V. I. Danilova

Calculation of the electronic structure and energetic characteristics of hydrocarbon molecules by the CNDO/BW method

Calculations of the energetic characteristics (the heat of atomization, the rotation barrier, and the ionization potential) and the dipole moments of several hydrocarbon molecules by the CNDO/BW method are discussed. The method gives a good description of these properties and correctly describes the structure of certain molecules (hyperconjugation and change in the inductive effect). The results of calculations by various versions of the CNDO method are compared.

Electron structure of organophosphorus compounds

The theory and parametrization of an iterative method of calculating the electron structure of molecules are presented. Use is made of the modified Mulliken equation for calculating the population of the atomic orbits, while group theory is employed for estimating the parameters. A comparison between the calculated and experimental ionization potentials of certain molecules confirms that the simple computing method here proposed yields reasonably satisfactory results.

A study of the electronic structure of nitrotoluenes in their nitro and aci-nitro forms and of the mechanism of their ground state interconversions using the CNDO/2 method

The CNDO/2 method (complete neglect of differential overlap for valence electrons) [1] was used to calculate the models of molecules of toluene (I), nitrobenzene (II), o-nitrotoluene (III), and 2,4-dinitrotoluene (IV). The π- and σ-electronic structure of these molecules was discussed in the ground electronic state. A comparison of the total energies of various forms of III and IV molecules was used to determine the most likely pathway of conversion of the aci-nitro form into the nitro form and to estimate the activation energy of this process.

Use of MO LCAO method to investigate the nature of the absorption band and interaction mechanism in nitrobenzene-aniline and nitrobenzene-phenol complexes

The electronic structure, band characteristics, and interaction mechanism in aniline-nitrobenzene and nitrobenzene-phenol complexes are discussed. The discussion is based on the results from calculations by the Hückel and self-consistent field methods [7, 8].Investigation of the electronic structure of the complexes, the nature of the absorption band, the oscillator forces, and the dipole moments has shown that the color in the nitrobenzene-aniline complex is due to the appearance of a charge-transfer band in the 4500 Å region. The absence of color in the nitrobenzene-phenol complex is due to a blue shift in the nitrobenzene band at λ = 3300 Å. A charge-transfer band in the 2740 Å region is predicted for the nitrobenzene-phenol complex.