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

Abstract Three novel 3D metal-organic frameworks, {[Zn 2 (L)(BDC) 2 ]·H 2 O} n ( 1 ), {[Cd 2 (L) 2 (BDC)]·(BDC)·7.7(H 2 O)} n ( 2 ), and {[Co(L)(H 2 O) 2 ]·(BDC)·5(H 2 O)} n ( 3 ) (L = tetrakis(imidazol-1-ylmethyl)methane, H 2 BDC = 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.