INTERACTION OF METHYLTITANIUM TRICHLORIDE WITH CHLORO(METHYL)ALUMOXANE AND ITS AQUA-COMPLEX - MECHANISM OF METHANE FORMATION

Certain aspects of the mechanism of interaction between the components of a catalytic system for polymerization of ethylene comprising CH3Ti Cl3 (I) and (CH3AlCl)20 (III) or (CH3AlCl)2O . H2O (IV) in toluene and toluene-d8 are studied. The formation of an equilibrium complex betwe en the components of the catalyst, rapid methyl group exchange between titanium and alumoxane derivatives, and the regeneration of CH3TiCl3 during the reaction are established. High yields of methane, which sig nificantly exceed the amount of I, and its isotope composition in the reactions CD3TiCl3 (II) + III and II + IV indicate that the Ti-CD3 and Al-CH3 bonds, which are involved in the formation of CD3H and CH4 are cleaved, and toluene-d8 is involved in the formation of CD4, CH3D, an d CH2D2. A conclusion is reached on a radical mechanism for the Ti-CH3 bond cleavage. The suggested reaction pathways account for the high c atalytic activity of the system in the presence of alumoxanes via the permanent regeneration of the Ti-CH3 bond.