Long Range Chiral Imprinting of Cu(110) by Tartaric Acid
Long Range Chiral Imprinting of Cu(110) by Tartaric Acid
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DOI：
10.1021/jp402015r
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发表时间：
2013-10-31
影响因子：
3.7
通讯作者：
Sykes, E. C. H.
中科院分区：
文献类型：
--
作者：
Lawton, T. J.;Pushkarev, V.;Sykes, E. C. H.
手性分子对金属表面化学的重组是诱导和控制对映选择性表面化学的重要途径。酒石酸在Cu（110）表面的吸附作为一个有用的系统，用于理解手性分子在金属表面上的吸附和有序的许多方面，并且已经报道了许多手性和非手性晶胞。在此，我们表明，给予适当的退火处理，单去质子化酒石酸单层可以重组的铜金属本身，并且所得到的结构是高度有序和手性。分子分辨率扫描隧道显微镜显示，单去质子化酒石酸提取铜原子从铜（110）表面层，并将它们纳入高度有序，手性吸附原子阵列由连续的分子层覆盖。表面重组的进一步证据来自于在该过程中在Cu（110）表面形成的原子深沟槽的图像。这些沟槽也在低对称性方向上延伸，并且本身是手性的。模拟的扫描隧道显微镜图像与添加的原子行和蚀刻的沟槽的外观一致。通过低能电子衍射证实，手性印迹导致覆盖整个表面的长程、高度有序的（2）（6）（-1）（7）晶胞。在高温下通过延时成像进一步研究了重组机制的细节。这项工作揭示了纳米级表面重构的阶段，并提供了一个有趣的方法，手性修饰的非手性金属表面。
Restructuring of metals by chiral molecules represents an important route to inducing and controlling enantioselective surface chemistry. Tartaric acid adsorption on Cu(110) has served as a useful system for understanding many aspects of chiral molecule adsorption and ordering on a metal surface, and a number of chiral and achiral unit cells have been reported. Herein, we show that given the appropriate annealing treatment, singly deprotonated tartaric acid monolayers can restructure the Cu metal itself, and that the resulting structure is both highly ordered and chiral. Molecular resolution scanning tunneling microscopy reveals that singly deprotonated tartaric acid extracts Cu atoms from the Cu(110) surface layer and incorporates them into highly ordered, chiral adatom arrays capped by a continuous molecular layer. Further evidence for surface restructuring comes from images of atom-deep trenches formed in the Cu(110) surface during the process. These trenches also run in low symmetry directions and are themselves chiral. Simulated scanning tunneling microscopy images are consistent with the appearance of the added atom rows and etched trenches. The chiral imprinting results in a long-range, highly ordered ((2)(6) (-1)(7)) unit cell covering the whole surface as confirmed by low energy electron diffraction. Details of the restructuring mechanism were further investigated via time-lapse imaging at elevated temperature. This work reveals the stages of nanoscale surface restructuring and offers an interesting method for chiral modification of an achiral metal surface.