Department of Chemistry &Biochemistry and the Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1253, USA.
Department of Physical Chemistry, University of Malaga, Campus de Teatinos s/n, 229071 Malaga, Spain.
Nat Chem. 2016 Aug;8(8):753-9. doi: 10.1038/nchem.2518. Epub 2016 May 23.
The consequence of unpaired electrons in organic molecules has fascinated and confounded chemists for over a century. The study of open-shell molecules has been rekindled in recent years as new synthetic methods, improved spectroscopic techniques and powerful computational tools have been brought to bear on this field. Nonetheless, it is the intrinsic instability of the biradical species that limits the practicality of this research. Here we report the synthesis and characterization of a molecule based on the diindeno[b,i]anthracene framework that exhibits pronounced open-shell character yet possesses remarkable stability. The synthetic route is rapid, efficient and possible on the gram scale. The molecular structure was confirmed through single-crystal X-ray diffraction. From variable-temperature Raman spectroscopy and magnetic susceptibility measurements a thermally accessible triplet excited state was found. Organic field-effect transistor device data show an ambipolar performance with balanced electron and hole mobilities. Our results demonstrate the rational design and synthesis of an air- and temperature-stable biradical compound.
有机分子中不成对电子的后果令化学家们着迷了一个多世纪。近年来，随着新的合成方法、改进的光谱技术和强大的计算工具被应用于这个领域，研究开壳分子的兴趣又重新燃起。尽管如此，双自由基物种的内在不稳定性限制了这项研究的实用性。在这里，我们报告了一种基于二茚并[ b ， i ]蒽骨架的分子的合成与表征，该分子表现出明显的开壳特性，但具有显著的稳定性。该合成路线快速、高效，并且可以在克级规模上进行。通过单晶 X 射线衍射确定了分子结构。从变温拉曼光谱和磁化率测量中发现了热激发三重态。有机场效应晶体管器件数据显示出具有平衡电子和空穴迁移率的双极性性能。我们的结果证明了一种空气和温度稳定的双自由基化合物的合理设计和合成。
