Copper-induced hydrolysis of the disulfide bond.
Abstract Hydrolysis of the disulfide bond of a model compound, the disodium salt of 2,2′-(2-hydroxy-6-sulfonaphthyl-1-azo) diphenyl disulfide, in the presence of cupric ion has been demonstrated by the change of the spectrum of the dye during reaction. The effect of pH and of anaerobic conditions upon the hydrolysis was investigated, and the activation energy of the reaction was determined. Solutions of Pb(NO 3 ) 2 , AgNO 3 , ZnCl 2 , and CoCl 2 were inactive in promoting hydrolysis at concentrations where copper salts readily activated the reaction. Kinetic evidence points to the formation of a metal-disulfide dye complex prior to nucleophilic attack upon the disulfide bond.