Synthesis Of Hexachlorocyclotriphosphazene In Dialkylimidazolium Ionic Liquids

Hexachlorocyclotriphosphazene are the phazene of hexacyclo or octacyclo structure with a backbone of alternating phosphorus and nitrogen atoms. Hexachlorocyclotripho- sphazene is the basic monomer for the synthesis of polyphosphazenes, which are used for fire retardancy, special rubber, medical material etc. Ionic liquids as a new, environmentally friendly catalyst and solvents are gaining worldwide academic and industrial attention as replacements of traditional organic solvents in catalysis, separations and electrochemistry.At first, we prepared 1-Ethyl-3-methylimidazolium tetrafluoroborate([emim]BF4), 1-n-Butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4), 1-Ethyl-3-methylimidazo- lium hexafluorophosphate([emim]PF6), 1-n-Butyl-3-methylimidazolium hexafluorophosph- ate([bmim]PF6), 1-n-Butyl-3-methylimidazolium chloro-aluminate(III)([bmim]Cl-AlCl3). Then, these ionic liquids have been characterized and analyzed by FT-IR.We have first used dialkylimidazolium as cation, BF4-, PF6- and AlCl4- as anion for the solvent used for the synthesis of hexachlorocyclotriphosphazene by PCl5 and NH4Cl. Compared with traditional methods, the yield and the purity have great raised in chloroaluminate(III) ionic liquids, which analyzed by melt point, IR and 31P NMR. Other virtue are advanced technology, easy post treatment and many times circulation of ionic liquids.In alkalescence chloroaluminate(III) ionic liquids, the productivity of hexachlorocyclo- triphosphazene is the highest and its purity is 100%. Although it has some by-products such as tetramer, pentamer and polyphosphazenes, the purity of hexachlorocyclotriphosphazene is high in neutral chloroaluminate(III) ionic liquids.