Fluorescence Detection And Regulation Of Rare Earth Coordination Polymers Constructed By Blue Light Emitting Ligands

Due to the unique electronic structure and excellent photophysical properties of rare earth elements,rare earth coordination polymers composed of rare earth metal ions and organic ligands have potential application value and development prospects in many fields especially in the field of fluorescence sensing and white light regulation.In this work,two series of rare earth coordination polymers were constructed by using rare earth metals,nitrogen heterocyclic polycarboxylic acid ligand and aminobenzoic acid ligand.The X-ray single crystal diffraction method was used to determine its structure.According to the crystallographic data,the lanthanide shrinkage law between rare earth elements was summarized.The structure and properties of 1-12 were studied by infrared spectra(IR),ultraviolet visible(UV-vis),thermogravimetry(TG),X-ray powder diffraction(PXRD)and fluorescence.Among them,based on the fluorescence characteristics of nitrogen heterocyclic europium coordination polymer,the fluorescence sensing effects on metal Fe³⁺,UO₂²⁺ions and small organic molecules(phenol,resorcinol and catechol)were investigated.The results showed that it has high sensitivity to these target analytes,especially for metal Fe³⁺ions with high selectivity and high sensitivity,which can be used as a candidate material in the field of fluorescence sensing detection.On the other hand,in view of the unique luminescence properties of rare earth ions,rare earth coordination polymers with nearly white light emission have been successfully prepared by method of mixing doping several rare earth ions,which can be used as potential white LED material.In addition,the fluorescence of the nitrogen heterocyclic europium coordination polymer was regulated by wrapping H₄TBAPy and the sensitivity of europium coordination polymer to colchicine was improved.Lanthanide metal coordination polymers 1-7 which are constructed by rare earth ions and5-methyl-1-(4-carboxylphenyl)-1H-1,2,3-triazole-4-carboxylic acid usually have high coordination numbers.And the rare earth ions in the structure are nine-coordinated,forming a slightly twisted three-cap triangular antiprism space configuration.The two-dimensional structure is further connected by hydrogen bonds to form a three-dimensional supramolecular network structure.The rare earth ions in coordination polymers 8-12 constructed by rare earth ions and 2-aminoterephthalic acid are octahedral,forming a dodecahedral space configuration and forming a three-dimensional network structure through ligands link.