Peculiarities of molecular light scattering in a chlorobenzene—o-dichlorobenzene system and their relationship to the solution structure

Resumo

The general coefficient of molecular light scattering (R₀), degree of depolarization (ΔU), and refractive index (n) in a system of o-dichlorobenzene—chlorobenzene solutions were measured. The anisotropic (R_a) and isotropic (R_is) contributions to scattering and the iso-thermal compressibility and its excess component were calculated. A complicated nonmono-tonic behavior was found for the concentration dependences of the coefficients of molecular light scattering with a minimum in a range of low concentrations from the side of chlorobenz-ene and a maximum from the side of o-dichlorobenzene, indicating a substantial rearrange-ment of the structure of the solutions with a change in the concentration. An analysis of the concentration dependences of the coefficients of molecular light scattering, excess isother-mal compressibility, and excess molar volume revealed four ranges differed in structure: 0—0.03, 0.03—0.65, 0.65—0.9, and 0.9—1.0. The solution structure was described in each range.