KINETICS ANALYSIS OF THE DECAY OF PHENYLHYDRAZONOPROPANEDINITRILE ADDITION PRODUCTS WITH THIOLS IN AQUEOUS SOLUTIONS
The reactions of phenylhydrazonopropanedinitriles with thiols are reversible and with increasing pH-values of aqueous solutions the equilibrium is shifted them to the side of the reactants.A mechanism of decay of corresponding addition products was proposed and the kinetic description based on this mechanism is in a good agreement with the obtained experimental data.From the viewpoint of the decay, the pH-dependent dissociation of the proton of the imino group formed by addition of thiol to the nitrile carbon atom plays a decisive role.The obtained knowledge is useful with respect to the use of phenylhydrazonopropanedinitriles as affinants for selective and reversible sorption of low-molecular thiols and thiol-proteins in affinity chromatography as well as for the study of the mechanism of the effect of these substances in oxidative and photosynthetic phosphorylation and biological systems in general.