Spectroscopic and theoretical study of vibrational spectra of hydrogen-bonded tropolone

Theoretical simulation of the bandshape and fine structure of the νs stretching band is presented for tropolone-H and tropolone-D taking into account an adiabatic coupling between the high-frequency O–H(D) stretching and the low-frequency intra- and intermolecular OO stretching modes, and linear and quadratic distortions of the potential energies for the low-frequency vibrations in the excited state of the O–H(D) stretching vibration. In order to determine the low-frequency vibrations, the experimental spectra of the polycrystalline tropolone in the far-infrared and the low-frequency Raman range have been recorded for the first time. The experimental frequencies in the low-frequency region are compared with the results of the HF/6-31G** and Becke3LYP/6-31G** calculations carried out for the tropolone dimer.