Analysis of Weak Interactions in Crystals of Fenamic Acids-Ethacridine Complexes

While searching for new drugs based on combina-tions of fenamic acid and its derivatives with other pharmaceuti-cally active substances, the syntheses of complexes of fenamic, flufenamic, mefenamic, and tolfenamic acids with ethacridine lactate were performed, and obtained complexes were charac-terized by X-ray diffraction. The inter-and intramolecular interactions were determined. An analysis of hydrogen bonds and other weak interactions was performed using Quantum Theory of Atoms in Molecules and noncovalent interaction approaches. The main force building the hydrogen-bond system are proton-accepting properties of the carboxylate group. Also, the presence of molecules of solvents in crystals results in the formation of interaction networks.