. . "groups present they may be the same or different, and when R is divalent it is directly attached to M, and replaces a Y ligand, wherein X is cyclopentadienyl or indenyl nucleus, M is a Group IVA metal, Y is a monovalent anionic ligand,and for formula I, n is an integer of 1 to 10 x is either 1 or 2, and when x=1, p=0 to 3, when x=2, p=0 to 2and for formula II n and m are integers or 0 such that n+" . .