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].

Benzylium

Formula: [C6H5CH2]+ (g)

CAS RN: 6711-19-9

ATcT ID: 6711-19-9*0

SMILES: c1ccc(cc1)[CH2+]

InChI: InChI=1S/C7H7/c1-7-5-3-2-4-6-7/h2-6H,1H2/q+1

InChIKey: URXQGZXYWAWBIG-UHFFFAOYSA-N

Hills Formula: C7H7+

2D Image:

Aliases: [C6H5CH2]+; Benzylium; Benzylium ion; Benzylium cation; Benzylium ion (1+); Benzyl cation; Benzyl ion (1+); Benzyl carbocation; Phenylmethylium; Phenylmethylium ion; Phenylmethylium cation; Phenylmethylium ion (1+); C6H5CH2+

Relative Molecular Mass: 91.1299 ± 0.0056

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
929.47	909.97	± 0.53	kJ/mol

3D Image of [C6H5CH2]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [C6H5CH2]+ (g)

The 20 contributors listed below account only for 58.5% of the provenance of Δ_fH° of [C6H5CH2]+ (g).
A total of 211 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
26.0	6868.1	[C6H5CH2]- (g) → C6H5CH2 (g)	Δ_rH°(0 K) = 0.912 ± 0.006 eV	Gunion 1992
5.8	6864.1	C6H5CH3 (l) + 9 O2 (g) → 7 CO2 (g) + 4 H2O (cr,l)	Δ_rH°(298.15 K) = -934.49 ± 0.12 kcal/mol	Prosen 1945a, as quoted by Cox 1970
5.8	6864.4	C6H5CH3 (l) + 9 O2 (g) → 7 CO2 (g) + 4 H2O (cr,l)	Δ_rH°(298.15 K) = -934.45 ± 0.12 kcal/mol	Good 1969
5.3	8938.1	C6H5CH2CH2C6H5 (g) → 2 C6H5CH2 (g)	Δ_rG°(1200 K) = 82.5 ± 4 kJ/mol	Hippler 1990, Muller-Markgraf 1988, 3rd Law, est unc
1.9	8938.3	C6H5CH2CH2C6H5 (g) → 2 C6H5CH2 (g)	Δ_rH°(0 K) = 67.13 ± 1.60 kcal/mol	Ruscic G4
1.0	8938.4	C6H5CH2CH2C6H5 (g) → 2 C6H5CH2 (g)	Δ_rH°(0 K) = 68.25 ± 2.16 kcal/mol	Ruscic CBS-n
1.0	2214.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
1.0	6874.5	C6H5CH2 (g) + CH3CH3 (g) → C6H5CH3 (g) + CH3CH2 (g)	Δ_rH°(0 K) = 10.34 ± 0.85 kcal/mol	Ruscic W1RO
1.0	6879.5	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.17 ± 0.85 kcal/mol	Ruscic W1RO
0.9	6873.5	C6H5CH3 (g) + CH3 (g) → C6H5CH2 (g) + CH4 (g)	Δ_rH°(0 K) = -14.13 ± 0.9 kcal/mol	Ruscic W1RO
0.9	6878.7	C6H5CH3 (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 11.134 ± 0.040 eV	Ruscic W1RO
0.8	6874.2	C6H5CH2 (g) + CH3CH3 (g) → C6H5CH3 (g) + CH3CH2 (g)	Δ_rH°(0 K) = 10.23 ± 0.90 kcal/mol	Ruscic G4
0.8	6874.4	C6H5CH2 (g) + CH3CH3 (g) → C6H5CH3 (g) + CH3CH2 (g)	Δ_rH°(0 K) = 9.99 ± 0.90 kcal/mol	Ruscic CBS-n
0.8	6879.1	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.77 ± 0.90 kcal/mol	Ruscic G3X
0.8	6879.2	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.09 ± 0.90 kcal/mol	Ruscic G4
0.8	6879.4	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 29.78 ± 0.90 kcal/mol	Ruscic CBS-n
0.8	6864.2	C6H5CH3 (l) + 9 O2 (g) → 7 CO2 (g) + 4 H2O (cr,l)	Δ_rH°(298.15 K) = -934.72 ± 0.11 (×2.89) kcal/mol	Coops 1946, as quoted by Cox 1970
0.8	6871.1	C6H5CH3 (g) → C6H5CH2 (g) + H (g)	Δ_rG°(1000 K) = 252.4 ± 4 kJ/mol	Hippler 1990, 3rd Law, note unc
0.7	6867.2	C6H5CH2 (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 58468 ± 5 cm-1	Eiden 1996
0.7	6873.2	C6H5CH3 (g) + CH3 (g) → C6H5CH2 (g) + CH4 (g)	Δ_rH°(0 K) = -14.19 ± 1.0 kcal/mol	Ruscic G4

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [C6H5CH2]+ (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
99.4	Benzyl	C6H5CH2 (g)	230.05	211.23	± 0.52	kJ/mol	91.1305 ± 0.0056	2154-56-5*0
56.4	Benzylide	[C6H5CH2]- (g)	141.95	123.04	± 0.40	kJ/mol	91.1310 ± 0.0056	18860-15-6*0
50.5	Toluene	C6H5CH3 (g)	73.34	50.05	± 0.31	kJ/mol	92.1384 ± 0.0056	108-88-3*0
49.6	Toluene	C6H5CH3 (l)	19.77	12.02	± 0.31	kJ/mol	92.1384 ± 0.0056	108-88-3*500
26.1	4,5-Bis(methylene)-2-cyclopenten-1-yl	CH(CHC(CH2)C(CH2)CH) (g)	315.2	297.0	± 2.0	kJ/mol	91.1305 ± 0.0056	302792-28-5*0
26.1	2-Methylphenyl	C6H4CH3 (g, ortho)	324.4	306.4	± 1.2	kJ/mol	91.1305 ± 0.0056	22904-44-5*0
26.0	2,5-Bis(methylene)-3-cyclopenten-1-yl	CH(C(CH2)CHCHC(CH2)) (g)	320.9	302.7	± 2.0	kJ/mol	91.1305 ± 0.0056	512782-58-0*0
25.6	4-Methylphenyl	C6H4CH3 (g, para)	327.1	309.1	± 1.2	kJ/mol	91.1305 ± 0.0056	2396-02-3*0
25.5	3-Methylphenyl	C6H4CH3 (g, meta)	324.3	306.3	± 1.2	kJ/mol	91.1305 ± 0.0056	3474-41-7*0
23.8	Tropyl	CH(CHCHCHCHCHCH) (g)	296.68	279.24	± 0.99	kJ/mol	91.1305 ± 0.0056	3551-27-7*0

Most Influential reactions involving [C6H5CH2]+ (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
0.872	6867.2	C6H5CH2 (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 58468 ± 5 cm-1	Eiden 1996
0.111	6867.1	C6H5CH2 (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 58456 ± 14 cm-1	Eiden 1991, Eiden 1991a
0.042	6947.7	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 7.04 ± 1.2 kcal/mol	Ruscic W1RO
0.036	6947.4	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 6.63 ± 1.3 kcal/mol	Ruscic G4
0.036	6947.6	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 8.02 ± 1.3 kcal/mol	Ruscic CBS-n
0.031	6947.3	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 6.67 ± 1.4 kcal/mol	Ruscic G3X
0.023	6947.5	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 7.77 ± 1.6 kcal/mol	Ruscic CBS-n
0.021	6879.5	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.17 ± 0.85 kcal/mol	Ruscic W1RO
0.019	6879.2	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.09 ± 0.90 kcal/mol	Ruscic G4
0.019	6879.4	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 29.78 ± 0.90 kcal/mol	Ruscic CBS-n
0.019	6879.1	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 30.77 ± 0.90 kcal/mol	Ruscic G3X
0.015	6879.3	[C6H5CH2]+ (g) + CH3CH3 (g) → C6H5CH3 (g) + [CH3CH2]+ (g)	Δ_rH°(0 K) = 29.93 ± 1.0 kcal/mol	Ruscic CBS-n
0.015	6939.1	CH2(CHCHCHCHCHCH) (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 9.738 ± 0.082 eV	Torma 2019
0.013	6878.7	C6H5CH3 (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 11.134 ± 0.040 eV	Ruscic W1RO
0.013	6867.3	C6H5CH2 (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 7.252 ± 0.005 eV	Savee 2015
0.011	6947.2	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 0.218 ± 0.080 (×1.242) eV	Torma 2019, est unc
0.011	6947.1	[CH(CHCHCHCHCHCH)]+ (g) → [C6H5CH2]+ (g)	Δ_rH°(0 K) = 0.218 ± 0.080 (×1.242) eV	Torma 2019, est unc
0.004	6878.4	C6H5CH3 (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 11.149 ± 0.073 eV	Ruscic G4
0.003	6878.6	C6H5CH3 (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 11.181 ± 0.075 eV	Ruscic CBS-n
0.003	6878.1	C6H5CH3 (g) → [C6H5CH2]+ (g) + H (g)	Δ_rH°(0 K) = 11.196 ± 0.080 (×1.067) eV	Torma 2019

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.