This invention relates to a composition of matter represented by the formula below, and to a polymerization process comprising combining an olefin in the gas or slurry phase with an activator, a support and a compound represented by the following formula: wherein M is a group 3 to 14 metal, each X is independently an anionic leaving group, n is the oxidation state of M, m is the formal charge of the YZL ligand, Y is a group 15 element, Z is a group 15 element, L is a group 15 or 16 element, R1 and R2 are independently a C1 to C20 hydrocarbon group, a heteroatom containing group, silicon, germanium, tin, lead, phosphorus, a halogen, R1 and R2 may also be interconnected to each other, R3 is absent, or is hydrogen, a group 14 atom containing group, a halogen, a heteroatom containing group, R4 and R5 are independently an aryl group, a substituted aryl group, a cyclic alkyl group, a substituted cyclic alkyl group, or multiple ring system, R6 and R7 are independently absent or hydrogen, halogen, a heteroatom or a hydrocarbyl group, or a heteroatom containing group.