Vibrational population relaxation of thiocyanate ion in polar solvents studied by ultrafast infrared spectroscopy

We investigated vibrational population relaxation for the anti-symmetric stretching mode of the thiocyanate ion in various polar solvents by ultrafast infrared spectroscopy. We found that the vibrational relaxation rates and linewidths of the absorption spectra in protic solvents were larger than those in aprotic solvents.