A theoretical investigation of structure of dinuclear titanium complexes

We investigate different couplings of TiCln (dimerisation to TiCln−1CH3 and complexation by magnesium chloride) and their consequences for the reactivity towards ethene. The dimerisation results from the donation of an electron pair from a chlorine ligand to the metal and leads to bridging structures. Alkyl groups also bridge two metal centres of the dinuclear complexes. This is much more favourable than the connection as terminal ligands that is the only possibility in the case of mononuclear complexes. This change in the adsorption mode favours the first step of the propagation reaction of the Ziegler–Natta reaction (CH3→C3H7) by a stabilisation of the end product.