A central μ<sub>3</sub>—O moiety linking two Fe<sup>III</sup> and one Ce<sup>III</sup> sites supported by two distinct heterometallic carboxylate bridging modes features in self-assembled [CeFe<sub>2</sub>(bpy)<sub>2</sub>(μ<sub>3</sub>—O)(μ—L)<sub>2</sub>(μ—LH)<sub>2</sub>(LH)(H<sub>2</sub>O)<sub>2</sub>]·0.5(bpy)·7H<sub>2</sub>O (<b>1</b>) (LH<sub>2</sub> = glycolic acid), and the structure models potential bonding modes of the Rare Earth corrosion inhibitor Ce(glycolate)<sub>3</sub> to iron or iron oxide.<br>