2 H -[1,3]Thia-zolo[5,4,3- ij ]quinolin-3-ium chloride monohydrate.

The structure of the title hydrated mol-ecular salt, C 10 H 8 NS + ·Cl - ·H 2 O, obtained by the reaction of sodium quinoline-8-thiolate Na(Quin-8-S) with CH 2 Cl 2 and an aqueous solution of [Bu 4 N]Cl, contains π-stacked cations [plane-to-plane separation = 3.338 (4)-3.356 (4) Å] and features chains built by alternating Cl - anions and H 2 O mol-ecules connected by O-H⋯O hydrogen bonds. The cation shows whole-mol-ecule disorder over two flipped orientations in a 0.853 (3):0.147 (3) ratio.