Studying thermodynamic aspects of sublimation, solubility and solvation processes and crystal structure analysis of some sulfonamides

Abstract

Crystal structures of N-(2-chlorophenyl)-benzene-sulfonamide ( I), N-(2,3-dichlorophenyl)-benzene-sulfonamide ( II), N-(4-chlorophenyl)-benzene-sulfonamide ( III) were solved by X-ray diffraction method. Temperature dependencies of saturated vapor pressure and thermodynamic functions of sublimation process were calculated ( I: Δ G sub 298 = 50.4 kJ mo l − 1 ; Δ H sub 298 = 114 ± 1 kJ mo l − 1 ; Δ S sub 298 = 213 ± 3 J mo l − 1 K − 1 ; II: Δ G sub 298 = 54.1 kJ mo l − 1 ; Δ H sub 298 = 124.9 ± 1.6 kJ mo l − 1 ; Δ S sub 298 = 237 ± 5 J mo l − 1 K − 1 ; III: Δ G sub 298 = 49.9 kJ mo l − 1 ; Δ H sub 298 = 98.6 ± 1.9 kJ mo l − 1 ; Δ S sub 298 = 163 ± 5 J mo l − 1 K − 1 ). Thermochemical parameters of fusion process for the compounds were obtained. Enthalpies of evaporation were estimated from enthalpies of sublimation and fusion. Temperature dependencies of the solubility in water, n-octanol and n-hexane were measured. The thermodynamic functions of solubility and solvation processes were deduced. Specific and non-specific solvation terms were distinguished using the transfer from the “inert” n-hexane to the other solvents. The transfer processes of the molecules from water to n-octanol were analyzed and main driven forces were established.