Chen Wangqiao, Li Xinxiong, Long Guankui, Li Yongxin, Ganguly Rakesh, Zhang Mingtao, Aratani Naoki, Yamada Hiroko, Liu Ming, Zhang Qichun
School of Materials Science and Engineering, Nanyang Technological University Singapore, 639798, Singapore, Singapore.
Temasek Laboratories @NTU, Nanyang Technological University Singapore, Research Techno Plaza, 50 Nanyang Drive, 637553, Singapore, Singapore.
Angew Chem Int Ed Engl. 2018 Oct 8;57(41):13555-13559. doi: 10.1002/anie.201808779. Epub 2018 Sep 7.
Success in obtaining higher-order twistarenes with precise structures is very important for fundamentally understanding the relationship between the structures and physical properties/optoelectronic applications. In this research, by using the advantages from a retro-Diels-Alder process (clean reaction) and the cross-conjugated nature of the pyrene unit, a novel dodeca-twistarene was prepared for the first time. Its structure, confirmed by single-crystal XRD analysis, indicates that it possesses a twisted angle (≈30°), and two neighboring molecules in the crystal lattice are perpendicular to each other because of the twisted character and the strong intermolecular CH-π interactions. However, its basic physicochemical properties suggest its instability in air derives from its elevated HOMO energy level, although NICS calculations confirm that the pyrene units contribution poorly to the π conjugation of the overall molecule.
成功获得具有精确结构的高阶扭曲芳烃对于从根本上理解结构与物理性质/光电应用之间的关系非常重要。在本研究中，利用逆狄尔斯-阿尔德反应（清洁反应）的优势和芘单元的交叉共轭性质，首次制备了一种新型十二扭曲芳烃。通过单晶XRD分析确定其结构，表明它具有扭曲角（≈30°），并且由于扭曲特性和强烈的分子间CH-π相互作用，晶格中的两个相邻分子相互垂直。然而，其基本物理化学性质表明，尽管NICS计算证实芘单元对整个分子的π共轭贡献不大，但其在空气中的不稳定性源于其较高的HOMO能级。
