STRUCTURAL STUDY OF THIOSACCHARIN BY SINGLE-CRYSTAL X-RAY-DIFFRACTIONAND INFRARED-SPECTROSCOPY

The structure of thiosaccharin (1,2-benzisothiazol-3(2H)-thione 1,1-di oxide) has been investigated by X-ray diffraction and infrared spectro scopic methods. The compound crystallizes in the orthorhombic space gr oup Fdd2 with a = 26.591(3), b = 25.058(3), c = 4.934(5)Angstrom, Z = 16. The structure consists of thiosaccharin molecules bonded to each o ther through N-H...O intermolecular hydrogen bonds. The infrared spect ra of the thiosaccharin at room and liquid-nitrogen temperature were r ecorded. The spectral features in the N-H stretching region were corre lated with the crystallographic data on the geometry of the N-H...O hy drogen bonding. In an attempt to assign the bands due to the SO2 stret ching modes, the spectrum of thiosaccharin was compared with that of s accharin (1,2-benzoisothiazole-3(2H)-one, 1,1-dioxide).