Reactions of Group 3 Metal Alkyls in the Gas Phase: Part 9.—Addition of Propene to Trimethylaluminium

Abstract

The thermal gas phase reaction of propene with monomeric trimethylaluminium has been studied at temperatures from 455 to 549 K using a static reaction system and Teflon coated reaction vessels. Initial propene pressures ranged from 190 to 370 Torr (25.33 to 49.33 kN m-2) and the ratio of propene to A1Mc3 varied from 4.9 to 24.1. Overall conversions between 0.4 and 12.4 % with respect to alkyl groups were observed. In excess propene the overall reaction involves the rate determining addition of propene to the Al—CH3 bond (ki) to give Mc2AIBu> followed by the fast elimination of isobutene and subsequent addition of propene to Me2AlH, yielding Mc2AlPrn. The rate constant A'i, corrected for path degeneracy, is given (with standard errors) by the Arrhenius relationship