Specific Chiral Sensing of Amino Acids Using Induced Circularly Polarized Luminescence of Bis(diimine)dicarboxylic Acid Europium(III) Complexes
Specific Chiral Sensing of Amino Acids Using Induced Circularly Polarized Luminescence of Bis(diimine)dicarboxylic Acid Europium(III) Complexes
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DOI：
10.1021/ic500196m
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发表时间：
2014-06-02
影响因子：
4.6
通讯作者：
Iwamura, Munetaka
中科院分区：
文献类型：
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作者：
Okutani, Kazuhiro;Nozaki, Koichi;Iwamura, Munetaka
研究了[Eu（pda）（2）]（-）（pda = 1，10-菲咯啉-2，9-二甲酸）和[Eu（bda）（2）]（-）（bda = 2，2 ′-联吡啶-6，6 ′-二甲酸）在不同氨基酸水溶液中的圆偏振发光。的铕（III）配合物表现出明亮的红色发光分配的Eu-III离子的F-F转换时，用紫外光照射。虽然在2.5固体状态或在水溶液中的发光不是圆偏振的，根据非手性共晶结构，在含有手性氨基酸的水溶液中的复合物表现出可检测的诱导CPL（iCPL）。在L-吡咯烷酮羧酸的存在下，[Eu（pda）（2）]（-）和[Eu（bda）（2）]（-）都显示出类似的iCPL强度（对于在氨基酸的1mol.dm（-3）处的D-5（0）-> F-7（1）转变，g（lum）类似于0.03）。另一方面，在L-组氨酸或L-精氨酸的存在下，[Eu（pda）（2）]（-）表现出强烈的CPL（g（lum），类似于0.08，对于氨基酸的0.10mol.dm（-3）处的D-5（0）-> F-7（1）转变），而在相同条件下观察到[Eu（bda）（2）]（-）的非常弱的CPL（g（lum）< 0.01）。通过对12种氨基酸的iCPL强度分析，发现[Eu（pda）（2）]（-）是一种良好的手性CPL探针，具有高灵敏度（约10（-2）mol.dm（-3））和高选择性，在pH 3时对L-组氨酸和在pH 7时对L-精氨酸具有高选择性。通过分析发光光谱中的精细结构和g（lum）的氨基酸浓度依赖性来评估iCPL的机制。对于[Eu（pda）（2）]（-）-组氨酸/精氨酸体系，铕（III）配合物具有类似于晶体中的配位结构，但由于与两个两性氨基酸的特异性相互作用而发生轻微的畸变，形成手性结构。这一机制与铕（III）络合物-吡咯烷酮羧酸体系形成鲜明对比，在该体系中，一个氨基酸与Eu-III离子配位以产生非手性配位结构。
The circularly polarized luminescence (CPL) from [Eu(pda)(2)](-) (pda = 1,10-phenanthroline-2,9-dicarboxylic acid) and [Eu(bda)(2)](-) (bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) in aqueous solutions containing various amino acids was investigated. The europium(III) complexes exhibited bright-red luminescence assignable to the f f transition of the Eu-III ion when irradiated with UV light. Although the luminescence was not circularly polarized in the 2.5 solid state or in aqueous solutions, in accordance with the achiral co crystal structure, the complexes exhibited detectable induced CPL (iCPL) in aqueous solutions containing chiral amino acids. In the presence of L-pyrrolidonecarboxylic acid, both [Eu(pda)(2)](-) and [Eu(bda)(2)](-) showed similar iCPL intensity (g(lum) similar to 0.03 for the D-5(0) -> F-7(1) transition at 1 mol.dm(-3) of the amino acid). On the other hand, in the presence of L-histidine or L-arginine, [Eu(pda)(2)](-) exhibited intense CPL (g(lum) similar to 0.08 for the D-5(0) -> F-7(1) transition at 0.10 mol.dm(-3) of the amino acid), whereas quite weak CPL was observed for [Eu(bda)(2)](-) under the same conditions (g(lum) < 0.01). On the basis of analysis of the iCPL intensities in the presence of 12 amino acids, [Eu(pda)(2)](-) was found to be a good chiral CPL probe with high sensitivity (about 10(-2) mol.dm(-3)) and high selectivity for L-histidine at pH 3 and for L-arginine at pH 7. The mechanism of iCPL was evaluated by analysis of the fine structures in the luminescence spectra and the amino acid concentration dependence of g(lum). For the [Eu(pda)(2)](-)-histidine/arginine systems, the europium(III) complexes possess coordination structures similar to that in the crystal with slight distortion to form a chiral structure due to specific interaction with two zwitterionic amino acids. This mechanism was in stark contrast to that of the europium(III) complex-pyrrolidonecarboxylic acid system in which one amino acid coordinates to the Eu-III ion to yield an achiral coordination structure.