Patent ID: 8772521

Claim:
A metal alkyl-arene having general formula (I) or (Ia): M(η 6 -arene) 2 Al q X r R s (I) M(η 6 -arene)Al q X r R s (Ia) wherein: M represents zirconium (Zr), hafnium (Hf), or mixtures thereof; arene represents a benzene, or a benzene substituted with from 1 to 6 linear or branched C 1 -C 6 alkyl groups, or mixtures thereof; X represents a halogen atom selected from the group consisting of chlorine, bromine, fluorine, and iodine; R represents a linear or branched C 1 -C 15 alkyl group; q is a number ranging from 2 to 6; r is a number ranging from 1 to 20; and s is a number ranging from 1 to 6.