The crystal structure of diethylene tetraxanthogen, the oxidation product of the diethylene dixanthate ion

Abstract

The structure of the oxidation product of the diethylene dixanthate anion, diethylene tetraxanthogen (Cl₁₂H₁₆0₆S₈), has been determined by single crystal X-ray diffraction methods. The crystals are tetragonal of space group Z4₁/acd with a 15.798(1), c 17.755(1) Å, containing eight molecules per unit cell. The structure was solved using conventional Patterson and Fourier methods and refined by a full-matrix least-squares method to R 0.055 for the 817 independent statistically significant reflections collected by counter methods. The crystals are composed of discrete molecules held together by van der Waals forces. Each molecule, situated about a site of symmetry 222, has the novel 22-membered ring structure involving disulphide bonds of length 2.035(2) Å. The planarity of the dithiocarbonate moiety and the relatively short carbon-to-oxygen and carbon-to-sulphur bond lengths correlate with extensive π-electron delocalization over the group.