This invention relates to transition metal complexes of a dianionic, tridentate ligand that features a central neutral heterocyclic Lewis base and two phenolate donors, where the tridentate ligand coordinates to the metal center to form two eight-membered rings. Preferably the bis(phenolate) complexes are represented by Formula (I): where M, L, X, m, n, E, E′, Q, R1, R2, R3, R4, R1′, R2′, R3′, R4′, A1, A1′, are as defined herein, where A1QA1′ are part of a heterocyclic Lewis base containing 4 to 40 non-hydrogen atoms that links A2 to A2′ via a 3-atom bridge with Q being the central atom of the 3-atom bridge.