Evaluation of the role of 'dilution' in ionic crystal formation by analysis of electron density distribution for two solvatomorphs of 4-amino-3,5-dinitropyrazole ammonium salt

摘要

The influence of "dilution" on the peculiarities of supramolecular organization in ionic crystals was analyzed by a detailed analysis of the electron density distribution function recovered by high-resolution X-ray diffraction experiments for two solvatomorphs of 4-amino-3,5-dinitropyrazole ammonium salt. The obtained results show that a decrease in the number of solvate water molecules unexpectedly increases the contribution from the anion—anion interactions to the lattice energy mainly due to the interactions between the it-systems of anions and between the nitro groups, which additionally confirms their binding nature. The latter indicates the general character of tendencies observed for hydrogen bonds and van der Waals interactions in the formation of crystalline materials in molecular and ionic crystals.