Valence Localization At A Bio-Inspired Mixed-Valent {Cu2s}(2+) Motif Upon Solvation In Acetonitrile: Effect On Nitrous Oxide Reductase (N(2)Or) Activity

We demonstrate, based on experimental and theoretical evidence, that the isolated [2(CH3CN)(2)](2+) complex prepared in CH3CN and containing a mixed-valent {(Cu2S)-S-II,I} core evolves towards a new [2(CH3CN)(3)](2+) species upon solvation in CH3CN. Unlike its type III structural analogue [2(H2O)(OTf)](+) active toward N2O reduction, this new type I compound is inactive. This outcome opens new perspectives for a rational for N2O activation using bio-inspired Cu/S complexes, especially on the role of the valence localization/delocalization and the Cu-Cu bond on the reactivity.