Absorption-cycle technology driven by low-grade thermal energy has attracted significant attention. Environment-friendly refrigerant/ionic-liquid absorbents have been currently proposed as promising candidates to traditional H2O/LiBr and NH3/H2O working pairs. The properties of refrigerant/absorbent pairs have a large impact on the performance of an absorption-refrigeration cycle, especially the solubility of the gaseous refrigerant in an absorbent. In this work, solubilities (vapor-liquid phase equilibrium) were measured for two new working pairs (isobutane/[P-66614]Cl and propane/[P-66614]Cl) from 278.15 to 348.15 K by an isochoric saturation method. Solubilities increase with a decrease in temperature and an increase in pressure. The new data were correlated by the nonrandom two-liquid (NRTL) equation. Results show that the NRTL model provides small deviations distributed as a function of pressure. Furthermore, the enthalpy, entropy, and Gibbs energy of dissolution were estimated. Calculated enthalpies are negative indicating that the process of dissolution is exothermic. The Gibbs energy accords with the classical thermodynamics theory: the lower is the value, the more favorable is the dissolution capacity.