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

摘要

Reaction of hexachlorocyclotriphosphazene, N3P3Cl6 (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 H-1, F-19 and P-31 NMR spectroscopy: the mono-ansa compound N3P3Cl4[OCH2(CF2)(4)CH2O](3); the single-bridged compound N3P3Cl5[OCH2(CF2)(4)CH2O]N3P3Cl5 (4), two double-bridged compounds N3P3Cl4(OCH2(CF2)(4)CH2O)(2)N3P3Cl4, (5-anti, 5-syn) and the triple-bridged compound N3P3Cl3(OCH2(CF2)(4)CH2O)(3)N3P3Cl3 (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.