Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia.
J Phys Chem A. 2013 Aug 8;117(31):6835-45. doi: 10.1021/jp404484q. Epub 2013 Jul 24.
Accurate gas-phase enthalpies of formation (ΔfH298°) of 29 azides are recommended by combining G4 theory calculations with an isodesmic reaction approach. The internal consistency over a set of ΔfH298° values was achieved by sequential adjustment of their values through the isodesmic reactions. The HN₃ was chosen as a key reference compound. Of the experimental data available for 16 compounds, our predictive values agree well with 9 of them, while the deviations from 25 to 55 kJ/mol are observed for 7 compounds; possible systematic errors in the experimental data for phenyl azide, 2-azidoethanol, azidocyclopentane, azidocyclohexane, 3-azido-3-ethylpentane, 2-azido-2-phenylpropane, and 1-azidoadamantane are discussed. The recommended enthalpies of formation of organic azides were used as reference values to estimate the enthalpy of formation of four nitrogen-rich carbon nitrides. The calculations do not support the high value of the solid-state enthalpy of formation of TAAT (4,4',6,6'-tetra(azido)azo-1,3,5-triazine); its value is estimated to be 300-400 kJ/mol lower than that measured experimentally.
通过结合 G4 理论计算和等电子反应方法，推荐了 29 种叠氮化物的准确气相生成焓（ΔfH298°）。通过等电子反应逐步调整其值，实现了一组 ΔfH298° 值的内部一致性。选择 HN₃作为关键参考化合物。在可用的 16 种化合物的实验数据中，我们的预测值与其中 9 种吻合较好，而对于 7 种化合物，观察到偏差为 25 至 55 kJ/mol；讨论了苯基叠氮化物、2-叠氮乙醇、叠氮环戊烷、叠氮环己烷、3-叠氮-3-乙基戊烷、2-叠氮-2-苯基丙烷和 1-叠氮金刚烷的实验数据中可能存在的系统误差。推荐的有机叠氮化物生成焓被用作参考值来估计四种富氮碳氮化物的生成焓。计算不支持 TAAT（4,4',6,6'-四（叠氮）偶氮-1,3,5-三嗪）的固态生成焓的高值；其值估计比实验测量值低 300-400 kJ/mol。
