Methods of preparation of sulfanes

Abstract

Sulfane crude oils obtained by acidification of aqueous sodium polysulfide solutions vary little in composition with varying sulfur content of the solution. Evidence presented suggests that the distribution of the sulfanes in such crude oils reflects the equilibrated distribution of the various polysulfide anions in the aqueous solution before acidification. The sulfane distribution in mixtures obtained by reaction of liquid H2S with Br2, SCl2, and S2Cl2 respectively varies over a wide range, depending on the molar ratio of the reactants. Liquid H2S reacts with Br2 or SCl2 to yield essentially the same products. These reactions, however, differ in the nature of their intermediates. By using a large excess of liquid H2S, H2S3 was directly synthesized in over 90% purity. Liquid H2S reacts with S2Cl2 to yield H2S4 in over 90% purity. Gaseous HCl catalyzes the reaction of H2S with the chlorosulfanes and a mechanism is suggested involving HCl as a proton transfer agent in the formation of the reactive intermediates.