Olefin Oligomerization and Isomerization Catalysts. The Preparation, Properties and Catalytic Action of Dithio Nickel(II) Complexes With Chelating Phosphines

The syntheses and properties of cationic nickel complexes containing dithio-β-diketonate and chelating bisphosphine ligands of general formula [Ni{R1C(S)CR2C(S)R3}{(PL1L2)R(PL3L4)}]X(Rj,Lj = alkyl or aryl, R = (CH2)n, n = 1-4, X = halide, BPh4, PF6, etc.) are described. The compounds are shown to be effective catalysts for the oligomerization and double bond shift isomerization of olefins with a high specificity for dimeric products rich in desirable linear and near linear isomers.