Chen Lisa, Arnold Mona, Blinder Rémi, Jelezko Fedor, Kuehne Alexander J C
Institute of Organic and Macromolecular Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
Institute for Quantum Optics, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany.
RSC Adv. 2021 Aug 13;11(44):27653-27658. doi: 10.1039/d1ra04638a. eCollection 2021 Aug 9.
Derivatives of the stable, luminescent tris-2,4,6-trichlorophenylmethyl (TTM) radical exhibit unique doublet spin properties that are of interest for applications in optoelectronics, spintronics, and energy storage. However, poor reactivity of the chloride-moieties limits the yield of functionalization and thus the accessible variety of high performance luminescent radicals. Here, we present a pathway to obtain mixed-bromide and chloride derivatives of TTM by simple Friedel-Crafts alkylation. The resulting radical compounds show higher stability and site-specific reactivity in cross-coupling reactions, due to the better leaving group character of the -bromide. The mixed halide radicals give access to complex, and so far inaccessible luminescent open-shell small molecules, as well as polymers carrying the radical centers in their backbone. The new mixed-halide triphenyl methyl radicals represent a powerful building block for customized design and synthesis of stable luminescent radicals.
稳定的发光三（2,4,6 - 三氯苯基）甲基（TTM）自由基的衍生物表现出独特的双重态自旋特性，这在光电子学、自旋电子学和能量存储应用中具有重要意义。然而，氯基团的低反应活性限制了官能化的产率，进而限制了高性能发光自由基的可及种类。在此，我们展示了一种通过简单的傅克烷基化反应获得TTM的混合溴化物和氯化物衍生物的途径。由于溴化物具有更好的离去基团特性，所得的自由基化合物在交叉偶联反应中表现出更高的稳定性和位点特异性反应活性。混合卤化物自由基可用于制备复杂的、迄今为止难以获得的发光开壳小分子以及在主链中带有自由基中心的聚合物。新型混合卤化物三苯基甲基自由基是定制设计和合成稳定发光自由基的有力构建单元。
