Olaru Marian, Mischin Alexandra, Malaspina Lorraine A, Mebs Stefan, Beckmann Jens
Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359, Bremen, Germany.
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany.
Angew Chem Int Ed Engl. 2020 Jan 20;59(4):1581-1584. doi: 10.1002/anie.201913081. Epub 2019 Dec 16.
The bis(ferrocenyl)phosphenium ion, [Fc P] , reported by Cowley et al. (J. Am. Chem. Soc. 1981, 103, 714-715), was the only claimed donor-free divalent phosphenium ion. Our examination of the molecular and electronic structure reveals that [Fc P] possesses significant intramolecular Fe⋅⋅⋅P contacts, which are predominantly electrostatic and moderate the Lewis acidity. Nonetheless, [Fc P] undergoes complex formation with the Lewis bases PPh and IPr to give the donor-acceptor complexes [Fc P(PPh )] and [Fc P(IPr)] (IPr=1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene).
考利等人（《美国化学会志》，1981年，第103卷，714 - 715页）报道的双（二茂铁基）鏻离子[Fc₂P]⁺，是唯一被宣称的无供体二价鏻离子。我们对其分子结构和电子结构的研究表明，[Fc₂P]⁺存在显著的分子内Fe⋅⋅⋅P接触，这种接触主要是静电作用，并且会缓和其路易斯酸性。尽管如此，[Fc₂P]⁺仍会与路易斯碱PPh₃和IPr形成配合物，生成给体 - 受体配合物[Fc₂P(PPh₃)]⁺和[Fc₂P(IPr)]⁺（IPr = 1,3 - 双（2,6 - 二异丙基苯基）咪唑 - 2 - 亚基）。
