Method of obtaining of dimers of alpha - ethylenic hydrocarbon and dimers obtained

摘要

An alpha olefin is dimerized in the presence of a catalyst comprising a complex organic compound of a Group VIII metal, an alkyl aluminium halide and a methylene halide at a temperature in the range -40 DEG to +200 DEG C. under such conditions of pressure that the reactants are maintained in the liquid or partially condensed phase, to give a product containing a high proportion of linear dimers having an internal double bond. The preferred catayst components are nickel acetyl acetonate, diethyl aluminium chloride and methylene chloride. Inert diluents such as saturated hydrocarbons or benzene may be present but it is preferred to use the methylene halide as sole solvent. The dimerization of ethylene, propylene or butene-1 may be carried out under a pressure of 200-2000 p.s.i.g. and the dimerization of 3-methyl-pentene-1 or 4-methylpentene-1 may be effected at atmospheric pressure. The molar ratio of Group VIII compound to alkyl aluminium halide is preferably from 1:1 to 1:10.