Piano stool complexes have been studied over many years and found widespread applications in organic synthesis, catalysis, materials and drug development. We now report the first examples of quantitative chiroptical molecular recognition of chiral compounds through click-like η6-arene coordination with readily available half sandwich complexes. This conceptually new approach to chirality sensing is based on irreversible acetonitrile displacement of [Cp*Ru(CH3CN)3]PF6 by an aromatic target molecule, a process that is fast and complete within a few minutes at room temperature. The metal coordination coincides with characteristic circular dichroism inductions that can be easily correlated to the absolute configuration and enantiomeric ratio of the bound molecule. A relay assay that decouples the determination of the enantiomeric composition and of the total sample amount by a practical CD/UV measurement protocol was developed and successfully tested. The introduction of piano stool complexes to the chiroptical sensing realm is mechanistically unique and extends the scope of currently known methods with small-molecule probes that require the presence of amino, alcohol, carboxylate or other privileged functional groups for binding of the target compound. A broad application range including pharmaceutically relevant multifunctional molecules and the use in chromatography-free asymmetric reaction analysis are also demonstrated.

中文翻译：

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通过类“点击”式 η6-芳烃与非手性 Cp*Ru(II) Piano Stool 复合物协调进行有机金属手性传感

钢琴凳复合物已被研究多年，并在有机合成、催化、材料和药物开发中广泛应用。我们现在报告了通过点击式 η6-芳烃与现成的半夹心配合物配位对手性化合物进行定量手性光学分子识别的第一个例子。这种概念性新的手性传感方法基于芳香族目标分子对 [Cp*Ru(CH3CN)3]PF6 的不可逆乙腈置换，该过程在室温下几分钟内快速完成。金属配位与特征圆二色性感应一致，可以很容易地将其与结合分子的绝对构型和对映体比率相关联。开发并成功测试了一种中继测定，该中继测定通过实用的 CD/UV 测量方案将对映体组成和总样品量的测定解耦。将钢琴凳复合物引入手性光学传感领域在机制上是独特的，并且扩展了目前已知的小分子探针方法的范围，这些探针需要氨基、醇、羧酸盐或其他特殊官能团的存在来结合目标化合物。还展示了广泛的应用范围，包括药学相关的多功能分子以及在无色谱不对称反应分析中的应用。