The TG-FTIR analysis of some new diazoaminoderivatives is aimed to follow the structure-thermal stability-degradation mechanism correlation. The TG-DTG-DTA curves are indicative of a complex and specific mechanism of thermal degradation in air of the diazoaminoderivatives under study which show a common characteristic regarding their degradation in air (30-900 degrees C) when two domains in function of temperature (time) can be noticed: an endothermic one, identical to the degradation under nitrogen atmosphere, and an exothermal one. The gaseous species resulting by degradation are also grouped in these domains. The identification by means of the specific absorbances of every gaseous species and those obtained by TG-FTIR revealed that N-2, NH3, H2C = NH, SO2, H2O, CO2, C4H8, C3H4 are eliminated within the first domain while SO2, H2O, CO2 within the second. These results afforded the most probable thermal degradation mechanism to be advanced. Since these compounds could show practical importance as initiators (generators of free radicals) and also as biologically active substances, their thermal stability and the degradation mechanism can give significant information on the temperature range proper for their practical application. Besides the compounds released by thermal degradation could give information about the potential environmental pollution. (C) 2010 Elsevier B.V. All rights reserved.