Chiral Sensing Using an Achiral Europium(III) Complex by Induced Circularly Polarized Luminescence
Chiral Sensing Using an Achiral Europium(III) Complex by Induced Circularly Polarized Luminescence
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DOI：
10.1021/ic202355s
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发表时间：
2012-04-02
影响因子：
4.6
通讯作者：
Nozaki, Koichi
中科院分区：
文献类型：
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作者：
Iwamura, Munetaka;Kimura, Yoshihiro;Nozaki, Koichi
[Eu（bda）（2）]（-）（bda = 2，2 '-bipyridine-6，6'-dicarboxylic acid）在（S）-2-pyrrolidone-S-carboxylic acid存在下，在紫外光照射下产生强烈的圆偏振发光（CPL），尽管铕（III）配合物的分子结构是非手性的。CPL的诱导机制初步归因于与氨基酸缔合以在非手性复合物中产生手性而诱导的扭曲。在1.0 mol dm（-3）氨基酸存在下，D-5（0）-> F-7（1）跃迁的光学各向异性因子（g（lum）值）为0.03。分析CPL强度作为氨基酸浓度的函数，得到[Eu（bda）（2）]（-）与氨基酸之间的缔合常数K-aso = 0.55 +/- 0.09 mol（-1）dm（3）。这些结果表明，[Eu（bda）（2）]（-）作为一个发光的手性传感试剂在显微光谱的潜力。
[Eu(bda)(2)](-) (bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) produces intense circularly polarized luminescence (CPL) in aqueous solutions in the presence of (S)-2-pyrrolidone-S-carboxylic acid upon UV irradiation, although the molecular structure of the europium(III) complex is achiral. The mechanism for the induction of CPL was preliminarily attributed to distortions induced by association with an amino acid to generate chirality in the achiral complex. The optical anisotropy factor (g(lum) value) for the D-5(0)-> F-7(1) transition was 0.03 in the presence of 1.0 mol dm(-3) of the amino acid. Analysis of the CPL intensity as a function of the amino acid concentration gave an association constant between those of [Eu(bda)(2)](-) and the amino acid, K-aso = 0.55 +/- 0.09 mol(-1) dm(3). These results demonstrate the potential of [Eu(bda)(2)](-) to act as a luminescent chiral-sensing reagent in microscopic spectroscopy.