The nitrogen atom in cyclic hetero-oligophosphane cyclo-P₄Mes₄C(NCy) (1) can be protonated with HCl or HBF₄. The resulting cation was isolated as the BF₄^–, AlCl₄^– and GaCl₄^– salts. According to quantum mechanical calculations, the basicity of compound 1 is comparable to that of methyl-substituted monophospha(III)guanidine. The experimentally determined pK_α value is in the range of 4.9–5.2.

中文翻译：

---

N-（四甲叉基四磷环戊叉基）环己胺的碱性：一种不常见的二磷（III）胍衍生物

环状杂-低聚膦环-P ₄ Mes ₄ C（NCy）（1）中的氮原子可以用HCl或HBF ₄质子化。分离出作为BF ₄ ^–，AlCl ₄ ^–和GaCl ₄ ^–盐的阳离子。根据量子力学计算，化合物1的碱度与甲基取代的单磷（III）胍的碱度相当。实验确定的pK _α值在4.9-5.2的范围内。