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Abstract: A new 3D Zn(II) MOF based on 2-(hydroxymethyl)-1H-imidazole-4,5-dicarboxylic acid (H4hmIDC), formulated as {[Zn3(HhmIDC)2(H2O)2]·2H2O}n, has been successfully prepared under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction, elemental analysis and infrared spectroscopy, as well as power X-ray diffraction. It is worth noting that the unique HhmIDC3− ligand in the title compound adopts an unusual coordination mode, namely µ4-kN,O: kN′,O′: kO″,O‴: kO′′′′ to link the Zn(II) ions into an interesting 3D coordination framework. Such a 3D network can be further simplified as a binodal 4-connected mog (moganite) topology with the Schläfli symbol of (4·64·8)2(42·62·82). Moreover, the title Zn(II) MOF shows a relatively high thermal stability up to 340 °C, and exhibits an intense blue emission centered at 450 nm upon excitation at 370 nm.Graphical Abstract: A new 3D microporous Zn(II) MOF with an uncommon binodal 4-connected mog topology has been constructed from 2-(hydroxymethyl)-1H-imidazole-4,5-dicarboxylic acid (H4hmIDC). Such a Zn(II) MOF displays a relatively high thermal stability and exhibits very strong blue photoluminescence with a maximum emission band at 450 nm when excited at 370 nm. [ABSTRACT FROM AUTHOR]

The imidazole-based dicarboxylate ligand 2-(4-(pyridin-4-yl)phenyl)-1H-imidazole-4,5-dicarboxylic acid (H3PyPhIDC), was synthesized and its coordination chemistry was studied. Solvothermal reactions of CaII, MnII, CoII, and NiII ions with H3PyPhIDC produced four coordination polymers, [Ca(µ3-HPyPhIDC)(H2O)2]n (1), {[M3(µ2- H2PyPhIDC)2(µ3-HPyPhIDC)26(H2O)2]·6H2O}n [M = Mn (2), Co (3)], and {[Ni(µ3-HPyPhIDC)(H2O)]·H2O}n (4). Compounds 1-4 were analyzed by IR spectroscopy, elemental analyses, and single-crystal and powder X-ray diffraction. Compound 1 displays a one-dimensional (1D) infinite chain. Compounds 2 and 3 are of similar structure, showing 2D network structures with a (4,4) topology based on trinuclear clusters. Compound 4 has another type of 2D network structure with a 3-connected (4.8²) topology. The results revealed that the structural diversity is attributed to the coordination numbers and geometries of metal ions as well as the coordination modes and conformations of H3PyPhIDC. Moreover, the thermogravimetric analyses of all the compounds as well as luminescence properties of the H3PyPhIDC ligand and compound 1 were also studied. [ABSTRACT FROM AUTHOR]