Catalyst for the production of olefin polymers

A catalyst composition comprising:

• a) a catalyst precursor compound having the formula:
• AqMLn wherein each A has the formula:
• M is a metal selected from the group consisting of Group 3 to 6 elements and Lanthanide series elements;
• each L is a monovalent, bivalent, or trivalent anion;
• Q is a bridging group containing one or more Group 13-16 atoms;
• X and Y are each heteroatoms selected from the group consisting of X, O, S and P, said Y being contained in a heterocyclic ring additionally comprising from 2 to 7 carbon atoms, and substituted with from 0 to 5 R2 groups, said Q being bonded to said heterocyclic ring at an atom other than Y;
• Cyclo is a cyclic moiety;
• each R1 is independently a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R1 groups may be joined to form a cyclic moiety;
• each R2 is independently a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R2 groups may be joined to form a cyclic moiety;
• each m is independently an integer from 0 to 5;
• n is an integer from 1 to 4;
• q is 1 or 2;
• and when q is 2, the A groups are optionally connected by a bridging group Z containing one or more Group IIIA, Group IVA, Group VA, or Group VIA elements;
• and
• b) an activating cocatalyst.