Browsing by Author "A.L. Zatikyan"
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    FTIR ATR SPECTRAL AND THEORETICAL VIBRATIONAL STUDIES OF URACIL IN DIMETHYLSULFOXIDE OR DIETHYLSULFOXIDE SOLUTIONS
    (Pleiades Publishing, 2022) A.L. Zatikyan ; Sh.A. Markarian
    In this work the solutions of uracil in pure dimethylsulfoxide (DMSO) and diethylsulfoxide (DESO) have been studied by both FTIR ATR spectroscopy and quantum-chemical calculations. The remarkable changes were observed in the C=O, N–H (1745-1630 cm–1) and in S=O stretching region (1100-970 cm–1). The changes of the aforementioned frequencies are explained by the destruction of self-associates of sulfoxides in the presence of uracil and formation of uracil/DMSO (DESO) complexes via hydrogen-bond of the uracil N–H group with the S=O group of sulfoxides. Structural, energetic and vibrational characteristics for the hydrogen-bonded molecular complex of uracil/DMSO (DESO) in the gas phase and in solution have been studied by DFT and ab initio MO theory. It revealed, that the uracil/DMSO complex is more compact compared with uracil/DESO complex due to additional hydrogen bonds via C=O group of uracil and –CH group of DMSO. The observed wavenumbers are in good agreement with calculated wavenumbers.