IR spectra of tropolone (OH) and gropolone (OD)

摘要

Infrared spectra of tropolone4OH) and tropolone(OD) obtained from vapor phase, solvated. and rare gas matrix-isolated samples. and from fluorescence dip infrared spectroscopy experiments by Frost et al. on jet-cooled samples. are analyzed with the guidance of high level ab initio molecular orbital (MO) computations. It is found that the anharmonicity of the double minimum global potential enerev surface of ~0 tropolone is manifested by multistate local resonance networks coupling fundamental vibrations to nearby overtone and combination states. These resonance networks pervade the IR spectrum of tropolone above 500 cm ~. and the absorbances are much more strongly perturbed from harmonic level predictions than the frequencies. Some of the JR absorbances are also sensitive to intermolecular interactions. At maximum spectral resolutions reaching —0.2 cm’ only the u and v2 (OH stretching and nascent skeletal tunneling) vibrations show resolved vibrational state-specific tunneling doublets. The tunneling behavior of tropolone is analyzed in the accompanying article.