Two polyoxometalate-based metal-organic complexes constructed from a pyridine-polyazole: Assembly, structures, electrochemistry and adsorption properties

Two new polyoxometalate-based metal-organic complexes, namely, [Ni-3(Htyptz)(2)(gamma-Mo8O26)(H2O)(8)]center dot 4H(2)O (1) and [Ni-3(H(2)typtz)(2)(TeMo6O24)(H2O)(8)]center dot 6H(2)O ( 2 ) H(2)typtz = 3-(tetrazol-5-yl)-5-(pyrid-3-yl)-1,2,4-triazolej have been successfully synthesized under hydrothermal conditions. Their structures have been identified by single crystal X-ray diffraction, and further characterized by elemental analysis, infrared spectra (IR), and powder X-ray diffraction (PXRD). In complex 1, the [Ni(Htyptz)(2)] mononuclear unit link the adjacent 1D Ni-gamma-Mo8O26 inorganic chains conducing to the formation of the 2D layer, then the adjacent 2D layers are connected through hydrogen bonds to construct a 3D supramolecular network. Complex 2 is a 2D coordination network, which is constructed from 1D [Ni-3(H(2)typtz)(2)] chains and TeMo6 anions. The different polyoxometalates play important roles in tuning the structures of the title complexes. In addition, the adsorption activities of complexes 1 and 2 for methylene blue (MB), neutral red (NR), rhodamine 6G (R6G), Orange II (OrII) have been investigated. Moreover, their electrochemical behaviors and electrocatalytic properties have also been studied. (C) 2019 Elsevier Ltd. All rights reserved.