Wünsche Marius A, Witteler Tim, Dielmann Fabian
Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149, Münster, Germany.
Angew Chem Int Ed Engl. 2018 Jun 11;57(24):7234-7239. doi: 10.1002/anie.201802900. Epub 2018 May 14.
Oxophosphonium ions (R P=O) are fascinating chemical intermediates related to the well-known acylium cations (RC=O) , and comprise a tricoordinate phosphorus(V) center with a phosphorus-oxygen double bond. Here, we report the synthesis of two oxophosphonium ions stabilized by bulky imidazolin-2-imine and imidazolin-2-olefin substituents attached to phosphorus. The novel species were characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis, and the bonding situation was probed by DFT calculations. Determination of the acceptor number and the fluoride ion affinity revealed that the choice of the substituents has a strong influence on the electrophilicity of the phosphorus center. Additionally, the formation of Lewis base adducts with pyridine derivatives and the reactivity with isopropyl alcohol was explored.
氧鎓离子（RP=O）是与著名的酰基阳离子（RC=O）相关的迷人化学中间体，它包含一个具有磷-氧双键的三配位磷（V）中心。在此，我们报告了两种由连接在磷上的庞大咪唑啉-2-亚胺和咪唑啉-2-烯烃取代基稳定的氧鎓离子的合成。通过核磁共振光谱和单晶X射线衍射分析对这些新物种进行了表征，并通过密度泛函理论计算探究了其成键情况。受体数和氟离子亲和力的测定表明，取代基的选择对磷中心的亲电性有很大影响。此外，还研究了与吡啶衍生物形成路易斯碱加合物以及与异丙醇的反应活性。
