Determination of the Enthalpies of Combustion and Formation of Substituted Triazines in an Adiabatic Rotating Bomb Calorimeter.

To obtain reliable thermodynamic data on substituted triazines, it is necessary to use a calorimeter that is capable of high precision with small quantities of sample and in which a homogeneous solution of the corrosive combustion products can be maintained. The enthalpies of combustion of six substituted triazines have been determined in a platinum-lined adiabatic rotating bomb calorimeter. These are the first determinations of enthalpies of combustion or formation to have been reported for these compounds. The values derived for the enthalpies of formation in kJ/mol at 25 °C are as Follows: 2,4,6-trimethoxy-l,3,5-triazine, - 478.60± 0.87; 2,4,6-triethozy- 1,3,5-triazine, - 584.99± 1.50; 2,4,6-tris(2-fluoro-2,2-dinitroethoxy)-l,3,5-triazine, -1109.80±l.53; 2,4-dimethoxy-6-(2-fluoro-2,2-dimtroethoxy)-l,3,5-triazine, -697.08± 1,15; 2-methoxy- 4,6-bis(2-fluoro-2,2-dinitroethoxy)-l,3,5-triazine, -907.71± 2.40; 2-amino-4,6-bis(2-fluoro-2,2-dinitroethoxy)-l,3,5-triazine, - 773-12±1.50.