Single-, double- and triple-bridged derivatives of cyclotriphosphazenes with an octafluorohexane-1,6-diol

Abstract

Reaction of hexachlorocyclotriphosphazene, N(3)P(3)Cl(6) (1), with the sodium derivative of the fluorinated diol, 2,2,3,3,4,4,5,5-octafluorohexane-1,6-diol, (2), in THF solution at room temperature afforded five products, whose structures have been characterised by (1)H, (19)F and (31)P NMR spectroscopy: the mono-ansa compound N(3)P(3)Cl(4)[OCH(2)(CF(2))(4)CH(2)O](3); the single-bridged compound N(3)P(3)Cl(5)[OCH(2)(CF(2))(4)CH(2)O]N(3)P(3)Cl(5) (4), two double-bridged compounds N(3)P(3)Cl(4)(OCH(2)(CF(2))(4)CH(2)O)(2)N(3)P(3)Cl(4), (5-anti, 5-syn) and the triple-bridged compound N(3)P(3)Cl(3)(OCH(2)(CF(2))(4)CH(2)O)(3)N(3)P(3)Cl(3) (6). X-ray crystallographic studies confirmed the structures of the ansa compound (3), the double-bridged compound (5-anti) and the first example of a tripie-bridged cyclotriphosphazene derivative (6). The results were also compared with those for reactions of (1) with analogous fluorinated shorter diols (1,4-butane- and 1,5-pentane-diols). It is found that on increasing the chain length of the diol, there is a decrease in the relative proportion of intramolecular reactions giving spiro and ansa derivatives and an increase in the amount of bridged cyclophosphazene derivatives via intermolecular reactions. (C) 2009 Elsevier Ltd. All rights reserved.