Crystal structures of sulfathiazole polymorphs in the temperature range 100–295 K: A comparative analysis

The response of four polymorph modifications of sulfathiazole C9H9N3O2S2 to variation of temperature was examined in the range 295–100 K by single crystal X-ray diffraction. No phase transitions occur in this temperature range; all the structures exhibit anisotropic contraction. The metastable sulfathiazole modification I is drastically different from the other modifications (II, III, and IV) in the anisotropy of structure distortions and changes in the intra-and intermolecular geometry, although bulk thermal expansion is virtually similar for all polymorphs within the temperature range studied.