Preparation of novel cationic acetylacetonate complexes of palladium with diimine ligands

Abstract

Catalytic systems based on palladium and nickel complexes with α-diimine ligands are known as the Brookhart catalysts [1, 2]; they are well known in modern practice of laboratory and industrial homogeneous catalysis of oligoand polymerization of lower alkenes. The strong point of such catalysts is their stability towards polar functional groups of the monomer, allowing preparation of hyperbranched polyolefines. Significant part of palladium complexes with α-diimine ligands described in the literature are neutral (halogenide or alkyl) complexes of palladium that generally require activation with organoaluminum compounds to initiate the active cationic sites [2]. A common feature of preparations of the known cationic palladium complexes is that they are multi-stage processes. On top of that, expensive starting materials are normally used (salts of silver and thallium) as well as magnesiumortincontaining chemicals [1]. There have been no examples of preparation of cationic acetylacetonato complexes of palladium with αdiimine ligands.