Thermally activated transformations of the dielectric response function of mono- and disaccharides in the THz range

The variety of physical and chemical properties of saccharides is determined, in particular, by their isomerism and the variability of their hydrogen bond parameters. We studied the transformation of the vibrational spectra of mono- and disaccharides using pulsed terahertz spectroscopy in a wide temperature range. The stability ranges of saccharides were determined from the temperature dependences of the vibrational spectra and resonance parameters. The revealed difference in frequencies and intensities of vibrational modes of the hydroxyl groups in different saccharides correlate with the parameters of hydrogen bonds. Based on the data over a wide temperature range, it was found that the anharmonicity of vibrational modes appears in the form of coupling between resonances and the formation of wide asymmetric bands. Temperature square dependence of the resonance eigenfrequencies in the disaccharides has been revealed.