Robust Anionic Ln-Organic Frameworks: Chemical Fixation of CO, Tunable Light Emission, and Fluorescence Recognition of Fe.

With the aim of exploring and enriching nanocaged functional platforms of lanthanide-organic frameworks, the subtle combination of [Ln(CO)] secondary building units and [Ln(CO)] units by employing the hexacarboxylic acid of 4,4',4″-(pyridine-2,4,6-triyl)tris(1,3-benzenedicarboxylic acid) (HPTTBA) successfully realized the self-assembly of highly robust multifunctional {Ln}Ln-organic anionic skeletons of {(MeNH)[Ln(PTTBA)]·DMF·HO} (), which had remarkable intrinsic nature of high thermal and water stability, large permanent porosity, interconnected nanocaged void volume, and high specific surface area. Here, only the Eu-based framework of was taken as one representative to discuss in detail. Gas-sorption experiments showed that the activated solvent-free framework possessed the outstanding ability to separate the mixed gases of CO/CH (50:50, v/v) with an ideal adsorbed solution theory selectivity of 14. Furthermore, was an efficient and recycled catalyst for the chemical cycloaddition of CO and epoxides into their corresponding carbonates, which possessed a better catalytic performance than the documented unique Eu-organic framework of [Eu(BTB)(phen)] and could be widely applied in industry because of its simple synthetic conditions and high yield. In the meantime, adjustable emission colors devoted by the efficient Tb → Eu energy transfer confirmed that Eu/Tb-organic framework could be taken as a good substitute for barcode materials by changing the ratio of Eu and Tb. Moreover, quantitative luminescence titration experiments exhibited that possessed good selectivity for the identification of Fe in aqueous solution by fluorescence quenching with a low limit of detection value of 6.32 × 10 M.