Crystal structure of 3,6,6-trimethyl-4-oxo-1-(pyridin-2-yl)-4,5,6,7-tetra-hydro-1H-indazol-7-aminium chloride and its monohydrate.

The title compounds, C(15)H(19)N(4)O(+)·Cl(-) and C(15)H(19)N(4)O(+)·Cl(-)·H(2)O, obtained in attempts to synthesize metal complexes using tetra-hydro-indazole as a ligand, were characterized by NMR, IR and X-ray diffraction techniques. The partially saturated ring in the tetra-hydro-indazole core adopts a sofa conformation. An intra-molecular N-H⋯N hydrogen bond formed by the protonated amino group and the N atom of the pyridyl substituent is found in the first structure. In the hydro-chloride, the organic moieties are linked by two N-H⋯Cl(-) hydrogen bonds, forming a C(4) graph-set. In the hydrate crystal, a Cl(-) anion and a water mol-ecule assemble the moieties into infinite bands showing hydrogen-bond patterns with graph sets C(6), R(6)(4)(12) and R(4)(2)(8). Organic moieties form π-π stacked supra-molecular structures running along the b axis in both structures.