Crystal structures of 4-(pyrimidin-2-yl)piperazin-1-ium chloride and 4-(pyrimidin-2-yl)piperazin-1-ium nitrate

Abstract

The title salts, C8H13N4+·Cl−, (I), and C8H13N4+·NO3−, (II), contain linked pyridinium–piperazine heterocycles. In both salts, the piperazine ring adopts a chair conformation with protonation at the N atom not linked to the other ring. In the crystal of (I), weak N—H...Cl interactions are observed, leading to zigzag chains along [100]. In the crystal of (II), both H atoms on the NH2+group form bifurcated N—H...(O,O) hydrogen bonds. Weak C—H...O interactions are also observed. These bonds collectively link the components into infinite chains along [100].