Correction: Controlling the preferential motion of chiral molecular walkers on a surface.
Correction: Controlling the preferential motion of chiral molecular walkers on a surface.
复制标题
修正：控制表面上手性分子步行者的优先运动。
DOI：
10.1039/c9sc90124h
复制
发表时间：
2019
期刊：
影响因子：
8.4
通讯作者：
Abbasi-Pérez D
中科院分区：
文献类型：
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作者：
Abbasi-Pérez D
在晶体表面的各向异性周期势上站立在两个或多个“脚”上的分子步行者可以在表面-真空界面处沿其迁移率最大的特定方向沿着进行一维布朗运动。在热平衡中，分子以相等的概率沿着这个方向向沿着运动，正如化学反应和分子发动机理论中众所周知的详细平衡原理所预期的那样。对于具有不对称势能面（PES）的分子，我们提出了一种通用的方法，基于应用程序的时间周期性的外部刺激，这将使分子优先在一个单一的方向移动，从而作为布朗棘轮。为了说明这种方法，我们考虑了一个典型的合成手性分子步行者，1，3-双（咪唑-1-基甲基）-5（1-苯乙基）苯，扩散在各向异性Cu（110）表面沿着Cu行。正如我们基于从头计算密度泛函理论计算的速率的动力学蒙特卡罗模拟所揭示的那样，这种分子通过所谓的尺蠖机制移动到最近的等效晶格位置，在该机制中，它首先用后脚，然后用前脚。因此，分子通过两步机制扩散，并且由于其固有的不对称性，相应的PES也是空间不对称的。利用这一事实，我们展示了如何调整外部刺激来分离不同手性，取向和构象的分子。这些发现的分子机器和对映体的分离的后果进行了讨论。
Molecular walkers standing on two or more “feet” on an anisotropic periodic potential of a crystal surface may perform a one-dimensional Brownian motion at the surface–vacuum interface along a particular direction in which their mobility is the largest. In thermal equilibrium the molecules move with equal probabilities both ways along this direction, as expected from the detailed balance principle, well-known in chemical reactivity and in the theory of molecular motors. For molecules that possess an asymmetric potential energy surface (PES), we propose a generic method based on the application of a time-periodic external stimulus that would enable the molecules to move preferentially in a single direction thereby acting as Brownian ratchets. To illustrate this method, we consider a prototypical synthetic chiral molecular walker, 1,3-bis(imidazol-1-ylmethyl)-5(1-phenylethyl)benzene, diffusing on the anisotropic Cu(110) surface along the Cu rows. As unveiled by our kinetic Monte Carlo simulations based on the rates calculated using ab initio density functional theory, this molecule moves to the nearest equivalent lattice site via the so-called inchworm mechanism in which it steps first with the rear foot and then with the front foot. As a result, the molecule diffuses via a two-step mechanism, and due to its inherent asymmetry, the corresponding PES is also spatially asymmetric. Taking advantage of this fact, we show how the external stimulus can be tuned to separate molecules of different chirality, orientation and conformation. The consequences of these findings for molecular machines and the separation of enantiomers are also discussed.