Energetic aspects of diclofenac acid in crystal modifications and in solutions--mechanism of solvation, partitioning and distribution.

Temperature dependency of saturated vapor pressure and heat capacity for the diclofenac acid (Form II) were measured and thermodynamic functions of sublimation calculated (DeltaG(sub)(298) = 49.3 kJ x mol(-1); DeltaH(sub)(298) = 115.6 +/- 1.

Toxaphene chemistry: separation and characterisation of selected enantiomers of the Polychloropinene mixtures.

The primary goal for the study presented here was the preparation and characterisation of enantiomeric pure chlorobornane standards (Toxaphene). In this context, we partially modeled the procedure for Polychloropinene production in the former USSR. The initial reaction was ionic addition of hydrogen chloride to (1S)-alpha-pinene resulting predominantly in (1S)-2-endo-chlorobornane.

Thermodynamics of sublimation, crystal lattice energies, and crystal structures of racemates and enantiomers: (+)- and (+/-)-ibuprofen.

Thermodynamic differences between ibuprofen (IBP) racemate and the (+)-enantiomer were studied by X-ray diffraction, thermoanalysis, and crystal energy calculations. The thermodynamic functions of sublimation (as a measure of crystal lattice energy) were obtained by the transpiration method. The sublimation enthalpies (DeltaH(sub)) of (+/-)-IBP and (+)-IBP are 115.

Interrelation between thermochemical and structural data of polymorphs exemplified by diflunisal.

Three known and one new unsolvated polymorphic phase A, B, C, and D of diflunisal were grown and studied by X-ray diffraction, IR-spectroscopy, solution calorimetry, and DSC methods. Their structures are compared to another previously described modification E.1 Relationships were studied between O-H and C=O stretching frequencies and between C=O stretching frequency and the molecular volume of diflunisal in the respective crystal lattice.