Abstract The interaction of o-nitro-and p-nitro-phenyl selenocyanate with aromatic thiols p- thiocresol, p-chlorothiophenol, 4-bromothiophenol, o-mercaptobenzoic acid and pentafluorothiophenol in non-aqueous media and under an atmosphere of dry nitrogen has been investigated. The main products are the diselenide or the selenenyl sulphide depending on the reactants. Hydrogen cyanide is given in all cases. The IR and Raman ...