Effect of halogen substitution on the enthalpies of solvation and hydrogen bonding of organic solutes in chlorobenzene and 1,2-dichlorobenzene derived using multi-parameter correlations

Abstract

Enthalpies of solution at infinite dilution at 298K, ΔsolnHA/Solvent, have been measured by isothermal solution calorimetry for 43 and 72 organic solutes dissolved in chlorobenzene and 1,2-dichlorobenzene, respectively. The measured ΔsolnHA/Solvent data, along with published ΔsolnHA/Solvent values taken from the published literature for solutes dissolved in both chlorobenzene solvents, were converted to enthalpies of solvation, ΔsolvHA/Solvent, using standard thermodynamic equations. Abraham model correlations were developed from the experimental ΔsolvHA/Solvent data. The best derived correlations describe the experimental gas-to-chlorobenzene and gas-to-1,2-dichlorobenzene enthalpies of solvation to within standard deviations of 1.5kJmol−1 and 1.9kJmol−1, respectively. Enthalpies of XH…π (X – O, N, and C) hydrogen bond formation of proton donor solutes (alcohols, amines, chlorinated hydrocarbons, etc.) with chlorobenzene and 1,2-dichlorobenzene were calculated based on the Abraham solvation equation. Obtained values are in good agreement with the results determined using conventional methods.