Wade Jessica, Salerno Francesco, Kilbride Rachel C, Kim Dong Kuk, Schmidt Julia A, Smith Joel A, LeBlanc Luc M, Wolpert Emma H, Adeleke Adebayo A, Johnson Erin R, Nelson Jenny, Mori Tadashi, Jelfs Kim E, Heutz Sandrine, Fuchter Matthew J
Department of Materials and London Centre for Nanotechnology, Imperial College London, London, UK.
Centre for Processable Electronics, Imperial College London, London, UK.
Nat Chem. 2022 Dec;14(12):1383-1389. doi: 10.1038/s41557-022-01044-6. Epub 2022 Oct 27.
Chiral π-conjugated molecules bring new functionality to technological applications and represent an exciting, rapidly expanding area of research. Their functional properties, such as the absorption and emission of circularly polarized light or the transport of spin-polarized electrons, are highly anisotropic. As a result, the orientation of chiral molecules critically determines the functionality and efficiency of chiral devices. Here we present a strategy to control the orientation of a small chiral molecule (2,2'-dicyano[6]helicene) by the use of organic and inorganic templating layers. Such templating layers can either force 2,2'-dicyano[6]helicene to adopt a face-on orientation and self-assemble into upright supramolecular columns oriented with their helical axis perpendicular to the substrate, or an edge-on orientation with parallel-lying supramolecular columns. Through such control, we show that low- and high-energy chiroptical responses can be independently 'turned on' or 'turned off'. The templating methodologies described here provide a simple way to engineer orientational control and, by association, anisotropic functional properties of chiral molecular systems for a range of emerging technologies.
手性π共轭分子为技术应用带来了新功能，是一个令人兴奋且迅速发展的研究领域。它们的功能特性，如圆偏振光的吸收和发射或自旋极化电子的传输，具有高度各向异性。因此，手性分子的取向对手性器件的功能和效率起着关键作用。在此，我们提出一种通过使用有机和无机模板层来控制小分子手性分子（2,2'-二氰基[6]螺旋烯）取向的策略。这种模板层可以迫使2,2'-二氰基[6]螺旋烯采取面朝上的取向并自组装成螺旋轴垂直于基板的直立超分子柱，或者采取边缘朝上的取向并形成平行排列的超分子柱。通过这种控制，我们表明低能和高能手性光学响应可以独立地“开启”或“关闭”。本文所述的模板方法提供了一种简单的方法来设计取向控制，并由此关联到手性分子系统对于一系列新兴技术的各向异性功能特性。
