Structural study of thiosaccharin by single crystal X-ray diffraction and infrared spectroscopy

The structure of thiosaccharin (1,2-benzisothiazol-3(2H)-thione 1,1-dioxide) has been investigated by X-ray diffraction and infrared spectroscopic methods. The compound crystallizes in the orthorhombic space groupFdd2 witha=26.591(3),b=25.058(3),c=4.934(5) Å,Z=16. The structure consists of thiosaccharin molecules bonded to each other through N–H...O intermolecular hydrogen bonds. The infrared spectra of the thiosaccharin at room and liquid-nitrogen temperature were recorded. The spectral features in the N–H stretching region were correlated with the crystallographic data on the geometry of the N–H...O hydrogen bonding. In an attempt to assign the bands due to the SO₂ stretching modes, the spectrum of thiosaccharin was compared with that of saccharin (1,2-benzoisothiazole-3(2H)-one, 1,1-dioxide).