Determination and discussion of molecular scattering of light in 56 pure liquids

Abstract

Abstract Relative measurements of the intensities of isotropic and anisotropic light scattered by 56 solvents have been performed at a scattering angle of 90° and at 20°C using Helium-Neon laser at wavelength 632.8 nm. The deduced value of Rayleigh ratio R is together with literature values of isothermal compressibility for these solvents were utilized for testing different relationships between density and refractive index of pure liquids. Additionally, these data yielded the absolute value of the Rayleigh ratio of the reference substance (benzene); the Rayleigh ratios of other solvents were computed from it. The isothermal compressibilities of all liquids were obtained from the Rayleigh ratios and the suggested rule. The value of Rayleigh ratio R an permits computing the effective molecular optical anisotropy γ 2 eff of the tested liquids. The real values of γ 2 were measured by studying the light scattering in liquid-liquid mixtures according to the method of dilution. The values of the integral parameter of molecular correlation j were calculated from the ratio γ 2 eff /γ 2 . The role of orientational interaction in anisotropic light scattering by the concerned solvents is discussed.