Thermal Studies of Some Biological Active Bis[1,2,4]triazolophthalazines: Non Isothermal Kinetic Study of one of the Potent 3,6-Bis(4-nitrophenyl) bis([1,2,4]triazolo)[3,4-a:4,3-c]phthalazine

Abstract

Thermal decomposition studies of twelve bis-1,2,4-triazolophthalazines (4a-l) have been investigated using TG and DSC techniques under argon atmosphere at a heating rate of 10 °C min-1. TG study shows that all halogen substituted compounds (4e-j) are thermally most stable except 4f. Mass percentage residues left at 550 °C lie in the range 29-52%. This shows that compounds are thermally stable at high temperatures. DSC curve shows two peaks except for 4c and 4d which are showing three DSC peaks degradation. Second peak of most of the compounds and third DSC peak of 4c-d shows exothermic decomposition. Activation energy calculated by model free methods for compound 4k show dependence on conversion value. Activation energy at conversion 0.8 for this compound is around 562.6 kJ mol-1 .