A structural and theoretical study of intermolecular interactions in nicotinohydrazide dihydrochloride

In the title compound [systematic name: 3-(azaniumylcarbamoyl)pyridinium dichloride], C(6)H(9)N(3)O2+center dot 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, pi-pi interactions do not occur.