Lin Hong-Yu, Yao Chao-Yi, Li Jialu, Nimal Gunaratne H Q, Singh Warispreet, Huang Meilan, Anslyn Eric V, de Silva A Prasanna
School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, United Kingdom.
School of Chemistry and Chemical Engineering, Central South University, Yuelu District, Changsha, Hunan Province 410006, P.R. China.
JACS Au. 2023 Jul 28;3(8):2257-2268. doi: 10.1021/jacsau.3c00279. eCollection 2023 Aug 28.
A recurring dream of molecular recognition is to create receptors that distinguish between closely related targets with sufficient accuracy, especially in water. The more useful the targets, the more valuable the dream becomes. We now present multianionic trimeric cyclophane receptors with a remarkable ability to bind the iconic (bipyridine)Ru(II) (with its huge range of applications) while rejecting the nearly equally iconic (phenanthroline)Ru(II). These receptors not only selectively capture (bipyridine)Ru(II) but also can be redox-switched to release the guest. 1D- and 2D(ROESY)-NMR spectroscopy, luminescence spectroscopy, and molecular modeling enabled this discovery. This outcome allows the control of these applications, e.g., as a photocatalyst or as a luminescent sensor, by selectively hiding or exposing (bipyridine)Ru(II). Overall, a 3D nanometric object is selected, picked-up, and dropped-off by a discrete molecular host. The multianionic receptors protect excited states of these metal complexes from phenolate quenchers so that the initial step in photocatalytic phenolate oxidation is retarded by nearly 2 orders of magnitude. This work opens the way for (bipyridine)Ru(II) to be manipulated in the presence of other functional nano-objects so that many of its applications can be commanded and controlled. We have a cyclophane-based toolkit that can emulate some aspects of proteins that selectively participate in cell signaling and metabolic pathways by changing shape upon environmental commands being received at a location remote from the active site.
分子识别领域反复出现的一个梦想是创造出能够以足够的精度区分密切相关目标的受体，尤其是在水中。目标越有用，这个梦想就越有价值。我们现在展示了一种多阴离子三聚体环番受体，它具有非凡的能力，能够结合标志性的（联吡啶）Ru(II)（其应用范围广泛），同时排斥几乎同样标志性的（菲咯啉）Ru(II)。这些受体不仅能选择性地捕获（联吡啶）Ru(II)，还能通过氧化还原切换来释放客体。一维和二维（ROESY）核磁共振光谱、发光光谱和分子建模促成了这一发现。这一成果使得通过选择性地隐藏或暴露（联吡啶）Ru(II)来控制这些应用成为可能，例如用作光催化剂或发光传感器。总体而言，一个离散的分子主体能够选择、拾取和放下一个三维纳米物体。多阴离子受体保护这些金属配合物的激发态免受酚盐猝灭剂的影响，从而使光催化酚盐氧化的初始步骤延迟了近两个数量级。这项工作为在其他功能性纳米物体存在的情况下对（联吡啶）Ru(II)进行操控开辟了道路，从而可以对其许多应用进行指挥和控制。我们拥有一个基于环番的工具包，它可以模拟蛋白质的某些方面，这些蛋白质通过在远离活性位点的位置接收到环境指令时改变形状，选择性地参与细胞信号传导和代谢途径。
