Octachlorotetraphosphazene Explained

Octachlorotetraphosphazene is an inorganic compound with the formula (NPCl₂)₄. The molecule has a cyclic, unsaturated backbone consisting of alternating phosphorus and nitrogen centers, and can be viewed as a tetramer of the hypothetical compound N≡PCl₂.

The compound has not been studied as much as the related species hexachlorotriphosphazene, in the samples of which octachlorotetraphosphazene is usually found as an unwanted contamintant.^[1]

Structure and bonding

Octachlorotetraphosphazene has a P₄N₄ core with six equivalent P–N bonds.

Synthesis

NH₄Cl + PCl₅ → 1/n (NPCl₂)_n + HCl

Reactions

Substitution at P

Some spiro-, ansa-, and spiro-ansa-cyclic derivatives have been prepared via nucleophilic substitution of octachlorotetraphosphazene with alkoxides.^[2]

Notes and References

1. Book: Allcock, H. R.. Phosphorus-nitrogen compounds ; cyclic, linear, and high polymeric systems. 1972. Academic Press. 978-0-323-14751-4. New York. 838102247.
2. Ture. Sedat. 2016-01-02. Synthesis and characterization of spiro-, ansa-, and spiro-ansa-cyclic derivatives of cyclotetraphosphazene with the reactions of pentane-1,5-diol. Phosphorus, Sulfur, and Silicon and the Related Elements . 191 . 1 . 129–139 . 10.1080/10426507.2015.1054483.