Ultrasonic velocity, permittivity, density, viscosity and proton nuclear magnetic resonance measurements of binary mixtures of benzonitrile with organic solvents

Abstract

The ultrasonic velocity, permittivity, density and viscosity of binary mixtures of benzonitrile (BN) with methanol (MeOH), acetone (AC), acetonitrile (AN), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), pyridine (Py) and carbon tetrachloride (CCl₄) have been measured at 25 °C. Ultrasonic velocity measurements of BN–MeOH, BN–CCl₄, BN–AN, AN–MeOH and CCl₄–MeOH mixtures have also been made at 35 and 45 °C. The excess permittivity (Δε), excess viscosity (Δη) and excess isentropic compressibility (Δκ_s) for various systems have been calculated and examined as a function of solvent composition. The excess parameters show strong deviations from ideal behaviour and indicate interactions between BN and most of these organic solvents. Mixtures of BN and DMF, however, show nearly ideal behaviour over the entire range of composition. The nature of interaction of BN with methanol is different and more interesting than for other solvents. BN, like CCl₄ and AN, is a strong structure breaker of methanol. Proton NMR chemical shift measurements of the OH proton of methanol in BN–MeOH mixtures confirm this observation.