Syntheses, Structures And Properties Of Coordination Polymer Based On Modified Isophthalate Carboxylate Ligands

In recent years, the design and syntheses of metal-organic coordination polymers are attracting increasing attention, due to their often novel structures and potentially useful applications such as luminescent, magnetic properties, adsorption, ferrielectrilic, catalysis and so on. In this paper, we have obtained five new functional coordination polymers by employing Cd(II) and Eu(III) metal ions with modified benzene dicarboxylato ligands (H2L1=2,4-dibenzoylisophthalic acid and H2L2= 2,5-dibenzoylterephthalic acid) under hydrothermal method. They were characterized by X-ray single crystal diffractions, elemental analysis, IR spectroscopy and thermogravimetric analysis, and luminescence properties were also investigated.1. Three new coordination compounds has been hydrothermally synthesized based on H2L1 ligand and the different N-containing heterocyclic ligands with CdⅡ (H2L1 2,4-dibenzoylisophthalic acid, and L1=1,6-di(1H-1,2,4-triazol-1-yl)hexane, L2= 1,4-bis(pyridin-4-ylmethyl)piperazine, L3=1,3-bis((1H-1,2,4-triazol-1-yl)methyl)benzene). Complexes 1 and 2 are isostructural, Cd(II) ions are connected by mixed ligands toform a 2D bi-layers, and adjacent bi-layers are further linked by C-H…O hydrogen bonds interactions to form a 3D supramolecular architecture. Compound 3 constructs a 36-hxl 2D layered topology. The luminescence properties and the thermal stabilities for 1-3 have been studied.2. A unique metal-organic framework (MOF) [Cd2(L2)1.5(μ3-OH)(H2O)2]·2H2O (4) (H2L2=2,5-dibenzoylterephthalic acid) has been synthesized under hydrothermal condition4 exhibits 3D framework with (412·63) topology, in which tetra-nuclear [Cd4(μ3-OH)2] clusters act as 4-connected nodes, and the L ligands can be simplified to be linear connectors. At the same, its luminescence propertie was also investigated.3. The new lanthanide complexe with benzene dicarboxylato ligands, [Eu2(L1)3(phen)2](H2L1=2,4-dibenzoylisophthalic acid; phen=1,10-phenanthroline),were synthesized under hydrothermal conditions.Complex 5 has a 2D layer structure. The adjacent 2D layers are further extended via O-H…O hydrogen bonds into a three-dimensional supramolecular structure. The fluorescence and thermal stabilitie for 5 have been studied.