Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Hydroxymethylium

Formula: [CH2OH]+ (g)

CAS RN: 18682-95-6

ATcT ID: 18682-95-6*0

SMILES: [CH2+]O

InChI: InChI=1S/CH3O/c1-2/h2H,1H2/q+1

InChIKey: NRCYHMDIJIIHBJ-UHFFFAOYSA-N

InChI: InChI=1S/CH2O/c1-2/h1H2/p+1

InChIKey: WSFSSNUMVMOOMR-UHFFFAOYSA-O

Hills Formula: C1H3O1+

2D Image:

Aliases: [CH2OH]+; Hydroxymethylium; Methylideneoxidanium; Hydroxymethyl cation; Hydroxymethyl ion (1+); Protonated formaldehyde; Formaldehyde, conjugate acid; CH2OH+; [H2COH]+; H2COH+; [OHCH2]+; OHCH2+; [HOCH2]+; HOCH2+

Relative Molecular Mass: 31.03337 ± 0.00088

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
717.80	709.86	± 0.17	kJ/mol

3D Image of [CH2OH]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [CH2OH]+ (g)

The 20 contributors listed below account only for 76.7% of the provenance of Δ_fH° of [CH2OH]+ (g).
A total of 156 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
26.1	2987.1	CH3OH (g) → [CH2OH]+ (g) + H (g)	Δ_rH°(0 K) = 11.6454 ± 0.0017 eV	Borkar 2011
15.2	2989.1	[CH2OH]+ (g) → CH2O (g) + H+ (g)	Δ_rH°(0 K) = 704.98 ± 0.39 kJ/mol	Czako 2009
13.7	2939.2	CH3OH (g) + 3/2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -182.72 ± 0.05 kcal/mol	Rossini 1932a, Domalski 1972, Weltner 1951, Rossini 1934a, note old units, mw conversion
8.3	2987.2	CH3OH (g) → [CH2OH]+ (g) + H (g)	Δ_rH°(0 K) = 11.649 ± 0.003 eV	Ruscic 1993
1.2	2941.1	CH3OH (g) → CH4 (g) + O (g, singlet)	Δ_rH°(0 K) = 133.94 ± 0.17 kcal/mol	Nguyen 2015a
1.1	2981.3	CH2OH (g) → [CH2OH]+ (g)	Δ_rH°(0 K) = 7.553 ± 0.006 (×1.542) eV	Ruscic 1991, Ruscic 1991a, Litorja 1998a
1.1	2940.1	CH3OH (g) → CH3 (g) + OH (g)	Δ_rH°(0 K) = 90.12 ± 0.17 kcal/mol	Nguyen 2015a
1.0	2943.1	CH3OH (g) → CH2 (g, triplet) + H2O (g)	Δ_rH°(0 K) = 81.77 ± 0.17 kcal/mol	Nguyen 2015a
1.0	2942.1	CH3OH (g) → CH2 (g, singlet) + H2O (g)	Δ_rH°(0 K) = 90.84 ± 0.17 kcal/mol	Nguyen 2015a
0.9	3013.1	CH3OH (g) → CH2O (g) + H2 (g)	Δ_rH°(0 K) = 20.28 ± 0.17 kcal/mol	Nguyen 2015a
0.9	4060.1	CH3OH (g) + [CH3CHOH]+ (g) → CH3CH2OH (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 0.848 ± 0.006 eV	Ruscic 1993, Ruscic 1994c
0.8	125.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
0.7	3059.6	CH3OH (g) → HCOH (g, trans) + H2 (g)	Δ_rH°(0 K) = 72.44 ± 0.17 kcal/mol	Nguyen 2015a
0.7	2359.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
0.6	2947.1	CH3OH (cr,l) + 3/2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(303.15 K) = -725.36 ± 0.13 (×7.179) kJ/mol	Chao 1965, mw conversion
0.6	3081.11	[HCO]+ (g) → H+ (g) + CO (g)	Δ_rH°(0 K) = 586.51 ± 0.2 kJ/mol	Czako 2008
0.6	2983.9	[CH2OH]+ (g) → C (g) + 3 H (g) + O (g)	Δ_rH°(0 K) = 212.63 ± 0.50 kcal/mol	Matus 2007
0.4	2652.8	CH3NH2 (g) + H2O (g) → CH3OH (g) + NH3 (g)	Δ_rH°(0 K) = 4.07 ± 0.25 kcal/mol	Karton 2011
0.4	2988.1	CH2OH (g) → CH2O (g) + H (g)	Δ_rH°(0 K) = 10160 ± 70 cm-1	Ryazanov 2012
0.4	2932.11	CH3OH (g) → 4 H (g) + C (g) + O (g)	Δ_rH°(0 K) = 480.94 ± 0.30 kcal/mol	Karton 2011

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [CH2OH]+ (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
66.3	Methanol	CH3OH (g)	-189.90	-200.79	± 0.13	kJ/mol	32.04186 ± 0.00090	67-56-1*0
64.6	Methanol	CH3OH (cr,l)	-235.15	-238.48	± 0.14	kJ/mol	32.04186 ± 0.00090	67-56-1*500
26.9	Methanol cation	[CH3OH]+ (g)	856.95	846.62	± 0.32	kJ/mol	32.04131 ± 0.00090	12538-91-9*0
26.6	Hydroxymethyl	CH2OH (g)	-10.07	-16.37	± 0.28	kJ/mol	31.03392 ± 0.00088	2597-43-5*0
24.8	Methoxy	CH3O (g)	29.01	21.64	± 0.26	kJ/mol	31.03392 ± 0.00088	2143-68-2*0
24.7	Methoxide	[CH3O]- (g)	-122.38	-130.11	± 0.26	kJ/mol	31.03447 ± 0.00088	3315-60-4*0
18.5	Formaldehyde	CH2O (g)	-105.381	-109.221	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*0
18.5	Formaldehyde	CH2O (g, singlet)	-105.381	-109.221	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*2
18.5	Formaldehyde	CH2O (g, para singlet)	-105.381	-109.221	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*21
18.5	Formaldehyde	CH2O (g, ortho singlet)	-105.255	-109.221	± 0.095	kJ/mol	30.02598 ± 0.00087	50-00-0*22

Most Influential reactions involving [CH2OH]+ (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
0.609	2987.1	CH3OH (g) → [CH2OH]+ (g) + H (g)	Δ_rH°(0 K) = 11.6454 ± 0.0017 eV	Borkar 2011
0.405	2746.1	HCN (g) + [CH2OH]+ (g) → [HCNH]+ (g) + CH2O (g)	Δ_rG°(300 K) = 0.5 ± 0.5 kcal/mol	Wolf 1977, est unc
0.330	4060.1	CH3OH (g) + [CH3CHOH]+ (g) → CH3CH2OH (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 0.848 ± 0.006 eV	Ruscic 1993, Ruscic 1994c
0.209	2989.1	[CH2OH]+ (g) → CH2O (g) + H+ (g)	Δ_rH°(0 K) = 704.98 ± 0.39 kJ/mol	Czako 2009
0.195	2987.2	CH3OH (g) → [CH2OH]+ (g) + H (g)	Δ_rH°(0 K) = 11.649 ± 0.003 eV	Ruscic 1993
0.172	4246.5	[CH2COH]+ (g, singlet) + CH2O (g) → CH2CO (g, singlet) + [CH2OH]+ (g)	Δ_rH°(0 K) = -15.35 ± 0.8 kcal/mol	Ruscic W1RO
0.110	4246.4	[CH2COH]+ (g, singlet) + CH2O (g) → CH2CO (g, singlet) + [CH2OH]+ (g)	Δ_rH°(0 K) = -15.75 ± 1.0 kcal/mol	Ruscic CBS-n
0.110	4246.2	[CH2COH]+ (g, singlet) + CH2O (g) → CH2CO (g, singlet) + [CH2OH]+ (g)	Δ_rH°(0 K) = -15.02 ± 1.0 kcal/mol	Ruscic G4
0.104	7334.5	[CH3C(OH)CH3]+ (g) + CH2O (g) → CH3C(O)CH3 (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 24.50 ± 0.8 kcal/mol	Ruscic W1RO
0.098	2981.3	CH2OH (g) → [CH2OH]+ (g)	Δ_rH°(0 K) = 7.553 ± 0.006 (×1.542) eV	Ruscic 1991, Ruscic 1991a, Litorja 1998a
0.076	4246.1	[CH2COH]+ (g, singlet) + CH2O (g) → CH2CO (g, singlet) + [CH2OH]+ (g)	Δ_rH°(0 K) = -15.14 ± 1.2 kcal/mol	Ruscic G3X
0.073	2997.9	[CH2OH]+ (g) → [CH3O]+ (g)	Δ_rH°(0 K) = 82.70 ± 0.50 kcal/mol	Matus 2007
0.067	7334.2	[CH3C(OH)CH3]+ (g) + CH2O (g) → CH3C(O)CH3 (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 24.40 ± 1.0 kcal/mol	Ruscic G4
0.067	7334.4	[CH3C(OH)CH3]+ (g) + CH2O (g) → CH3C(O)CH3 (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 24.32 ± 1.0 kcal/mol	Ruscic CBS-n
0.065	4246.3	[CH2COH]+ (g, singlet) + CH2O (g) → CH2CO (g, singlet) + [CH2OH]+ (g)	Δ_rH°(0 K) = -14.97 ± 1.3 kcal/mol	Ruscic CBS-n
0.046	7334.1	[CH3C(OH)CH3]+ (g) + CH2O (g) → CH3C(O)CH3 (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 24.50 ± 1.2 kcal/mol	Ruscic G3X
0.039	7334.3	[CH3C(OH)CH3]+ (g) + CH2O (g) → CH3C(O)CH3 (g) + [CH2OH]+ (g)	Δ_rH°(0 K) = 24.38 ± 1.3 kcal/mol	Ruscic CBS-n
0.031	2981.1	CH2OH (g) → [CH2OH]+ (g)	Δ_rH°(0 K) = 7.56 ± 0.01 (×1.646) eV	Dyke 1984, Baker 1995a
0.021	4916.1	CH3CH2CH2CH2OH (g) → [CH2OH]+ (g) + CH3CHCH3 (g)	Δ_rH°(0 K) = 11.10 ± 0.03 (×1.067) eV	Torma 2021
0.021	2981.2	CH2OH (g) → [CH2OH]+ (g)	Δ_rH°(0 K) = 7.56 ± 0.02 eV	Tao 1992

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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
6		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]
7		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] and Ruscic and Bross[7]).
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.