Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

neo-Pentane

Formula: C(CH3)4 (l)

CAS RN: 463-82-1

ATcT ID: 463-82-1*500

SMILES: CC(C)(C)C

InChI: InChI=1S/C5H12/c1-5(2,3)4/h1-4H3

InChIKey: CRSOQBOWXPBRES-UHFFFAOYSA-N

Hills Formula: C5H12

2D Image:

Aliases: C(CH3)4; neo-Pentane; Neopentane; tert-Pentane; t-Pentane; 2,2-Dimethylpropane; 1,1,1-Trimethylethane; Tetramethylmethane; (CH3)4C; CH3C(CH3)3; (CH3)3CCH3

Relative Molecular Mass: 72.1488 ± 0.0041

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
	-189.52	± 0.38	kJ/mol

Top contributors to the provenance of Δ_fH° of C(CH3)4 (l)

The 20 contributors listed below account only for 75.5% of the provenance of Δ_fH° of C(CH3)4 (l).
A total of 69 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
29.8	3894.1	C(CH3)4 (l) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -834.70 ± 0.14 kcal/mol	Good 1970
9.4	3895.1	C(CH3)4 (l) → CH3CH2CH2CH2CH3 (cr,l)	Δ_rH°(298.15 K) = 3.98 ± 0.21 kcal/mol	Good 1970
8.7	3890.1	C(CH3)4 (g) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -839.87 ± 0.23 (×1.114) kcal/mol	Pilcher 1967
6.0	3896.1	C(CH3)4 (l) → CH3CH2CH(CH3)2 (l)	Δ_rH°(298.15 K) = 2.86 ± 0.24 kcal/mol	Good 1970
3.7	3891.1	C(CH3)4 (g) → CH3CH2CH2CH2CH3 (g)	Δ_rH°(298.15 K) = 5.11 ± 0.33 kcal/mol	Pilcher 1967
3.3	3892.1	C(CH3)4 (g) → CH3CH2CH(CH3)2 (g)	Δ_rH°(298.15 K) = 3.43 ± 0.32 kcal/mol	Pilcher 1967
3.0	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
1.7	3889.5	C(CH3)4 (g) → 5 C (g) + 12 H (g)	Δ_rH°(0 K) = 1501.86 ± 0.60 kcal/mol	Karton 2009b
1.6	2359.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
1.3	3979.1	CH3CH2C(CH3)3 (cr,l) → CH3CH2CH2CH2CH2CH3 (cr,l)	Δ_rH°(298.15 K) = 3.49 ± 0.21 kcal/mol	Prosen 1941
0.9	2357.7	CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -890.578 ± 0.078 kJ/mol	Schley 2010
0.8	2214.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
0.7	3886.1	CH3CH2CH(CH3)2 (l) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -837.56 ± 0.20 kcal/mol	Good 1970
0.6	3885.1	CH3CH2CH(CH3)2 (g) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -843.30 ± 0.22 kcal/mol	Pilcher 1967
0.6	3891.7	C(CH3)4 (g) → CH3CH2CH2CH2CH3 (g)	Δ_rH°(0 K) = 3.99 ± 0.35 (×2.327) kcal/mol	Karton 2009b
0.5	3698.1	C(CH3)4 (g) → [(CH3)3C]+ (g) + CH3 (g)	Δ_rH°(0 K) = 10.564 ± 0.025 eV	Stevens 2010b
0.5	3891.6	C(CH3)4 (g) → CH3CH2CH2CH2CH3 (g)	Δ_rH°(0 K) = 4.02 ± 0.85 kcal/mol	Karton 2009b, Ruscic W1RO
0.5	3880.1	CH3CH2CH2CH2CH3 (cr,l) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -838.68 ± 0.16 kcal/mol	Good 1970
0.5	3893.5	C(CH3)4 (g) + 2 CH3CH3 (g) → 3 CH3CH2CH3 (g)	Δ_rH°(0 K) = 4.52 ± 0.35 (×2.768) kcal/mol	Karton 2009b
0.5	3893.3	C(CH3)4 (g) + 2 CH3CH3 (g) → 3 CH3CH2CH3 (g)	Δ_rH°(0 K) = 5.47 ± 1.0 kcal/mol	Ruscic CBS-n

Top 10 species with enthalpies of formation correlated to the Δ_fH° of C(CH3)4 (l)

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
99.0	neo-Pentane	C(CH3)4 (g)	-134.25	-167.13	± 0.38	kJ/mol	72.1488 ± 0.0041	463-82-1*0
35.6	n-Pentane	CH3CH2CH2CH2CH3 (g)	-114.17	-146.05	± 0.29	kJ/mol	72.1488 ± 0.0041	109-66-0*0
35.6	n-Pentane	CH3CH2CH2CH2CH3 (cr,l)	-155.81	-172.78	± 0.29	kJ/mol	72.1488 ± 0.0041	109-66-0*500
33.8	Carbonic acid	C(O)(OH)2 (aq, undissoc)		-698.670	± 0.028	kJ/mol	62.0248 ± 0.0012	463-79-6*1000
32.8	iso-Pentane	CH3CH2CH(CH3)2 (l)		-178.18	± 0.39	kJ/mol	72.1488 ± 0.0041	78-78-4*500
32.8	iso-Pentane	CH3CH2CH(CH3)2 (g)	-118.91	-152.96	± 0.39	kJ/mol	72.1488 ± 0.0041	78-78-4*0
31.8	Water	H2O (cr,l)	-286.274	-285.802	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*500
31.8	Water	H2O (l)		-285.802	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*590
31.8	Oxonium	[H3O]+ (aq)		-285.802	± 0.022	kJ/mol	19.02267 ± 0.00037	13968-08-6*800
31.8	Water	H2O (l, eq.press.)		-285.804	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*589

Most Influential reactions involving C(CH3)4 (l)

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
0.774	3897.2	C(CH3)4 (l) → C(CH3)4 (g)	Δ_rH°(298.15 K) = 5.351 ± 0.014 kcal/mol	Good 1970, Scott 1951
0.350	3894.1	C(CH3)4 (l) + 8 O2 (g) → 5 CO2 (g) + 6 H2O (cr,l)	Δ_rH°(298.15 K) = -834.70 ± 0.14 kcal/mol	Good 1970
0.219	3897.1	C(CH3)4 (l) → C(CH3)4 (g)	Δ_rH°(298.15 K) = 22.39 ± 0.11 kJ/mol	Majer 1985
0.190	3896.1	C(CH3)4 (l) → CH3CH2CH(CH3)2 (l)	Δ_rH°(298.15 K) = 2.86 ± 0.24 kcal/mol	Good 1970
0.189	3895.1	C(CH3)4 (l) → CH3CH2CH2CH2CH3 (cr,l)	Δ_rH°(298.15 K) = 3.98 ± 0.21 kcal/mol	Good 1970

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. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
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]
7		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 [6] and Ruscic and Bross[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.