Thermodynamic parameters for transfer of resorcinol monoethers from water to heptane and to propylene carbonate. Derivation and analysis of group transfer thermodynamic parameters

Abstract

Partition coefficients have been measured over a range of temperature for transfer of a series of resorcinol monoethers from water to heptane and to propylene carbonate (all solvents mutually saturated). These data have been used to evaluate ΔG_trs, ΔH_trs and ΔS_trs. Further analysis allows assignment of ΔG_trs, ΔH_trs and ΔS_trs values for transfer of a lipophilic group (CH₂) and the ‘parent’ structure between the selected solvents. Transfer of a CH₂ group is shown to be accompanied by a zero enthalpy change, whereas transfer of the parent structure results in ΔH_trs values dependent upon the non-aqueous solvent involved. These data are discussed in terms of partitioning and the use of a suitable bulk solvent to represent a biological lipid phase.