Resonance Raman spectra of reaction intermediates in oxidation process of ruthenium(II) and iron(II) porphyrins

The dioxo ruthenium porphyrins, RuP(O){sub 2} (P = TPP and TMP), were prepared by the oxidation of RuP(CO) with m-chloroperoxybenzoic acid (m-CPBA). The resonance Raman and IR spectra of RuP(O){sub 2} were measured and their O{double bond}Ru{double bond}O vibrations including the {sup 16}O{double bond}Ru{double bond}{sup 18}O and {sup 18}O{double bond}Ru{double bond}{sup 18}O analogues assigned by normal coordinate calculations. A reaction scheme involving two successive O-O bond cleavages of m-CPBA was proposed based on the observed intensity patterns of the O{double bond}Ru{double bond}O vibrations. In all cases, the peroxo-bridged species and the ferryl species are present at low temperature, and the former is converted into the latter by raising the temperature.