The Dimerization of Ethylene Using Palladous Chloride as the Catalyst

Abstract

The dimerization of ethylene was carried out using palladous chloride as the catalyst. Acetic acid, ethylene dichloride, ethylene tetrachloride, benzene, chlorobenzene, triethyleneglycol, acetic acid esters, chloroform, cyclohexane and ethanol were employed as the reaction solvents, and the effects of these solvents on the reaction were investigated. The best yield of butylene (about 1500 mol.% to palladous chloride) was obtained, when acetic acid was used as the solvent; the yield decreased gradually following the above order of solvents until, when ethanol was used as the solvent, it yielded only 96 mol.%. However, in all solvents dimerization was carried out predominantly, and only a few higher polymers were obtained. It is very interesting that the solvent effect mentioned above was different from the effect of solvents in the isomerization of olefin when metal carbonyl was used as the catalyst. To explain these results, a hydride ion-shift mechanism has been proposed.