The Molecular Design,synthesis,structures And Luminescence Sensing Performance Research Of Heterocyclic/Carboxylate Lanthanide Coordination Complexes

In recent years,lanthanide coordination complexes has potential research value and development prospects which has become a research hotspot due to the novel structure,unique properties and irreplaceable role in the field of optical sensing.This article is aimed to research the synthesis,structure,properties and application of lanthanide coordination complexes deeply and systematically.A new series of lanthanide coordination complexes have been synthesized under the condition of hydrothermal and solvent-thermal via the self-assembly by the reaction of Ln(NO₃)₃?6H₂O(Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy)as the metal source,adipic acid and N-heterocyclic derivatives(H₂L₁=2,6-di-(5-methyl-1Hpyrazol-3-yl)pyridine;H₂L₂=2,6-di-(5-phenyl-1H-pyrazol-3-yl)pyridine)as organic ligands in aqueous system.At the same time,lanthanide coordination complexes 1-20 were measured by single-crystal X-ray diffraction,and which were explored lanthanide contraction phenomenon between lanthanide elements by analyzing the crystal structure data systematically.In addition,they were also characterized by Elemental analysis(C,H,N),Infrared spectra(IR),Thermal-thermogravimetric analysis(TG),Powder X-ray diffraction(PXRD)and Luminescence spectra.Based on the luminescent properties of the lanthanide coordination complexes(Eu,Tb),we found that very fast and extremely sensitive optical detection of the thiamines can be achieved for the first time,which are the better performing luminescent sensing materials.Typically,rare earth ions are involved in coordination with a higher coordination number.In this work,the center rare earth ions of complexes 1-11 are ten-coordinated,come into being a mildly twisty bicapped square antiprism polyhedron configuration;the center rare earth ions of complexes 12-20 are nine-coordinated,to form a mildly twisty tricapped trigonal prism polyhedron configuration.For the complexes 12-14,can be formed one dimensional chain structure by covalent linking,the rest are discrete structures.Through the effect of hydrogen bond,complexes 1-8 can be formed one-dimensional chain structures;complexes 9-11 can be formed three-dimensional network structures;complexes 12-14 can be formed two-dimensional layer structures.The formulas of lanthanide coordination complexes 1-20 as shown in the figure below:...