Study On The Synthesis Of Terbium Bifunctional Chelating Agent

Lanthanide organic chelating agent is the core of time-resolved fluorescence immunoassay,which is widely used in biological analysis,clinical medicine,food safety and other fields.In order to prepare lanthanide organic chelating agents with high stability,good water solubility and high coordination with terbium ions,the optimum synthesis route of organic ligands matching with the energy levels of terbium ion was determined by adjusting pH,optimizing reaction temperature and time.Several organic intermediates were synthesized.Bifunctional terbium organic chelating agents were successfully synthesized and their spectral properties were improved.The results show that good fluorescence lifetime,large Stokes shift and high quantum yield were obtained.The structure and properties of terbium organic chelating agent were characterized by ¹H-NMR,MS,elemental analysis and fluorescence spectroscopy.1.Using 3-methyl-2-hydroxybenzoic acid as raw material and dimethyl sulfate as methylation reagent,2-methoxy-bis（2-mercaptothiazolide）isophthalamide was successfully synthesized.The synthesis method of intermediate product was optimized by adjusting reaction temperature,pH value and material ratio.The structures of these compounds were characterized by ¹H-NMR,MS and elemental analysis.The yield of2-methoxy-bis（2-mercaptothiazolide）isophthalamide was up to 85%,which was effectively increased by recrystallization of ethyl acetate.2.Theinitialreactantswere2-chloroethylaminehydrochlorideand4-methylbenzenesulfonyl chloride and the reaction conditions were adjusted by reaction temperature,reaction time and so on.The structures of the reaction products were further characterized by ¹H-NMR,MS and elemental analysis.And the yield of N,N,N’,N’-tetrakis（2-aminoethyl）ethylenediamine was about 95%.A kind of controllable preparation of polydentate polyamine compounds was achieved.3.Firstly,a novel eight coordinated acupoint organic ligand,Me₄BocLysBH（2,2）IMA,was synthesized.Then,chelating agents Tb³⁺?LysBH（2,2）IMA（TbL）and Eu³⁺?LysBH（2,2）IMA（EuL）were prepared by reaction with Tb³⁺and Eu³⁺,their spectral properties were studied.The maximum excitation wavelength,maximum emission wavelength,the Stokes shift,the fluorescence lifetime,the quantum yield of TbL are 357nm,543 nm,186 nm,1018μs,37%,respectively.As comparison,these data of EuL are 333nm,613 nm,280 nm,758μs,10.2%,respectively.