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
Acetylene cation[HCCH]+ (g)C#[CH+]1328.851328.18± 0.14kJ/mol26.0367 ±
0.0016
25641-79-6*0

Representative Geometry of [HCCH]+ (g)

spin ON           spin OFF
          

Top contributors to the provenance of ΔfH° of [HCCH]+ (g)

The 20 contributors listed below account only for 27.9% of the provenance of ΔfH° of [HCCH]+ (g).
A total of 563 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
3.51565.2 CO (g) → C+ (g) O (g) ΔrH°(0 K) = 22.3713 ± 0.0015 eVNg 2007
2.2117.2 1/2 O2 (g) H2 (g) → H2O (cr,l) ΔrH°(298.15 K) = -285.8261 ± 0.040 kJ/molRossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
2.21779.1 C2H4 (g) + 3 O2 (g) → 2 CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -1411.18 ± 0.30 kJ/molRossini 1937
1.81642.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
1.51856.1 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.135 ± 0.005 (×1.139) eVMalow 1999, est unc
1.51856.2 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.135 ± 0.005 (×1.139) eVMahnert 1996
1.41840.7 HCCH (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 1626.04 ± 0.56 kJ/molHarding 2008
1.31573.5 C (graphite) CO2 (g) → 2 CO (g) ΔrG°(1165 K) = -33.545 ± 0.058 kJ/molSmith 1946, note COf, 3rd Law
1.21879.1 HCCH (g) → C2H (g) H (g) ΔrH°(0 K) = 46074 ± 8 cm-1Mordaunt 1994
1.11839.13 HCCH (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 388.71 ± 0.15 kcal/molKarton 2007a
1.01853.1 HCCH (g) + 2 H2 (g) → C2H6 (g) ΔrH°(355.15 K) = -75.078 ± 0.150 (×1.269) kcal/molConn 1939, note C2H2
1.01722.1 C2H6 (g) + 7/2 O2 (g) → 2 CO2 (g) + 3 H2O (cr,l) ΔrH°(298.15 K) = -1560.68 ± 0.25 kJ/molPittam 1972
0.91870.7 C2H (g) → 2 C (g) H (g) ΔrH°(0 K) = 1075.25 ± 0.56 kJ/molHarding 2008
0.92359.1 CH3CCH (g) + 4 O2 (g) → 3 CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -463.131 ± 0.204 kcal/molWagman 1945, Wagman 1945a
0.91854.6 HCCH (g) H2 (g) → C2H4 (g) ΔrH°(0 K) = -167.71 ± 0.70 kJ/molHarding 2007
0.91853.11 HCCH (g) + 2 H2 (g) → C2H6 (g) ΔrH°(0 K) = -71.01 ± 0.20 kcal/molKarton 2007
0.91519.7 C (graphite) O2 (g) → CO2 (g) ΔrH°(298.15 K) = -393.464 ± 0.024 kJ/molHawtin 1966, note CO2e
0.91840.4 HCCH (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 1626.21 ± 0.70 kJ/molBomble 2006
0.91840.11 HCCH (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 1626.15 ± 0.70 kJ/molHarding 2007
0.91840.5 HCCH (g) → 2 C (g) + 2 H (g) ΔrH°(0 K) = 1626.04 ± 0.70 kJ/molHarding 2008, Ferguson 2013

Top 10 species with enthalpies of formation correlated to the ΔfH° of [HCCH]+ (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
100.0 AcetyleneHCCH (g)C#C228.83228.27± 0.14kJ/mol26.0373 ±
0.0016
74-86-2*0
84.2 EthynylC2H (g)[CH][C]563.87567.99± 0.15kJ/mol25.0293 ±
0.0016
2122-48-7*0
82.1 Ethynylium[C2H]+ (g)[CH][C+]1687.591690.93± 0.16kJ/mol25.0288 ±
0.0016
16456-59-0*0
66.2 Ethynide[C2H]- (g)[CH][C-]277.42280.83± 0.19kJ/mol25.0299 ±
0.0016
29075-95-4*0
64.5 Carbon atomC (g, triplet)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*1
64.5 Carbon atomC (g)[C]711.401716.886± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*0
64.5 Carbon atomC (g, singlet)[C]833.332838.478± 0.050kJ/mol12.01070 ±
0.00080
7440-44-0*2
64.5 Carbon atom cationC+ (g)[C+]1797.8531803.451± 0.050kJ/mol12.01015 ±
0.00080
14067-05-1*0
64.3 Carbon atom anionC- (g)[C-]589.624594.771± 0.050kJ/mol12.01125 ±
0.00080
14337-00-9*0
57.0 Methyliumylidene[CH]+ (g)[CH+]1619.7581623.102± 0.057kJ/mol13.01809 ±
0.00080
24361-82-8*0

Most Influential reactions involving [HCCH]+ (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
0.9801842.1 HCCH (g) → [HCCH]+ (g) ΔrH°(0 K) = 91953.77 ± 0.06 cm-1Tang 2006
0.0531856.2 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.135 ± 0.005 (×1.139) eVMahnert 1996
0.0531856.1 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.135 ± 0.005 (×1.139) eVMalow 1999, est unc
0.0311888.1 HCCH (g) → [HCCH]+ (g) H (g) [C2H]- (g) ΔrH°(0 K) = 14.145 ± 0.008 eVRuscic 1990, note C2H
0.0181809.3 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -0.7 ± 1.0 kcal/molHawley 1992, est unc
0.0181809.2 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -0.9 ± 1.0 kcal/molHawley 1989, est unc
0.0171856.3 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.14 ± 0.01 eVStockbauer 1975a
0.0141842.2 HCCH (g) → [HCCH]+ (g) ΔrH°(0 K) = 91953.5 ± 0.5 cm-1Rupper 2004
0.0081809.8 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -1.10 ± 1.50 kcal/molRuscic W1RO
0.0071809.7 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -0.95 ± 1.60 kcal/molRuscic CBS-n
0.0071809.5 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -2.09 ± 1.60 kcal/molRuscic G4
0.0061809.4 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -2.41 ± 1.72 kcal/molRuscic G3X
0.0041809.1 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(300 K) = -1.6 ± 2 kcal/molSmith 1984, est unc
0.0041856.4 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.13 ± 0.02 eVChupka 1969
0.0031809.6 [C2H3]+ (g) H (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = -2.37 ± 2.16 kcal/molRuscic CBS-n
0.0031842.3 HCCH (g) → [HCCH]+ (g) ΔrH°(0 K) = 91953.5 ± 1.0 cm-1Yang 2006
0.0011856.5 C2H4 (g) → [HCCH]+ (g) H2 (g) ΔrH°(0 K) = 13.12 ± 0.03 eVBotter 1966
0.0003774.1 CH2CHBr (g) → [HCCH]+ (g) HBr (g) ΔrH°(0 K) = 12.5 ± 0.2 eVLohr 1975
0.0001842.4 HCCH (g) → [HCCH]+ (g) ΔrH°(0 K) = 91952 ± 2 cm-1Pratt 1993
0.0001842.5 HCCH (g) → [HCCH]+ (g) ΔrH°(0 K) = 91956 ± 1 (×2.278) cm-1Shafizadeh 1997


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.