Interaction of phenol with xenon and nitrogen: spectroscopic and computational characterization

Intermolecular complexes of phenol with xenon and nitrogen are studied by infrared absorption spectroscopy in a neon matrix and by quantum chemistry calculations. The π complex is theoretically the most stable 1:1 phenol⋅⋅⋅Xe structure, but it has no characteristic shifts in the calculated vibrational spectrum, which complicates its experimental characterization. However, the formation of the π complex finds indirect but significant support from the experimental results. The calculated spectrum of the less stable H-bonded complex shows a number of characteristic absorptions, but they are not observed in the experiment, indicating the lack of its formation. For the phenol⋅⋅⋅Xe(n) (n = 2-4) complexes, the calculations predict substantial changes in the vibrational spectra, and the corresponding bands are observed in the matrices with large concentrations of xenon. Our experiments show the high efficiency of the formation of large xenon clusters in a neon matrix that can accommodate a major part of phenol molecules. In contrast to the case of xenon, the H-bonded 1:1 phenol⋅⋅⋅N(2) complex is found in a neon matrix, and the formation of large N(2) clusters embedding phenol molecules is relatively inefficient.