Binary catalyst system for dimerisation of lower olefins - comprising nickel salt complex with phosphorus cpd. and organo-aluminium cpd.

摘要

olefins are dimerised by mixing the olefins(s) with an opt. halogenated hydrocarbon solvent at 0-100 degree C under 1-40 atm. using a binary catalyst comprising an organo-aluminium cpd. (I) and a complex of a Ni salt of an (in)-organic salt with a tert. phosphine or phosphite, the Al/Ni atomic ratio being 1-100. The novelty comprises the use, as (I), of a natural or synthetic rubber with carbon chains, which is swellable in the solvent and contains 2-50 mole % -AlRx units, where R is 8C alkyl and x is a halogen. The catalyst has high selectivity: dimerisation of ethylene gives 80% butene-1, and that of propylene gives 90-95% methylpentenes. The catalyst is also stable and is recoverable.