Selected ATcT [1, 2] enthalpy of formation based on version 1.130 of the Thermochemical Network [3]

This version of ATcT results[4] was generated by additional expansion of version 1.128 [5,6] to include with the calculations provided in reference [4].

Carbide

Formula: [C2]- (g)
CAS RN: 12595-78-7
ATcT ID: 12595-78-7*0
SMILES: [C]=[C-]
InChI: InChI=1S/C2/c1-2/q-1
InChIKey: XHWLRFQJZNQFGO-UHFFFAOYSA-N
Hills Formula: C2-

2D Image:

[C]=[C-]
Aliases: [C2]-; Carbide; Carbide ion; Carbide anion; Carbide ion (1-); Ethynylene anion; Ethynylene ion (1-); 1,2-Ethynediyl anion; 1,2-Ethynediyl ion (1-); 2-Ethynidyl; Carbon dimer anion; Carbon dimer ion (1-); Diatomic carbon anion; Diatomic carbon ion (1-); Dicarbon anion; Dicarbon ion (1-); Carbon molecule anion; Carbon molecule ion (1-); Carbon cluster anion; Carbon cluster ion (1-)
Relative Molecular Mass: 24.0219 ± 0.0016

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
504.40510.98± 0.31kJ/mol

3D Image of [C2]- (g)

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Top contributors to the provenance of ΔfH° of [C2]- (g)

The 4 contributors listed below account for 90.1% of the provenance of ΔfH° of [C2]- (g).

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
52.72199.1 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.272 ± 0.004 eVFeller 2016, note unc2
23.42198.2 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.269 ± 0.006 eVErvin 1991
13.12198.1 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.273 ± 0.008 eVArnold 1991
0.82210.1 C2 (g, triplet) → 2 C (g) ΔrH°(0 K) = 49786.7 ± 2.4 cm-1Borsovszky 2021, Schmidt 2020, Haris 2017

Top 10 species with enthalpies of formation correlated to the ΔfH° of [C2]- (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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
28.3 EthynyleneC2 (g)[C]=[C]819.991828.457± 0.087kJ/mol24.0214 ±
0.0016
12070-15-4*0
28.3 EthynyleneC2 (g, singlet)[C]=[C]819.991826.564± 0.087kJ/mol24.0214 ±
0.0016
12070-15-4*2
28.3 EthynyleneC2 (g, triplet)[C]=[C]827.214833.919± 0.087kJ/mol24.0214 ±
0.0016
12070-15-4*1
26.8 Carbon cationC+ (g)[C+]1797.8491803.447± 0.041kJ/mol12.01015 ±
0.00080
14067-05-1*0
26.8 CarbonC (g, quintuplet)[C]1114.9591120.105± 0.041kJ/mol12.01070 ±
0.00080
7440-44-0*3
26.8 CarbonC (g, singlet)[C]833.327838.474± 0.041kJ/mol12.01070 ±
0.00080
7440-44-0*2
26.8 CarbonC (g, triplet)[C]711.396716.881± 0.041kJ/mol12.01070 ±
0.00080
7440-44-0*1
26.8 CarbonC (g)[C]711.396716.881± 0.041kJ/mol12.01070 ±
0.00080
7440-44-0*0
26.8 Carbon dication[C]+2 (g)[C++]4150.4664155.612± 0.041kJ/mol12.00960 ±
0.00080
16092-61-8*0
26.7 Carbon anionC- (g)[C-]589.620594.766± 0.041kJ/mol12.01125 ±
0.00080
14337-00-9*0

Most Influential reactions involving [C2]- (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
0.7862129.1 [C2]- (g) → 2 [C]-4 (g) ΔrH°(0 K) = 50.968 ± 0.061 eVRuscic G4
0.5732199.1 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.272 ± 0.004 eVFeller 2016, note unc2
0.4312200.5 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.520 ± 0.050 eVRuscic W1RO
0.2892200.2 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.450 ± 0.061 eVRuscic G4
0.2542198.2 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.269 ± 0.006 eVErvin 1991
0.1432198.1 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.273 ± 0.008 eVArnold 1991
0.1332200.4 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.491 ± 0.090 eVRuscic CBS-n
0.0922200.1 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.616 ± 0.085 (×1.269) eVRuscic G3X
0.0472200.3 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.659 ± 0.092 (×1.646) eVRuscic CBS-n
0.0082129.3 [C2]- (g) → 2 [C]-4 (g) ΔrH°(0 K) = 50.361 ± 0.090 (×6.442) eVRuscic CBS-n
0.0062200.6 [C2]-2 (g) → [C2]- (g) ΔrH°(0 K) = -3.2 ± 0.4 eVSommerfeld 1997, est unc
0.0052199.2 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.264 ± 0.043 eVLu 2004
0.0032198.13 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.261 ± 0.050 eVRuscic W1RO
0.0022199.3 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.29 ± 0.06 eVSordo 2001, est unc, Huber 1979
0.0022202.8 [C2]- (g) → 2 C (g) ΔrH°(0 K) = 218.61 ± 1.50 kcal/molRuscic W1RO
0.0012202.4 [C2]- (g) → 2 C (g) ΔrH°(0 K) = 220.26 ± 1.60 kcal/molRuscic G4
0.0012202.7 [C2]- (g) → 2 C (g) ΔrH°(0 K) = 218.42 ± 1.60 kcal/molRuscic CBS-n
0.0012205.1 [C2]- (g) → C (g) C- (g) ΔrH°(0 K) = 188.7 ± 1.5 (×1.139) kcal/molSordo 2001, Chan 2004
0.0012202.3 [C2]- (g) → 2 C (g) ΔrH°(0 K) = 219.94 ± 1.72 kcal/molRuscic G3X
0.0012198.12 [C2]- (g) → C2 (g) ΔrH°(0 K) = 3.214 ± 0.090 eVRuscic 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 21st 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. 1.130 of the Thermochemical Network. Argonne National Laboratory, Lemont, Illinois 2023; available at ATcT.anl.gov
[DOI: 10.17038/CSE/1997229]
4   N. Genossar, P. B. Changala, B. Gans, J.-C. Loison, S. Hartweg, M.-A. Martin-Drumel, G. A. Garcia, J. F. Stanton, B. Ruscic, and J. H. Baraban
Ring-Opening Dynamics of the Cyclopropyl Radical and Cation: the Transition State Nature of the Cyclopropyl Cation
J. Am. Chem. Soc. 144, 18518-18525 (2022) [DOI: 10.1021/jacs.2c07740]
5   B. Ruscic and D. H. Bross
Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects.
Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6   J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton,
Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions
J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7   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]
8   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]).
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.