Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Ethanium

Formula: [C2H7]+ (g, bridged C2)

CAS RN: 24669-33-8

ATcT ID: 24669-33-8*1

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
874.37	858.11	± 0.61	kJ/mol

3D Image of [C2H7]+ (g, bridged C2)

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Top contributors to the provenance of Δ_fH° of [C2H7]+ (g, bridged C2)

The 20 contributors listed below account only for 74.8% of the provenance of Δ_fH° of [C2H7]+ (g, bridged C2).
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
21.7	2485.3	[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	2483.2	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(405 K) = 1.65 ± 0.4 kcal/mol	Hiraoka 1976, 3rd Law
3.9	2485.2	[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	2486.2	[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	2484.2	[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	2480.5	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.04 ± 0.8 kcal/mol	Ruscic W1RO
3.0	2479.5	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.50 ± 0.8 kcal/mol	Ruscic W1RO
2.8	2483.1	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rH°(416 K) = 11.8 ± 0.4 (×2) kcal/mol	Hiraoka 1976, 2nd Law
2.6	2478.5	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 10.71 ± 0.8 kcal/mol	Ruscic W1RO
2.4	2477.7	[C2H7]+ (g, bridged C2) → CH3CH3 (g) + H+ (g)	Δ_rH°(0 K) = 139.99 ± 0.90 kcal/mol	Ruscic W1RO
1.9	2480.2	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.61 ± 1.0 kcal/mol	Ruscic G4
1.9	2480.4	[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	2479.4	[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	2479.2	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.55 ± 1.0 kcal/mol	Ruscic G4
1.7	2483.5	[C2H7]+ (g) → [CH3CH2]+ (g) + H2 (g)	Δ_rG°(375 K) = 2.5 ± 1 kcal/mol	Szulejko 1993, est unc
1.6	2478.2	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 11.24 ± 1.0 kcal/mol	Ruscic G4
1.6	2478.4	[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	2480.1	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.66 ± 1.2 kcal/mol	Ruscic G3X
1.3	2479.1	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.15 ± 1.2 kcal/mol	Ruscic G3X
1.1	2480.3	[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, bridged C2)

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)	874.37	858.13	± 0.61	kJ/mol	31.0764 ± 0.0017	24669-33-8*0
22.2	Ethanium	[C2H7]+ (g, classical Cs I)	888.7	870.3	± 1.8	kJ/mol	31.0764 ± 0.0017	24669-33-8*2
19.9	Ethanium	[C2H7]+ (g, classical Cs II)	895.1	877.3	± 1.9	kJ/mol	31.0764 ± 0.0017	24669-33-8*3
16.5	Ethylium	[CH3CH2]+ (g)	915.16	903.09	± 0.29	kJ/mol	29.0606 ± 0.0016	14936-94-8*0
16.4	Ethane	CH3CH3 (g)	-68.40	-84.03	± 0.12	kJ/mol	30.0690 ± 0.0017	74-84-0*0
12.2	Methanium	[CH5]+ (g)	921.99	911.75	± 0.44	kJ/mol	17.04985 ± 0.00087	15135-49-6*0
11.7	Ethylene	CH2CH2 (g)	60.89	52.38	± 0.11	kJ/mol	28.0532 ± 0.0016	74-85-1*0
11.7	Ethylene cation	[CH2CH2]+ (g)	1075.21	1067.99	± 0.11	kJ/mol	28.0526 ± 0.0016	34470-02-5*0
11.5	Propane	CH3CH2CH3 (g)	-82.73	-105.01	± 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, bridged C2)

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	2482.1	[C2H7]+ (g) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic W1RO, Ruscic G4, Ruscic G3B3, Carneiro 1994, East 1998
0.138	2475.6	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.38 ± 1.2 kcal/mol	Ruscic W1RO
0.118	2475.4	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.99 ± 1.3 kcal/mol	Ruscic G4
0.115	2474.7	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -2.92 ± 1.2 kcal/mol	Ruscic W1RO
0.102	2475.3	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.30 ± 1.4 kcal/mol	Ruscic G3X
0.098	2474.6	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.64 ± 1.3 kcal/mol	Ruscic CBS-n
0.098	2474.4	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.45 ± 1.3 kcal/mol	Ruscic G4
0.084	2474.3	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.82 ± 1.4 kcal/mol	Ruscic G3X
0.078	2475.5	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.11 ± 1.6 kcal/mol	Ruscic CBS-n
0.064	2474.5	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.82 ± 1.6 kcal/mol	Ruscic CBS-n
0.043	2478.5	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 10.71 ± 0.8 kcal/mol	Ruscic W1RO
0.041	2474.8	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.0 ± 2 kcal/mol	Carneiro 1994, est unc
0.033	2479.5	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.50 ± 0.8 kcal/mol	Ruscic W1RO
0.032	2480.5	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.04 ± 0.8 kcal/mol	Ruscic W1RO
0.027	2478.2	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 11.24 ± 1.0 kcal/mol	Ruscic G4
0.027	2478.4	[C2H7]+ (g, bridged C2) + CH4 (g) → [CH5]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 11.75 ± 1.0 kcal/mol	Ruscic CBS-n
0.025	2477.7	[C2H7]+ (g, bridged C2) → CH3CH3 (g) + H+ (g)	Δ_rH°(0 K) = 139.99 ± 0.90 kcal/mol	Ruscic W1RO
0.021	2479.2	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.55 ± 1.0 kcal/mol	Ruscic G4
0.021	2479.4	[C2H7]+ (g, bridged C2) + H2O (g) → [H3O]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = -23.42 ± 1.0 kcal/mol	Ruscic CBS-n
0.020	2480.2	[C2H7]+ (g, bridged C2) + H2 (g) → [H3]+ (g) + CH3CH3 (g)	Δ_rH°(0 K) = 40.61 ± 1.0 kcal/mol	Ruscic G4

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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
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.