Rottschäfer Dennis, Neumann Beate, Stammler Hans-Georg, Ghadwal Rajendra S
Universität Bielefeld, Fakultät für Chemie, Centrum für Molekulare Materialien, Anorganische Molekülchemie und Katalyse am Lehrstuhl für Anorganische Chemie und Strukturchemie, Universitätsstr. 25, 33615, Bielefeld, Germany.
Chemistry. 2017 Jul 6;23(38):9044-9047. doi: 10.1002/chem.201702433. Epub 2017 Jun 27.
Four-membered biradicaloid compounds containing a N E (E=main group element) framework have been thoroughly investigated; however, the synthesis of stable analogues with a C P skeleton remains a challenge. Base-mediated double C-H functionalization of IPr=CH (1) (IPr=C[N(2,6-iPr -C H )CH] ) with PCl affords [{(IPr)CP} Cl]Cl (2) as a royal blue solid. Treatment of 2 with KC yields the stable phosphorus biradicaloid [(IPr)CP] (3) featuring a four-membered C P ring. Compound 3 is diamagnetic and shows sharp and temperature-independent NMR resonances, revealing its singlet biradicaloid nature. The stability of 3 is attributed to the σ- and π-electron-donating property of the N-heterocyclic vinylidene [(IPr)C] group.
含有NE（E=主族元素）骨架的四元双自由基化合物已得到深入研究；然而，合成具有CP骨架的稳定类似物仍然是一项挑战。在碱介导下，IPr=CH（1）（IPr=C[N(2,6-iPr₂-C₆H₃)CH]₂）与PCl₃发生双C-H官能化反应，得到[{(IPr)CP}Cl]Cl（2），为皇家蓝色固体。用KC₈处理2得到稳定的磷双自由基[(IPr)CP]（3），其具有四元CP环。化合物3是抗磁性的，并且显示出尖锐的、与温度无关的NMR共振，揭示了其单线态双自由基性质。3的稳定性归因于N-杂环亚乙烯基[(IPr)C]基团的σ-和π-给电子性质。
