No abstract

No abstract

A molecular dynamics method is used to simulate liquid mixtures of benzene and chlorobenzene at different concentrations. Radial angular distribution functions (RADFs) for distances between the benzene ring planes and the angle between them were calculated to analyze the structure of pure components and mixtures. In chlorobenzene, the highest RADF maximum at a distance between the mass centers of the benzene rings of about 4 Å corresponds to the stacked configurations of molecules, and at 5-7 Å the number of stacked contacts are much less than that at 4 Å and is comparable with the orthogonal ones. In liquid benzene, the number of stacked and orthogonal configurations is approximately equal in a range from 4 Å to 7 Å. RADF for benzene reveals extended regions of correlation, which gives evidence of the occurrence of agglomerates bound by specific interactions between the benzene rings. These agglomerates are not characteristic of chlorobenzene, but the presence of maxima on the radial distribution function for the distances between chlorine atoms indicates chlorine aggregation. The effect of halogen aggregation on the structure of benzene-chlorobenzene mixtures is considered. The obtained results are compared with the data on molecular light scattering.

The energy band structure for hexagonal TaN is calculated.

No abstract

No abstract

No abstract

An analysis of the concentration dependences of the molecular light scattering parameters in chlorobenzene-о-chlorotoluene solutions shows that the entire concentration range can be split into three intervals with different structural features: 0-0.2 ppm, 0.2-0.9 ppm, and 0.9-1 ppm chlorobenzene. The features are manifest in physicochemical properties such as sound velocity and excess molar volume, adiabatic compressibility, and molar refraction. Experimental data are compared with those obtained by molecular dynamics simulation. It is concluded that the chlorobenzene structure is determined by Cl…Cl interactions while the structuring of liquid o-chlorotoluene and its solutions is largely determined by intermolecular Cl…Me interactions.It is natural to assume that chlorine aggregation, which is very common in the crystalline phase [1], must be a typical phenomenon in the liquid phase as well. In this perspective, a study was conducted to investigate the structure of the benzene-chlorobenzene system. A molecular dynamics simulation [2] was performed of the structure of the pure components and solutions with a chlorobenzene (CB) content of 0.05 ppm, 0.1 ppm, 0.25 ppm, 0.5 ppm, 0.75 ppm, 0.9 ppm, and 0.95 ppm; the simulation results were compared with molecular light scattering data [3]. CB molecules were found to interact with one another more effectively in solution than with benzene molecules, which results in the aggregation of chlorine atoms.A very convenient object for the study of chlorine aggregation in the liquid phase is the chlorobenzene-о-chlorotoluene (CB-о-CT) system because both molecules of the pure components contain chlorine atoms. Moreover, this system allows researchers to compare the impacts of specific interactions between benzene rings and chlorine aggregation on the solution structure and determine the effect of the o-CT methyl group on these phenomena. To this end, CB-о-CT solutions were studied by experimental methods (molecular light scattering, molar refraction, molar volume, and adiabatic compressibility were investigated at a temperature of 298.15 K) and computer simulation (molecular dynamics). The entire range of solutions (0-1 ppm) was investigated, paying particular attention to high dilution regions both for CB and o-CT. Previously, we reported nontrivial dependences for the optical and bulk elastic properties in these regions [4,5].