Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Dinitrogen tetraoxide

Formula: O2NNO2 (g)

CAS RN: 10544-72-6

ATcT ID: 10544-72-6*0

SMILES: O=N(=O)N(=O)=O

InChI: InChI=1S/N2O4/c3-1(4)2(5)6

InChIKey: WFPZPJSADLPSON-UHFFFAOYSA-N

Hills Formula: N2O4

2D Image:

Aliases: O2NNO2; Dinitrogen tetraoxide; Dinitrogen tetroxide; Nitrogen tetraoxide; Nitrogen tetroxide; Nitrogen oxide; N2O4

Relative Molecular Mass: 92.0111 ± 0.0012

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
20.17	10.88	± 0.14	kJ/mol

3D Image of O2NNO2 (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of O2NNO2 (g)

The 20 contributors listed below account only for 80.6% of the provenance of Δ_fH° of O2NNO2 (g).
A total of 49 contributors would be needed to account for 90% of the provenance.

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
21.2	1483.1	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Callear 1970
21.2	1483.2	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Dingle 1975
15.7	1483.4	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52408 ± 10 (×1.164) cm-1	Kley 1973, Miescher 1974, est unc
3.6	1483.3	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52420 ± 12 (×2) cm-1	Miescher 1974, Huber 1979
3.0	1614.6	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(342.9 K) = -3.020 ± 0.041 kJ/mol	Bodenstein 1922, 3rd Law
2.2	1436.3	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2880 ± 0.0009 eV	Tang 2005
1.8	1436.1	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2888 ± 0.0010 eV	Tang 2005
1.8	1436.2	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2883 ± 0.0010 eV	Tang 2005
1.7	1725.3	(NH4)NO3 (cr,l) → N2 (g) + 1/2 O2 (g) + 2 H2O (cr,l)	Δ_rH°(293.65 K) = -49.44 ± 0.06 kcal/mol	Becker 1934
0.9	1486.4	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 626.47 ± 0.56 kJ/mol	Harding 2008
0.8	1613.6	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(304.0 K) = 3.755 ± 0.076 kJ/mol	Harris 1967, 3rd Law
0.7	1485.10	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 149.82 ± 0.15 kcal/mol	Karton 2007a, Karton 2008
0.7	1413.11	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.14 ± 0.15 kJ/mol	Thorpe 2021
0.7	1483.6	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 6.503 ± 0.004 (×1.682) eV	Brewer 1956, Frisch 1965
0.7	1613.4	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(258.0 K) = 11.844 ± 0.085 kJ/mol	Vosper 1970, 3rd Law
0.6	1484.10	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 149.78 ± 0.16 kcal/mol	Feller 2014
0.6	1952.4	HNO (g) → H (g) + N (g) + O (g)	Δ_rH°(0 K) = 823.10 ± 0.56 kJ/mol	Harding 2008
0.6	1486.2	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 626.74 ± 0.70 kJ/mol	Harding 2008
0.5	1498.1	1/2 N2 (g) + 1/2 O2 (g) → NO (g)	Δ_rH°(0 K) = 90.0 ± 0.8 kJ/mol	Szakacs 2011
0.5	1959.4	HNO (g) → H (g) + NO (g)	Δ_rH°(0 K) = 16450 ± 10 cm-1	Dixon 1981, Dixon 1984, Dixon 1996

Top 10 species with enthalpies of formation correlated to the Δ_fH° of O2NNO2 (g)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation Coefficent (%)	Species Name	Formula	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
97.2	Nitrogen dioxide	ONO (g)	36.866	34.059	± 0.064	kJ/mol	46.00554 ± 0.00060	10102-44-0*0
97.1	Nitric oxide	NO (g)	90.627	91.131	± 0.064	kJ/mol	30.00614 ± 0.00031	10102-43-9*0
96.9	Nitrosyl ion	[NO]+ (g)	984.494	984.489	± 0.064	kJ/mol	30.00559 ± 0.00031	14452-93-8*0
93.7	Nitrosyl chloride	ClNO (g)	54.461	52.559	± 0.067	kJ/mol	65.45884 ± 0.00095	2696-92-6*0
91.5	Dioxohydrazine	ONNO (g)	172.91	171.14	± 0.14	kJ/mol	60.01228 ± 0.00062	16824-89-8*0
91.5	Dioxohydrazine	ONNO (g, cis)	172.91	171.14	± 0.14	kJ/mol	60.01228 ± 0.00062	16824-89-8*2
87.1	Nitrogen sesquioxide	ONN(O)O (g)	90.73	86.17	± 0.15	kJ/mol	76.01168 ± 0.00091	10544-73-7*0
80.1	Nitrous acid	HONO (g)	-72.986	-78.643	± 0.078	kJ/mol	47.01348 ± 0.00061	7782-77-6*0
80.1	Nitrous acid	HONO (g, trans)	-72.986	-79.130	± 0.078	kJ/mol	47.01348 ± 0.00061	7782-77-6*1
79.7	Nitric oxide	NO (aq, undissoc)		79.218	± 0.078	kJ/mol	30.00614 ± 0.00031	10102-43-9*1000

Most Influential reactions involving O2NNO2 (g)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
1.000	1618.1	O2NNO2 (cr,l) → O2NNO2 (g)	Δ_rH°(294.30 K) = 9.11 ± 0.03 kcal/mol	Giauque 1938
0.562	1614.6	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(342.9 K) = -3.020 ± 0.041 kJ/mol	Bodenstein 1922, 3rd Law
0.427	1609.4	O2NNO2 (g) → [O2NNO2]+ (g)	Δ_rH°(0 K) = 10.497 ± 0.040 eV	Ruscic W1RO
0.234	1610.4	[O2NNO2]- (g) → O2NNO2 (g)	Δ_rH°(0 K) = 2.083 ± 0.050 eV	Ruscic W1RO
0.163	1613.6	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(304.0 K) = 3.755 ± 0.076 kJ/mol	Harris 1967, 3rd Law
0.157	1610.2	[O2NNO2]- (g) → O2NNO2 (g)	Δ_rH°(0 K) = 2.169 ± 0.061 eV	Ruscic G4
0.134	1624.6	O2NNO2 (g) → ONONO2 (g, cis-perp)	Δ_rH°(0 K) = 9.72 ± 1.2 kcal/mol	Ruscic W1RO
0.131	1613.4	O2NNO2 (g) → 2 ONO (g)	Δ_rG°(258.0 K) = 11.844 ± 0.085 kJ/mol	Vosper 1970, 3rd Law
0.121	1623.5	O2NNO2 (g) → ONONO2 (g, trans)	Δ_rH°(0 K) = 6.58 ± 1.2 kcal/mol	Ruscic W1RO
0.115	1633.3	O2NNO2 (g) → ON(O2)NO (g, perp)	Δ_rH°(0 K) = 12.14 ± 1.2 kcal/mol	Ruscic W1RO
0.114	1624.5	O2NNO2 (g) → ONONO2 (g, cis-perp)	Δ_rH°(0 K) = 8.94 ± 1.3 kcal/mol	Ruscic CBS-n
0.114	1624.3	O2NNO2 (g) → ONONO2 (g, cis-perp)	Δ_rH°(0 K) = 9.65 ± 1.3 kcal/mol	Ruscic G4
0.103	1623.3	O2NNO2 (g) → ONONO2 (g, trans)	Δ_rH°(0 K) = 6.91 ± 1.3 kcal/mol	Ruscic G4
0.099	1624.2	O2NNO2 (g) → ONONO2 (g, cis-perp)	Δ_rH°(0 K) = 9.65 ± 1.4 kcal/mol	Ruscic G3X
0.098	1633.2	O2NNO2 (g) → ON(O2)NO (g, perp)	Δ_rH°(0 K) = 12.53 ± 1.3 kcal/mol	Ruscic G4
0.089	1623.2	O2NNO2 (g) → ONONO2 (g, trans)	Δ_rH°(0 K) = 6.79 ± 1.4 kcal/mol	Ruscic G3X
0.084	1633.1	O2NNO2 (g) → ON(O2)NO (g, perp)	Δ_rH°(0 K) = 11.75 ± 1.4 kcal/mol	Ruscic G3X
0.081	1610.1	[O2NNO2]- (g) → O2NNO2 (g)	Δ_rH°(0 K) = 2.086 ± 0.085 eV	Ruscic G3X
0.079	1609.2	O2NNO2 (g) → [O2NNO2]+ (g)	Δ_rH°(0 K) = 10.439 ± 0.093 eV	Ruscic G3X
0.075	1624.4	O2NNO2 (g) → ONONO2 (g, cis-perp)	Δ_rH°(0 K) = 10.71 ± 1.6 kcal/mol	Ruscic CBS-n

References

1		B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner, Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2		B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner, Active Thermochemical Tables: Thermochemistry for the 21^st Century. J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3		B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
5		B. Ruscic, Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables. Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
6		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.000₅ kJ/mol.

Website Functionality Credits

The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

Acknowledgement

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.