence of a sacrificial electron source. Finally, the covalent association of the two partners favors Cu/O-2-based catalysis at the expense of a O-1(2)-centered reactivity for a bimolecular mixture.