Molecular dynamics simulation of liquid mixtures of benzene with chlorobenzene

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.

Chlorine aggregation in the supramolecular structure of chlorobenzene-o-chlorotoluene solutions

“…However, the Cl δ-…Me δ+ interactions in pure o-CT lead to the formation of extended agglomerates involving up to a half of the molecules in the calculation cell (given that the average amount of molecules in the agglomerates is 13). In contrast to chlorine aggregates, which are characterized by great structural diversity [2], the Cl δ-…Me δ+ interactions lead, as a rule, to the formation of chain structures (Fig. 3e) and more elongated agglomerates than the corresponding halogen aggregates in CB.…”

“…We analyzed the topology of the Cl…Cl and Cl…Me aggregates in the pure components and solutions. As in [2], we identified molecules bound by chlorine aggregation using the distance 4.55 Å as a geometric criterion. Based on the van der Waals radius of the methyl group carbon, we adopted the same criterion for the Cl…Ме distances.…”

The Thermochemistry of Alkyne Insertion into a Palladacycle Outlines the Solvation Conundrum in DFT

“…[29] Chlorobenzene is indeed known to establish a range of noncovalent interactions with itself [30] and other molecular or atomic partners [31] in the gas or liquid phase. [32] However, the relevance of such explicit interactions is hardly either predictable or detectable from NMR data or ITC outputs. In a number of previous reports of our's such an explicit interference of PhCl was a priori not considered as no significant discrepancy between ITC-determined and static COSMO/PCM-DFT computed reaction enthalpies were noted.…”

Prediction of diffusion coefficients of chlorophenols in water by computer simulation

“…Structural studies were done for chlorobenzene, benzene and o-chlorotoluene modeled by AMBER, where the mutual orientation of molecules in pure state was investigated and the formation of agglomerates was reported for binary mixtures involving these molecules [33,34]. Also using the general AMBER force field, chlorobenzene was used as a probe to map the ligand binding sites on protein surfaces by molecular dynamics simulations [35].…”