A Stable Crystalline Copper(I)–N₂O Complex Stabilized as the Salt of a Weakly Coordinating Anion

Abstract

Nitrous oxide is considered a poor ligand, and therefore only a handful of well-defined metal-N₂ O complexes are known. Oxidation of copper powder with an extreme oxidant, [Ag₂ I₂ ][An]₂ ([An]^- =[Al(OC(CF₃ )₃ )₄ ]^- ) in perfluorinated hexane leads to Cu^I [An], the first auxiliary ligand-free Cu^I salt of the perfluorinated alkoxyaluminate anion. The compound is capable of forming a stable and crystalline complex with nitrous oxide, Cu(N₂ O)[An], where the Cu-N₂ O bond is by far the strongest among all other molecular metal-N₂ O complexes known. Thorough characterization of the compounds together with the crystal structure of Cu(N₂ O)[An] complex supported with DFT calculations are presented. These give insight into the bonding in the Cu⁺ -N₂ O system and confirm N-end coordination of the ligand.