Selected ATcT [1, 2] enthalpy of formation based on version 1.124 of the Thermochemical Network [3]

This version of ATcT results was generated by additional expansion of version 1.122x [4] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm^-1 [6], as well as the study of the reversible reaction C₂H₃ + H₂ ⇌ C₂H₄ + H ⇌ C₂H₅ [7]

Formic acid cation

Formula: [HC(O)OH]+ (g)

CAS RN: 50614-05-6

ATcT ID: 50614-05-6*0

SMILES: [CH+](=O)O

InChI: InChI=1S/CH2O2/c2-1-3/h1H,(H,2,3)/q+1

InChIKey: XSJNNNMNFREUJX-UHFFFAOYSA-N

Hills Formula: C1H2O2+

2D Image:

Aliases: [HC(O)OH]+; Formic acid cation; Formic acid ion (1+); HC(O)OH+; [HCOOH]+; HCOOH+

Relative Molecular Mass: 46.0248 ± 0.0010

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
721.93	715.40	± 0.25	kJ/mol

3D Image of [HC(O)OH]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [HC(O)OH]+ (g)

The 20 contributors listed below account only for 73.9% of the provenance of Δ_fH° of [HC(O)OH]+ (g).
A total of 161 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
13.5	4293.2	HC(O)OH (g, syn) → [HC(O)OH]+ (g, syn)	Δ_rH°(0 K) = 11.329 ± 0.002 eV	Bell 1975
12.4	4316.2	HC(O)OH (cr,l) + 1/2 O2 (g) → CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -60.807 ± 0.074 kcal/mol	Lebedeva 1964
8.7	4293.1	HC(O)OH (g, syn) → [HC(O)OH]+ (g, syn)	Δ_rH°(0 K) = 91370 ± 20 cm-1	Price 1937, est unc
8.5	4316.1	HC(O)OH (cr,l) + 1/2 O2 (g) → CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -60.851 ± 0.089 kcal/mol	Sinke 1959
8.2	4317.1	HC(O)OH (cr,l) → HC(O)OH (g)	Δ_rH°(298.15 K) = 46.30 ± 0.23 kJ/mol	Majer 1985
4.7	4293.8	HC(O)OH (g, syn) → [HC(O)OH]+ (g, syn)	Δ_rH°(0 K) = 11.3246 ± 0.0020 (×1.682) eV	Leach 2003, Schwell 2001
2.9	2974.2	HC(O)OH (g, syn) → [HCO]+ (g) + OH (g)	Δ_rH°(0 K) = 12.81 ± 0.01 eV	Traeger 1985, AE corr
2.7	4315.2	HC(O)OH (g) → [HCO]+ (g) + OH (g)	Δ_rH°(0 K) = 1235.7 ± 1.0 kJ/mol	Shuman 2010a, Bomble 2006
2.7	4317.2	HC(O)OH (cr,l) → HC(O)OH (g)	Δ_rH°(298.15 K) = 46.15 ± 0.40 kJ/mol	NBS Tables 1989
1.9	4291.3	HC(O)OH (g, syn) → C (g) + 2 H (g) + 2 O (g)	Δ_rH°(0 K) = 479.81 ± 0.30 kcal/mol	Karton 2011
1.7	4317.3	HC(O)OH (cr,l) → HC(O)OH (g)	Δ_rH°(298.15 K) = 46.3 ± 0.5 kJ/mol	Konicek 1970
1.0	4290.10	HC(O)OH (g, syn) → C (g) + 2 H (g) + 2 O (g)	Δ_rH°(0 K) = 480.1 ± 0.4 kcal/mol	Feller 2003c
0.7	4428.14	HC(O)OH (g, syn) → [HOCO]+ (g) + H (g)	Δ_rH°(0 K) = 1187.3 ± 1.0 kJ/mol	Shuman 2010a
0.7	4371.11	CH2(OO) (g) → HC(O)OH (g, syn)	Δ_rH°(0 K) = -90.89 ± 0.25 kcal/mol	Karton 2011
0.7	4305.1	CH4 (g) + 2 H2O (g) → HC(O)OH (g, syn) + 3 H2 (g)	Δ_rH°(0 K) = 173.33 ± 2.00 kJ/mol	Klippenstein 2017
0.5	4291.2	HC(O)OH (g, syn) → C (g) + 2 H (g) + 2 O (g)	Δ_rH°(0 K) = 479.82 ± 0.56 kcal/mol	Karton 2011
0.4	4428.2	HC(O)OH (g, syn) → [HOCO]+ (g) + H (g)	Δ_rH°(0 K) = 12.316 ± 0.013 eV	Ruscic 1989
0.4	4363.11	CH2(OO) (g) → C (g) + 2 H (g) + 2 O (g)	Δ_rH°(0 K) = 388.92 ± 0.30 kcal/mol	Karton 2011
0.3	2974.1	HC(O)OH (g, syn) → [HCO]+ (g) + OH (g)	Δ_rH°(0 K) = 12.84 ± 0.03 eV	Matthews 1969, AE corr
0.2	4371.10	CH2(OO) (g) → HC(O)OH (g, syn)	Δ_rH°(0 K) = -91.10 ± 0.40 kcal/mol	Karton 2011

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [HC(O)OH]+ (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	Formic acid cation	[HC(O)OH]+ (g, syn)	721.93	714.84	± 0.25	kJ/mol	46.0248 ± 0.0010	50614-05-6*1
84.4	Formic acid	HC(O)OH (g, syn)	-371.05	-378.37	± 0.22	kJ/mol	46.0254 ± 0.0010	64-18-6*1
84.4	Formic acid	HC(O)OH (g)	-371.05	-378.34	± 0.22	kJ/mol	46.0254 ± 0.0010	64-18-6*0
56.6	Formic acid	HC(O)OH (cr,l)	-431.51	-424.67	± 0.20	kJ/mol	46.0254 ± 0.0010	64-18-6*500
45.6	Formic acid	HC(O)OH (g, anti)	-354.72	-361.82	± 0.38	kJ/mol	46.0254 ± 0.0010	64-18-6*2
25.0	Formate	[HC(O)O]- (aq)		-425.48	± 0.45	kJ/mol	45.0180 ± 0.0010	71-47-6*800
25.0	Formic acid	HC(O)OH (aq)		-425.48	± 0.45	kJ/mol	46.0254 ± 0.0010	64-18-6*800
25.0	Formic acid	HC(O)OH (aq, undissoc)		-425.38	± 0.45	kJ/mol	46.0254 ± 0.0010	64-18-6*1000
22.6	Carbonic acid	C(O)(OH)2 (g, cis-cis)	-602.53	-612.70	± 0.75	kJ/mol	62.0248 ± 0.0012	463-79-6*1
22.6	Carbonic acid	C(O)(OH)2 (g)	-602.53	-611.84	± 0.75	kJ/mol	62.0248 ± 0.0012	463-79-6*0

Most Influential reactions involving [HC(O)OH]+ (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	4307.1	[HC(O)OH]+ (g) → [HC(O)OH]+ (g, syn)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, Ruscic G3B3

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. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923]
4		Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara, Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction. Atmos. Chem. Phys. 21, 13537-13551 (2021) [DOI: 10.5194/acp2021-228]
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		T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton, Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss. , (Advance Article) (2022) [DOI: 10.1039/D1FD00124H]
8		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]
9		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 [8,9]).
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.