Formation and nature of microheterogeneous catalysts based on palladium complexes

The mechanism of the formation and the nature of microheterogeneous catalys ts for hydrogenation are discussed using acetylacetonate complexes of palla dium with phosphine ligands as an example. Polynuclear palladium complexes with phosphide and phosphinidene ligands are obtained, and their role in th e formation of hydrogenation catalysts is found. As distinct from phosphide complexes, amide complexes of palladium are unstable in a hydrogen atmosph ere and undergo reduction to form highly dispersed palladium black.