| Abstract
| - The standard enthalpy of formation and the enthalpy of sublimation of crystalline 2-hydroxyphenazine-di-N-oxide, at T = 298.15 K, were determined from isoperibol static bomb combustion calorimetry and fromKnudsen effusion experiments, as −76.7 ± 4.2 kJ·mol-1 and 197 ± 5 kJ·mol-1, respectively. The sum ofthese two quantities gives the standard enthalpy of formation in the gas-phase for this compound,(g) =120 ± 6 kJ·mol-1. This value was combined with the gas-phase standard enthalpy of formation for2-hydroxyphenazine retrieved from a group estimative method yielding the mean (N−O) bond dissociationenthalpy, in the gas-phase, for 2-hydroxyphenazine-di-N-oxide. The result obtained with this strategy is〈(N − O)〉 = 263 ± 4 kJ·mol-1, which is in excellent agreement with the B3LYP/6-311+G(2d,2p)//B3LYP/6-31G(d) computed value, 265 kJ·mol-1.
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