Crystal structure of a 1,1,2,2-tetra-chloro-ethane-solvated hydrazinecarbo-thio-amide compound

The title compound, [(1-{4-[2-(2,4-di-hydroxy-phen-yl)diazen-1-yl]phen-yl}ethyl-idene)amino]-thio-urea, 1,1,2,2-tetra-chloro-ethane monosolvate, C₁₅H₁₅N₅O₂S·C₂H₂Cl₄, was prepared from 4-(4-acetyl-phenyl-diazendi-yl)resorcinol and thio-semicarbazide and recrystallized from mixed solvents of tetra-chloro-ethane and n-hexane. ¹H NMR and X-ray diffraction data are in support of the thione tautomeric form. The X-ray analysis shows the mol-ecule 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 intra-molecular N-H⋯O hydrogen bond is formed. In the crystal, N-H⋯O, N-H⋯N and O-H⋯S hydrogen bonds connect the mol-ecules into a three-dimensional network. The tetra-chloro-ethane solvent mol-ecules are linked to this network through weak C-H⋯O linkages.