Selected ATcT [1, 2] enthalpy of formation based on version 1.130 of the Thermochemical Network [3]

This version of ATcT results[4] was generated by additional expansion of version 1.128 [5,6] to include with the calculations provided in reference [4].

Ketene

Formula: CH2CO (g)

CAS RN: 463-51-4

ATcT ID: 463-51-4*0

SMILES: C=C=O

InChI: InChI=1S/C2H2O/c1-2-3/h1H2

InChIKey: CCGKOQOJPYTBIH-UHFFFAOYSA-N

Hills Formula: C2H2O1

2D Image:

Aliases: CH2CO; Ketene; Ethenone; Carbomethene; H2CCO; H2C=C=O

Relative Molecular Mass: 42.0367 ± 0.0016

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-45.36	-48.42	± 0.11	kJ/mol

3D Image of CH2CO (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CH2CO (g)

The 20 contributors listed below account only for 52.7% of the provenance of Δ_fH° of CH2CO (g).
A total of 267 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
11.0	2327.1	CH2 (g, triplet) → CH2 (g, singlet)	Δ_rH°(0 K) = 3147 ± 5 cm-1	Jensen 1988, Jacox 1994
6.5	2315.9	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.80 ± 0.06 kcal/mol	Feller 2016, note unc2
5.2	2190.9	C (graphite) + CO2 (g) → 2 CO (g)	Δ_rG°(1165 K) = -33.545 ± 0.058 kJ/mol	Smith 1946, note COf, 3rd Law
4.6	2315.8	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.76 ± 0.07 (×1.022) kcal/mol	Feller 2014
4.1	2333.1	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 109.26 ± 0.08 kcal/mol	Feller 2016, est unc, note unc2
2.4	2279.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
1.8	2357.8	CH2 (g, triplet) → CH (g) + H (g)	Δ_rH°(0 K) = 417.85 ± 0.35 kJ/mol	Csaszar 2003
1.7	2358.5	CH2 (g, singlet) → CH (g) + H (g)	Δ_rH°(0 K) = 90.97 ± 0.12 kcal/mol	Feller 2014
1.7	2317.9	CH2 (g, singlet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 170.98 ± 0.11 (×1.384) kcal/mol	Feller 2014
1.4	2332.8	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 457.05 ± 0.56 kJ/mol	Harding 2008
1.3	2862.1	CH3OH (g) → CH2 (g, singlet) + H2O (g)	Δ_rH°(0 K) = 90.84 ± 0.17 kcal/mol	Nguyen 2015a
1.3	2330.1	CH3 (g) → [CH2]+ (g) + H (g)	Δ_rH°(0 K) = 15.120 ± 0.006 eV	Litorja 1998
1.3	2314.9	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 752.45 ± 0.56 kJ/mol	Harding 2008
1.2	2327.4	CH2 (g, triplet) → CH2 (g, singlet)	Δ_rH°(0 K) = 3156 ± 15 cm-1	Bunker 1986, note CH2
1.1	2332.4	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 109.22 ± 0.15 kcal/mol	Karton 2008
1.0	2134.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
1.0	2315.1	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 753.03 ± 0.62 kJ/mol	Csaszar 2003
1.0	2343.12	CH (g) → C (g) + H (g)	Δ_rH°(0 K) = 80.01 ± 0.04 kcal/mol	Feller 2014
1.0	2337.1	[CH2]- (g) → C- (g) + 2 H (g)	Δ_rH°(0 K) = 165.69 ± 0.12 kcal/mol	Feller 2016, note unc2
1.0	2314.5	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.86 ± 0.15 kcal/mol	Karton 2008

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH2CO (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	Ketene	CH2CO (g, singlet)	-45.36	-48.42	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*2
100.0	Ketene	CH2CO (g, para singlet)	-45.36	-48.42	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*21
100.0	Ketene	CH2CO (g, ortho singlet)	-45.24	-48.42	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*22
99.7	Ketene cation	[CH2CO]+ (g)	882.21	879.04	± 0.11	kJ/mol	42.0361 ± 0.0016	64999-16-2*0
97.1	Methylene	CH2 (g, singlet)	428.71	429.12	± 0.11	kJ/mol	14.02658 ± 0.00081	2465-56-7*2
84.8	Methylene	CH2 (g)	391.050	391.596	± 0.095	kJ/mol	14.02658 ± 0.00081	2465-56-7*0
84.8	Methylene	CH2 (g, triplet)	391.050	391.596	± 0.095	kJ/mol	14.02658 ± 0.00081	2465-56-7*1
79.4	Methyliumyl	[CH2]+ (g)	1393.18	1394.04	± 0.11	kJ/mol	14.02603 ± 0.00081	15091-72-2*0
38.5	Carbon	C (g)	711.396	716.881	± 0.041	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
38.5	Carbon	C (g, triplet)	711.396	716.881	± 0.041	kJ/mol	12.01070 ± 0.00080	7440-44-0*1

Most Influential reactions involving CH2CO (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	4148.1	CH2CO (g, para singlet) → CH2CO (g)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv
1.000	4147.1	CH2CO (g) → CH2CO (g, singlet)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, Ruscic G3B3
0.890	4140.1	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 77538.7 ± 0.7 cm-1	Willitsch 2002a
0.246	6493.9	OCCCO (g) + 2 CH2CH2 (g) → 2 CH2CO (g) + CH2CCH2 (g)	Δ_rH°(0 K) = 78.36 ± 2.00 kJ/mol	Klippenstein 2017
0.232	4259.13	HCCOH (g, singlet) → CH2CO (g)	Δ_rH°(0 K) = -140.21 ± 1.5 kJ/mol	Klippenstein 2017
0.200	4142.8	[CH2CO]- (g) → CH2CO (g)	Δ_rH°(0 K) = -0.320 ± 0.050 eV	Ruscic W1RO
0.134	4142.3	[CH2CO]- (g) → CH2CO (g)	Δ_rH°(0 K) = -0.278 ± 0.061 eV	Ruscic G4
0.128	7167.5	CH3C(CO)CH3 (g) + CH2CO (g) → 2 CH3CHCO (g)	Δ_rH°(0 K) = 2.41 ± 0.85 kcal/mol	Ruscic W1RO
0.120	7951.5	OCC(CHCHCHCH) (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CHCHCHCH) (g)	Δ_rH°(0 K) = 1.51 ± 0.85 kcal/mol	Ruscic W1RO
0.114	7167.4	CH3C(CO)CH3 (g) + CH2CO (g) → 2 CH3CHCO (g)	Δ_rH°(0 K) = 2.41 ± 0.90 kcal/mol	Ruscic CBS-n
0.114	7167.2	CH3C(CO)CH3 (g) + CH2CO (g) → 2 CH3CHCO (g)	Δ_rH°(0 K) = 2.63 ± 0.90 kcal/mol	Ruscic G4
0.114	7167.1	CH3C(CO)CH3 (g) + CH2CO (g) → 2 CH3CHCO (g)	Δ_rH°(0 K) = 2.60 ± 0.90 kcal/mol	Ruscic G3X
0.109	4140.2	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 77539.4 ± 2.0 cm-1	Wang 2002a
0.107	7951.2	OCC(CHCHCHCH) (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CHCHCHCH) (g)	Δ_rH°(0 K) = 1.94 ± 0.90 kcal/mol	Ruscic G4
0.107	7951.1	OCC(CHCHCHCH) (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CHCHCHCH) (g)	Δ_rH°(0 K) = 2.15 ± 0.90 kcal/mol	Ruscic G3X
0.107	7951.4	OCC(CHCHCHCH) (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CHCHCHCH) (g)	Δ_rH°(0 K) = 2.44 ± 0.90 kcal/mol	Ruscic CBS-n
0.095	7169.5	CH3C(CO)CH3 (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CH3)2 (g)	Δ_rH°(0 K) = -7.17 ± 0.85 kcal/mol	Ruscic W1RO
0.092	7167.3	CH3C(CO)CH3 (g) + CH2CO (g) → 2 CH3CHCO (g)	Δ_rH°(0 K) = 2.52 ± 1.00 kcal/mol	Ruscic CBS-n
0.090	7359.5	OC(CHCH) (g) + CH2CH2 (g) → CH2(CHCH) (g) + CH2CO (g)	Δ_rH°(0 K) = 5.38 ± 0.85 kcal/mol	Ruscic W1RO
0.087	7951.3	OCC(CHCHCHCH) (g) + CH2CH2 (g) → CH2CO (g) + CH2C(CHCHCHCH) (g)	Δ_rH°(0 K) = 2.30 ± 1.00 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. 1.130 of the Thermochemical Network. Argonne National Laboratory, Lemont, Illinois 2023; available at ATcT.anl.gov [DOI: 10.17038/CSE/1997229]
4		N. Genossar, P. B. Changala, B. Gans, J.-C. Loison, S. Hartweg, M.-A. Martin-Drumel, G. A. Garcia, J. F. Stanton, B. Ruscic, and J. H. Baraban Ring-Opening Dynamics of the Cyclopropyl Radical and Cation: the Transition State Nature of the Cyclopropyl Cation J. Am. Chem. Soc. 144, 18518-18525 (2022) [DOI: 10.1021/jacs.2c07740]
5		B. Ruscic and D. H. Bross Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects. Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6		J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton, Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7		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]
8		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]).
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.