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].

Ethanium

Formula: [C2H7]+ (g)

CAS RN: 24669-33-8

ATcT ID: 24669-33-8*0

SMILES: C[H+]C

InChI: InChI=1S/C2H7/c1-3-2/h1-2H3/q+1

InChIKey: UQJIDEGGAKZKSY-UHFFFAOYSA-N

SMILES: C[CH4+]

InChI: InChI=1S/C2H7/c1-2/h1H3,2H4/q+1

InChIKey: NICMOOFHGOXOMH-UHFFFAOYSA-N

SMILES: [CH3].[CH3].[H+]

InChI: InChI=1S/2CH3/h2*1H3/p+1

InChIKey: VTAZUWUUXWLYBW-UHFFFAOYSA-O

SMILES: CC.[H+]

InChI: InChI=1S/C2H6/c1-2/h1-2H3/p+1

InChIKey: OTMSDBZUPAUEDD-UHFFFAOYSA-O

SMILES: C[CH2+].[H][H]

InChI: InChI=1S/C2H5.H2/c1-2;/h1H2,2H3;1H/q+1;

InChIKey: OHNVDYOFVILXCI-UHFFFAOYSA-N

Hills Formula: C2H7+

2D Image:

Aliases: [C2H7]+; Ethanium; Ethanium ion; Ethanium cation; Ethanium ion (1+); Protonated ethane; Protonated ethane cation; Protonated ethane ion (1+); Monoprotonated ethane; Monoprotonated ethane cation; Monoprotonated ethane ion (1+); Dicarbon heptahydride cation; Dicarbon heptahydride ion (1+); 12540-55-5; 37275-28-8

Relative Molecular Mass: 31.0764 ± 0.0017

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
874.39	858.15	± 0.61	kJ/mol

3D Image of [C2H7]+ (g)

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Top contributors to the provenance of Δ_fH° of [C2H7]+ (g)

The 20 contributors listed below account only for 74.8% of the provenance of Δ_fH° of [C2H7]+ (g).
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
21.6	2468.3	[C2H7]+ (g) + CO (g) → [HCO]+ (g) + CH3CH3 (g)	Δ_rG°(298.15 K) = 1.43 ± 0.3 kcal/mol	Mackay 1981, 3rd Law, note unc5
11.2	2466.2	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(405 K) = 1.65 ± 0.4 kcal/mol	Hiraoka 1976, 3rd Law
3.9	2468.2	[C2H7]+ (g) + CO (g) → [HCO]+ (g) + CH3CH3 (g)	Δ_rG°(337 K) = 1.7 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
3.5	2469.2	[C2H7]+ (g) + CH2CH2 (g) → [CH3CH2]+ (g) + CH3CH3 (g)	Δ_rG°(373 K) = -19.5 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
3.3	2467.2	[C2H7]+ (g) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rG°(334 K) = 10.5 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
3.1	2463.5	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.04 ± 0.8 kcal/mol	Ruscic W1RO
3.0	2462.5	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.50 ± 0.8 kcal/mol	Ruscic W1RO
2.8	2466.1	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rH°(416 K) = 11.8 ± 0.4 (×2) kcal/mol	Hiraoka 1976, 2nd Law
2.6	2461.5	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 10.71 ± 0.8 kcal/mol	Ruscic W1RO
2.4	2460.7	[C2H7]+ (g, bridged C2) → CH3CH3 (g) + H+ (g)	Δ_rH°(0 K) = 139.99 ± 0.90 kcal/mol	Ruscic W1RO
1.9	2463.2	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.61 ± 1.0 kcal/mol	Ruscic G4
1.9	2463.4	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.36 ± 1.0 kcal/mol	Ruscic CBS-n
1.9	2462.4	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.42 ± 1.0 kcal/mol	Ruscic CBS-n
1.9	2462.2	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.55 ± 1.0 kcal/mol	Ruscic G4
1.7	2466.5	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(375 K) = 2.5 ± 1 kcal/mol	Szulejko 1993, est unc
1.6	2461.2	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 11.24 ± 1.0 kcal/mol	Ruscic G4
1.6	2461.4	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 11.75 ± 1.0 kcal/mol	Ruscic CBS-n
1.3	2463.1	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.66 ± 1.2 kcal/mol	Ruscic G3X
1.3	2462.1	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.15 ± 1.2 kcal/mol	Ruscic G3X
1.1	2463.3	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.47 ± 1.3 kcal/mol	Ruscic CBS-n

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [C2H7]+ (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	Ethanium	[C2H7]+ (g, bridged C2)	874.39	858.13	± 0.61	kJ/mol	31.0764 ± 0.0017	24669-33-8*1
22.2	Ethanium	[C2H7]+ (g, classical Cs I)	888.8	870.3	± 1.8	kJ/mol	31.0764 ± 0.0017	24669-33-8*2
19.9	Ethanium	[C2H7]+ (g, classical Cs II)	895.2	877.3	± 1.9	kJ/mol	31.0764 ± 0.0017	24669-33-8*3
16.6	Ethylium	[CH3CH2]+ (g)	915.18	903.10	± 0.29	kJ/mol	29.0606 ± 0.0016	14936-94-8*0
16.5	Ethane	CH3CH3 (g)	-68.38	-84.01	± 0.12	kJ/mol	30.0690 ± 0.0017	74-84-0*0
12.3	Methanium	[CH5]+ (g)	922.00	911.76	± 0.44	kJ/mol	17.04985 ± 0.00087	15135-49-6*0
11.9	Ethylene	CH2CH2 (g)	60.91	52.40	± 0.11	kJ/mol	28.0532 ± 0.0016	74-85-1*0
11.9	Ethylene cation	[CH2CH2]+ (g)	1075.22	1068.01	± 0.11	kJ/mol	28.0526 ± 0.0016	34470-02-5*0
11.7	Propane	CH3CH2CH3 (g)	-82.71	-104.99	± 0.15	kJ/mol	44.0956 ± 0.0025	74-98-6*0
11.4	Hydroxyoxomethylium	[HOCO]+ (g)	600.69	597.60	± 0.43	kJ/mol	45.0169 ± 0.0010	638-71-1*0

Most Influential reactions involving [C2H7]+ (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	2465.1	[C2H7]+ (g) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic W1RO, Ruscic G4, Ruscic G3B3, Carneiro 1994, East 1998
0.230	2468.3	[C2H7]+ (g) + CO (g) → [HCO]+ (g) + CH3CH3 (g)	Δ_rG°(298.15 K) = 1.43 ± 0.3 kcal/mol	Mackay 1981, 3rd Law, note unc5
0.141	2466.2	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(405 K) = 1.65 ± 0.4 kcal/mol	Hiraoka 1976, 3rd Law
0.057	2467.2	[C2H7]+ (g) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rG°(334 K) = 10.5 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
0.046	2469.2	[C2H7]+ (g) + CH2CH2 (g) → [CH3CH2]+ (g) + CH3CH3 (g)	Δ_rG°(373 K) = -19.5 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
0.042	2468.2	[C2H7]+ (g) + CO (g) → [HCO]+ (g) + CH3CH3 (g)	Δ_rG°(337 K) = 1.7 ± 0.7 kcal/mol	Szulejko 1993, 3rd Law, note unc5
0.035	2466.1	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rH°(416 K) = 11.8 ± 0.4 (×2) kcal/mol	Hiraoka 1976, 2nd Law
0.022	2466.5	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(375 K) = 2.5 ± 1 kcal/mol	Szulejko 1993, est unc
0.014	2467.1	[C2H7]+ (g) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(334 K) = 11.9 ± 0.7 (×1.957) kcal/mol	Szulejko 1993, 2nd Law, note unc5
0.007	2467.3	[C2H7]+ (g) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(298.15 K) = 10 ± 2 kcal/mol	French 1975, est unc
0.005	2466.4	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rH°(375 K) = 12.8 ± 2 kcal/mol	Szulejko 1993, est unc
0.005	2466.3	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rH°(303 K) = 10.5 ± 2 kcal/mol	French 1975
0.005	2468.1	[C2H7]+ (g) + CO (g) → [HCO]+ (g) + CH3CH3 (g)	Δ_rH°(337 K) = 0.8 ± 0.7 (×2.828) kcal/mol	Szulejko 1993, 2nd Law, note unc5
0.004	2469.1	[C2H7]+ (g) + CH2CH2 (g) → [CH3CH2]+ (g) + CH3CH3 (g)	Δ_rH°(373 K) = -19.9 ± 0.7 (×3.084) kcal/mol	Szulejko 1993, 2nd Law, note unc5

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.