One mononuclear iron(II)-phenylpyruvate complex [Tp(Ph2)Fe(II)(PPH)] (1) of the tridentate face-capping Tp(Ph2) ligand and two dinuclear iron(II)-phenylpyruvate enolate complexes [(6-Me-3-TPA)(2)Fe-2(II)(PP)](2+) (2) and [(6-Me-3-TPA)(2)Fe-2(II)(2-NO2- PP)](2+) (3) of the tetradentate 6-Me3-TPA ligand are reported to demonstrate two different binding modes of phenylpyruvate to the iron(II) centers. Phenylpyruvate binds in a kappa(2)-(O,O) manner to the mononuclear Fe-II(Tp(Ph2)) center of 1 but bridges in a kappa(3)-(O,O,O) fashion to the two Fe-II(6-Me-3-TPA) centers of 2 and 3. Mononuclear complex 1 reacts with O-2 to undergo oxidative decarboxylation and ottho-hydroxylation of one of the aromatic rings of the Tp(Ph2) ligand. In contrast, dinuclear complexes 2 and 3 react with O-2 to undergo oxidative cleavage of the C2-C3 bond of phenylpyruvate.