Vinyloxycyclophosphazenes

Abstract

Numerous vinyloxyphosphazenes, N_yP_yX_2y-n (OCH=CH₂)_n (y=3,4; X=Cl, F; n=1–2y) are available via reactions of the enolate anion of acetaldehyde with halocyclophosphazenes. We have now shown that the cis stereoisomer is the predominant species formed in many of these reactions. An electrostatic model has been proposed to account for this observation. The reaction of vinyloxyphosphazenes with other nucleophiles has been examined. Mixed vinyloxy/trifluoroethoxy derivative have been prepared. Studies involving ¹³C nmr spectroscopy and vinyl addition polymerization show that the electron distribution in the vinyl group is strongly influenced by the electron donor ability of the geminal phosphazene substituent. The methacryloyl ethylenedioxy derivative, N₃P₃Cl₅OCH₂CH₂OC(O)C(CH₃)=CH₂, was prepared. This material undergoes a slow phosphazene-phosphazane rearrangement.