†Key Laboratory of Theoretical and Computational Photochemistry of the Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
‡Department of Chemistry, The State University of New York at Buffalo, Buffalo, New York 14260, United States.
J Am Chem Soc. 2015 May 13;137(18):5879-82. doi: 10.1021/jacs.5b02552. Epub 2015 Apr 30.
Unlike the precise structural control typical of closed assemblies, curbing the stacking of disc- and ring-shaped molecules is quite challenging. Here we report the discrete stacking of rigid aromatic oligoamide macrocycles 1. With increasing concentration, the aggregation of 1 quickly plateaus, forming a discrete oligomer, as suggested by 1D (1)H, 2D nuclear Overhauser effect, and diffusion-ordered NMR spectroscopy. Quantum-chemical calculations indicate that the tetramer of 1 is the most stable among oligomeric stacks. X-ray crystallography revealed a tetrameric stack containing identical molecules adopting two different conformations. With a defined length and an inner pore capable of accommodating distinctly different guests, the tetramers of 1 densely pack into 2D layers. Besides being a rare system of conformation-regulated supramolecular oligomerization, the discrete stacks of 1, along with their higher-order assemblies, may offer new nanotechnological applications.
与典型的封闭组装中精确的结构控制不同，限制盘状和环状分子的堆叠是相当具有挑战性的。在这里，我们报告了刚性芳香族寡肽大环 1 的离散堆叠。随着浓度的增加，1 的聚集迅速达到平台期，形成离散的低聚物，这一点可以通过 1D（1）H、2D 核 Overhauser 效应和扩散有序 NMR 光谱得到证实。量子化学计算表明，1 的四聚体是寡聚体堆叠中最稳定的。X 射线晶体学揭示了一个包含相同分子的四聚体堆叠，这些分子采用两种不同的构象。具有确定的长度和能够容纳明显不同客体的内部孔，1 的四聚体密集地堆积成二维层。除了是一个罕见的构象调节超分子寡聚的系统外，1 的离散堆叠及其更高阶的组装可能提供新的纳米技术应用。
