Ultrasonic and dielectric behaviour of binary systems of quinoline with methylene chloride, chloroform, carbon tetrachloride, benzene and cyclohexane

Abstract

Ultrasonic velocities, u, and isentropic compressibilities, κs, have been measured for binary mixtures of quinoline (C9H7N) with carbon tetrachloride (CCl4), benzene (C6H6) and chloroform (CHCl3) at 303.15 and 313.15 K, for mixtures of C9H7N with methylene chloride (CH2Cl2) at 293.15 and 303.15 K, and for mixtures of C9H7N with cyclohexane (c-C6H12) at 303.15 K. Measurements of relative permittivities, Iµ, and refractive indices, n, have also been made for binary mixtures of C9H7N with CCl4, CHCl3, CH2Cl2, C6H6 and c-C6H12 at 303.15 K. The quantities Δκs and ΔIµ which refer, respectively, to the deviations of the isentropic compressibilities and relative permittivities of the mixtures from the values arising from the mole-fraction mixture law, have been calculated. Δκs is negative throughout the whole range of composition in each case. ΔIµ is large and positive for mixtures of C9H7N with CHCl3 and CH2Cl2, practically zero at low mole fractions of C9H7N and small and positive for high mole fractions in the case of C9H7N–CCl4 and C9H7N–C6H6. For C9H7N–c-C6H12, ΔIµ is very slightly negative at low mole fractions of C9H7N and very slightly positive for high mole fractions. The Kirkwood correlation parameter, g, as calculated from the data on Iµ and n, for C9H7N–CHCl3 and C9H7N–CH2Cl2 was used to obtain Δg, which refers to the deviation of the Kirkwood correlation parameter of the mixture from the values arising from the mole-fraction mixture law. Δg is large and positive for these systems. The equilibrium constants Kf for the formation of a 1 : 1 complex of C9H7N with CHCl3 and CH2Cl2, as calculated from the relative permittivity data, are in accord with the theory of Barriol and Weisbecker, which is based upon the electrostatic interactions of the solute with the liquid. The apparent dipole moments, µapp, of C9H7N in CCl4 and C6H6 have been calculated. ΔIµ, Δg and Kf show that C9H7N forms strong complexes with CHCl3 and CH2Cl2, and that the interaction of C9H7N is stronger with CHCl3 than that with CH2Cl2. ΔIµ and µapp show that there is a specific interaction of C9H7N with CCl4 and C6H6, being stronger with CCl4 than that with C6H6.