Combined Spectroscopic and Theoretical Evidence for a Persistent End‐On Copper Superoxo Complex

Abstract

A tale of two modes: An end-on copper superoxo complex was identified in a combined experimental and theoretical study. Theory clearly discloses the presence of an end-on complex (see picture, O red, Cu pink, N green) with a minute isotopic resonance Raman splitting below experimental resolution. The results cast doubts on the uncritical use of 16O,18O isotopic-labeling Raman experiments to discriminate end-on from side-on bonding modes in M(O2) complexes.