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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 effects of Eu3 + and N, N’-ethylidene-bis [2- (2- (2-hydroxyethyl) Hydroxyphenyl) glycine] (EHPG). The results show that Eu3 + forms a 1/1 complex with EHPG. Cyclic voltammetry Eu3 + has a pair of redox peaks at the bare glassy carbon electrode in the potential range of -0.2 ~ -1.2V. EHPG has no electrochemical activity. Eu-EHPG exhibits quasi-reversible electrochemical behavior at the electrode. Fluorescence spectrometry showed that the maximum fluorescence peak intensity of EHPG at 310 nm decreased gradually with the continuous dropping of Eu3 +. However, the UV absorption spectra at 240 nm and 293 nm gradually increase. When the amount of Eu3 + reaches a certain level, the fluorescence intensity at 310 nm and the absorption intensity at 240 nm and 292 nm will not change any more. The calculated molar absorption coefficient of the complex Eu-EHPG at 240 nm was Δε = 19.06 × 103 cm-1.mol-1.L and the conditional stability constant was lgKEu-EHPG = 13.90.