Abstract Some new substituted cyclotriphosphazenes were prepared by the reaction of hexachlorocy-clotriphosphazene and 4-hydroxyazo compounds such as 4-hydroxyazobenzene, 4′-ethyl-4-hydroxyazobenzene, 4′-ethyl-4-hydroxyazobenzene, 4′-tertbutyl-4-hydroxyazobenzene, 4′-methoxy-4-hydroxyazobenzene, 3′,4′-dichloro-4-hydroxyazobenzene, 2′-chloro-4-hydroxyazobezene and 2′-methoxy-5′-chloro-4-hydroxyazobenzene