Coordination polymers and metal-organic frameworks have been studied extensively over the past decade. These materials, constructed through the polymerization of metal centers through functionalized organic components, have many potentially useful applications based on their unique construction. The choice of a lanthanide element as the metal center may impart luminescent properties that would be of interest in optical or sensing applications. Our laboratory has synthesized a material we call GWMOF-6, [Ln₂(C₆H₈O₄)₃(H₂O)₂] • (C₁₀H₈N₂), where Ln = Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, and various combinations of each. Here we take advantage of the “antenna effect” to sensitize lanthanide luminescence through the uncoordinated 4,4'-bipyridine molecule residing in the channels. By changing the lanthanide center or combining two lanthanides into the same structure, we are able to control the luminescent behavior of this material. For example, the combination of terbium and europium in the framework leads to a near quenching of terbium emission and an almost two-fold increase in europium emission. Our work in this area will be presented, including quantum yield and lifetime measurements to quantify the observed luminescent behavior.