Selected ATcT [1, 2] enthalpy of formation based on version 1.118 of the Thermochemical Network [3]

This version of ATcT results was partially described in Ruscic et al. [4], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [5].

Species Name Formula    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
PropynylideneHCCCH (g, trans singlet)596.6598.4± 1.1kJ/mol38.0480 ±
0.0024		67152-18-5*4

Top contributors to the provenance of ΔfH° of HCCCH (g, trans singlet)

The 20 contributors listed below account only for 52.8% of the provenance of ΔfH° of HCCCH (g, trans singlet).
A total of 92 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 listed Reaction acts as a link to the relevant references 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
(%)		 Reaction Measured Quantity
9.7 [HCCCH]- (g, transoid 2B) → HCCCH (g, trans singlet) ΔrH°(0 K) = 1.656 ± 0.005 eV
4.4 [HCCCH]- (g, transoid 2B) → [HCCCH]- (g, cisoid 2A) ΔrH°(0 K) = 0.6 ± 0.5 kcal/mol
3.2 HCCCH (g, trans singlet) → CH2CC (g) ΔrH°(0 K) = -10.53 ± 1.2 kcal/mol
3.1 [HCCCH]- (g, cisoid 2A) → HCCCH (g, triplet) ΔrH°(0 K) = 1.070 ± 0.009 eV
3.0 [HCCCH]- (g, transoid 2B) → [HCCCH]- (g, cisoid 2A) ΔrH°(0 K) = 0.54 ± 0.6 kcal/mol
2.7 HCCCH (g, trans singlet) → CH2CC (g) ΔrH°(0 K) = -10.53 ± 1.3 kcal/mol
2.4 HCCCH (g, trans singlet) → CH2CC (g) ΔrH°(0 K) = -10.51 ± 1.4 kcal/mol
2.2 [HCCCH]- (g, transoid 2B) + CH3 (g) → CH2CCH (g) + [CH2]- (g) ΔrH°(0 K) = 23.82 ± 1.2 kcal/mol
2.2 [CH2CC]- (g) → [HCCCH]- (g, transoid 2B) ΔrH°(0 K) = 13.04 ± 1.2 kcal/mol
1.9 [HCCCH]- (g, transoid 2B) + CH3 (g) → CH2CCH (g) + [CH2]- (g) ΔrH°(0 K) = 24.11 ± 1.3 kcal/mol
1.9 [CH2CC]- (g) → [HCCCH]- (g, transoid 2B) ΔrH°(0 K) = 13.76 ± 1.3 kcal/mol
1.9 HCCCH (g, triplet) → HCCCH (g, trans singlet) ΔrH°(0 K) = 4191 ± 450 cm-1
1.8 HCCCH (g, triplet) → HCCCH (g, trans singlet) ΔrH°(0 K) = 4925 ± 420 (×1.091) cm-1
1.8 HCCCH (g, trans singlet) → CH2CC (g) ΔrH°(0 K) = -10.97 ± 1.6 kcal/mol
1.8 [HCCCH]- (g, transoid 2B) → 3 C (g) + 2 H (g) ΔrH°(0 K) = 509.67 ± 1.50 kcal/mol
1.6 [CH2CC]- (g) → [HCCCH]- (g, transoid 2B) ΔrH°(0 K) = 13.83 ± 1.4 kcal/mol
1.6 HCCCH (g, triplet) → HCCCH (g, trans singlet) ΔrH°(0 K) = 4293 ± 490 cm-1
1.5 [HCCCH]- (g, transoid 2B) → 3 C (g) + 2 H (g) ΔrH°(0 K) = 510.33 ± 1.60 kcal/mol
1.5 [HCCCH]- (g, transoid 2B) → HCCCH (g, triplet) ΔrH°(0 K) = 1.098 ± 0.050 eV
1.5 [HCCCH]- (g, transoid 2B) → HCCCH (g, triplet) ΔrH°(0 K) = 1.146 ± 0.05 eV
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, Active Thermochemical Tables (ATcT) values based on ver. 1.118 of the Thermochemical Network (2015); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Dissociation Energies of Several Homonuclear First-Row Diatomics and Related Thermochemical Values.
Theor. Chem. Acc. 133, 1415/1-12 (2005) [DOI: 10.1007/s00214-013-1415-z]
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 in preparation (2016)
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]
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.