Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Carbon monoxide

Formula: CO (g, triplet)

CAS RN: 630-08-0

ATcT ID: 630-08-0*1

SMILES: [C-]#[O+]

InChI: InChI=1S/CO/c1-2

InChIKey: UGFAIRIUMAVXCW-UHFFFAOYSA-N

Hills Formula: C1O1

2D Image:

Aliases: CO; Carbon monoxide; Carbon monooxide; Oxomethylidene; Methylidyneoxonium; Carbon oxide

Relative Molecular Mass: 28.01010 ± 0.00085

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
465.588	469.295	± 0.026	kJ/mol

3D Image of CO (g, triplet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CO (g, triplet)

The 20 contributors listed below account only for 89.7% of the provenance of Δ_fH° of CO (g, triplet).
A total of 21 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
60.3	2286.9	C (graphite) + CO2 (g) → 2 CO (g)	Δ_rG°(1165 K) = -33.545 ± 0.058 kJ/mol	Smith 1946, note COf, 3rd Law
4.5	2228.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
2.9	2284.4	CO (g) + 1/2 O2 (g) → CO2 (g)	Δ_rH°(303.15 K) = -282.974 ± 0.116 kJ/mol	Rossini 1931a, Rossini 1931b, Rossini 1939, note CO
2.7	2282.7	CO2 (g) → CO (g) + O+ (g)	Δ_rH°(0 K) = 19.0701 ± 0.0010 (×1.242) eV	Liu 2003, note unc
2.2	2286.5	C (graphite) + CO2 (g) → 2 CO (g)	Δ_rG°(1236.8 K) = -46.195 ± 0.3 kJ/mol	Peters 1958, note COe, 3rd Law
1.8	2284.6	CO (g) + 1/2 O2 (g) → CO2 (g)	Δ_rH°(293.15 K) = -283.036 ± 0.146 kJ/mol	Fenning 1933, note COb
1.8	2228.5	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.468 ± 0.038 kJ/mol	Fraser 1952, note CO2f
1.8	2228.4	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.462 ± 0.038 kJ/mol	Lewis 1965, note CO2d
1.7	2284.3	CO (g) + 1/2 O2 (g) → CO2 (g)	Δ_rG°(1173 K) = -180.655 ± 0.150 kJ/mol	Caneiro 1981, note COc
1.7	2268.11	CO (g) → C (g) + O (g)	Δ_rH°(0 K) = 1071.92 ± 0.10 kJ/mol	Thorpe 2021
1.2	2283.5	CO2 (g) → [CO]+ (g) + O (g)	Δ_rH°(0 K) = 19.4687 ± 0.0010 (×1.834) eV	Liu 2003, note unc
1.2	2228.11	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -94.051 ± 0.011 kcal/mol	Prosen 1944a, Cox 1970, NBS TN270, NBS Tables 1989
0.8	2375.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
0.8	2228.6	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.462 ± 0.056 kJ/mol	Hawtin 1966, note CO2e
0.8	2278.2	CO (g) → C+ (g) + O (g)	Δ_rH°(0 K) = 22.3713 ± 0.0015 eV	Ng 2007
0.6	2228.2	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.498 ± 0.062 kJ/mol	Dewey 1938, note CO2, Rossini 1938, note CO2c
0.6	2228.3	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(303.15 K) = -393.447 ± 0.064 kJ/mol	Jessup 1938, note CO2a, Rossini 1938, note CO2c
0.5	2285.3	CO (g) + H2O (g) → CO2 (g) + H2 (g)	Δ_rG°(893 K) = -6.369 ± 0.283 kJ/mol	Meyer 1938, note COi, 3rd Law
0.5	1542.4	NNO (g) + CO (g) → CO2 (g) + N2 (g)	Δ_rH°(293.15 K) = -365.642 ± 0.243 kJ/mol	Fenning 1933, note N2Oa
0.4	2262.1	CO (g) → C (g) + O (g)	Δ_rH°(0 K) = 89597.3 ± 12.0 (×1.384) cm-1	Kepa 2014, note unc2

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CO (g, triplet)

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	Carbon monoxide	CO (g, singlet)	-113.794	-110.514	± 0.026	kJ/mol	28.01010 ± 0.00085	630-08-0*2
100.0	Carbon monoxide	CO (g)	-113.794	-110.514	± 0.026	kJ/mol	28.01010 ± 0.00085	630-08-0*0
99.0	Carbon monoxide cation	[CO]+ (g)	1238.315	1241.595	± 0.026	kJ/mol	28.00955 ± 0.00085	12144-04-6*0
36.1	Carbon dioxide	CO2 (g)	-393.111	-393.478	± 0.015	kJ/mol	44.00950 ± 0.00100	124-38-9*0
35.7	Carbon dioxide cation	[CO2]+ (g)	936.089	936.924	± 0.017	kJ/mol	44.00895 ± 0.00100	12181-61-2*0
32.2	Ketene	CH2CO (g, ortho singlet)	-45.22	-48.40	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*22
32.2	Ketene	CH2CO (g, para singlet)	-45.34	-48.40	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*21
32.2	Ketene	CH2CO (g)	-45.34	-48.40	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*0
32.2	Ketene	CH2CO (g, singlet)	-45.34	-48.40	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*2
32.1	Ketene cation	[CH2CO]+ (g)	882.23	879.06	± 0.11	kJ/mol	42.0361 ± 0.0016	64999-16-2*0

Most Influential reactions involving CO (g, triplet)

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
0.999	2288.1	CO (g, singlet) → CO (g, triplet)	Δ_rH°(0 K) = 48432.58653 ± 0.00006 cm-1	de Nijs 2011, Velichko 2012, note unc
0.028	3075.5	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -59.63 ± 1.50 kcal/mol	Ruscic W1RO
0.024	3075.2	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -57.98 ± 1.60 kcal/mol	Ruscic G4
0.024	3075.4	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -58.88 ± 1.60 kcal/mol	Ruscic CBS-n
0.021	3075.1	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -57.27 ± 1.72 kcal/mol	Ruscic G3X
0.017	3088.1	H2OC (g, triplet) → CO (g, triplet) + H2 (g)	Δ_rH°(0 K) = 7.7 ± 2.0 (×1.114) kcal/mol	Schreiner 2006, est unc
0.015	3075.6	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -58.70 ± 2.0 kcal/mol	Schreiner 2006, est unc
0.013	3075.3	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -57.74 ± 2.16 kcal/mol	Ruscic CBS-n
0.000	2288.2	CO (g, singlet) → CO (g, triplet)	Δ_rH°(0 K) = 48432.65 ± 0.1 cm-1	Field 1972, Field 1971, est unc
0.000	2288.5	CO (g, singlet) → CO (g, triplet)	Δ_rH°(0 K) = 48518 ± 420 cm-1	Ruscic W1RO
0.000	2288.3	CO (g, singlet) → CO (g, triplet)	Δ_rH°(0 K) = 48484 ± 450 cm-1	Ruscic G4
0.000	2288.4	CO (g, singlet) → CO (g, triplet)	Δ_rH°(0 K) = 48485 ± 455 cm-1	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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument, Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
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.