Extended supramolecular structures derived from metal pseudohalides and 4,4′-bipyridinium derivative: Synthesis, structures and optical properties

Four novel extended supramolecular structures based on pseudohalides (SCN) and the flexible cationic ligand 1,4-bis(4,4'-bipyridinium)butane ditetrafluoroborate (bbpyb), namely [bbpyb][Hg(SCN)(4)] (1), [Cu-2(bbpyb)(SCN)(4)](n) (2), [Ag-2(bbpyb)(SCN)(4)](n) (3) and [Cu-6(bbpyb)(SCN)(8)](n) (4) have been solvothermally synthesized and characterized by IR spectroscopy, thermal gravimetric analysis(TGA), PXRD, UV-Vis diffuse reflectance spectra and single-crystal X-ray diffraction in the solid state. Compound 1 is a 0D supramolecular structure consisted of one linear cationic ligand bbpyb(2+) and inorganic mononuclear anion [Hg(SCN)(4)](2). Compounds 2 and 3 exhibit infinite two-dimensional anionic architecture, which represent the same (6,3) topology. In compound 4, the cationic ligand bbpyb(2+) bridge [Cu-6(SCN)(8)] cluster unit to generate a 3D coordination framework. The structural diversities show that the pseudohalides (SCN) and cationic ligand should very likely be excellent candidates to construct higher dimensional extend supramolecular architectures. In addition, the optical band gap and photocatalytic properties of compounds 1-4 were also investigated. (C) 2015 Elsevier B.V. All rights reserved.