Baumgärtner Kevin, Hoffmann Marvin, Rominger Frank, Elbert Sven M, Dreuw Andreas, Mastalerz Michael
Organisch-Chemisches Institut, Ruprecht-Karls Universität-Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany.
J Org Chem. 2020 Dec 4;85(23):15256-15272. doi: 10.1021/acs.joc.0c02100. Epub 2020 Nov 4.
Homoconjugation and intramolecular "through-space" charge transfers are molecular phenomena that have been studied since the 1960s. A detailed understanding and control of these effects would provide a tool to tune the optoelectronic properties of organic molecules in respect of the necessities for applications such as for organic electronics. Triptycene is a perfect candidate to investigate homoconjugation effects due to its three-dimensional alignment of three aromatic phenylene units, separated by two methine bridges. Here, a series of 16 π-extended triptycenes with up to three different permuted electron-accepting units and an electron-rich veratrole unit are studied in detail by UV/vis spectroscopy and cyclovoltammetry in combination with DFT calculations to get a deeper understanding of homoconjugation and charge-transfer processes of triptycenes. Furthermore, the gained knowledge can be exploited to construct triptycene-based electron acceptors with fine-tuned adjustment of electronic properties, such as electron affinities, by thorough choice of the aromatic blades that interact through homoconjugation.
同共轭作用和分子内“空间贯穿”电荷转移是自20世纪60年代以来就被研究的分子现象。对这些效应的详细理解和控制将提供一种工具，可根据有机电子学等应用的需求来调节有机分子的光电性质。由于其三个芳基亚苯基单元通过两个亚甲基桥隔开而呈三维排列，三蝶烯是研究同共轭效应的理想候选物。在此，通过紫外/可见光谱、循环伏安法并结合密度泛函理论计算，对一系列16种π-扩展三蝶烯进行了详细研究，这些三蝶烯含有多达三种不同排列的电子接受单元和一个富电子的藜芦醚单元，以更深入地了解三蝶烯的同共轭作用和电荷转移过程。此外，通过透彻选择通过同共轭作用相互作用的芳环，所获得的知识可用于构建具有精细调节电子性质（如电子亲和势）的基于三蝶烯的电子受体。
