Thermal decomposition of a compound consisting of a tetrachloroferrate(III) anion and a quinolinium cation, of general formula [QH][FeCl4], has been studied using TG-FTIR, TG-MS, DTA and DTG techniques. The measurements were carried out in an argon atmosphere over the temperature range 20-800 degrees C. The solid products of the thermal decomposition were identified by IR, FIR and Mossbauer spectroscopy. (c) 2006 Elsevier B.V. All rights reserved.