Cyclotriphosphazene

A cyclotriphosphazene contains an alternating six-membered ${\mathrm{P}}_3{\mathrm{N}}_3$ ring. Substitution at its phosphorus atoms can generate geminal, non-geminal and spiro derivatives.

The cyclic trimer ${\mathrm{P}}_3{\mathrm{N}}_3\mathrm{C}{\mathrm{l}}_6$, a precursor to linear polydichlorophosphazene under controlled ring-opening conditions.