Crystal structure and Hirshfeld surface analysis of the hydro­chloride salt of 8-{4-[(6-phenyl­pyridin-3-yl)meth­yl]piperazin-1-yl}-3,4-di­hydro­quinolin-2(1H)-one

The amine 8-{4-[(6-phenyl­pyridin-3-yl)meth­yl]piperazin-1-yl}-3,4-di­hydro­quinolin-2(1H)-one was crystallized as the hydro­chloride salt, 4-(2-oxo-1,2,3,4-tetra­hydro­quinolin-8-yl)-1-[(6-phenyl­pyridin-3-yl)meth­yl]piperazin-1-ium chloride, C25H27N4+·Cl− (I·HCl). The conformation of the organic cation is half-moon in shape enclosing the chloride anion. The piperidine ring of the 3,4-di­hydro­quinolin-2(1H)-one moiety has a screw-boat conformation, while the piperazine ring has a chair conformation. In the biaryl group, the pyridine ring is inclined to the phenyl ring by 40.17 (7) and by 36.86 (8)° to the aromatic ring of the quinoline moiety. In the crystal, the cations are linked by pairwise N—H⋯O hydrogen bonds, forming inversion dimers enclosing an R22(8) ring motif. The Cl− anion is linked to the cation by an N—H⋯Cl hydrogen bond. These units are linked by a series of C—H⋯O, C—H⋯N and C—H⋯Cl hydrogen bonds, forming layers lying parallel to the ab plane.