Studies of phosphazenes. Part 17. Reaction of hexachlorocyclotriphosphazatriene with N-methylethanolamine: X-ray crystal structure of a dispirocyclotriphosphazatriene, N3P3(NMeCH2CH2O)2Cl2

Abstract

Hexachlorocyclotriphosphazatriene, N₃P₃Cl₆, reacts with N-methylethanolamine to give the spirocyclic derivatives, N₃P₃(NMeCH₂CH₂O)_nCl_{6 – 2n}(n= 1–3), whose structures have been elucidated by ¹H and ³¹P n.m.r. spectroscopy. The structure of the dispiro compound, N₃P₃(NMeCH₂CH₂O)₂Cl₂, has been determined by X-ray crystallography; the exocyclic nitrogen atoms are in a ‘cis’ configuration and the phosphazene and the two spiro rings are planar. The observed chlorine replacement pattern is discussed briefly. Variations in the ³¹P chemical shifts of spirocyclic phosphorus nuclei with the size of the spiro ring are correlated with differences in structural features.