Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Nitrogen atom

Formula: N (g)

CAS RN: 17778-88-0

ATcT ID: 17778-88-0*0

SMILES: [N]

InChI: InChI=1S/N

InChIKey: QJGQUHMNIGDVPM-UHFFFAOYSA-N

Hills Formula: N1

2D Image:

Aliases: N; Nitrogen atom; Nitrogen; Atomic nitrogen; Nitrogen radical; Mononitrogen; N-atom

Relative Molecular Mass: 14.006740 ± 0.000070

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
470.583	472.445	± 0.022	kJ/mol

3D Image of N (g)

spin ON spin OFF

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

The 19 contributors listed below account for 90.2% of the provenance of Δ_fH° of N (g).

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
24.5	1422.3	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2880 ± 0.0009 eV	Tang 2005
19.8	1422.2	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2883 ± 0.0010 eV	Tang 2005
19.8	1422.1	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2888 ± 0.0010 eV	Tang 2005
8.2	1399.11	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.14 ± 0.15 kJ/mol	Thorpe 2021
6.3	1423.2	[N2]+ (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 70248 ± 12 (×1.189) cm-1	Hertzler 1992, Douglas 1952, Hertzler 1990, Janin 1957, est unc
3.9	1406.8	N2 (g) → 2 N (g, doublet)	Δ_rH°(0 K) = 117127.5 ± 18.0 cm-1	Roncin 1984, note N2
2.5	1406.7	N2 (g) → 2 N (g, doublet)	Δ_rH°(0 K) = 117105.5 ± 22.7 cm-1	Roncin 1984, note N2
0.7	1396.2	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 78716 ± 40 (×1.022) cm-1	Carroll 1965, note N2
0.5	1399.7	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.56 ± 0.56 kJ/mol	Harding 2008
0.5	1396.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 78715 ± 50 cm-1	Buttenbender 1935, Gaydon 1968, note N2, as quoted by CODATA Key Vals
0.4	1398.4	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 225.01 ± 0.15 kcal/mol	Karton 2007a, Karton 2006, Karton 2011
0.3	1399.4	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.61 ± 0.70 kJ/mol	Bomble 2006
0.3	1399.5	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.74 ± 0.70 kJ/mol	Harding 2008
0.3	1399.6	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.09 ± 0.74 kJ/mol	Harding 2008
0.3	1399.3	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.14 ± 0.75 kJ/mol	Bomble 2006
0.3	1399.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.07 ± 0.75 kJ/mol	Tajti 2004, est unc
0.2	1399.2	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 941.78 ± 0.80 kJ/mol	Bomble 2006
0.2	1400.1	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 225.0 ± 0.2 kcal/mol	Feller 2006a
0.2	1400.6	N2 (g) → 2 N (g)	Δ_rH°(0 K) = 224.99 ± 0.20 kcal/mol	Feller 2014

Top 10 species with enthalpies of formation correlated to the Δ_fH° of N (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
100.0	Nitrogen atom	N (g, quartet)	470.583	472.445	± 0.022	kJ/mol	14.006740 ± 0.000070	17778-88-0*1
100.0	Nitrogen atom	N (g, doublet)	700.558	702.461	± 0.022	kJ/mol	14.006740 ± 0.000070	17778-88-0*2
99.9	Nitrogen atom cation	N+ (g)	1872.911	1875.692	± 0.022	kJ/mol	14.006191 ± 0.000070	14158-23-7*0
93.0	Nitrogen atom dication	[N]+2 (g)	4728.997	4731.826	± 0.024	kJ/mol	14.005643 ± 0.000070	17439-59-7*0
30.9	Nitric oxide	NO (g)	90.628	91.132	± 0.065	kJ/mol	30.00614 ± 0.00031	10102-43-9*0
30.9	Nitrosyl ion	[NO]+ (g)	984.496	984.490	± 0.065	kJ/mol	30.00559 ± 0.00031	14452-93-8*0
30.9	Nitrogen dioxide	ONO (g)	36.867	34.060	± 0.065	kJ/mol	46.00554 ± 0.00060	10102-44-0*0
30.0	Dinitrogen tetraoxide	O2NNO2 (g)	20.17	10.88	± 0.14	kJ/mol	92.0111 ± 0.0012	10544-72-6*0
29.9	Nitrosyl chloride	ClNO (g)	54.462	52.560	± 0.067	kJ/mol	65.45884 ± 0.00095	2696-92-6*0
29.1	Dioxohydrazine	ONNO (g, cis)	172.91	171.15	± 0.14	kJ/mol	60.01228 ± 0.00062	16824-89-8*2

Most Influential reactions involving N (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	1424.1	N (g, quartet) → N (g)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, NIST Atomic Web
0.658	1410.1	N (g) → N+ (g)	Δ_rH°(0 K) = 117225.4 ± 0.1 cm-1	McConkey 1968, Moore 1970
0.554	1421.1	[N]-3 (g) → N (g)	Δ_rH°(0 K) = -14.625 ± 0.061 eV	Ruscic G4
0.397	2153.6	NF (g, triplet) → N (g) + F (g)	Δ_rH°(0 K) = 75.35 ± 0.3 kcal/mol	Feller 2008
0.354	2680.14	CH2NH (g) → C (g) + 3 H (g) + N (g)	Δ_rH°(0 K) = 1733.46 ± 0.56 kJ/mol	Gratzfeld 2017
0.332	1419.4	[N]-2 (g) → N (g)	Δ_rH°(0 K) = -6.106 ± 0.050 eV	Ruscic W1RO
0.266	2120.5	FNO (g) → F (g) + N (g) + O (g)	Δ_rH°(0 K) = 210.16 ± 0.35 kcal/mol	Karton 2017
0.261	2728.9	CNH2 (g) → C (g) + N (g) + 2 H (g)	Δ_rH°(0 K) = 296.69 ± 0.50 kcal/mol	Puzzarini 2010, est unc
0.257	1469.1	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Callear 1970
0.257	1469.2	NO (g) → N (g) + O (g)	Δ_rH°(0 K) = 52400 ± 10 cm-1	Dingle 1975
0.250	7813.5	[CCCN]+ (g) → 3 C (g) + N (g)	Δ_rH°(0 K) = 175.96 ± 1.50 kcal/mol	Ruscic W1RO
0.249	2141.6	NF2 (g) → N (g) + 2 F (g)	Δ_rH°(0 K) = 140.92 ± 0.3 kcal/mol	Feller 2008
0.245	1422.3	N2 (g) → N+ (g) + N (g)	Δ_rH°(0 K) = 24.2880 ± 0.0009 eV	Tang 2005
0.237	1905.9	[NH2O]- (g) → N (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 263.07 ± 0.80 kcal/mol	Dixon 2006
0.236	5893.6	[CNN]+ (g) → 2 N (g) + C (g)	Δ_rH°(0 K) = 2.64 ± 1.50 kcal/mol	Ruscic W1RO
0.223	1419.1	[N]-2 (g) → N (g)	Δ_rH°(0 K) = -6.191 ± 0.061 eV	Ruscic G4
0.219	7813.4	[CCCN]+ (g) → 3 C (g) + N (g)	Δ_rH°(0 K) = 175.55 ± 1.60 kcal/mol	Ruscic CBS-n
0.219	7813.2	[CCCN]+ (g) → 3 C (g) + N (g)	Δ_rH°(0 K) = 175.95 ± 1.60 kcal/mol	Ruscic G4
0.219	1817.11	HNNH (g, cis) → 2 N (g) + 2 H (g)	Δ_rH°(0 K) = 273.69 ± 0.30 kcal/mol	Karton 2011
0.217	1411.6	N- (g) → N (g)	Δ_rH°(0 K) = -0.151 ± 0.050 eV	EA(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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
6		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]
7		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 [6] and Ruscic and Bross[7]).
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.