Enthalpies of interaction of aromatic solutes with organic solvents

Abstract

Heats of solution of several aromatic solutes (benzene, toluene, mesitylene, nitrobenzene, α,α,α-trifluorotoluene, anisole) and model compounds (n-butyl methyl ether, cyclohexane) in 17 organic solvents (n-heptane, cyclohexane, carbon tetrachloride, 1,2-dichloroethane, α,α,α-trifluorotoluene, triethylamine, butyl ether, ethyl acetate, dimethylformamide, dimethyl sulfoxide, benzene, toluene, mesitylene, t-butyl alcohol, 1-octanol, methanol, 2,2,2-trifluoroethanol) have been combined with solute heats of vaporization to give enthalpies of transfer from vapor to solvent (ΔH(v → S)). Differences between solute and model values (ΔΔH(v → S) = ΔH(v → S) (aromatic solute)–ΔH(v → S) (model) were used to evaluate aromatic solute–solvent polar interactions. Correlations of ΔΔH(v → S) with solvent dipolarity–polarizability (Taft–Kamlet π* parameter) have been determined.