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, classical Cs II)

CAS RN: 24669-33-8

ATcT ID: 24669-33-8*3

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
895.2	877.3	± 1.9	kJ/mol

3D Image of [C2H7]+ (g, classical Cs II)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [C2H7]+ (g, classical Cs II)

The 15 contributors listed below account for 90.2% of the provenance of Δ_fH° of [C2H7]+ (g, classical Cs II).

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
12.4	2458.6	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.38 ± 1.2 kcal/mol	Ruscic W1RO
10.6	2458.4	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.99 ± 1.3 kcal/mol	Ruscic G4
9.1	2458.3	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.30 ± 1.4 kcal/mol	Ruscic G3X
9.0	2456.6	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 489.00 ± 1.50 kcal/mol	Ruscic W1RO
7.9	2456.4	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.51 ± 1.60 kcal/mol	Ruscic G4
7.0	2458.5	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.11 ± 1.6 kcal/mol	Ruscic CBS-n
6.9	2456.3	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.47 ± 1.72 kcal/mol	Ruscic G3X
6.1	2459.6	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.45 ± 1.2 kcal/mol	Ruscic W1RO
5.2	2459.4	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.54 ± 1.3 kcal/mol	Ruscic G4
4.5	2459.3	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.48 ± 1.4 kcal/mol	Ruscic G3X
4.3	2456.5	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.54 ± 2.16 kcal/mol	Ruscic CBS-n
3.4	2459.5	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.30 ± 1.6 kcal/mol	Ruscic CBS-n
1.0	2457.7	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -2.92 ± 1.2 kcal/mol	Ruscic W1RO
1.0	2455.7	[C2H7]+ (g, classical Cs I) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 490.45 ± 1.50 kcal/mol	Ruscic W1RO
0.9	2457.4	[C2H7]+ (g, classical Cs I) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -3.45 ± 1.3 kcal/mol	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [C2H7]+ (g, classical Cs II)

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
37.4	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, bridged C2)	874.39	858.13	± 0.61	kJ/mol	31.0764 ± 0.0017	24669-33-8*1
19.9	Ethanium	[C2H7]+ (g)	874.39	858.15	± 0.61	kJ/mol	31.0764 ± 0.0017	24669-33-8*0
3.9	Ethane	CH3CH3 (g)	-68.38	-84.01	± 0.12	kJ/mol	30.0690 ± 0.0017	74-84-0*0
3.5	Ethylium	[CH3CH2]+ (g)	915.18	903.10	± 0.29	kJ/mol	29.0606 ± 0.0016	14936-94-8*0
3.2	Carbon	C (g, singlet)	833.331	838.477	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*2
3.2	Carbon cation	C+ (g)	1797.853	1803.451	± 0.040	kJ/mol	12.01015 ± 0.00080	14067-05-1*0
3.2	Carbon	C (g, triplet)	711.400	716.885	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*1
3.2	Carbon	C (g)	711.400	716.885	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
3.2	Carbon	C (g, quintuplet)	1114.963	1120.109	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*3

Most Influential reactions involving [C2H7]+ (g, classical Cs II)

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
0.164	2459.6	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.45 ± 1.2 kcal/mol	Ruscic W1RO
0.139	2459.4	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.54 ± 1.3 kcal/mol	Ruscic G4
0.138	2458.6	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.38 ± 1.2 kcal/mol	Ruscic W1RO
0.120	2459.3	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.48 ± 1.4 kcal/mol	Ruscic G3X
0.118	2458.4	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -4.99 ± 1.3 kcal/mol	Ruscic G4
0.102	2458.3	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.30 ± 1.4 kcal/mol	Ruscic G3X
0.092	2459.5	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, classical Cs I)	Δ_rH°(0 K) = -1.30 ± 1.6 kcal/mol	Ruscic CBS-n
0.091	2456.6	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 489.00 ± 1.50 kcal/mol	Ruscic W1RO
0.080	2456.4	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.51 ± 1.60 kcal/mol	Ruscic G4
0.078	2458.5	[C2H7]+ (g, classical Cs II) → [C2H7]+ (g, bridged C2)	Δ_rH°(0 K) = -5.11 ± 1.6 kcal/mol	Ruscic CBS-n
0.069	2456.3	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.47 ± 1.72 kcal/mol	Ruscic G3X
0.044	2456.5	[C2H7]+ (g, classical Cs II) → 2 C (g) + 7 H (g)	Δ_rH°(0 K) = 486.54 ± 2.16 kcal/mol	Ruscic CBS-n

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.