Selected ATcT [1, 2] enthalpy of formation based on version 1.122b of the Thermochemical Network [3]

This version of ATcT results was generated from an expansion of version 1.122 [4][5] to include the best possible isomerization of HCN and HNC [6].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
VinylideneCCH2 (g)[C]=C411.28412.20± 0.33kJ/mol26.0373 ±
0.0016
2143-69-3*0

Representative Geometry of CCH2 (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of CCH2 (g)

The 20 contributors listed below account only for 75.5% of the provenance of ΔfH° of CCH2 (g).
A total of 104 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
19.71863.1 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.53 ± 0.15 kcal/molLee 2013
7.01863.4 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2011
7.01863.5 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2006, Karton 2008
5.51857.12 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 345.10 ± 0.30 kcal/molKarton 2008
5.51857.11 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 345.10 ± 0.30 kcal/molKarton 2011
5.41865.9 C2H4 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 83.71 ± 0.30 kcal/molKarton 2011
4.91864.12 CCH2 (g) → C2H (g) H (g) ΔrH°(0 K) = 88.02 ± 0.30 kcal/molKarton 2011
3.71812.9 C2H3 (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2008
3.71812.8 C2H3 (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2011
2.71863.3 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.59 ± 0.40 kcal/molKarton 2011
1.51857.10 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 344.97 ± 0.56 kcal/molKarton 2011
1.51865.8 C2H4 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 83.78 ± 0.56 kcal/molKarton 2011
1.41864.11 CCH2 (g) → C2H (g) H (g) ΔrH°(0 K) = 88.08 ± 0.56 kcal/molKarton 2011
1.21863.6 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 15199 ± 205 cm-1Stanton 1999
1.01812.7 C2H3 (g) → CCH2 (g) H (g) ΔrH°(0 K) = 78.01 ± 0.56 kcal/molKarton 2011
0.61863.11 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 44.08 ± 0.8 kcal/molNguyen 2008
0.61857.13 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 344.37 ± 0.9 kcal/molNguyen 2008
0.61565.2 CO (g) → C+ (g) O (g) ΔrH°(0 K) = 22.3713 ± 0.0015 eVNg 2007
0.41779.1 C2H4 (g) + 3 O2 (g) → 2 CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -1411.18 ± 0.30 kJ/molRossini 1937
0.41863.10 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 42.95 ± 1.0 kcal/molChang 1997, est unc

Top 10 species with enthalpies of formation correlated to the ΔfH° of CCH2 (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
50.2 Vinylidene anion[CCH2]- (g)[C-]=C364.15363.96± 0.62kJ/mol26.0378 ±
0.0016
66295-36-1*0
32.5 AcetyleneHCCH (g)C#C228.83228.27± 0.14kJ/mol26.0373 ±
0.0016
74-86-2*0
32.5 Acetylene cation[HCCH]+ (g)C#[CH+]1328.851328.18± 0.14kJ/mol26.0367 ±
0.0016
25641-79-6*0
29.1 EthynylC2H (g)[CH][C]563.87567.99± 0.15kJ/mol25.0293 ±
0.0016
2122-48-7*0
26.7 Ethynylium[C2H]+ (g)[CH][C+]1687.591690.93± 0.16kJ/mol25.0288 ±
0.0016
16456-59-0*0
26.4 Carbon atom cationC+ (g)[C+]1797.8531803.451± 0.050kJ/mol12.01015 ±
0.00080
14067-05-1*0
26.4 Carbon atomC (g, singlet)[C]833.332838.478± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*2
26.4 Carbon atomC (g, triplet)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*1
26.4 Carbon atomC (g)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*0
26.3 Carbon atom anionC- (g)[C-]589.624594.771± 0.050kJ/mol12.01125 ±
0.00080
14337-00-9*0

Most Influential reactions involving CCH2 (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
0.8371859.1 [CCH2]- (g) → CCH2 (g) ΔrH°(0 K) = 0.490 ± 0.006 eVErvin 1990, Ervin 1989
0.2351863.1 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.53 ± 0.15 kcal/molLee 2013
0.2221858.8 CCH2 (g) → [CCH2]+ (g) ΔrH°(0 K) = 11.343 ± 0.040 eVRuscic W1RO
0.1021812.8 C2H3 (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2011
0.1021812.9 C2H3 (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2008
0.0841863.4 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2011
0.0841863.5 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2006, Karton 2008
0.0751859.2 [CCH2]- (g) → CCH2 (g) ΔrH°(0 K) = 0.47 ± 0.02 eVBurnett 1983
0.0661858.4 CCH2 (g) → [CCH2]+ (g) ΔrH°(0 K) = 11.375 ± 0.073 eVRuscic G4
0.0641865.9 C2H4 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 83.71 ± 0.30 kcal/molKarton 2011
0.0631858.7 CCH2 (g) → [CCH2]+ (g) ΔrH°(0 K) = 11.323 ± 0.075 eVRuscic CBS-n
0.0632871.5 CCO (g, singlet) C2H4 (g) → CCH2 (g) CH2CO (g) ΔrH°(0 K) = -36.24 ± 0.85 kcal/molRuscic W1RO
0.0611864.12 CCH2 (g) → C2H (g) H (g) ΔrH°(0 K) = 88.02 ± 0.30 kcal/molKarton 2011


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. 1.122b of the Thermochemical Network (2016); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry.
J. Phys. Chem. A 119, 7810-7837 (2015) [DOI: 10.1021/acs.jpca.5b01346]
5   S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A 121, 6580-6602 (2017) [DOI: 10.1021/acs.jpca.7b05945]
6   T. L. Nguyen, J. H. Baraban, B. Ruscic, and J. F. Stanton,
On the HCN – HNC Energy Difference.
J. Phys. Chem. A 119, 10929-10934 (2015) [DOI: 10.1021/acs.jpca.5b08406]
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]

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 [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.