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A new polyoxometalate (POM) based on a flexible bidentate ligand and "inverted Keggin" inorganic building block, namely, [Cu8L8[Mo12O46(AsPh)4]2]∙H2O (1), where L is 1,3-bis(1,2,4-triazol-1-yl)propane, has been synthesized under hydrothermal condition. In 1, the "inverted Keggin" [Mo12O46(AsPh)4]4- building blocks are linked by the one-dimensional (1D) zigzag [CuI(trans-L)]+ chains and [CuI4(cis-L)4]4+ macrocycles to yield a three-dimensional (3D) framework. The compound 1 represents the first 3D "inverted Keggin" polyoxometalate modified by a transition-metal complex. Topologically, the 3D framework can be considered as an 8-connected net with a Schlafli symbol of 422∙66. As far as we know, compound 1 is the highest-connected uninodal network topology presently known for POM-based materials. The compound was characterized by its IR spectrum, UV—vis spectrum, thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD) patterns. Remarkably, compound 1 exhibits photocatalytic activity for dye degradation under visible light irradiation and shows good stability toward visible-light photocatalysis. [ABSTRACT FROM AUTHOR]

Two novel Cu(II) compounds [Cu2(btb)3.5(C4AS)(H2O)]·2.5(H2O) (1) and [Cu2.5(btp)2(C4AS)(htz)(H2O)3]·4.75(H2O) (2) have been hydrothermally synthesized and structurally determined by single-crystal X-ray diffraction analyses (btb = 1,4-bis(1,2,4-triazol-1-yl)butane, btp = 1,5-bis(1,3,4-triazol-1-yl)pentane, htz = 1,3,4-triazolate, and C4AS = p-sulfonato-calix[4]arene). In 1, the btb ligands connect Cu(II) atoms to form a 3D porous framework. The 1D chains constructed by C4AS and Cu(II) atoms are further bonded to the 3D porous framework through the Cu–O bonds. Topologically, structure 1belongs to a 3D (3,6)-connected net with the Schläfli symbol of (42·6)(46·68·8). In 2, the C4AS links the Cu(II) atoms to form 1D chains, which are further connected by the btp and htz to generate a 3D (3,4,6)-connected framework with the Schläfli symbol of (62·8)(52·62·7·8)(54·62·7·87·9). The two compounds have been further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD), thermogravimetric (TG) analyses, and UV–vis absorption spectra. [ABSTRACT FROM AUTHOR]

A series of structurally diverse metal–organic frameworks (MOFs), [Co4(TPOM)2(L1)4(H2O)4]·H2O (1), [Ni2(TPOM)(L2)2(H2O)2]·2H2O (2), [Co2(TPOM)(L2)2(H2O)2]·H2O (3), [Cu4(TPOM)2(L3)4]·3H2O (4), [Co2(TPOM)0.5(L4)] (5), and [Cd(TPOM)(L3)3]·7H2O (6), where TPOM = tetrakis(4-pyridyloxymethylene)methane, H2L1 = 1,3-benzenedicarboxylic acid, H2L2 = 5-hydroxyisophthalic acid, H3L3 = 1,3,5-benzenetricarboxylic acid, and H4L4 = 1,2,4,5-benzenetetracarboxylic acid, have been hydrothermally synthesized. These complexes were structurally characterized by X-ray diffraction analyses and further characterized by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Compound 1shows a 3D 4-connected framework with a rare (84·62) topology. Compounds 2and 3are isostructural and display 3D 2-fold interpenetrating frameworks with (64·82)(66)2topologies. Compound 4exhibits a 2-fold interpenetrating structure with a scarce trinodal (3,4,5)-connected (4·62)(4·69)66topology. Compound 5possesses a 3D 4-connected net with the TPOM ligands located in the 3D channels. Compound 6features 2D square layers (sql). The free TPOM ligands and L3 anions form discrete fragments through hydrogen bonds and π–π interactions. Interestingly, the fragments penetrate the 2D networks above and below to yield a unique 2D → 3D polythreading framework. The structural differences among such compounds show the effects of the carboxylates and central metals on the complex structures. The UV–vis absorption spectra, optical energy gap, and luminescent properties were also investigated for the compounds. [ABSTRACT FROM AUTHOR]