The structural parameters and vibrational IR and Raman spectra of the molecular unit of the chitosan polymer, chitosan dimer, and chitosan dimer in complex with SWCN fragment were calculated. It is shown that the interaction of the chitosan dimer with SWCNTs leads to a change in the valence angle of the COS linking the elementary units of the chitosan biopolymer and the valence angle of the hydrogen bond bridge C ... .NO. In the IR spectra, an increase in the intensity of the absorption bands in the region of ~1000 cm-1 is observed, and in the Raman spectra – an increase in the intensity of the lines in the low-frequency region of ~400-600 cm-1.
The calculation and interpretation of the IR of three Proline (Pro) conformers were performed. It is shown that the vibrational spectrum of Pro in the gas phase is a superposition of the vibrational spectra of conformers Pro 1 (60%) and Pro 2 (40%). The calculated total IR spectrum is in good agreement with the experimental Pro spectrum recorded at 520 K.
Vibrational IR and Raman spectra of fullerene derivatives – fullerene-glycine (C60-Gly) and fullerene-phenylalanine (C60-Phe) were calculated. The parameters of hydrogen bridges of hydrogen bonds formed by water molecules with Gly and Phe fragments were determined. The vibrational spectra are analyzed and the frequency and intensity shifts corresponding to the q(OH) and q(NH) valence vibrations in the formation of hydrogen bonds were identified.
The electronic absorption spectra of two bovine serum albumin fragments containing tryptophan residues [Trp(134) and Trp (213)] were calculated and interpreted. The electronic spectra of both fragments were compared and the influence of amino acids in their composition on the electronic absorption spectra was considered. It was shown that the electron spectrum of lysine has absorption bands in the region above 300 nm, and the spectrum of alanine – absorption band in the region of 250-300 nm.