Patent ID: 7851644

Claim:
A metallocene of formula (I): Y j R″ i Z jj MeQ k P l (I) wherein: (1) Y is a coordinating group containing a six π electron central radical directly coordinating Me, to which are associated one or more radicals containing at least one non-carbon atom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Sc, In, Sn, Sb and Te; (2) R″ is a divalent bridge between the Y and Z groups; (3) Z is a coordinating group having the same meaning as Y or is an open pentadienyl containing group, a cyclopentadienyl containing group, a heterocyclopentadienyl containing group, a nitrogen containing group, a phosphorous containing group, an oxygen containing group or a sulfur containing group; (4) Me is an element belonging to Group 3, 4, 5, 6 or to the lanthanide or actinide series of the Periodic Table of the Elements; (5) Q is a linear or branched, saturated or unsaturated alkyl radical, aryl radical, alkylaryl radical, arylalkyl radical or an halogen atom; (6) P is a stable non-coordinating or pseudo non-coordinating counterion; (7) i is an integer having a value of 0 or 1; (8) j is an integer having a value from 1 to 3; (9) jj is an integer having a value from 0 to 2; (10) k is an integer having a value from 1 to 3; and (11) l is an integer having a value from 0 to 2.