"One-Step" Synthesis of Ionic Ferrocenyl Compounds of Ferrocenylmethyldimethylamine. Characterization, Migration, and Catalytic Properties During Combustion

Alkylferrocene-based burning rate catalysts exhibit high migration tendency and volatility during prolonged storage and fabrication process of the solid propellants. To retard the migration problems, eight ionic compounds composed of ferrocenylmethyldimethylammonium cation paired with a common energetic anion, were synthesized by "one-step" procedure. The compounds were characterized by FTIR, NMR, and UV/Vis spectroscopy as well as elementary analysis. Their crystal structures were confirmed by single-crystal X-ray diffraction. The TG and DSC analyses indicated that they exhibit high thermal stability. Cyclic voltammetry studies suggested that most of them show reversible or quasi-reversible redox waves. The anti-migration results revealed that 1-4 are low-migratory compounds, but 5 exhibits high migration trends. The TG curves at 70 degrees C for 24 h showed that all of them have low volatility. They have from high to low impact sensitivity depending on the anions of the compounds. They all exhibit significant effect on the thermal decomposition of ammonium perchlorate (AP) and some of them accelerate the thermal degradation of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX). Among them 4 is the best one. Unexpectedly, compound 5, with 1H-tetrazolate as anion, can decompose into its original reactants at the temperature just higher than its melting point and could show smart-material functionality in solid propellants.