Three new 3D metal-organic frameworks based on the tetrakis(imidazol-1-ylmethyl)methane and 1,4-benzenedicarboxylic acid ligands with transition metal (Zn/Cd/Co) and properties research

Three novel 3D metal-organic frameworks, {[Zn-2(L)(BDC)(2)]center dot H2O}(n) (1), {[Cd-2(L)(2)(BDC)]center dot(BDC)center dot 7.7(H2O)}(n) (2), and {[Co(L)(H2O)(2)]center dot(BDC)center dot 5(H2O)) (3) (L = tetrakis(imidazol-1-ylmethyl)methane, H2BDC = 1,4-benzenedicarboxylic acid), have been successfully synthesized by self-assembly of transition-metal salts with a flexible N-containing ligand and 1,4-dicarboxybenzene ligand. Complexes 1-3 have 3D structures with various topologies. In complex 1, the L connects Zn(II) atoms to form 2D layers, which are linked by two kinds of 1D [Zn(BDC)](n) chains to generate a 4-connected three-dimensional structure with (6.8(5)) (6(4).8(2))(8(6)) topology. In complex 2, Cd(II) atoms are coordinated by L to furnish a 2D layer, and the adjacent layers are linked by BDC ligands as bridging ligands to general a new (4,5)-connected three-dimensional network with a point symbol of (4(4).6(2))(4(4).6(6)). In Complex 3, the L ligands act as 4-connected linkers connecting Co(II) ions to display a 4-connected three-dimensional structure with 4.6(5) topological net directly. In addition, the solid-state fluorescence, infrared spectra, magnetic property and thermal stability of these complexes have also been investigated. (C) 2016 Elsevier B.V. All rights reserved.