Ligand exchange reactions of vanadium(III) β diketonate complexes

Abstract

The kinetics of ligand exchange reactions of V(III) β diketonates have been studied. The replacement of acetylacetone by hexafluoroacetylacetone involves a rate law with both first- and second-order terms in the incoming ligand. The replacement of acetylacetone by deuteroacetyl-acetone involves terms zero-order and first-order in the incoming ligand. Both reactions are markedly catalyzed by acids and inhibited by bases. A mechanism involving a dangling ligand intermediate is suggested. The rates of ligand exchange are much less than the rates of isomerization.