Jia Xiangqing, Nitsch Jörn, Wu Zhu, Friedrich Alexandra, Krebs Johannes, Krummenacher Ivo, Fantuzzi Felipe, Braunschweig Holger, Moos Michael, Lambert Christoph, Engels Bernd, Marder Todd B
Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany.
Chem Sci. 2021 Jul 27;12(35):11864-11872. doi: 10.1039/d1sc02409d. eCollection 2021 Sep 15.
One-electron chemical reduction of 10-(dimesitylboryl)-,-di--tolylbenzo[]phenanthrene-4-amine (3-B(Mes)-[4]helix-9-N(-Tol)) and 13-(dimesitylboryl)-,-di--tolyldibenzo[,]phenanthrene-8-amine (3-B(Mes)-[5]helix-12-N(-Tol)) gives rise to monoanions with extensive delocalization over the annulated helicene rings and the boron p orbital. Two-electron chemical reduction of and produces open-shell biradicaloid dianions with temperature-dependent population of the triplet states due to small singlet-triplet gaps. These results have been confirmed by single-crystal X-ray diffraction, EPR and UV/vis-NIR spectroscopy, and DFT calculations.
10-(二甲基苯基硼基)-α,α-二-对甲苯基苯并[ghi]菲-4-胺（3-B(Mes)-[4]螺旋烯-9-N(-Tol)）和13-(二甲基苯基硼基)-α,α-二-对甲苯基二苯并[a,c]菲-8-胺（3-B(Mes)-[5]螺旋烯-12-N(-Tol)）的单电子化学还原产生单阴离子，其电子在稠合螺旋烯环和硼p轨道上广泛离域。对它们进行双电子化学还原会产生开壳双自由基型二价阴离子，由于单重态-三重态能隙较小，三重态的丰度与温度有关。这些结果已通过单晶X射线衍射、电子顺磁共振和紫外/可见-近红外光谱以及密度泛函理论计算得到证实。
