Eu(Ⅲ)与EHPG配合反应的循环伏安特性和光谱研究  

Studies on the Interaction between Europium Ion and N,N′-Ethylenebis-[2-(o-hydroxyphenolic)glycine)] by Means of Voltammetric and Spectroscopic Methods

作　　者：赵静[1] 田燕妮[1] 杨斌盛[1] 

机构地区：[1]山西大学分子科学研究所化学生物学与分子工程教育部重点实验室,太原030006

出　　处：《化学通报》2007年第4期304-308,共5页Chemistry

基　　金：山西省归国留学基金;山西省自然科学基金(2006011016)资助项目

摘　　要：在0.02mol/LpH6.0的HAc-NaAc缓冲溶液和室温条件下,用循环伏安法、荧光光谱和紫外差光谱研究了Eu3+与N,N′-亚乙基-二[2-(2-羟基苯基)甘氨酸](EHPG)的配合反应。结果表明,Eu3+与EHPG形成1/1的配合物。循环伏安法测定Eu3+在-0.2～-1.2V电位扫描范围内裸玻碳电极上有一对氧化还原峰,EHPG无电化学活性,Eu-EHPG在电极上呈现准可逆电化学行为。荧光光谱测定表明,随着Eu3+的不断滴加EHPG在310nm处的最大荧光峰强度逐渐降低。而其紫外差光谱在240nm和293nm处的吸收峰逐渐增强,当Eu3+达到一定量时,在310nm处的荧光强度、240nm和292nm处的吸收峰强度不再发生变化。通过计算,在240nm处配合物Eu-EHPG的摩尔吸光系数为Δε=19.06×103cm-1.mol-1.L,条件稳定常数为lgKEu-EHPG=13.90。The binding of europium to N, N＇-ethylenebis[2-（o-hydroxyphenolic）glycine） ] （EHPG） had been studied by means of cyclic voltammetry, fluorescence spectra and difference UV spectra. A couple quasi-reversible redox peaks of Eu^3＋ from the cyclic voltammogram shifted with the addition of EHPG and the peak current of Eu^3＋ decreased accompanying the formal potential shifted, indicated that a complex was formed. Fluorescence measurements show that europium binding to EHPG leads to a quenching of the fluorescence of EHPG at near 310nm. At the same conditions, two peaks at 240 and 293nm appeared in difference UV spectra after europium ion binding to EHPG. The 1/1 stable Eu-EHPG complex can be confirmed from spectral titration curves and the molar extinction coefficient of the complex is △ε = 19.06 ×10^3 cm^-1· mol^-1 L at 240nm. Using EDTA as a competitor, the conditional equilibrium constants of the complex is lgKEu-EHPG=13.90 by calculation.

关 键 词：EU^3+ 循环伏安 紫外差光谱荧光光谱 

分 类 号：O641.4[理学—物理化学]