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Infrared absorption spectra of n-hexanol isolated in an argon matrix are recorded at temperatures varying between 20 and 50 K. The temperature evolution of the recorded spectra across several spectral regions is analyzed. The experimental data are interpreted using the results of quantum-chemical modeling [DFT/B3LYP/6-31G (d,p)] of the structure and the vibrational spectra of chain and cyclic clusters that included between one and four hexanol molecules. It is shown that as the temperature of the isolating matrix is increased, there is a gradual transformation of the hexanol cluster structure.

Recorded infrared absorption spectra of water, trapped in an argon matrix at temperatures ranging from 9 to 50 K. The observed spectral bands are assigned to water clusters composed of different numbers of molecules. The temperature dependence of the recorded spectra makes it possible to construct a model of the structural transformations that take place in the water during the phase transition from the gaseous to the condensed state.

Low-temperature infrared absorption spectra are obtained for ethanol isolated in an argon matrix at temperatures of 20–45 K range for ratios of the numbers of the molecules being studied to the numbers of matrix atoms of 1:1000 and 1:2000. A preliminary interpretation of the spectra is obtained on the basis of the temperature variations in the spectra and published data. The structure of the ethanol conformers, rotational constants, and internal rotation barriers of the methyl and hydroxyl groups are calculated in the B3LYP/cc-pVQZ approximation. The harmonic and anharmonic IR spectra of the gauche- and trans-conformers are calculated in the same approximation. The force fields of the two conformers and the distributions of the potential energy of the normal vibrations are calculated and compared for a general set of dependent coordinates. Anharmonicity effects are taken into account by introducing spectroscopic masses for the hydrogen atoms when calculating the normal vibrations in the harmonic approximation.

Infrared absorption spectra of methyl alcohol isolated in an argon matrix are recorded experimentally. The transformation of the structure of the spectral bands with rising matrix temperature is analyzed in the spectral region of the C–O and O–H stretch deformation vibrations (1000–1100 and 3000–3800 cm−1). The experimental data are interpreted using quantum-chemical modelling of an optimal spatial structure and of the vibrational spectra of different nano-sized methyl alcohol clusters. The structure of the clusters changes gradually as the temperature of the argon matrix is raised from 10 to 50 K.