Crystal structure and Hirshfeld surface analysis of ( E )-5-phenyl-3-[(pyridin-4-yl-methyl-idene)amino]-thia-zolidin-2-iminium bromide monohydrate.

In the cation of the title salt, C ₁₅ H ₁₅ N ₄ S ⁺ ·Br ^- ·H ₂ O, the central thia-zolidine ring adopts an envelope conformation with puckering parameters Q (2) = 0.279 (4) Å and φ(2) = 222.5 (9)°. The mean plane of the thia-zolidine ring makes dihedral angles of 12.4 (2) and 66.8 (3)° with the pyridine and phenyl rings, respectively. The pyridine ring in the title mol-ecule is essentially planar (r.m.s deviation = 0.005 Å). In the crystal, the cations, anions and water mol-ecules are linked into a three-dimensional network, which forms cross layers parallel to the (120) and (20) planes via O-H⋯Br, N-H⋯Br and N-H⋯N hydrogen bonds. C-H⋯π inter-actions also help in the stabilization of the mol-ecular packing. Hirshfeld surface analysis and 2D (two-dimensional) fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (35.5%), C⋯H/H⋯C (23.9%), Br⋯H/H⋯Br (16.4%), N⋯H/H⋯N (10.6%) and S⋯H/H⋯S (7.9%) inter-actions.