Coordination polymers constructed by diverse metal centers and the rigid ligand 3,5-di(1H-imidazol-1-yl)pyridine: Synthesis, structure and properties

Six new coordination polymers, [Cu(L)(2)(H2O)(2)](NO3)(2) (1), [Cu( 1)(2)](ClO4)(2) (2), [Cd(L)(2)(H2O)(2)](ClO4)(2) (3), [Cd(L)(OAc)(2)( H2O)] (4), [Cu-3(L)(4)(H2O)(2)(SO4)](SO4)(2).3OH(2)O (5), and [Ni(L)(H2O)(3)(SO4)] (6) [L = 3,5-di(1Himidazol-1-yl)pyridine, OAc- = CH3COO-], have been prepared and characterized by X-ray diffraction, IR, elemental and thermogravimetric analyses. Complexes 1, 4 and 6 have different one-dimensional (1D) chain structures, while 2 and 4 are two-dimensional (2D) networks. The chains and layers are further linked together by hydrogen bonds to generate three-dimensional (3D) frameworks. Complex 5 is a (3,4,4)-connected 3D framework with a Point (Schlafli) symbol of (4.8(2))(4)(4.8(3). 10(2))(2)(4(2).8(2).10(2)). The influences of the coordination modes of the ligand L, metal center as well as the counteranion on the structures of the complexes are discussed. Furthermore, the reversible anion exchange property of 3 and the photoluminescence properties of 3 and 4 have been investigated. (C) 2012 Elsevier Ltd. All rights reserved.