Metal−Organogermanate Frameworks Built by Two Kinds of Infinite Ge−O Chains with High Thermostability and Luminescent Properties

A bifunctional metalloligand with metal−C (Ge−C) bonds, bis(carboxyethylgermanium) sesquioxide (H₂E₂Ge₂O₃, where E = −CH₂CH₂COO⁻), has been used to make metal−organometallic frameworks (MOMFs) Cd_1.5(E₃Ge₃O₅) (1) and Pb(E₂Ge₂O₃) (2). In the structures, the inorganic Ge₂O₃ cores of the metalloligands polymerize to form two kinds of infinite Ge−O chains, and the organic carboxyls induce the Cd and Pb ions to produce Cd−O and Pb−O chains. Further, the Ge−O chains link the Cd−O/Pb−O chains via −CH₂CH₂− groups to result in two novel MOMFs, showing high thermostability and blue-violet emission.