Ga(Ⅲ)与EHPG配合反应的光谱研究

Studies on the Interaction between Gallium Ion and N,N′-Ethylenebis-[2-(o-Hydroxyphenolic)Glycine)] by Spectrometry

在0.1mol/LpH7.2,Tris-HCl缓冲溶液和室温条件下,用荧光光谱和紫外差光谱研究了Ga3+与N,N′-乙烯-二[2-(2-羟基苯基)甘氨酸](EHPG)的配合反应。结果表明:Ga3+与EHPG的配位比为1/1。随着Ga3+的不断滴加,EHPG的荧光光谱在310nm处的最大荧光峰强度逐渐降低,其紫外差光谱在240nm和293nm处的吸收峰逐渐增强。当Ga3+达到一定量时,310nm处的荧光强度、紫外光谱中240nm和293nm处的吸收峰强度不再发生变化。通过计算可得:在240nm处配合物Ga-EHPG的摩尔吸光系数为ε=5.41×103L.mol-1.cm-1,条件稳定常数为lgKGa-EHPG=22.83。

The binding of Gallium to N, N＇-ethylenebis [2-（o-hydroxyphenolic）glycine）] （EHPG） was studied by means of fluorescence spectra and difference UV spectra. Fluorescence measurements show that Gallium binding to EHPG leads to a quenching of the fluorescence of EHPG at about 310nm. At the same conditions,two peaks at 240 and 293nm appeared in difference UV spectra after gallium ion binding to EHPG. The 1/1 stable Ga-EHPG complex can be confirmed from spectral titration curves and the molar extinction coefficient of the complex is ε= 5. 41 × 10^3cm^-1 ·complex is lgKGa-EHPG= 22. 83 by calculation.