ИСТИНА

This invention relates to a compound represented by the formula: TyCp'mMGnXq wherein: Cp' is a tetrahydroindacenyl group which may be substituted or unsubstituted, provided that when Cp' is tetrahydro-s-indecenyl: 1) the 3 and/or 4 positions are not aryl or substituted aryl, 2) the 3 position is not directly bonded to a group 15 or 16 heteroatom, 3) there are no additional rings fused to the tetrahydroindacenyl ligand, 4) T is not bonded to the 2-position, and 5) the 5, 6, or 7-position is geminally disubstituted; M is a group 3, 4, 5, or 6 transition metal; G is a heteroatom group represented by the formula JRi z where J is N, P, O or S, Ri is a C1 to C20 hydrocarbyl group, and z is 1 or 2; T is a bridging group; y is 0 or 1; X is a leaving group; m = 1; n = 1, 2 or 3; q = 1, 2 or 3, and the sum of m+n+q is equal to the oxidation state of the transition metal.