Desroches Maude, Morin Jean-Francois
Département de Chimie et, Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, Pavillon A.-Vachon, 1045 Ave de la Médecine, Québec, G1V 0A6, Canada.
Chemistry. 2018 Feb 26;24(12):2858-2862. doi: 10.1002/chem.201706081. Epub 2018 Jan 31.
Three new and stable diradical dications based on the 4,10-dibromoanthanthrone have been synthesized and characterized. In their dicationic state, the amines show a biradical character in the ground state. Their magnetic properties have been investigated by NMR and EPR spectroscopies. The dicationic salts shows strong and broad optical absorption in the near-infrared region. The main driving force to obtain a ground state biradical is the high steric hindrance that prevents planarization of the diphenylamines with the anthanthrone aromatic core. The radical cations are isolated in two perpendicular π-systems as demonstrated by X-ray diffraction structures. This work provides a new bridging unit in the search for biradical bis(triarylamines) salts.
基于4,10-二溴蒽酮合成并表征了三种新型稳定的双自由基双阳离子。在其二阳离子状态下，胺类在基态表现出双自由基特征。通过核磁共振（NMR）和电子顺磁共振（EPR）光谱对其磁性进行了研究。双阳离子盐在近红外区域表现出强烈且宽泛的光吸收。获得基态双自由基的主要驱动力是位阻大，这阻止了二苯胺与蒽酮芳香核的平面化。如X射线衍射结构所示，自由基阳离子被隔离在两个相互垂直的π体系中。这项工作为寻找双自由基双（三芳基胺）盐提供了一个新的桥连单元。
