| La(Ⅲ)、Eu(Ⅲ)与HBED配合的紫外差光谱研究 |
| UV Difference Spectra Studies on the Binding of La(Ⅲ) and Eu(Ⅲ) to HBED |
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| 摘要: 在0.01mol· L-1N-2-羟乙基哌嗪-N'-2-乙磺酸(Hepes), pH 7.4,室温条件下,用紫外差光谱滴定观察了La(Ⅲ),Eu(Ⅲ)与N,N'-二(2-羟苄基)乙二胺-N,N'-二乙酸(HBED)的结合。La(Ⅲ),Eu(Ⅲ)与HBED的结合均形成 1: l的配合物,其紫外差光谱均于238和292nm处出现吸收峰,在238nm处配合物La-HBED与Eu-HBED的摩尔吸光系数分别为:εLa=(9.82±0.24)× 103 |
| 关键词: 转铁蛋白 HBED 镧系离子 紫外差光谱 |
| 基金项目: 国家自然科学基金资助项目(No.20071022);山西省自然科学基金资助课题(No.991013). |
| Abstract: In 0.01mol· L-1 N-(2-hydroxyethyl) -piperazine-N'-2-ethanesulfonic acid (Hepes), at room temperature and pH7.4, the reaction N, N'-Bis(2-hydroxybenzyl) ethylenedinitrilo-N, N'-diacetic acid(HBED) with La (Ⅲ) or Eu (Ⅲ) was monitored by UVdifference spectrophotometry.The molar absorptivities for La-HBED and Eu-HBED complexes are εLa = (9.82 ± 0.24) × 103cm-1· mol-1· L, △εEu = (16.21± 0.12) × 103cm-1· mol-1·L, respectively.When EDTA was added, the UV difference peak at 238um of La-HBED or Eu-HBED decreased.Using EDTA as competing agent conditional equilibrium constants for the complexes were measured.They are lgKLa-HSED = 11.52 ± 0.22 and lgKEu-HBED= 14.16 ±0.38.Alinear free energy relationship for the complexes of Lanthanum and Europium has been established by using equilibrium data on19 complexes produced by these metal ions with low molecular weight ligands.The HBED inding constants for La (Ⅲ) and Eu (Ⅲ) are in agreement with the linear free energy relationship.Under the same conditions the human serum apotransferrin(apoTf) has been titrated with La (Ⅲ), Eu(Ⅲ).The UV difference spectrophotometry for the binding ｏf Eu (Ⅲ) with apoTf is similar to that of Eu (Ⅲ) with HBED, except a little red shift of the maximum absorptivity peaks.The binding Of La (Ⅲ) with apoTf, however, hardly happens. |
| Keywords: transferrin HBED lanthanide ions UV difference spectrophotometry |
| 投稿时间：2000-12-25 修订日期：2001-03-19 |
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| 白海静,刘文,杨斌盛.La(Ⅲ)、Eu(Ⅲ)与HBED配合的紫外差光谱研究[J].无机化学学报,2001,17(3):389-394. |
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