Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Nanoscale. 2018 Oct 4;10(38):18119-18123. doi: 10.1039/c8nr06045b.
Molecular machines have received considerable attention due to their various applications. Except for mechanical motion, it is essential to design advanced molecular machines with integrated functions. In this study, the triptycene rotor has been covalently linked to paramagnetic metallofullerene Sc3C2@C80 with an unpaired electron spin, resulting in a coupled system between spin flip and rotor speed. Two types of triptycene rotors were employed, one is pristine triptycene and another one has a sterically hindered methyl group. Temperature-dependent electron paramagnetic resonance (EPR) spectroscopy revealed that spin-rotor coupling can be modulated by the rotation speed of triptycene rotors, which was further illustrated by variable-temperature 1H NMR. EPR simulation revealed that the rotations of the attached triptycene rotors can greatly influence the spin relaxation and spin-metal hyperfine couplings of Sc3C2@C80, realizing remote control on neighboring electron spin states. These findings of the coupled system between the molecular rotor and spin flip would provide an approach to design advanced molecular machines with magnetic function.
由于其各种应用，分子机器受到了相当多的关注。除了机械运动之外，设计具有集成功能的先进分子机器也是至关重要的。在这项研究中，三并苯转子通过共价键与具有不成对电子自旋的顺磁金属富勒烯 Sc3C2@C80 相连，从而形成了自旋翻转和转子速度之间的耦合系统。使用了两种类型的三并苯转子，一种是原始的三并苯，另一种是具有空间位阻的甲基。温度依赖的电子顺磁共振（EPR）光谱表明，自旋-转子耦合可以通过三并苯转子的旋转速度来调节，这一点通过变温 1H NMR 进一步说明了。EPR 模拟表明，附着的三并苯转子的旋转可以极大地影响 Sc3C2@C80 的自旋弛豫和自旋-金属超精细耦合，从而实现对相邻电子自旋状态的远程控制。这种分子转子和自旋翻转之间的耦合系统的发现为设计具有磁功能的先进分子机器提供了一种方法。
