Four New 3D Metal-Organic Frameworks Constructed by a V-shaped Tetracarboxylates Ligand: Selective CO2 Sorption and Luminescent Sensing

摘要

Employing a V-shaped rigid multicarboxylate ligand 1,3-di(2',5'-dicarboxypheny)benzene acid (H4L), three microporous metal-organic frameworks (MOFs), H-2[Co-4(O)L-2(H2O)(2)]center dot 3DMA center dot 8H(2)O (1), H-3[Zn2.5L2]center dot NMP center dot 5H(2)O (2), and H-3[Cd2.5L2]center dot 4DMF center dot 3H(2)O (3) were synthesized and characterized. Compound 1 exhibits a cage-based (3,6)-connected rtl topological MOF with [Co4O(COO)(8)] clusters and highly selective adsorption of CO2 over CH4. Compounds 2 and 3 are isostructural and display a rare 4,8-connected flu net with linear trinuclear [Zn-3(COO)(6)] clusters. Interestingly, when compound 3 was soaked in DMF solution containing Eu3+ ions, an Eu-loaded compound Eu@3 with bright red fluorescence was obtained, which reveals highly selective sensing for Cu2+, Fe3+, and Cr2O72- ions. This represents an unusual example to achieve the detection of Cu2+, Fe3+, and Cr2O72- ions simultaneously by fluorescence spectrometry based on a recyclable Eu-loaded MOF sensor.