Chiral Eutectic Mixtures and Deep Eutectic Solvents for Induced Circularly Polarized Luminescence
Chiral Eutectic Mixtures and Deep Eutectic Solvents for Induced Circularly Polarized Luminescence
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DOI：
10.1002/cptc.202100139
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发表时间：
2021-09
期刊：
影响因子：
3.7
通讯作者：
T. Hopkins;Brian P. Nelson;Liam VandenElzen;Grace Whitacre
中科院分区：
文献类型：
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作者：
T. Hopkins;Brian P. Nelson;Liam VandenElzen;Grace Whitacre
低共熔溶剂（DES）或用手性组分制备的低共熔混合物可以产生新的手性溶剂，其应用包括不对称合成和手性发光材料。DES具有低熔点，因为混合物的组分之间存在强相互作用，例如氢键。用铵盐、四丁基氯化铵（[TBA]Cl）和氯化胆碱（[Ch]Cl）作为氢键受体（HBA）和L-乳酸、L-亮氨酸、L-抗坏血酸、R/S-乙酰氧基丙酸和（S）-乳酸甲酯作为手性氢键供体（HBD）制备混合物。制备了八种铕和HBD的组合，并将不对称手性铕络合物的外消旋混合物溶解在混合物中。用圆偏振发光光谱测定了这些手性溶剂对手性的分辨能力。CPL光谱表明，手性HBD的手性是重要的手性歧视表现。然而，在1：3 [TBA]Cl：L-乳酸与1：3 [Ch]Cl：L-乳酸以及1：1.5 [Ch] Cl：L-亮氨酸与1：1 [TBA]Cl：L-亮氨酸中CPL光谱的符号反转表明，非手性HBA在手性溶剂的手性辨别的手性中也起关键作用。
Deep eutectic solvents (DES) or eutectic mixtures prepared with a chiral component can lead to new chiral solvents with applications that include asymmetric synthesis and chiral light emitting materials. DES have low melting points, because of strong interactions, such as hydrogen bonding, between components of the mixture. Mixtures are prepared with ammonium salts, tetrabutylammonium chloride ([TBA]Cl) and choline chloride ([Ch]Cl), as hydrogen bond acceptor (HBA) and L‐lactic acid, L‐leucic acid, L‐ascorbic acid, R/S‐acetoxypropionic acid, and methyl‐(S)‐lactate as chiral hydrogen bond donors (HBD). Eight combinations of the HBAs and HBDs were prepared, and a racemic mixture of dissymmetric chiral europium complexes was dissolved in the mixtures. The circularly polarized luminescence (CPL) spectra were measured to determine the chiral discrimination by these chiral solvents. The CPL spectra show that the handedness of the chiral HBD is important to the chiral discrimination exhibited. However, the inversion of the sign of the CPL spectra in 1 : 3 [TBA]Cl:L‐lactic acid vs. 1 : 3 [Ch]Cl:L‐lactic acid, and 1 : 1.5 [Ch]Cl:L‐leucic acid vs. 1 : 1 [TBA]Cl:L‐leucic acid shows that the achiral HBA also plays a critical role in the handedness of the chiral discrimination by the chiral solvent.