The imidazolinium and benzimidazolium bromide salts with pentafluor substituents on N atom were synthesized. The structures
of imidazolinium and benzimidazolium bromide salts obtained were conformed by 1H and 13C NMR, 19F NMR and elemental analysis. It was found that pyrolytic decomposition occurs with melting in salts. The imidazolinium and
benzimidazolium bromide salts were studied by TG-DTG and DTA from ambient temperature to 1000°C in nitrogen atmosphere. The
decomposition occurred mainly in one stage and the values of activation energy E, frequency factor A, reaction order n, enthalpy change ΔH#, entropy change ΔS# and Gibbs free energy ΔG#, of the thermal decomposition were calculated by means of Coats-Redfern (CR), MacCallum-Tanner (MC) and van Krevelen (vK)
methods. The activation energy value obtained by CR and MC methods were in good agreement with each other while those obtained
by vK were found to be 10–12 kJ mol−1 larger.