Crystal structure of a 1,1,2,2-tetra­chloro­ethane-solvated hydrazinecarbo­thio­amide compound

The title compound, [(1-{4-[2-(2,4-di­hydroxy­phen­yl)diazen-1-yl]phen­yl}ethyl­idene)amino]­thio­urea, 1,1,2,2-tetra­chloro­ethane monosolvate, C(15)H(15)N(5)O(2)S·C(2)H(2)Cl(4), was prepared from 4-(4-acetyl­phenyl­diazendi­yl)resorcinol and thio­semicarbazide and recrystallized from mixed solvents of tetra­chloro­ethane and n-hexane. (1)H NMR and X-ray diffraction data are in support of the thione tautomeric form. The X-ray analysis shows the mol­ecule crystallizes as a zwitterion, with proton transfer from the nominal phenol to the azide group; the N—N bond length is 1.291 (5) Å, and an intra­molecular N—H⋯O hydrogen bond is formed. In the crystal, N—H⋯O, N—H⋯N and O—H⋯S hydrogen bonds connect the mol­ecules into a three-dimensional network. The tetra­chloro­ethane solvent mol­ecules are linked to this network through weak C—H⋯O linkages.