Patent ID: 7863210

Claim:
A compound having the formula: wherein: X 1 and X 2 independently are a halide or a substituted or unsubstituted aliphatic, aromatic, or cyclic group, or a combination thereof; X 3 and X 4 independently are a substituted cyclopentadienyl, indenyl, or fluorenyl group, any substituents on X 3 and X 4 other than a bridging group independently are a hydrogen atom or a substituted or unsubstituted alkyl or alkenyl group; A 2 is a substituted bridging group connecting X 3 and X 4 , the substituted bridging group comprising either a silicon bridging atom, a germanium bridging atom, a tin bridging atom, a carbon bridging atom, or a bridging chain of 2 to 5 carbon atoms, any substituents on A 2 other than an alkenyl linking group independently are a hydrogen atom, or a substituted or unsubstituted aliphatic, aromatic, or cyclic group, or a combination thereof; M is Zr, Hf, or Ti; R X , R Y , and R Z independently are a hydrogen atom, or a substituted or unsubstituted aliphatic, aromatic, or cyclic group, or a combination thereof; and n is an integer in a range from 0 to 12, inclusive.