A supramolecular assembly dominated by N-H•••S hydrogen bonds:: Structure of 2-thioureidobenzoxazole by single crystal X-ray diffraction

2-Thioureidobenzoxazole (1) was synthesized using 5-amino-3H-1,2,4-dithiazole-3-thione and 2-aminophenol and characterized by X-ray crystallography. The molecule of 1 is essentially planar due to pi conjugation and an intramolecular N-(HN)-N-... hydrogen bond also contributes towards its planarity. The crystal lattice is built up of stacks of dimers of 1 generated by N-(HS)-S-... hydrogen bonds. The supramolecular assembly is dictated by weaker N-(HS)-S-... interactions to the exclusion of more stronger N-(HX)-X-... (X = O, N) hydrogen bonds which are normally expected. (C) 2004 Elsevier B.V. All rights reserved.