5,6-Dioxo-1,10-phenanthrolin-1-ium chloride

The title compound, C12H7N2O2+·Cl−, is isostructural with its bromide analogue. The compound exhibits a layered structure in which all atoms lie on a crystallographic mirror plane. N+—H⋯Cl− hydrogen bonds, C—H⋯O and C—H⋯Cl− contacts are formed within each layer. The perpendicular separation between the layers is 3.141 (1) A.