Phosphorus-Nitrogen Compounds: Novel Spirocyclic Phosphazene Derivatives. Structure of 3,3″-Propane-1,3-diylbis[4′,4′,6′,6′-tetrachloro-3,4-dihydrospiro[1,3,2-benzoxazaphosphorine-2,2′λ5-[4λ5,6λ5][1,3,5,2,4,6]triazatriphosphorine]]

The reactions of N2O2‐donor‐type aminopodands 1–3 with trimer N3P3Cl6 led to the novel spirocyclic phosphazene derivatives 4–10 (Scheme). Compounds 4–7 and 8–10 are the first examples of the substituted spiro‐ansa‐spiro and spiro‐bino‐spiro phosphazene derivatives, respectively. The pyrrolidinyl‐substituted phosphazene derivatives 7 and 10 were synthesized from 5 and 9, respectively, with an excess of pyrrolidine. The reaction of aminopodand 3 (R(CH2)4) with N3P3Cl6 in dry THF afforded only spiro‐ansa‐spiro phosphazene 6. The molecular structure of compound 9 was determined by X‐ray diffraction: it shows the novel spiro‐bino‐spiro phosphazene architecture.