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′ λ 5 ‐[4 λ 5 ,6 λ 5 ][1,3,5,2,4,6]triazatriphosphorine]]

The reactions of N 2 O 2 ‐donor‐type aminopodands 1 – 3 with trimer N 3 P 3 Cl 6 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(CH 2 ) 4 ) with N 3 P 3 Cl 6 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.