ИСТИНА

This invention relates to a compound represented by the formula: TyLAMXn-2 wherein: A is a substituted or unsubstituted tetrahydro-as-indacenyl group bonded to M; L is substituted or unsubstituted monocyclic or polycyclic arenyl ligand or monocyclic or polycyclic heteroarenyl ligand bonded to M; M is a group 3, 4, 5, or 6 transition metal (preferably group 4); T is a bridging group bonded to L and A; y is 0 or 1, indicating the absence or presence of T; X is a leaving group, typically a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene; n is the oxidation state of M and is 3, 4, 5, or 6.