THE RATES AND MECHANISMS OF SUBSTITUTION REACTIONS OF PALLADIUM(II) DITHIOLATE COMPLEXES

Publisher Website
Google Scholar
Abstract
The kinetics of the substitution reactions of planar palladium(II) dithiolate complexes with both monodentate and bidentate nucleophiles have been studied in aqueous solution at 25°C using the stopped-flow technique. For both monodentate and bidentate nucleophiles, most of the reactions are second-order overall, first-order in the metal complex and first-order in the nucleophile. Mechanisms are proposed for the substitution reactions. The results demonstrate that palladium(II) dithiolates have a smaller tendency to form five-coordinate adducts than do nickel(K) dithiolates. The rates of the substitution reactions are slower than might have been expected from a consideration of the corresponding reaction with nickel(II). This correlates with the instability of five-coordinated intermediates.