Z. Naturforsch. 2013,
68b, 778 – 788
doi:10.5560/ZNB.2013-3007
Three 3D Metal-Organic Frameworks Constructed from Keggin Polyanions and Multi-nuclear AgI Clusters: Assembly, Structures and Properties
Xiu-Li
Wang,
Na
Li,
Ai-Xiang
Tian,
Jun
Ying,
Guo-Cheng
Liu,
Hong-Yan
Lin, and
Dan
Zhao
Department of Chemistry, Bohai University, Liaoning Province Silicon Materials Engineering Technology Research Center, Jinzhou 121013, P. R. China
Received January 10, 2013 / published online July 19, 2013
Three Keggin-based metal-organic frameworks (MOFs) containing multi-nuclear silver subunits, [Ag7(ptz)5(H2O)2][H2SiMo12O40] (1), [Ag8(ptz)5(H2O)2][AsW12O40] (2) and [Ag7(ptz)5(H2O)][HAsMo12O40] (3) (ptzH = 5-(4-pyridyl)-tetrazole), have been synthesized under hydrothermal conditions by changing the inorganic polyanions. The new compounds have been characterized by elemental analyses, TG analyses, IR spectroscopy, and single-crystal X-ray diffraction. In compound 1, the multi-nuclear Ag5(ptz)5 subunits are interconnected to form chains, which are further linked by AgI cations to construct a 3D MOF with large channels. Pairs of SiMo12O404− polyanions reside in the channels as penta-dentate inorganic ligands. In 2, six AgI cations link five ptz− anions to construct a hexa-nuclear subunit [Ag6(ptz)5]+, which is interconnected to form chains. These chains are further linked by AgI cations to construct a 3D MOF, where AsW12O403− polyanions reside as hexa-dentate ligands. Compound 3 exhibits a 3D MOF based on Ag5(ptz)5 subunits, in which the hexa-dentate AsMo12O403− polyanions are incorporated. The rigid tetrazole-based ligand ptz− plays an important role in the formation of the multi-nuclear subunits of the title compounds. The electrochemical properties of compound 1 and the photocatalytic properties of compounds 1 and 3 have been investigated.
Key words: Keggin Polyoxometalate, Tetrazole-based Ligand, Metal-Organic Framework, Photocatalytic Properties, Electrochemical Properties