DEFORMATION ELECTRON-DENSITY DISTRIBUTIONS OF TETRAAZATHIAPENTALENES WITH HYPERVALENT S-N BONDS

The deformation electron-density distributions of 6a-thia-1,3,4,6-tetraazapentalene derivatives (I,II) and bis(phenylthio)dibenzothiophene (III) were investigated by the X-ray diffraction method. For I and II, a structure around the hypervalent S atom is a trigonal bipyramid with equatorial sp(2) hybrid of S-C bond and lone-pair electrons and apical polarized S-N bonds. In III lone-pair electron densities are observed perpendicular to the thiophene ring and the C-S-C sulfide planes.