Sidler Eric, Zwick Patrick, Kress Charlotte, Reznikova Ksenia, Fuhr Olaf, Fenske Dieter, Mayor Marcel
Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland.
Institute for Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), P. O. Box 3640, 76021, Karlsruhe, Germany.
Chemistry. 2022 Sep 22;28(53):e202201764. doi: 10.1002/chem.202201764. Epub 2022 Aug 3.
The synthetic access to macrocyclic molecular topologies with interesting photophysical properties has greatly improved thanks to the successful implementation of organic and inorganic corner units. Based on recent reports, we realized that pseudo-meta [2.2]paracyclophanes (PCPs) might serve as optimal corner units for constructing 3D functional materials, owing to their efficient electronic communication, angled substituents and planar chirality. Herein, we report the synthesis, characterization and optical properties of four novel all-carbon enantiopure macrocycles bearing three to six pseudo-meta PCPs linked by 1,3-butadiyne units. The macrocycles were obtained by a single step from enantiopure, literature-known dialkyne pseudo-meta PCP and were unambiguously identified and characterized by state of the art spectroscopic methods and in part even by x-ray crystallography. By comparing the optical properties to relevant reference compounds, it is shown that the pseudo-meta PCP subunit effectively elongates the conjugated system throughout the macrocyclic backbone, such that already the smallest macrocycle consisting of only three subunits reaches a polymer-like conjugation length. Additionally, it is shown that the chiral pseudo-meta PCPs induce a remarkable chiroptical response in the respective macrocycles, reaching unprecedented high molar circular dichroism values for all-carbon macrocycles of up to 1307 L mol cm .
由于有机和无机角单元的成功应用，合成具有有趣光物理性质的大环分子拓扑结构的方法有了很大改进。基于最近的报道，我们意识到伪间位[2.2]对环芳烷（PCPs）可能是构建三维功能材料的理想角单元，这是由于它们具有高效的电子通信、成角取代基和平面手性。在此，我们报道了四个新型全碳对映体纯大环化合物的合成、表征及光学性质，这些大环化合物由1,3 - 丁二炔单元连接三个至六个伪间位PCP。这些大环化合物是通过一步反应从对映体纯且文献已知的二炔伪间位PCP获得的，并通过先进的光谱方法进行了明确鉴定和表征，部分甚至通过X射线晶体学进行了表征。通过将光学性质与相关参考化合物进行比较，结果表明伪间位PCP亚基有效地延长了整个大环主链中的共轭体系，以至于仅由三个亚基组成的最小大环就达到了类似聚合物的共轭长度。此外，结果表明手性伪间位PCP在各自的大环化合物中诱导出显著的手性光学响应，对于全碳大环化合物，其摩尔圆二色性值达到了前所未有的高达1307 L mol⁻¹ cm⁻¹。
