Structure and Raman spectra of transient species in the catalytic disproportionation of hydrogen peroxide by molybdate ions

The Raman spectra of the transient peroxo species [MoO4](2-), [MoO3(O-2)](2-), [MoO2(O-2)(2)](2-), [MoO(O-2)(3)](2-) and [Mo(O-2)(4)](2-) appearing during the catalytic disproportionation of hydrogen peroxide, were recorded and characterized in solutions corresponding to concentrations varying from 0 to 8.5 m H2O2. These spectra were assigned with the help of quantum chemical normal mode analyses using configuration interaction (CISD) and the B3LYP approximation. It turns out that by increasing the number of peroxo groups around the molybdenum atom the stability of the molecule and its oxidizing power are increased. Copyright (C) 2002 John Wiley Sons, Ltd.