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

Int J Pharm. 2007 Apr 4;334(1-2):115-24. doi: 10.1016/j.ijpharm.2006.10.033. Epub 2006 Oct 28.

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: DeltaG(sub)(298)=50.4kJmol(-1); DeltaH(sub)(298)=114+/-1kJmol(-1); DeltaS(sub)(298)=213+/-3Jmol(-1)K(-1); II: DeltaG(sub)(298)=54.1kJmol(-1); DeltaH(sub)(298)=124.9+/-1.6kJmol(-1); DeltaS(sub)(298)=237+/-5Jmol(-1)K(-1); III: DeltaG(sub)(298)=49.9kJmol(-1); DeltaH(sub)(298)=98.6+/-1.9kJmol(-1); DeltaS(sub)(298)=163+/-5Jmol(-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Octanol / chemistry
  • Calorimetry, Differential Scanning
  • Crystallization
  • Hexanes / chemistry
  • Solubility
  • Solvents / chemistry*
  • Sulfonamides / chemical synthesis
  • Sulfonamides / chemistry*
  • Temperature
  • Thermodynamics*
  • Water / chemistry
  • X-Ray Diffraction

Substances

  • Hexanes
  • Solvents
  • Sulfonamides
  • Water
  • n-hexane
  • 1-Octanol