Synthesis,Structures And Properties Of Complexes Based On Thiophenamide And Imidazole Carboxylic Acid

The combination of aromatic carboxylic acids and N-containing ligands is an effective method for the synthesis of novel coomplexes.By changing the different carboxyl-assisted ligands and metal salts can be a variety of different results of the coordination polymers.The aromatic carboxylic acid ligands containing the N-donor are also synthetic organic llikers of various structures.In this paper,12 coordination polymers were synthesized by using thiophene-2-carboxylic acid pyridine-3-amide and 5-（1H-imidazol-1-yl）isophthalic acid as the main ligands.The coordination polymers were characterized by elemental analysis,IR sp,Thermal analysis and single crystal X-ray diffraction.The fluorescence properties of complexes 7-12 were studied.The application of complex 10 in the detection of was discussed.First,the ligand complex ligand ligand thiophene-2-carboxylic acid pyridine-3-amide was synthesized and six new coordination polymers [Cu（HIP）（TCPA）₂]n（1）,[Cd（HIP）（TCPA）（H₂O）₂]n（2）,{[Cd（HBTC）（TCPA）（H₂O）₂]·H₂O（3）,{[Na（HBTC）₂Zn2（TCPA）4（H₂O）₂]·H₂O}n（4）,[Co2（BTA）（TCPA）4（H₂O）4]}n（5）and [Ni2（BTA）（TCPA）4（H₂O）4]n（6）were synthesized using the synthesized ligand with different aromatic carboxylic acid auxiliary ligands and metal salts.The complex 1 forms a two-dimensional structure by coordinating Cu（II）with the hydroxyl of the auxiliary ligand.Both complex 2 and complex 3 are all one-dimensional,and interestingly,TCPA is different in position.The complex 4 forms a one-dimensional strand via sodium,and the ligand TCPA is on both sides of the chain.Complex 5 and complex 6 are hetero-isomeric compounds,all of which are linked by a hydrogen bond of a ligand’s water molecule into a two-dimensional structure by a metal chain of different coordination environments and then deposited by ππ into a three-dimensional structureThen two new coordination polymers [Cd₂（imip）₂（H₂O）₃]n（7）and [Cu（Himipi）₂]n（8）were synthesized by using 5-（1H-imidazol-1-yl）isophthalic acid and copper and cadmium.The 5-（1H-imidazol-1-yl）isophthalic acid in complex 7 takes two different coordination modes.Among them,the ligand carboxyl and Cd1 take μ3-η1:η2:η1 coordination mode,and Cd₂ take μ2-η1: η2 coordination mode.In the ligand,5-（1H-imidazol-1-yl）isophthalic acid and Cu take the μ1-η1:η1 coordination mode.Different structures exhibit different properties in fluorescent properties.Among them,the good fluorescence properties of complex 7 have good application prospect in molecular fluorescence detection.Finally,four hetero-isomeric coordination polymers [Mn（imip）（H₂O）₂]n（9）,{[Zn（imip）（H₂O）₂]·0.5H₂O}n（10）,{[Co（imip）（H₂O）₂]·0.5H₂O}n（11）and [Ni（imip）（H₂O）₂]（12）were synthesized by 5-（1H-imidazol-1-yl）isophthalic acid and four transition metals.The two carboxyl groups of 5-（1H-imidazol-1-yl）isophthalic acid in complex 10 are connected into a two-dimensional structure by means of bridging and bridging,and then the hydrogen bonds of the ligand water molecules form a three-dimensional structure The Among the four complexes,complex 10 has good fluorescence properties and exhibits good application in the detection of nitroaromatic compounds.