| Coordination polymers(CPs)constructed from metal ions and organic ligands have currently become a hot topic in the field of coordination chemistry and material chemistry,owing to their intriguing topological structures and their potential applications in the area of gas adsorption,catalysis,luminescence and magnetism.In fact,organic ligands such as nitrogen-containing heterocyclic and multiple acid compounds are widely used to construct a variety of CPs,while their halogenated analogues are seldom employed.Recently,we have focused on the design and synthesis of CPs with various halogenated bidentate ligands and studied their physical and chemical properties.Moreover,on the basis of the characteristics of them,their related properties including luminescence,electrochemistry,magnetism,catalysis and biomedicine have also been investigated.These results are described briefly as follows:Halogenated aromatic dicarboxylic acids were reacted with main group,transition and lanthanide ions under solvothermal or room temperature conditions,afforded five coordination polymers(1,2,5,6 and 9)with different structures,respectively.All the five complexes are sensitive to water,and another five new coordination polymers(3,4,7,8 and 10)were obtained upon slowly evaporating their aqueous solution.X-ray single-crystal diffraction analyses indicated that their structures varied from zero-,one-,two-and three-dimensional architectures depend on the radii of the corresponding metal ions.To our knowledge,this work represents the first example of systematically studying the structural transformation of water-sensitive coordination polymers in aqueous solution.By modulation of organic templates,the reaction of tetrafluorophthalic acid with silver(I)nitrate generated three isomeric coordination polymers(11-13).X-ray single-crystal diffraction analyses revealed that three complexes are made up of penta-,tetra-and trinuclear fundamental units,respectively,and all contain the unprecedented inorganic Ag-O-Ag layers.Further investigation on the electrochemistry shows that they have similar performance with the silver(I)oxide.In water solution,they dissociate into several stable polynuclear silver(I)oligomers and exhibit extraordinary antimicrobial activities against three common bacteria involving Staphylococcus aureus,Escherichia coli and Bacillus subtilis.Solvothermal reaction of a perfluorinated isophthalate ligand with copper(Ⅱ)nitrate afforded a fluorous CP(14),which shows a three-dimensional framework based on bicopper(Ⅱ)paddle-wheel building units.Complex 14 exhibits extremely strong antiferromagnetic coupling at low temperatures.It is important to note that in this complex the SOMOs are not the HOMO and HOMO-1 as expected according to the aufbau principle.This complex is the typical non-aufbau system in which the SOMO is well below the HOMO.In addition,four new cobalt(II)-based CPs(15-18)with different architectures were synthesized by the hydrothermal reactions of cobalt(II)salts,2,3,5,6-tetrafluoro-1,4-bis(1,2,4-triazol-1-ylmethyl)benzene and chlorinated benzenedicarboxylic acids.All the cobalt(Ⅱ)complexes display strong antiferromagnetic coupling at low temperatures.By varying the molar ratio of organic ligands,four new CPs(19-22)were prepared from zinc(II)salts,2,3,5,6-tetrachloro-N,N’-bis(4-pyridyl)terephthalamide and dicarboxylic acids under solvothermal conditions.X-ray structural analyses show that they are three-dimensional 4-fold interpenetrated dia net,three-dimensional eight-connected non-interpenetrated network,two-dimensional 3-fold parallel interpenetrated net and three-dimensional 2-fold interpenetrated mab framework,respectively.To our knowledge,this is the first example of control interpenetration via altering the ratio of organic ligands.Moreover,the as-synthesized zinc(Ⅱ)-based CPs shows efficient catalytic activities toward the ring-opening polymerization of glycolide. |
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