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].

Cyclopentadiene

Formula: CH2(CHCHCHCH) (g)

CAS RN: 542-92-7

ATcT ID: 542-92-7*0

SMILES: C1C=CC=C1

InChI: InChI=1S/C5H6/c1-2-4-5-3-1/h1-4H,5H2

Hills Formula: C5H6

2D Image:

Aliases: CH2(CHCHCHCH); Cyclopentadiene; 1,3-Cyclopentadiene; cyc-C5H6; Pentole; Pyropentylene; R-Pentine; InChIkey=ZSWFCLXCOIISFI-UHFFFAOYSA-N

Relative Molecular Mass: 66.1011 ± 0.0040

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
151.87	134.75	± 0.49	kJ/mol

3D Image of CH2(CHCHCHCH) (g)

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Top contributors to the provenance of Δ_fH° of CH2(CHCHCHCH) (g)

The 20 contributors listed below account only for 40.4% of the provenance of Δ_fH° of CH2(CHCHCHCH) (g).
A total of 230 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
15.5	3969.1	CH2(CHCHCHCH) (g) + 2 H2 (g) → CH2(CH2CH2CH2CH2) (g)	Δ_rH°(355.15 K) = -50.907 ± 0.200 kcal/mol	Kistiakowsky 1936
4.8	3959.4	CH2(CH2CH2CH2CH2) (l) + 15/2 O2 (g) → 5 CO2 (g) + 5 H2O (l)	Δ_rH°(298.15 K) = -786.84 ± 0.14 kcal/mol	Kaarsemaker 1952, as quoted by Cox 1970
4.7	3966.6	CH2(CHCHCHCH) (g) → 5 C (g) + 6 H (g)	Δ_rH°(0 K) = 1123.70 ± 0.50 kcal/mol	Karton 2017
1.9	3959.1	CH2(CH2CH2CH2CH2) (l) + 15/2 O2 (g) → 5 CO2 (g) + 5 H2O (l)	Δ_rH°(298.15 K) = -3290.85 ± 0.72 (×1.269) kJ/mol	Johnson 1946
1.4	7026.1	CH2(CHCHCHCHCHCH) (g) + 3 H2 (g) → CH2(CH2CH2CH2CH2CH2CH2) (g)	Δ_rH°(355.15 K) = -72.862 ± 0.300 kcal/mol	Conn 1939
1.0	3959.3	CH2(CH2CH2CH2CH2) (l) + 15/2 O2 (g) → 5 CO2 (g) + 5 H2O (l)	Δ_rH°(298.15 K) = -786.61 ± 0.30 kcal/mol	Spitzer 1947
0.9	7101.1	C6H4(CHCHCH2) (cr,l) + 11 O2 (g) → 9 CO2 (g) + 4 H2O (cr,l)	Δ_rH°(298.15 K) = -1146.12 ± 0.30 kcal/mol	Stull 1961
0.8	3972.5	CH2(CHCHCHCH) (g) + 2 CH3CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH2CH2 (g)	Δ_rH°(0 K) = 15.37 ± 0.85 kcal/mol	Ruscic W1RO
0.8	3971.5	CH2(CHCHCHCH) (g) + 2 CH3CH2CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH3CHCH2 (g)	Δ_rH°(0 K) = 9.86 ± 0.85 kcal/mol	Ruscic W1RO
0.7	7370.5	O(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH3OCH3 (g)	Δ_rH°(0 K) = 21.33 ± 0.85 kcal/mol	Ruscic W1RO
0.7	7569.5	(CHCH)(CHCH2CH)(CHCH) (g) + CH2(CHCH) (g) → 2 CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -61.60 ± 1.2 kcal/mol	Ruscic W1RO
0.7	3969.6	CH2(CHCHCHCH) (g) + 2 H2 (g) → CH2(CH2CH2CH2CH2) (g)	Δ_rH°(0 K) = -47.16 ± 0.9 kcal/mol	Ruscic W1RO
0.7	3972.4	CH2(CHCHCHCH) (g) + 2 CH3CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH2CH2 (g)	Δ_rH°(0 K) = 15.76 ± 0.90 kcal/mol	Ruscic CBS-n
0.7	3972.1	CH2(CHCHCHCH) (g) + 2 CH3CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH2CH2 (g)	Δ_rH°(0 K) = 14.76 ± 0.90 kcal/mol	Ruscic G3X
0.7	3972.2	CH2(CHCHCHCH) (g) + 2 CH3CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH2CH2 (g)	Δ_rH°(0 K) = 14.93 ± 0.90 kcal/mol	Ruscic G4
0.7	125.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
0.7	3971.1	CH2(CHCHCHCH) (g) + 2 CH3CH2CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH3CHCH2 (g)	Δ_rH°(0 K) = 9.40 ± 0.90 kcal/mol	Ruscic G3X
0.7	3971.2	CH2(CHCHCHCH) (g) + 2 CH3CH2CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH3CHCH2 (g)	Δ_rH°(0 K) = 9.50 ± 0.90 kcal/mol	Ruscic G4
0.7	3971.4	CH2(CHCHCHCH) (g) + 2 CH3CH2CH3 (g) → CH2(CH2CH2CH2CH2) (g) + 2 CH3CHCH2 (g)	Δ_rH°(0 K) = 10.07 ± 0.90 kcal/mol	Ruscic CBS-n
0.7	7370.2	O(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH3OCH3 (g)	Δ_rH°(0 K) = 21.04 ± 0.90 kcal/mol	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of CH2(CHCHCHCH) (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	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
41.7	Cyclopentane	CH2(CH2CH2CH2CH2) (g)	-43.39	-75.96	± 0.38	kJ/mol	70.1329 ± 0.0041	287-92-3*0
41.5	Cyclopentane	CH2(CH2CH2CH2CH2) (l)		-104.65	± 0.38	kJ/mol	70.1329 ± 0.0041	287-92-3*590
36.2	Cyclopentene	CH2(CH2CHCHCH2) (g)	59.91	35.65	± 0.43	kJ/mol	68.1170 ± 0.0040	142-29-0*0
34.1	Norbornadiene	(CHCH)(CHCH2CH)(CHCH) (g)	265.0	239.5	± 1.5	kJ/mol	92.1384 ± 0.0056	121-46-0*0
31.8	Cyclopentene	CH2(CH2CHCHCH2) (l)		7.37	± 0.48	kJ/mol	68.1170 ± 0.0040	142-29-0*590
31.3	Norbornadiene	(CHCH)(CHCH2CH)(CHCH) (l)		206.2	± 1.6	kJ/mol	92.1384 ± 0.0056	121-46-0*500
29.1	Indene	C6H4(CHCHCH2) (g)	183.77	159.88	± 0.72	kJ/mol	116.1598 ± 0.0072	95-13-6*0
28.9	5-Ethenyl-1,3-cyclopentadiene	CH2CHCH(CHCHCHCH) (g, perp)	237.1	215.3	± 1.4	kJ/mol	92.1384 ± 0.0056	29647-85-6*1
28.9	5-Ethenyl-1,3-cyclopentadiene	CH2CHCH(CHCHCHCH) (g)	237.1	216.3	± 1.4	kJ/mol	92.1384 ± 0.0056	29647-85-6*0
28.8	Indene cation	[C6H4(CHCHCH2)]+ (g)	969.94	946.70	± 0.73	kJ/mol	116.1593 ± 0.0072	42949-13-3*0

Most Influential reactions involving CH2(CHCHCHCH) (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
0.319	3969.1	CH2(CHCHCHCH) (g) + 2 H2 (g) → CH2(CH2CH2CH2CH2) (g)	Δ_rH°(355.15 K) = -50.907 ± 0.200 kcal/mol	Kistiakowsky 1936
0.178	8422.5	CH3C(CHCHCHCH) (g) + CH2(CHCHCHCH) (g) → CH3CH(CHCHCHCH) (g) + CH(CHCHCHCH) (g)	Δ_rH°(0 K) = 4.20 ± 0.85 kcal/mol	Ruscic W1RO
0.159	8422.4	CH3C(CHCHCHCH) (g) + CH2(CHCHCHCH) (g) → CH3CH(CHCHCHCH) (g) + CH(CHCHCHCH) (g)	Δ_rH°(0 K) = 4.90 ± 0.90 kcal/mol	Ruscic CBS-n
0.159	8422.1	CH3C(CHCHCHCH) (g) + CH2(CHCHCHCH) (g) → CH3CH(CHCHCHCH) (g) + CH(CHCHCHCH) (g)	Δ_rH°(0 K) = 4.27 ± 0.90 kcal/mol	Ruscic G3X
0.159	8422.2	CH3C(CHCHCHCH) (g) + CH2(CHCHCHCH) (g) → CH3CH(CHCHCHCH) (g) + CH(CHCHCHCH) (g)	Δ_rH°(0 K) = 4.67 ± 0.90 kcal/mol	Ruscic G4
0.154	3995.5	CH2CHCH(CHCHCHCH) (g, perp) + CH(CHCHCHCH) (g) → CH2CHC(CHCHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -10.32 ± 0.85 kcal/mol	Ruscic W1RO
0.148	7124.5	C6H4(CHCHCH2) (g) + CH(CHCHCHCH) (g) → C6H4(CHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -1.92 ± 0.85 kcal/mol	Ruscic W1RO
0.137	3995.2	CH2CHCH(CHCHCHCH) (g, perp) + CH(CHCHCHCH) (g) → CH2CHC(CHCHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -11.28 ± 0.90 kcal/mol	Ruscic G4
0.137	3995.1	CH2CHCH(CHCHCHCH) (g, perp) + CH(CHCHCHCH) (g) → CH2CHC(CHCHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -11.02 ± 0.90 kcal/mol	Ruscic G3X
0.137	8414.5	CH3CH(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH(CH3)3 (g)	Δ_rH°(0 K) = -1.30 ± 0.85 kcal/mol	Ruscic W1RO
0.132	7124.1	C6H4(CHCHCH2) (g) + CH(CHCHCHCH) (g) → C6H4(CHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -1.84 ± 0.90 kcal/mol	Ruscic G3X
0.132	7124.2	C6H4(CHCHCH2) (g) + CH(CHCHCHCH) (g) → C6H4(CHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -2.80 ± 0.90 kcal/mol	Ruscic G4
0.132	7124.4	C6H4(CHCHCH2) (g) + CH(CHCHCHCH) (g) → C6H4(CHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -2.04 ± 0.90 kcal/mol	Ruscic CBS-n
0.131	3983.5	CH2CHCH(CHCHCHCH) (g, perp) + CH4 (g) → CH2(CHCHCHCH) (g) + CH3CHCH2 (g)	Δ_rH°(0 K) = 3.24 ± 0.85 kcal/mol	Ruscic W1RO
0.129	8422.3	CH3C(CHCHCHCH) (g) + CH2(CHCHCHCH) (g) → CH3CH(CHCHCHCH) (g) + CH(CHCHCHCH) (g)	Δ_rH°(0 K) = 4.05 ± 1.00 kcal/mol	Ruscic CBS-n
0.123	7568.6	(CHCH)(CHCH2CH)(CHCH) (g) → CH2(CHCHCHCH) (g) + HCCH (g)	Δ_rG°(607.6 K) = 2.189 ± 0.192 (×4.861) kcal/mol	Walsh 1975, 3rd Law
0.122	8414.2	CH3CH(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH(CH3)3 (g)	Δ_rH°(0 K) = -1.09 ± 0.90 kcal/mol	Ruscic G4
0.122	8414.1	CH3CH(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH(CH3)3 (g)	Δ_rH°(0 K) = -1.09 ± 0.90 kcal/mol	Ruscic G3X
0.122	8414.4	CH3CH(CHCHCHCH) (g) + CH3CH2CH3 (g) → CH2(CHCHCHCH) (g) + CH(CH3)3 (g)	Δ_rH°(0 K) = -1.08 ± 0.90 kcal/mol	Ruscic CBS-n
0.117	3983.2	CH2CHCH(CHCHCHCH) (g, perp) + CH4 (g) → CH2(CHCHCHCH) (g) + CH3CHCH2 (g)	Δ_rH°(0 K) = 4.35 ± 0.90 kcal/mol	Ruscic G4

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. 1.172 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.