THEORETICAL STUDY OF HYDROPHOBICITY AND HYDROPHILICITY OF INDOLE, SKATOLE, AND ETHANOLE
G. N. Ten1, A. A. Yakovleva1, V. I. Baranov2
1N. G. Chernyshevsky Saratov State University, Saratov
2V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow
Keywords: indole, skatole, ethanole, complexes with water, hydrophobicity, geometric parameters of the hydrogen bridge, stretching vibrational frequencies
Abstract
The structures of indole, skatole, and ethanole complexes with water molecules are calculated by the DFT method. Radial and angular dependences of hydrogen bridge parameters on the number of water molecules are analyzed. Two models are determined which enable the study of the reason for the hydrophobicity of indole and skatole. Frequencies and intensities of absorption bands corresponding to stretching vibrations of the NH bond of indole, skatole, and ethanol in complexes with water are compared. It is shown that the main reason for the domination of the hydrophobic component over the hydrophilic one is the taking into account of the interaction of water molecules with the aromatic system of indole and skatole, finally resulting in a substantial decrease in the HB strength.
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