Structural-dynamic model of 2-biphenylmethanol in an anharmonic approximation

Abstract

539.194Using a density functional B3LYP/6-31G(d) method, the geometry, electro-optical parameters, quartic force field, and vibrational spectra (IR and Raman) of 2-biphenylmethanol have been calculated. A vibrational analysis was performed. The resulting IR and Raman spectra were interpreted in detail.Introduction. The construction of structural-dynamic models of the molecular systems comprising a compound on the basis of quantum-mechanical methods has become an integral part of research on its structure, optical spectra, and properties. The accuracy of quantum-mechanical calculations has increased substantially. This has made it possible to use the results in molecular spectroscopy. Good agreement of the calculated and measured spectroscopic parameters is a criterion of the correctness of the selected quantum-mechanical methods and approximations. Density functional theory (DFT) B3LYP performed by the modern program set GAUSSIAN [1] and used widely in practice around the world to construct structural-dynamic models of molecular systems in most instances satisfies this criterion. The discrepancy between the calculated and measured frequencies of normal vibrations is less than 4-5%. However, the absolute value is different for different spectral regions. The discrepancy is 150-200 cm -1 for the region of

Calculation of the Structure and IR Spectrum of 2,3-di-O-Nitromethyl-β-D-Glucopyranoside by the Density Functional Method

“…Basis set 6-31G(d) was chosen owing to results from calibration of several basis sets that were used in similar calculations. It turned out to be optimal for application to alcohols [14][15][16][17][18][19][20], ketones (benzophenone and its bromo-substituted derivatives [21][22][23]), cyanobiphenyls [22], and glucose derivatives [1-3, 12, 13]. Therefore, we considered it to be universal and applicable to the studied species.…”