Dankert Fabian, Muhm Simon P, Nandi Chandan, Danés Sergi, Mullassery Sneha, Herbeck-Engel Petra, Morgenstern Bernd, Weiss Robert, Salvador Pedro, Munz Dominik
Coordination Chemistry, Saarland University, Campus C4.1, D-66123 Saarbrücken, Germany.
Institut de Química Computacional I Catàlisi, Departament de Química, Universitat de Girona, C/M. Aurelia Capmany 69, 17003 Girona, Spain.
J Am Chem Soc. 2025 May 7;147(18):15369-15376. doi: 10.1021/jacs.5c01271. Epub 2025 Apr 24.
The oxidation of triphenylphosphine by perfluorinated phenazinium aluminate in difluorobenzene affords hexaaryl-1,2-diphosphonium dialuminate . Dication is valence isoelectronic with elusive hexaphenylethane, where instead the formation of a mixture of the trityl radical and Gomberg's dimer is favored. Quantum-chemical calculations in combination with Raman/IR spectroscopies rationalize the stability of the P-P bonded dimer in and suggest, akin to the halogens, facile homolytic as well as heterolytic scission. Thus, serves as a surrogate of both the triphenylphosphorandiylium dication (PhP) and the triphenylphosphine radical monocation (PhP). Treating with dimethylaminopyridine (DMAP) or BuP replaces triphenylphosphine under heterolytic P-P bond scission. Qualifying as a superoxidant ( vs Fc/Fc = +1.44 V), oxidizes trimethylphosphine. Based on halide abstraction experiments (BF, PF, SbCl, SbF) as well as the deoxygenation of triethylphosphine oxide, triflate anions as well as toluic acid, also features Lewis superacidity. The controlled hydrolysis affords Hendrickson's reagent, which itself finds broad use as a dehydration agent. Formally, homolytic P-P bond scission occurs with diphenyldisulfide (PhSSPh) and the triple bonds in benzo- and acetonitrile. The irradiation by light cleaves the P-P bond homolytically and generates transient triphenylphosphine radical cations, which engage in H-atom abstraction as well as CH phosphoranylation.
全氟吩嗪铝酸盐在二氟苯中氧化三苯基膦生成六芳基 - 1,2 - 二鏻二铝酸盐。双阳离子与难以捉摸的六苯乙烷价电子等排，而在后者中三苯甲基自由基和贡伯格二聚体的混合物的形成更有利。量子化学计算结合拉曼/红外光谱解释了二聚体中P - P键合的稳定性，并表明，类似于卤素，其容易发生均裂和异裂。因此，它可作为三苯基磷鎓双阳离子（PhP）和三苯基膦自由基单阳离子（PhP）的替代物。用二甲基氨基吡啶（DMAP）或BuP处理会在异裂P - P键断裂下取代三苯基膦。作为一种超强氧化剂（相对于Fc/Fc = +1.44 V），它能氧化三甲基膦。基于卤化物萃取实验（BF、PF、SbCl、SbF）以及三乙膦氧化物、三氟甲磺酸根阴离子和甲苯甲酸的脱氧反应，它还具有路易斯超强酸性。受控水解得到亨德里克森试剂，其本身作为脱水剂有广泛用途。形式上，二苯基二硫化物（PhSSPh）以及苯并腈和乙腈中的三键会发生P - P键均裂。光照射会均裂P - P键并产生瞬态三苯基膦自由基阳离子，其会进行H原子抽取以及CH磷酰化反应。
