Solvent-dependent intra- and intermolecular vibrational energy transfer of W(CO) 6 probed with sub-picosecond time-resolved infrared spectroscopy

Abstract

Solvent-dependent intra- and intermolecular vibrational energy transfer from the triply degenerate CO stretch mode of W(CO) 6 is observed in nine alkanes (C n H 2 n + 2 , n = 5–13) with single-color sub-picosecond time-resolved infrared spectroscopy. In all the solvents, the vibrational relaxation process is well characterized by three time constants: τ 1 (<1 ps), τ 2 (3–13 ps) and τ 3 (124–160 ps). The solvent dependence of τ 2 and τ 3 cannot be explained by the macroscopic properties of the solvent. In particular, the longest time constant τ 3 shows the minimum value of 124 ps in decane among the nine alkanes. The rate of the vibrational energy relaxation is a sensitive measure of the microscopic environments.