Reductive NO Coupling at Dicopper Center via a [Cu2(NO)2]2+Diamond-Core Intermediate

Treatment of a dicopper(I,I) complex with excess amounts of NO leads to the formation of a dicopper dinitrosyl [Cu2(NO)2]2+ complex capable of (i) releasing two equivalents of NO reversibly in 90% yield and (ii) reacting with another equivalent of NO to afford N2O and dicopper nitrosyl oxo species [Cu2(NO)(O)]2+. Resonance Raman characterization of the [Cu2(NO)2]2+ complex shows a 15N-sensitive N=O stretch at 1527.6 cm-1 and two Cu-N stretches at 390.6 and 414.1 cm-1, supporting a symmetric diamond-core structure with bis-mu-NO ligands. The conversion of [Cu2(NO)2]2+ to [Cu2(NO)O]2+ occurs via a rate-limiting reaction with NO and bypasses the dicopper oxo intermediate, a mechanism distinct from that of diFe-mediated NO reduction to N2O.

Automated summary

Treatment of a dicopper(I,I) complex with excess amounts of NO leads to the formation of a dicopper dinitrosyl complex capable of releasing NO and reacting to produce N2O.