Phase Transition Thermodynamic Properties of 2-Methylquinoline, 2- Chloroquinoline and 2-Phenylquinoline

Abstract

Abstract Quinoline derivatives are extremely used in medicine and industry. Therefore, the thermodynamic properties of them are essential to know their quality and stability in use. In this work, the thermodynamic characters of 2-methylquinoline (quinaldine), 2-chloroquinoline, and 2-phenylquinoline were investigated. Moreover, the evaporation enthalpy of the compounds were determined the solution calorimetry-additivity scheme approach at 298.15 K. The solution calorimetry was used to measure solution enthalpies of the compounds in benzene solvent at 298.15 K. While, the solvation enthalpy of the compounds were calculated by additivity scheme approach. In addition, the transpiration method was applied to determine the vapor pressure at various temperatures for 2-Chloroquinoline for the first time. As a result, the thermochemical properties; enthalpy, entropy, and Gibbs energy for 2-methylquinoline, 2-chloroquinoline and 2-phenylquinoline were determined from crystalline/liquid to gas phase. Moreover, the thermochemical characteristics values exhibited smaller uncertainties than those in literature data. Consequently, the phase transition thermodynamically studied on 2-position of the quinoline compound when substituted methyl, chloro and phenyl groups.