Verification of a new concept for stabilizing radicals with elements of group 15 and studies concerning their use in one electron transfer reactions

在第一个资助期，我们通过使用立体要求的取代基（动力学稳定）或强σ给体的配位（碱稳定）以及在自由基中心引入电正配体（电子稳定），合成了重15族元素（As, Sb, Bi）的几个同渗和异渗自由基并对其进行了结构表征。除了中性自由基，我们还成功地分离和结构表征几乎未知的自由基阴离子。系统研究揭示了13基团二烷基还原电位的总体趋势以及pnic原和离去基R对反应活性/选择性的影响，而依赖于温度和时间的核磁共振波谱研究则对反应的机理有了更深入的了解。在第一期研究成果的基础上，我们将在第二期研究中继续合成重烟基因的未知自由基类型，即双烟烯自由基阳离子、gallapnictene自由基阳离子和阴离子以及烟烯自由基阳离子，并详细研究其电子性质。这些研究得到了我们的合作者Cutsail博士（EPR光谱）和Haberhauer教授（DFT计算）的支持，以便对这些自由基的成键性质有一个基本的了解。此外，环伏安法研究将为这些自由基的氧化还原行为提供见解，而主族元素-氢（E-H）化合物的键激活反应将为这些自由基的化学势提供见解。此外，我们将研究卤化物抽象反应，这可能提供额外的未知中性和阳离子自由基的途径。所有的研究都与时间和温度相关的核磁共振光谱研究以及量子化学计算相结合，以提供基本的机制理解。

In the first funding period we have synthesized and structurally characterized several homoleptic and heteroleptic radicals of heavy group 15 elements (As, Sb, Bi) by using sterically demanding substituents (kinetic stabilisation) or by coordination of strong σ donors (base stabilisation) as well as by introducing electropositive ligands at the radical center (electronic stabilisation). Apart from neutral radicals we also succeeded in the isolation and structural characterization of virtually unknown radical anions. Systematic studies revealed general trends in the reduction potential of group 13 diyls as well as the influence of the pnictogen and the leaving group R on the reactivity / selectivity of the reactions, while temperature and time dependent NMR spectroscopic studies provided a deeper mechanistic understanding of the reactions.Based on the findings of the first funding period we will in the second funding period continue to synthesize unknown radical types of heavy pnictogenes, i.e. dipnictene radical cations, gallapnictene radical cations and anions as well as pnictinidene radical cations, and to study their electronic nature in detail. These studies are supported by our collaborateurs Dr. Cutsail (EPR spectroscopy) and Prof. Haberhauer (DFT calculations) in order to develop a fundamental understanding of the bonding nature in such radicals. In addition, cyclovoltammetric studies will provide insights into the redox behavior of such radicals, while bond activation reactions of main group element-hydrogen (E-H) compounds will provide insights into the chemical potential of such radicals. In addition, we will investigate halide abstraction reactions, which may provide access to additional unknown neutral and cationic radicals. All studies are flanked by time and temperature dependent NMR spectroscopic studies as well as quantum chemical calculations to provide a fundamental mechanistic understanding.