Apparent dipole moments and molar volumes of β-carbolines and carbazole in dioxane solution

Abstract

The apparent molecular polarization at infinite dilution, P_2∞, molecular refraction, R_D, dipole moment, µ₂, and partial molar volume, V₂°, of carbazole and some β-carboline derivatives have been determined from dielectric permittivity, specific volume, and refractive index measurements in 1,4-dioxane solutions at 25 °C. Evidence of hydrogen-bonding interaction with solvent has been found from i.r. spectroscopy and the apparent molar volumes. A relation has been found between literature pK_a values of β-carboline derivatives studied in the ground state and their corresponding dipole moments in solution.