The synthesis and thermal properties of fluorodioxy-substituted N,N-spiro bridged cyclotriphosphazenes

Abstract

Fluorodioxy substituted mono-spiro (1a,b), di-spiro (2a,b) and mono-ansa (3a-c) cyclotriphosphazene derivatives were reacted with n-butylamine to obtain fluorodioxy cyclotriphosphazenes bearing a P-NH group. Then, the fluorodioxy cyclotriphosphazene derivatives containing one NH moiety (4a,b; 5a,5b and 6a-c) which can give a deprotonation reaction were treated with sodium hydride giving rise to new types of bis-cyclophosphazenes bridged with a four-membered cyclophosphazane ring in a spiro arrangement (7, 8, 9a,b and 10a-c). The deprotonation reactions of substituted cyclotriphosphazenes were investigated for the first time and rigid and stable spiro- and ansa-derivatives of N,N-spiro bridged biscyclotriphosphazenes were obtained. Additionally, the thermal stabilities of all new compounds were investigated and found that the thermal stability increases with the formation of N,N-spiro bridge. (C) 2017 Elsevier Ltd. All rights reserved.