ESR STUDY OF PI-ALLYL CO(II) COMPLEXES IN ZIEGLER TYPE CATALYTIC-SYSTEMS

ESR study of the interaction between the components of the catalytic s ystem Co(acac)(2)-PBu(3)-LiBu in the presence of butadiene revealed th e formation of stable paramagnetic cobalt complexes containing a PBu(3 ) ligand and butadiene molecules. Complexes (eta(3)-R)(2)CoPBu(3) (whe re R is allyl, crotyl, benzyl) have been synthesized by ordinary metho ds in situ, in order to identify the structures of the complexes. ESR parameters and geometry of the central core have been determined. The influence of the nature of phosphine ligands on the parameters of the ESR spectra has been studied. The general regularities in the ESR spec tra of (eta(3)-R)(2)CoPBu(3) and the complexes formed in the catalytic system have been revealed.