OSCILLATING BRIGGS-RAUSCHER-REACTIONS CATALYZED BY MACROCYCLIC NICKEL-COMPLEXES

A number of nickel complexes with various macrocyclic Ligands were stu died as catalysts of the Briggs-Rauscher reaction. Various types of no nlinear behavior were discovered, and the relationships between variou s parameters of oscillating reactions and the initial reactant concent rations were determined. A mechanism of catalysis and criteria for the choice of a catalyst were proposed. In particular, one may choose bet ween one-electron pairs of transition metal complexes M-ox/M-red with a rather broad range of redox potentials (0.7-1.7 V relative to the st andard hydrogen electrode) if labile coordination sites are available, which allow the interaction of a metal ion with a substrate inside th e coordination sphere.