Chemical Physics Letters, Vol.344, No.1-2, 113-119, 2001
OH stretching vibrations of the phenol(H2O)(+)(1) cation
In this Letter, we report on the application of infrared/photo induced Rydberg ionisation (IR/PIRI) spectroscopy to the hydrogen-bonded phenol(H2O)(1)(+) cluster yielding the frequency of the symmetric OH stretching vibration of the bare cluster ion. By comparing IR/PIRI and IR-photodissociation spectra the symmetric OH stretching mode of the water moiety turns out to be a localised uncoupled vibration, Furthermore, CASSCF calculations for the phenolic OH stretching vibration of phenol(H2O)(1) in the S-0, S-1, and D-0 states are performed by using a very large active space including sigma- and pi -orbitals, These calculations yield OH stretching frequencies which are in good agreement with the experimentally observed vibrational frequencies of the S-0 and S-1 states. The OH stretching vibration of the D-0 state is predicted to be lower than 2800 cm(-1).