Vibrational relaxation of carbon monoxide bound to a series of metalloporphyrin complexes (M-(coproporphyrinate-I tetraisopropyl ester)(CO)(pyridine); M = Fe, Ru, Os) was measured using picosecond infrared pump-probe experiments. The vibrational relaxation rates ((1-2.5) × 1010 s-1) increased with increasing mass of the metal ion. This effect is opposite that predicted by through-σ-bond models and is interpreted as arising from a through-π-bond coupling between the CO vibrational fundamental and porphyrin vibrations.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry