Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Hydroxymethylene

Formula: HCOH (g, gauche triplet)

CAS RN: 19710-56-6

ATcT ID: 19710-56-6*3

SMILES: [CH]O

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

InChIKey: UUOIGPDTLYBNGY-UHFFFAOYSA-N

Hills Formula: C1H2O1

2D Image:

Aliases: HCOH; Hydroxymethylene; Hydroxymethylidene; Hydroxycarbene; CHOH; HOCH

Relative Molecular Mass: 30.02598 ± 0.00087

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
219.3	216.4	± 1.1	kJ/mol

3D Image of HCOH (g, gauche triplet)

spin ON spin OFF

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

The 20 contributors listed below account only for 61.7% of the provenance of Δ_fH° of HCOH (g, gauche triplet).
A total of 44 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
6.2	2957.9	HCOH (g, gauche triplet) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 279.95 ± 1 kcal/mol	Matus 2006
6.0	2974.11	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 24.8 ± 1.0 kcal/mol	Hwang 1999, est unc
4.2	2974.8	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8811 ± 420 cm-1	Ruscic W1RO
3.6	2974.4	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8970 ± 450 cm-1	Ruscic G4
3.5	2974.7	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8735 ± 455 cm-1	Ruscic CBS-n
3.0	2974.3	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8900 ± 490 cm-1	Ruscic G3X
2.8	2989.5	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -59.63 ± 1.50 kcal/mol	Ruscic W1RO
2.7	2957.8	HCOH (g, gauche triplet) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 280.46 ± 1.50 kcal/mol	Ruscic W1RO
2.7	2988.8	CH2O (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 77.37 ± 1.50 kcal/mol	Parthiban 2001
2.6	2960.8	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.097 ± 0.040 eV	Ruscic W1RO
2.5	3003.5	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.61 ± 1.2 kcal/mol	Ruscic W1RO
2.4	2989.4	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -58.88 ± 1.60 kcal/mol	Ruscic CBS-n
2.4	2989.2	CO (g, triplet) + H2 (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -57.98 ± 1.60 kcal/mol	Ruscic G4
2.4	2957.4	HCOH (g, gauche triplet) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 280.14 ± 1.60 kcal/mol	Ruscic G4
2.4	2957.7	HCOH (g, gauche triplet) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 280.26 ± 1.60 kcal/mol	Ruscic CBS-n
2.4	2988.4	CH2O (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 77.97 ± 1.60 kcal/mol	Ruscic G4
2.4	2988.7	CH2O (g) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 77.60 ± 1.60 kcal/mol	Ruscic CBS-n
2.3	2974.6	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 9065 ± 560 cm-1	Ruscic CBS-n
2.1	3003.4	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.71 ± 1.3 kcal/mol	Ruscic CBS-n
2.1	3003.2	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.60 ± 1.3 kcal/mol	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of HCOH (g, gauche 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
23.5	Hydroxymethylene cation	[HCOH]+ (g, gauche quartet)	1482.1	1479.4	± 1.9	kJ/mol	30.02543 ± 0.00087	135395-06-1*3
20.7	Aquacarbon	H2OC (g, triplet)	442.7	441.1	± 1.3	kJ/mol	30.02598 ± 0.00087	81434-73-3*1
20.7	Hydroxymethylene anion	[HCOH]- (g, gauche quartet)	334.0	334.8	± 2.1	kJ/mol	30.02653 ± 0.00087	207914-87-2*3
7.8	Hydroxymethylene	HCOH (g, trans)	112.71	108.94	± 0.27	kJ/mol	30.02598 ± 0.00087	19710-56-6*1
7.8	Hydroxymethylene	HCOH (g)	112.71	108.95	± 0.27	kJ/mol	30.02598 ± 0.00087	19710-56-6*0
6.5	Hydroxymethylene cation	[HCOH]+ (g)	971.9	968.3	± 1.4	kJ/mol	30.02543 ± 0.00087	135395-06-1*0
6.5	Hydroxymethylene cation	[HCOH]+ (g, trans)	971.9	968.2	± 1.4	kJ/mol	30.02543 ± 0.00087	135395-06-1*1
5.9	Hydroxymethylene	HCOH (g, cis)	131.12	127.38	± 0.29	kJ/mol	30.02598 ± 0.00087	19710-56-6*2
5.8	Hydroxymethylene anion	[HCOH]- (g, trans)	147.2	144.1	± 1.6	kJ/mol	30.02653 ± 0.00087	207914-87-2*1
5.8	Hydroxymethylene anion	[HCOH]- (g)	147.2	144.2	± 1.6	kJ/mol	30.02653 ± 0.00087	207914-87-2*0

Most Influential reactions involving HCOH (g, gauche 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
0.235	2960.8	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.097 ± 0.040 eV	Ruscic W1RO
0.190	2963.6	[HCOH]- (g, gauche quartet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -1.185 ± 0.050 eV	Ruscic W1RO
0.128	2963.4	[HCOH]- (g, gauche quartet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -1.202 ± 0.061 eV	Ruscic G4
0.081	3003.5	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.61 ± 1.2 kcal/mol	Ruscic W1RO
0.070	2960.4	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.071 ± 0.073 eV	Ruscic G4
0.069	3003.4	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.71 ± 1.3 kcal/mol	Ruscic CBS-n
0.069	3003.2	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.60 ± 1.3 kcal/mol	Ruscic G4
0.066	2960.7	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.111 ± 0.075 eV	Ruscic CBS-n
0.066	2963.3	[HCOH]- (g, gauche quartet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -1.199 ± 0.085 eV	Ruscic G3X
0.064	2974.11	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 24.8 ± 1.0 kcal/mol	Hwang 1999, est unc
0.063	2957.9	HCOH (g, gauche triplet) → C (g) + O (g) + 2 H (g)	Δ_rH°(0 K) = 279.95 ± 1 kcal/mol	Matus 2006
0.060	3003.1	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -53.06 ± 1.4 kcal/mol	Ruscic G3X
0.056	2963.5	[HCOH]- (g, gauche quartet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -1.211 ± 0.092 eV	Ruscic CBS-n
0.046	3003.3	H2OC (g, triplet) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = -54.02 ± 1.6 kcal/mol	Ruscic CBS-n
0.044	2974.8	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8811 ± 420 cm-1	Ruscic W1RO
0.043	2960.3	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.067 ± 0.093 eV	Ruscic G3X
0.039	2974.4	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8970 ± 450 cm-1	Ruscic G4
0.038	2960.6	HCOH (g, gauche triplet) → [HCOH]+ (g, gauche quartet)	Δ_rH°(0 K) = 13.148 ± 0.099 eV	Ruscic CBS-n
0.038	2974.7	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8735 ± 455 cm-1	Ruscic CBS-n
0.032	2974.3	HCOH (g, trans) → HCOH (g, gauche triplet)	Δ_rH°(0 K) = 8900 ± 490 cm-1	Ruscic G3X

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. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
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.