Reversible binding of dioxygen by the copper(I) complex with tris(2-dimethylaminoethyl)amine (Me6tren) ligand

At low temperatures, the mononuclear copper(l) complex of the tetradentate tripodal aliphatic amine Me(6)tren (Me(6)tren = tris(2-dimethylaminoethyl)amine) [Cu-I(Me(6)tren)(RCN)](+) first reversibly binds dioxygen to form a 1:1 Cu-O-2 species which further reacts reversibly with a second [Cu-I(Me(6)tren)(RCN)](+) ion to form the dinuclear 2:1 Cu2O2 adduct. The reaction can be observed using low temperature stopped-flow techniques. The copper superoxo complex as well as the peroxo complex were characterized by resonance Raman spectroscopy. The spectral characteristics and full kinetic and thermodynamic results for the reaction of [Cu-I(Me(6)tren)(RCN)](+) with dioxygen are reported.