Wu Fupeng, Ma Ji, Lombardi Federico, Fu Yubin, Liu Fupin, Huang Zhijie, Liu Renxiang, Komber Hartmut, Alexandropoulos Dimitris I, Dmitrieva Evgenia, Lohr Thorsten G, Israel Noel, Popov Alexey A, Liu Junzhi, Bogani Lapo, Feng Xinliang
Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062, Dresden, Germany.
Department of Materials, University of Oxford, Oxford, OX1 3PH, UK.
Angew Chem Int Ed Engl. 2022 Jun 7;61(23):e202202170. doi: 10.1002/anie.202202170. Epub 2022 Apr 5.
Open-shell non-alternant polycyclic hydrocarbons (PHs) are attracting increasing attention due to their promising applications in organic spintronics and quantum computing. Herein we report the synthesis of three cyclohepta[def]fluorene-based diradicaloids (1-3), by fusion of benzo rings on its periphery for the thermodynamic stabilization, as evidenced by multiple characterization techniques. Remarkably, all of them display a very narrow optical energy gap (E =0.52-0.69 eV) and persistent stability under ambient conditions (t =11.7-33.3 h). More importantly, this new type of diradicaloids possess a low-lying triplet state with an extremely small singlet-triplet energy gap, as low as 0.002 kcal mol , with a clear dependence on the molecular size. This family of compounds thus offers a new route to create non-alternant open-shell PHs with high-spin ground states, and opens up novel possibilities and insights into understanding the structure-property relationships.
开壳非交替多环烃（PHs）因其在有机自旋电子学和量子计算中的应用前景而受到越来越多的关注。在此，我们报道了三种基于环庚[def]芴的双自由基类化合物（1-3）的合成，通过在其外围稠合苯环以实现热力学稳定，多种表征技术证明了这一点。值得注意的是，它们都表现出非常窄的光学能隙（E = 0.52 - 0.69 eV），并且在环境条件下具有持久稳定性（t = 11.7 - 33.3 h）。更重要的是，这种新型双自由基类化合物具有一个低能三重态，其单重态 - 三重态能隙极小，低至0.002 kcal·mol ，且明显依赖于分子大小。因此，这类化合物为创建具有高自旋基态的非交替开壳PHs提供了一条新途径，并为理解结构 - 性质关系开辟了新的可能性和见解。
