Synthesis of 2-Ferrocenyl-4, 5-Diphenylimidazolium Ionic Liquids and Their Catalysis Performance for Thermal Decomposition of Ammonium Perchlorate

Compounds 2a-2f were synthesized by the substitution reaction of 2-ferrocenyl-4,5-diphenylimi-dazole(1) with different halohydrocarbons. Then compounds 2a-2f were reacted with iodomethane to get compounds 3a-3f. Finally, compounds 3a-3f were exchanged anion with ammonium hexafluorophosphate to get compounds 4a-4f. All these compounds were structurally characterized by means of infrared(IR), mass spectrometry(MS), nuclear magnetic resonance(NMR), high-resolution mass spectrometry(HRMS) and X-ray crystal diffraction. Electrochemical properties of these compounds were studied by cyclic voltammetry(CV). Thermal behavior and catalytic performance for thermal decomposition of ammonium perchlorate(AP) were studied by thermogravimetric(TG) and differential scanning calorimetry(DSC). The results indicate that all the synthetic products have efficient catalytic effect on the thermal decomposition of AP. The iodized salts(3a-3f) indicate better catalytic effect than the hexafluorophosphate(4a-4f). The most outstanding compound is 3b, which makes the second decomposition stage of AP disappear, and the first stage is advanced to 270.5 degrees C. The novel dinuclear ferrocen-based imidazolium derivatives would have great value in preparing high-burning-rate catalyst for composite solid propellants.