Adamantane derivatives of sulfonamide molecular crystals: structure, sublimation thermodynamic characteristics, molecular packing, and hydrogen bond networks

Abstract

The crystal structures of six adamantane derivatives of sulfonamides have been determined by X-ray diffraction. The molecular conformational states, packing architecture, and hydrogen bond networks were analyzed. The conformational flexibility of the bridge connecting the phenyl ring and the adamantane fragment was studied. The molecular packing architectures of the selected crystals can be for convenience divided into three different groups. The thermodynamic aspects of the sublimation processes of the compounds were studied by determining the temperature dependence of vapor pressure using the transpiration method. The thermophysical characteristics of the fusion processes of the molecular crystals were measured and analyzed. Correlations between the sublimation thermodynamic functions and physico-chemical descriptors were revealed. A regression equation correlating the sublimation Gibbs energies with the van der Waals molecular volumes was derived. The influence of various molecular fragments on the crystal lattice energy was analyzed. The relationship between the melting points of the studied substances and the free volume per molecule in the crystal lattices was evaluated.