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].

Hydroxymethylene cation

Formula: [HCOH]+ (g)

CAS RN: 135395-06-1

ATcT ID: 135395-06-1*0

SMILES: [CH+]O

InChI: InChI=1S/CH2O/c1-2/h1-2H/q+1

InChIKey: MUGROOOPPWVLAI-UHFFFAOYSA-N

Hills Formula: C1H2O1+

2D Image:

Aliases: Hydroxymethylene cation; Hydroxymethylene ion (1+); Hydroxycarbene cation; Hydroxycarbene ion (1+); HCOH+; [CHOH]+; CHOH+; [HOCH]+; HOCH+; //difference not clear!; 86549-47-5; [HCOH]+; Hydroxymethyliumyl; Hydroxymethyliumyl ion; Hydroxymethyliumyl cation; Hydroxymethyliumyl ion (1+)

Relative Molecular Mass: 30.02543 ± 0.00087

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
971.9	968.3	± 1.4	kJ/mol

3D Image of [HCOH]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [HCOH]+ (g)

The 20 contributors listed below account only for 75.9% of the provenance of Δ_fH° of [HCOH]+ (g).
A total of 30 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
11.9	2947.8	HCOH (g, trans) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 8.903 ± 0.040 eV	Ruscic W1RO
10.4	2953.9	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 99.78 ± 1 kcal/mol	Matus 2006
4.6	2953.8	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 100.36 ± 1.50 kcal/mol	Ruscic W1RO
4.6	2981.3	[CH2O]+ (g) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 6.3 ± 1.5 kcal/mol	Sears 2008, est unc
4.5	2948.8	HCOH (g, cis) → [HCOH]+ (g, cis)	Δ_rH°(0 K) = 8.861 ± 0.040 eV	Ruscic W1RO
4.0	2953.7	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 100.28 ± 1.60 kcal/mol	Ruscic CBS-n
4.0	2953.4	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 100.25 ± 1.60 kcal/mol	Ruscic G4
3.5	2947.4	HCOH (g, trans) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 8.913 ± 0.073 eV	Ruscic G4
3.5	2953.3	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 99.98 ± 1.72 kcal/mol	Ruscic G3X
3.3	2947.7	HCOH (g, trans) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 8.888 ± 0.075 eV	Ruscic CBS-n
2.6	2981.4	[CH2O]+ (g) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 6.7 ± 2.0 kcal/mol	Sears 2008, est unc
2.2	2953.6	[HCOH]+ (g, trans) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 100.03 ± 2.16 kcal/mol	Ruscic CBS-n
2.2	2966.8	[HCOH]+ (g, trans) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 42645 ± 500 cm-1	Ruscic W1RO
2.2	2947.3	HCOH (g, trans) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 8.928 ± 0.093 eV	Ruscic G3X
2.0	2965.8	[HCOH]+ (g, trans) → [HCOH]+ (g, cis)	Δ_rH°(0 K) = 1194 ± 300 cm-1	Ruscic W1RO
2.0	2966.7	[HCOH]+ (g, trans) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 42802 ± 525 cm-1	Ruscic CBS-n
2.0	2966.4	[HCOH]+ (g, trans) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 42511 ± 525 cm-1	Ruscic G4
1.9	2947.6	HCOH (g, trans) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 8.920 ± 0.099 eV	Ruscic CBS-n
1.9	2965.7	[HCOH]+ (g, trans) → [HCOH]+ (g, cis)	Δ_rH°(0 K) = 1296 ± 310 cm-1	Ruscic CBS-n
1.9	2965.4	[HCOH]+ (g, trans) → [HCOH]+ (g, cis)	Δ_rH°(0 K) = 1178 ± 310 cm-1	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [HCOH]+ (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	Hydroxymethylene cation	[HCOH]+ (g, trans)	971.9	968.2	± 1.4	kJ/mol	30.02543 ± 0.00087	135395-06-1*1
54.7	Hydroxymethylene cation	[HCOH]+ (g, cis)	986.4	982.8	± 1.6	kJ/mol	30.02543 ± 0.00087	135395-06-1*2
25.5	Hydroxymethylene cation	[HCOH]+ (g, gauche quartet)	1482.1	1479.4	± 1.9	kJ/mol	30.02543 ± 0.00087	135395-06-1*3
7.5	Hydroxymethylene	HCOH (g, trans)	112.68	108.91	± 0.27	kJ/mol	30.02598 ± 0.00087	19710-56-6*1
7.5	Hydroxymethylene	HCOH (g)	112.68	108.92	± 0.27	kJ/mol	30.02598 ± 0.00087	19710-56-6*0
6.9	Hydroxymethylene	HCOH (g, cis)	131.10	127.35	± 0.29	kJ/mol	30.02598 ± 0.00087	19710-56-6*2
6.5	Hydroxymethylene	HCOH (g, gauche triplet)	219.3	216.4	± 1.1	kJ/mol	30.02598 ± 0.00087	19710-56-6*3
2.8	Formaldehyde	CH2O (g)	-105.392	-109.232	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*0
2.8	Formaldehyde	CH2O (g, singlet)	-105.392	-109.232	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*2
2.8	Formaldehyde	CH2O (g, para singlet)	-105.392	-109.232	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*21

Most Influential reactions involving [HCOH]+ (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	2964.1	[HCOH]+ (g) → [HCOH]+ (g, trans)	Δ_rH°(0 K) = 0 ± 0 cm-1	triv, Ruscic G3B3, Yu 2004

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.