Syntheses and Structures of Trilithium Cyclotriphosphazenates Equipped with 2‐Halo‐aryl Substituents

Hexakis (2‐halo‐anilino) cyclotriphosphazenes (2‐X‐C₆H₄NH)₆P₃N₃ {X = F ( 1d ), Cl ( 1e ), Br ( 1f )} were prepared by refluxing mixtures of hexachloro cyclotriphosphazene, 2‐haloaniline and triethylamine in toluene and characterized by single crystal X‐ray diffraction. 1d , 1e and 1f were reacted with ⁿBuLi in thf. Reactions were monitored with ³¹P NMR. Addition of three equivalents of ⁿBuLi yields lithium complexes of trianionic phosphazenates {(thf)₂Li}₃{(2‐X‐C₆H₄N)₃(2‐X‐C₆H₄NH)₃P₃N₃}] {X= F ( 2d ), Cl ( 2e ) and Br ( 2f )}. 2d , 2e and 2f were structurally characterized by X‐ray diffraction, which reveals monomeric cis‐metalated phosphazenates featuring central P₃N₃ ring systems of chair conformation. Lithium ions reside in three N(eq)‐P‐N(endo) chelation sites at one face of the P₃N₃ ring system. Li…X distances are rather long (> 3Å) indicating no Li‐X interactions.