CAS Key Laboratory of Molecular Nanostructures and Nanotechnology, Beijing 100190, China.
Nat Commun. 2013;4:1389. doi: 10.1038/ncomms2403.
Understanding the chirality induction and amplification processes, and the construction of globally homochiral surfaces, represent essential challenges in surface chirality studies. Here we report the induction of global homochirality in two-dimensional enantiomorphous networks of achiral molecules via co-assembly with chiral co-absorbers. The scanning tunnelling microscopy investigations and molecular mechanics simulations demonstrate that the point chirality of the co-absorbers transfers to organizational chirality of the assembly units via enantioselective supramolecular interactions, and is then hierarchically amplified to the global homochirality of two-dimensional networks. The global homochirality of the network assembly shows nonlinear dependence on the enantiomeric excess of chiral co-absorber in the solution phase, demonstrating, for the first time, the validation of the 'majority rules' for the homochirality control of achiral molecules at the liquid/solid interface. Such an induction and nonlinear chirality amplification effect promises a new approach towards two-dimensional homochirality control and may reveal important insights into asymmetric heterogeneous catalysis, chiral separation and chiral crystallization.
理解手性诱导和放大过程，以及构建全局手性表面，是表面手性研究中的重要挑战。在这里，我们通过与手性共吸附剂共组装，报告了在非手性分子的二维对映异构网络中诱导全局手性。扫描隧道显微镜研究和分子力学模拟表明，共吸附剂的点手性通过对映选择性超分子相互作用传递到手性组装单元的组织手性，然后逐级放大到二维网络的全局手性。网络组装的全局手性在手性共吸附剂在溶液相中的对映过量上呈非线性依赖关系，首次证明了在液/固界面上控制非手性分子手性的“多数规则”的有效性。这种诱导和非线性手性放大效应为二维手性控制提供了一种新方法，并可能为不对称多相催化、手性分离和手性结晶提供重要的启示。
