Crystal structure and Hirshfeld surface analysis of 2,4,6-tri-amino-pyrimidine-1,3-diium dinitrate.

The title compound, C 4 H 9 N 5 2+ ·2NO 3 - , crystallizes in the monoclinic crystal system, space group P 2 1 / c . The asymmetric unit, which comprises a diprotonated tri-amino-pyrimidine dication and two nitrate anions, has an almost planar geometry with a dihedral angle of 0.92 (4)° between the mean plane of the cation and that defined by both anions. In the crystal, hydrogen-bonding inter-actions between the 2,4,6-tri-amino-pyrimidine cation and the nitrate anions lead to a one-dimensional supra-molecular network with weak anionic inter-actions forming a three-dimensional network. These inter-actions were investigated using Hirshfeld surface analysis, which indicates that the most important contributions for the packing arrangement are from O⋯H/H⋯O (53.2%), N⋯H/H⋯N (12.5%) and C⋯H/H⋯C (9.6%) inter-actions. Energy framework analysis showed that of the components of the framework energies, electrostatic repulsion ( E rep ) is dominant.