Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

2-Propenylidene

Formula: CHCHCH2 (g, triplet syn)

CAS RN: 19527-08-3

ATcT ID: 19527-08-3*12

SMILES: [CH]C=C

SMILES: [CH2]C=[CH]

InChI: InChI=1S/C3H4/c1-3-2/h1,3H,2H2

InChIKey: OQOPKWGTWCVGHN-UHFFFAOYSA-N

Hills Formula: C3H4

2D Image:

Aliases: CHCHCH2; 2-Propenylidene; Allylidene; Vinylcarbene; Vinylmethylene; CH-CH=CH2; CH2CHCH; 60089-54-5; 1-Propene-1,3-diyl; CH2-CH=CH; CH=CH-CH2

Relative Molecular Mass: 40.0639 ± 0.0024

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
419.1	411.6	± 2.3	kJ/mol

3D Image of CHCHCH2 (g, triplet syn)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of CHCHCH2 (g, triplet syn)

The 20 contributors listed below account only for 88.5% of the provenance of Δ_fH° of CHCHCH2 (g, triplet syn).
A total of 23 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
12.5	3511.5	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 142 ± 300 cm-1	Ruscic W1RO
11.7	3511.4	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 129 ± 310 cm-1	Ruscic CBS-n
11.7	3511.2	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 142 ± 310 cm-1	Ruscic G4
11.3	3511.1	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 128 ± 315 cm-1	Ruscic G3X
9.1	3511.3	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 125 ± 350 cm-1	Ruscic CBS-n
4.2	3512.5	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, singlet)	Δ_rH°(0 K) = 2954 ± 300 cm-1	Ruscic W1RO
3.9	3512.4	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, singlet)	Δ_rH°(0 K) = 3242 ± 310 cm-1	Ruscic CBS-n
3.9	3512.2	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, singlet)	Δ_rH°(0 K) = 2811 ± 310 cm-1	Ruscic G4
3.8	3512.1	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, singlet)	Δ_rH°(0 K) = 2810 ± 315 cm-1	Ruscic G3X
3.1	3512.3	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, singlet)	Δ_rH°(0 K) = 3024 ± 350 cm-1	Ruscic CBS-n
1.7	3507.5	CHCHCH2 (g, triplet anti) → CH3CHC (g, triplet)	Δ_rH°(0 K) = 50.33 ± 1.2 kcal/mol	Ruscic W1RO
1.7	3508.5	CHCHCH2 (g, triplet anti) → C(CH2CH2) (g, triplet)	Δ_rH°(0 K) = 30.10 ± 1.2 kcal/mol	Ruscic W1RO
1.4	3507.2	CHCHCH2 (g, triplet anti) → CH3CHC (g, triplet)	Δ_rH°(0 K) = 50.44 ± 1.3 kcal/mol	Ruscic G4
1.4	3508.2	CHCHCH2 (g, triplet anti) → C(CH2CH2) (g, triplet)	Δ_rH°(0 K) = 30.17 ± 1.3 kcal/mol	Ruscic G4
1.4	3508.4	CHCHCH2 (g, triplet anti) → C(CH2CH2) (g, triplet)	Δ_rH°(0 K) = 30.58 ± 1.3 kcal/mol	Ruscic CBS-n
1.2	3507.1	CHCHCH2 (g, triplet anti) → CH3CHC (g, triplet)	Δ_rH°(0 K) = 50.48 ± 1.4 kcal/mol	Ruscic G3X
1.2	3508.1	CHCHCH2 (g, triplet anti) → C(CH2CH2) (g, triplet)	Δ_rH°(0 K) = 30.96 ± 1.4 kcal/mol	Ruscic G3X
0.9	3507.3	CHCHCH2 (g, triplet anti) → CH3CHC (g, triplet)	Δ_rH°(0 K) = 51.21 ± 1.6 kcal/mol	Ruscic CBS-n
0.9	3508.3	CHCHCH2 (g, triplet anti) → C(CH2CH2) (g, triplet)	Δ_rH°(0 K) = 31.12 ± 1.6 kcal/mol	Ruscic CBS-n
0.6	3490.5	CH3CHC (g, triplet) + HCCH (g) → CCH2 (g, triplet) + CH3CCH (g)	Δ_rH°(0 K) = -13.16 ± 0.85 kcal/mol	Ruscic W1RO

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CHCHCH2 (g, triplet syn)

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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
65.9	2-Propenylidene	CHCHCH2 (g, triplet anti)	417.5	410.0	± 1.5	kJ/mol	40.0639 ± 0.0024	19527-08-3*11
65.9	2-Propenylidene	CHCHCH2 (g)	417.5	410.6	± 1.5	kJ/mol	40.0639 ± 0.0024	19527-08-3*0
65.9	2-Propenylidene	CHCHCH2 (g, triplet)	417.5	410.6	± 1.5	kJ/mol	40.0639 ± 0.0024	19527-08-3*1
26.7	2-Propenylidene	CHCHCH2 (g, singlet)	452.73	445.60	± 0.90	kJ/mol	40.0639 ± 0.0024	19527-08-3*2
21.7	Cyclopropylidene	C(CH2CH2) (g, triplet)	544.8	536.0	± 1.5	kJ/mol	40.0639 ± 0.0024	2143-70-6*2
19.1	1-Propenylidene	CH3CHC (g, triplet)	630.5	623.0	± 1.7	kJ/mol	40.0639 ± 0.0024	70277-78-0*2
10.8	Cyclopropylidene	C(CH2CH2) (g, singlet)	475.03	467.01	± 0.84	kJ/mol	40.0639 ± 0.0024	2143-70-6*1
10.8	Cyclopropylidene	C(CH2CH2) (g)	475.03	467.01	± 0.84	kJ/mol	40.0639 ± 0.0024	2143-70-6*0
10.4	1-Methylethylidene	CH3CCH3 (g, triplet)	326.9	313.7	± 1.2	kJ/mol	42.0797 ± 0.0024	40852-89-9*1
6.5	1-Propenylidene	CH3CHC (g, singlet)	392.5	388.1	± 1.1	kJ/mol	40.0639 ± 0.0024	70277-78-0*1

Most Influential reactions involving CHCHCH2 (g, triplet syn)

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
0.221	3511.5	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 142 ± 300 cm-1	Ruscic W1RO
0.207	3511.2	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 142 ± 310 cm-1	Ruscic G4
0.207	3511.4	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 129 ± 310 cm-1	Ruscic CBS-n
0.200	3511.1	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 128 ± 315 cm-1	Ruscic G3X
0.162	3511.3	CHCHCH2 (g, triplet anti) → CHCHCH2 (g, triplet syn)	Δ_rH°(0 K) = 125 ± 350 cm-1	Ruscic 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 21^st 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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
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.