【摘要】 在pH7.4、0.01mol·L-1Hepes及室温条件下,通过监测215～330nm范围内紫外差光谱的变化进行了Lu(Ⅲ)对N,N′ 二(2 羟苄基)乙二胺 N,N′ 二乙酸(HBED)、N,N′ 乙烯 二(2 羟基苄基)苷氨酸(EHPG)的滴定。结果表明:两者的紫外差光谱非常相似,均于238和292nm处出现最大吸收峰,且随着Lu(Ⅲ)的滴加,吸收峰强度逐渐增大。238nm处的滴定曲线表明:Lu(Ⅲ)与HBED、EHPG均形成1∶1的稳定配合物,配合物Lu(Ⅲ) HBED与Lu(Ⅲ) EHPG的摩尔吸光系数分别为:ΔεLu-HBED=(16.01±0.38)×103cm-1·mol-1·L,ΔεLu-EHPG=(16.99±0.56)×103cm-1·mol-1·L;条件稳定常数分别为:lgKLu-HBED=16.58±0.13,lgKLu-EHPG=15.56±0.20。同样实验条件下,荧光光谱测定表明:配体HBED、EHPG均在310nm处有最大荧光峰,配合物Lu(Ⅲ) HBED、Lu(Ⅲ) EHPG的形成都使其最大荧光峰红移,Lu(Ⅲ) HBED的形成使HBED的荧光增强约2.3倍,而Lu(Ⅲ) EHPG的形成却使EHPG的荧光有约65%的淬灭。更多还原

【Abstract】 The binding of Lu(Ⅲ) to HBED or EHPG were monitored by UV difference spectra in 0.01 mol·L-1 Hepes, pH 7.4 and room temperature. The results show that two peaks at 238 and 292 nm appear while Lu(Ⅲ) binds to HBED or EHPG. At 238 nm the molar extinction coefficient of Lu(Ⅲ)HBED and Lu(Ⅲ)EHPG complexes are ΔεLuHBED=(16.01±038)×103 cm-1·mol-1·L and ΔεLuEHPG=(16.99±056)×103 cm-1·mol-1·L, respectively. Adding competing agent EDTA leads to the decrease of the absorptivity of the complexes. According to it, the conditional equilibrium constants of the complexes are lgKLuHBED=16.58±0.13 and lgKLuEHPG=15.56±020, respectively. At the same conditions the influence of Lu(Ⅲ) on the fluorescence spectra of HBED and EHPG were measured. The results show that there are a little red shift of maximum peak, and that the fluorescence of HBED is increased by 2.3 times, but the fluorescence of EHPG is quenched about 65%. 更多还原