Thermal behavior of nitro-, amino-, and azo-phenylfuroxans

4-Nitro-3-phenylfuroxan ( 1 ), 4-amino-3-phenylfuroxan ( 2 ), and 4,4’-azo-3,3’-diphenylfuroxan ( 3 ) were synthesized using previously described methods and their thermochemical characteristics were experimentally studied. The kinetics of thermal transformation reactions of the substances was investigated using thermogravimetry (under isothermal and nonisothermal conditions) and differential scanning calorimetry. Possible pathways of thermal decomposition of the compounds were simulated by quantum chemistry methods. It is shown that for all the compounds considered, the most energetically favorable primary limiting stage of thermal transformations is the formation of the corresponding intermediate dinitrosoethylene. Isothermal kinetic data obtained using isoconversion method applied to initial stages of the studied reactions are in good agreement with quantum chemical calculations. Discrepancies between theoretical and nonisothermal kinetic experimental data obtained using the Kissinger and Ozawa-Doyle equations are noted and probable causes of these differences are considered. (1) Kinetics of thermal transformations of phenylfuroxan derivatives. (2) Study and comparison of theoretical and experimental kinetic characteristics. (3) Modeling and determination of the mechanism of thermal decomposition