A structural and theoretical study of intermolecular interactions in nicotinohydrazide dihydrochloride

In the title compound systematic name: 3‐(azaniumylcarbamoyl)pyridinium dichloride], C₆H₉N₃O²⁺·2Cl^?, the ions are connected by N—H...Cl hydrogen bonds to form layers and C—H...Cl interactions expand the layers into a three‐dimensional net. The energies of the N—H...Cl interactions range from typical for very weak interactions (0.17 kcal mol^?1) to those observed for relatively strong interactions (29.1 kcal mol^?1). C—H...Cl interactions can be classified as weak and mildly strong (energies ranging from 2.2 to 8.2 kcal mol^?1). Despite the short contacts existing between the parallel aromatic rings of the cations, π–π interactions do not occur.