Selected ATcT [1, 2] enthalpy of formation based on version 1.202 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.176 in order to include species related to the thermochemistry of glycine[4].

2,2,4-Trimethylpentane

Formula: (CH3)2CHCH2C(CH3)3 (cr,l)

CAS RN: 540-84-1

ATcT ID: 540-84-1*500

SMILES: CC(C)CC(C)(C)C

InChI: InChI=1S/C8H18/c1-7(2)6-8(3,4)5/h7H,6H2,1-5H3

InChIKey: NHTMVDHEPJAVLT-UHFFFAOYSA-N

Hills Formula: C8H18

2D Image:

Aliases: (CH3)2CHCH2C(CH3)3; 2,2,4-Trimethylpentane; iso-Octane; Isooctane; Isobutyltrimethylmethane; (CH3)3CCH2CH(CH3)2; i-C8H18; iso-C8H18; UN 1262

Relative Molecular Mass: 114.2285 ± 0.0065

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-224.2	-258.6	± 1.5	kJ/mol

Top contributors to the provenance of Δ_fH° of (CH3)2CHCH2C(CH3)3 (cr,l)

The 1 contributors listed below account for 97.8% of the provenance of Δ_fH° of (CH3)2CHCH2C(CH3)3 (cr,l).

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
97.8	7778.1	(CH3)2CHCH2C(CH3)3 (cr,l) + 25/2 O2 (g) → 8 CO2 (g) + 9 H2O (cr,l)	Δ_rH°(298.15 K) = -1305.30 ± 0.35 kcal/mol	Prosen 1945b, as quoted by Pedley 1986

Top 10 species with enthalpies of formation correlated to the Δ_fH° of (CH3)2CHCH2C(CH3)3 (cr,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
99.9	2,2,4-Trimethylpentane	(CH3)2CHCH2C(CH3)3 (g)	-171.1	-223.5	± 1.5	kJ/mol	114.2285 ± 0.0065	540-84-1*0
13.6	Carbonic acid	C(O)(OH)2 (aq, undissoc)		-698.669	± 0.028	kJ/mol	62.0248 ± 0.0012	463-79-6*1000
12.6	Water	H2O (g, para)	-238.903	-241.806	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*2
12.6	Water	H2O (g)	-238.903	-241.806	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*0
12.6	Water	H2O (cr, l, eq.press.)	-286.275	-285.802	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*499
12.6	Water	H2O (l, eq.press.)		-285.802	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*589
12.6	Oxonium	[H3O]+ (aq)		-285.801	± 0.022	kJ/mol	19.02267 ± 0.00037	13968-08-6*800
12.6	Water	H2O (l)		-285.801	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*590
12.6	Water	H2O (cr,l)	-286.273	-285.801	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*500
12.6	Water	H2O (g, ortho)	-238.618	-241.806	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*1

Most Influential reactions involving (CH3)2CHCH2C(CH3)3 (cr,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
1.000	7779.1	(CH3)2CHCH2C(CH3)3 (cr,l) → (CH3)2CHCH2C(CH3)3 (g)	Δ_rH°(298.15 K) = 8.40 ± 0.01 kcal/mol	Osborne 1947, as quoted by Pedley 1986
1.000	7778.1	(CH3)2CHCH2C(CH3)3 (cr,l) + 25/2 O2 (g) → 8 CO2 (g) + 9 H2O (cr,l)	Δ_rH°(298.15 K) = -1305.30 ± 0.35 kcal/mol	Prosen 1945b, as quoted by Pedley 1986

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. 1.202 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		B. Ruscic and D. H. Bross Accurate and Reliable Thermochemistry by Data Analysis of Complex Thermochemical Networks using Active Thermochemical Tables: The Case of Glycine Thermochemistry Faraday Discuss. (in press) (2024) [DOI: 10.1039/D4FD00110A]
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.