Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Vinylidene

Formula: CCH2 (g, triplet)
CAS RN: 2143-69-3
ATcT ID: 2143-69-3*1
SMILES: [C]=C
InChI: InChI=1S/C2H2/c1-2/h1H2
InChIKey: SNVLJLYUUXKWOJ-UHFFFAOYSA-N
Hills Formula: C2H2

2D Image:

[C]=C
Aliases: CCH2; Vinylidene; Ethenylidene; Methylenecarbene; Methylidenecarbene; CH2C; H2CC
Relative Molecular Mass: 26.0373 ± 0.0016

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
610.62610.33± 0.39kJ/mol

3D Image of CCH2 (g, triplet)

spin ON           spin OFF
          

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

The 20 contributors listed below account only for 81.8% of the provenance of ΔfH° of CCH2 (g, triplet).
A total of 64 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
31.12622.1 [CCH2]- (g) → CCH2 (g, triplet) ΔrH°(0 K) = 20602 ± 24 cm-1DeVine 2016, note unc
9.32625.1 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.53 ± 0.15 kcal/molLee 2013
8.72621.1 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.065 ± 0.006 eVErvin 1989
3.32625.4 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2011
3.32625.5 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.62 ± 0.25 kcal/molKarton 2006, Karton 2008
2.62615.12 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 345.10 ± 0.30 kcal/molKarton 2008
2.62615.11 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 345.10 ± 0.30 kcal/molKarton 2011
2.62627.9 CH2CH2 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 83.71 ± 0.30 kcal/molKarton 2011
2.32626.12 CCH2 (g) → CCH (g) H (g) ΔrH°(0 K) = 88.02 ± 0.30 kcal/molKarton 2011
2.12617.1 [CCH2]- (g) → CCH2 (g) ΔrH°(0 K) = 0.4866 ± 0.0008 eVDeVine 2017
2.02566.9 CH2CH (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2008
2.02566.8 CH2CH (g) → CCH2 (g) H (g) ΔrH°(0 K) = 77.96 ± 0.30 kcal/molKarton 2011
1.82627.11 CH2CH2 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 350.63 ± 1.5 kJ/molKlippenstein 2017
1.62626.13 CCH2 (g) → CCH (g) H (g) ΔrH°(0 K) = 368.45 ± 1.5 kJ/molKlippenstein 2017
1.62624.10 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 182.22 ± 1.5 kJ/molKlippenstein 2017
1.32625.3 HCCH (g) → CCH2 (g) ΔrH°(0 K) = 43.59 ± 0.40 kcal/molKarton 2011
0.72615.10 CCH2 (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 344.97 ± 0.56 kcal/molKarton 2011
0.72627.8 CH2CH2 (g) → CCH2 (g) H2 (g) ΔrH°(0 K) = 83.78 ± 0.56 kcal/molKarton 2011
0.62626.11 CCH2 (g) → CCH (g) H (g) ΔrH°(0 K) = 88.08 ± 0.56 kcal/molKarton 2011
0.67719.6 CH2CCHO (g) → CCH2 (g) HCO (g) ΔrH°(0 K) = 274.15 ± 2.0 kJ/molKlippenstein 2017

Top 10 species with enthalpies of formation correlated to the ΔfH° of CCH2 (g, triplet)

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
75.8 Vinylidene anion[CCH2]- (g)[C-]=C364.25364.06± 0.31kJ/mol26.0378 ±
0.0016
66295-36-1*0
74.4 VinylideneCCH2 (g)[C]=C411.21412.12± 0.30kJ/mol26.0373 ±
0.0016
2143-69-3*0
22.1 AcetyleneHCCH (g)C#C228.86228.30± 0.12kJ/mol26.0373 ±
0.0016
74-86-2*0
22.1 Acetylene cation[HCCH]+ (g)C#[CH+]1328.881328.21± 0.12kJ/mol26.0367 ±
0.0016
25641-79-6*0
17.4 Ethynylium[CCH]+ (g)C#[C+]1687.621690.95± 0.15kJ/mol25.0288 ±
0.0016
16456-59-0*0
17.4 1-PropenylideneCH3CHC (g, triplet)CC=[C]630.5623.0± 1.7kJ/mol40.0639 ±
0.0024
70277-78-0*2
17.2 EthynylCCH (g)C#[C]563.73567.85± 0.15kJ/mol25.0293 ±
0.0016
2122-48-7*0
16.2 CarbonC (g)[C]711.381716.866± 0.039kJ/mol12.01070 ±
0.00080
7440-44-0*0
16.2 CarbonC (g, triplet)[C]711.381716.866± 0.039kJ/mol12.01070 ±
0.00080
7440-44-0*1
16.2 Carbon cationC+ (g)[C+]1797.8341803.432± 0.039kJ/mol12.01015 ±
0.00080
14067-05-1*0

Most Influential reactions involving CCH2 (g, triplet)

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
0.7822622.1 [CCH2]- (g) → CCH2 (g, triplet) ΔrH°(0 K) = 20602 ± 24 cm-1DeVine 2016, note unc
0.2133490.5 CH3CHC (g, triplet) HCCH (g) → CCH2 (g, triplet) CH3CCH (g) ΔrH°(0 K) = -13.16 ± 0.85 kcal/molRuscic W1RO
0.2012621.1 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.065 ± 0.006 eVErvin 1989
0.1903490.1 CH3CHC (g, triplet) HCCH (g) → CCH2 (g, triplet) CH3CCH (g) ΔrH°(0 K) = -13.72 ± 0.90 kcal/molRuscic G3X
0.1903490.2 CH3CHC (g, triplet) HCCH (g) → CCH2 (g, triplet) CH3CCH (g) ΔrH°(0 K) = -13.27 ± 0.90 kcal/molRuscic G4
0.1543490.3 CH3CHC (g, triplet) HCCH (g) → CCH2 (g, triplet) CH3CCH (g) ΔrH°(0 K) = -14.18 ± 1.00 kcal/molRuscic CBS-n
0.0812623.5 HCCH (g, cis-triplet) → CCH2 (g, triplet) ΔrH°(0 K) = 770 ± 420 cm-1Ruscic W1RO
0.0702623.2 HCCH (g, cis-triplet) → CCH2 (g, triplet) ΔrH°(0 K) = 1006 ± 450 cm-1Ruscic G4
0.0692623.4 HCCH (g, cis-triplet) → CCH2 (g, triplet) ΔrH°(0 K) = 789 ± 455 cm-1Ruscic CBS-n
0.0592623.1 HCCH (g, cis-triplet) → CCH2 (g, triplet) ΔrH°(0 K) = 910 ± 490 cm-1Ruscic G3X
0.0452623.3 HCCH (g, cis-triplet) → CCH2 (g, triplet) ΔrH°(0 K) = 527 ± 560 cm-1Ruscic CBS-n
0.0082621.7 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 16720 ± 230 cm-1Sherrill 2000
0.0022621.6 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.057 ± 0.052 eVRuscic W1RO
0.0022621.3 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.070 ± 0.056 eVRuscic G4
0.0022621.5 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.063 ± 0.057 eVRuscic CBS-n
0.0022621.2 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.060 ± 0.061 eVRuscic G3X
0.0012621.4 CCH2 (g) → CCH2 (g, triplet) ΔrH°(0 K) = 2.048 ± 0.070 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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4   K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument,
Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide
J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
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.