Thermally Controlled Exciplex Fluorescence in a Dynamic Homo[2]catenane
Thermally Controlled Exciplex Fluorescence in a Dynamic Homo[2]catenane
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DOI：
10.1021/jacs.2c10591
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发表时间：
2022-12-13
影响因子：
15
通讯作者：
Stoddart, J. Fraser
中科院分区：
文献类型：
--
作者：
Garci, Amine;David, Arthur H. G.;Stoddart, J. Fraser
运动诱导发射变化（MICE）是一种现象，可以用来开发各种类型的探头，包括温度和粘度传感器。虽然MICE是由特定化合物的构象运动引起的，已经得到了广泛的研究，但在发生构象变化的机械互锁分子（mim）中，这种现象尚未得到深入的研究。本文报道了一种含芘单元的热响应动态homo[2]链烷的研究，并显示了其环烷的相对旋转运动，这得到了变温1H核磁共振光谱的证明，并得到了分子动力学模拟和量子力学计算的可视化支持。相对的共构象运动诱导同源b[2]链烷的荧光发射随温度的变化与其组分环烷相比有显著的变化。通过四个完整的冷却和加热循环，证明了homo[2] - catenane的异构体发射的这种变化是可逆的。这项研究开辟了利用基于mims的发色团的共构象变化来探测温度波动的可能性，这可能导致在生物医学或材料科学中的应用。
Motion-induced change in emission (MICE) is a phenomenon that can be employed to develop various types of probes, including temperature and viscosity sensors. Although MICE, arising from the conformational motion in particular compounds, has been studied extensively, this phenomenon has not been investigated in depth in mechanically interlocked molecules (MIMs) undergoing coconformational changes. Herein, we report the investigation of a thermoresponsive dynamic homo[2]catenane incorporating pyrene units and displaying relative circumrotational motions of its cyclophanes as evidenced by variable-temperature 1H NMR spectroscopy and supported by its visualization through molecular dynamics simulations and quantum mechanics calculations. The relative coconformational motions induce a significant change in the fluorescence emission of the homo[2]catenane upon changes in temperature compared with its component cyclophanes. This variation in the exciplex emission of the homo[2]catenane is reversible as demonstrated by four complete cooling and heating cycles. This research opens up possibilities of using the coconformational changes in MIMs-based chromophores for probing fluctuations in temperature which could lead to applications in biomedicine or materials science.