Accurate Prediction of Enthalpies of Formation of
Organic Azides by Combining G4 Theory Calculations with an Isodesmic
Reaction Scheme
Olga V. Dorofeeva
Oxana N. Ryzhova
Marina A. Suntsova
10.1021/jp404484q.s001
https://acs.figshare.com/articles/journal_contribution/Accurate_Prediction_of_Enthalpies_of_Formation_of_Organic_Azides_by_Combining_G4_Theory_Calculations_with_an_Isodesmic_Reaction_Scheme/2389072
Accurate
gas-phase enthalpies of formation (Δ<sub>f</sub><i>H</i><sub>298</sub><sup>°</sup>)
of 29 azides are recommended by combining G4 theory calculations with
an isodesmic reaction approach. The internal consistency over a set
of Δ<sub>f</sub><i>H</i><sub>298</sub><sup>°</sup> values was achieved by sequential
adjustment of their values through the isodesmic reactions. The HN<sub>3</sub> 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.
2013-08-08 00:00:00
sequential adjustment
Organic Azides
TAAT
29 azides
G 4 Theory Calculations
HN 3
formation
reference compound
7 compounds
phenyl azide
Accurate Prediction
isodesmic reactions
16 compounds
G 4 theory calculations
reference values
isodesmic reaction approach