Phosphazenium cations were first characterized 60 years ago and yet little is known of their reactivity. The bidentate phosphonium dicationic salts [(C₆H₄)(PPh₂F)₂][B(C₆F₅)₄]₂ 2 and [(C₆H₄)(PPh₂Cl)₂][Cl]₂ 3 were prepared. Reaction of 2 with (Me₃Si)₂NMe gave the phosphazenium dication [(C₆H₄)(PPh₂)₂(μ-NMe)][B(C₆F₅)₄]₂ 4, while reaction of 3 with two equivalents of Me₂N(SiMe₃) gave the related dication [(C₆H₄)(PPh₂NMe₂)₂][Cl]₂ 5. Compound 3 also reacted with (Me₃Si)₂NH affording the monocationic salt [(C₆H₄)(PPh₂)₂(μ-N)]Cl 6, with the liberation of HCl. Interestingly 4 reacted with [nBu₄N]Cl generating the related salt [(C₆H₄)(PPh₂)₂(μ-N)][B(C₆F₅)₄] 6′ with concurrent formation of MeCl. This reactivity was extended to [(C₂H₄)(PPh₂F)₂][B(C₆F₅)₄]₂ 7 which afforded [(C₂H₄)(PPh₂)₂(μ-NR)][B(C₆F₅)₄]₂ (R = Me 8, CH₂CHCH₂ 9, CH₂Ph 10) upon reaction with (Me₃Si)₂NR. These dications were shown to react with [nBu₄N]Cl affording [(CH₂PPh₂)₂(μ-N)][B(C₆F₅)₄] 11 and the corresponding alkyl-chloride. The mechanism of these N–C bond cleavage reactions is considered.

中文翻译：

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环状磷氮鎓的合成和 N-C 键裂解反应


磷锌阳离子在 60 年前首次被表征，但人们对它们的反应性知之甚少。制备了双齿鏻盐 [（C₆H₄）（PPh₂F）₂][B（C₆F₅）₄]₂2 和 [（C₆H₄）（PPh₂Cl）₂][Cl]₂3。2 与 （Me₃Si）₂NMe 反应得到磷氮鎓 [（C₆H₄）（PPh₂）₂（μ-NMe）][B（C₆F₅）₄]₂4，而 3 与 Me₂N（SiMe₃） 的两个当量反应得到相关的dication [（C₆H₄）（PPh₂NMe₂）₂][Cl]₂5.化合物 3 还与 （Me₃Si）₂NH 反应，得到单阳离子盐 [（C₆H₄）（PPh₂）₂（μ-N）]Cl 6，释放出 HCl。 有趣的是，4 与 [nBu₄N]Cl 反应生成相关的盐 [（C₆， H₄）（PPh₂）₂（μ-N）][B（C，₆， F₅）₄] 6′，同时形成 MeCl。该反应性扩展到 [（C₂H₄）（PPh₂F）₂][B（C₆F₅）₄]₂7，得到 [（C₂H₄）（PPh₂）₂（μ-NR）][B（C₆F₅）_[4]₂ （R = Me 8， CH₂CHCH₂9， CH₂Ph 10） 与 （Me₃Si）₂NR 反应。这些离子显示与 [nBu₄N]Cl 反应，得到 [（CH₂PPh₂）₂（μ-N）][B（C₆F₅）₄] 11 和相应的烷基氯。考虑了这些 N-C 键裂解反应的机制。