Synthesis,Characterization And Properties Of Several Nitrogen-containing Functional Ligands And Their Corresponding Complexes

In this paper,six nitrogen-containing functional ligands L1-L6 are synthesized,in which L1,L2 and L5 were three novel ligands,and a cadmium coordination polymer[Cd₂（2-NH₂bdc）₄（4-bpmh）₄]（1）was synthesized by hydrothermal method of terephthalic acid as the auxiliary ligand.These compounds were characterized by mass spectrometry,infrared radiation（IR）,hydrogen nuclear magnetic resonance（H¹NMR）and X-ray single crystal diffraction（XRD）.The dyestuffs of the two ligands L1 and L2 are characterized by UV-Vis spectrophotometer.The specific results were as follows:First,two new flexible tripod Schiff base ligands having dyed property for cotton fabrics are synthesized by the synthetic method in the literature.The ligand L1 is bright yellow and the ligand L2 is orange-red and both structures are optimized by structural optimization.We have studied the dye of the cotton fabric in the absence of any dispersant and fixing agent.The cotton fabric was soaked through the dye solution,dyeing,and natural drying to gain dyeing uniformity of bright yellow fabric.And after optimizing the conditions（similar ligands L3,L4 were synthesized）,we have found that the two dyes have the best dyeing performance.In the follow-up of the sewage treatment process,we have used salting out the dye recovery,the recovery rate is up to 98%.Our research shows that cotton fabric is stable in alkali condition;both of these dyes have good acid degradation;the environment pollution is effectively reduced in the whole coloring and subsequent sewage treatment,thereby their practical application can be expected.We apply the flexible tripod ligand of L1and the auxiliary ligand of terephthalic acid and the metal Cd（II）salt to synthesize a metal-organic complex.Due to the particularity of the ligand structure,an in situ reaction is occurred during the reaction.There are radical reactions in the reaction process,resulting in the formation of a bis-Schiff base ligand of L1’which is different from the original ligand.L1’is a planar constitutive molecule which further reacts with terephthalic acid and metal Cd（II）to produce the compound[Cd₂（2-NH₂bdc）₄（4-bpmh）₄]（1）.Compound 1 is a double interpenetrated 3D frame work which is bridged by terephthalic acid and 4-bpmh linker.Secondly,two novel tetrazolium derivatives L5 and L6 were synthesized by improving the synthesis methods and optimizing the experimental conditions.Then their purification and characterization were carried out.The crystal 2 of L6 ligand were synthesized by hydrothermal method,and its crystal structure was carefully analyzed.