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].

Indenylium

Formula: [C6H4(CHCHCH)]+ (g)

CAS RN: 12203-21-3

ATcT ID: 12203-21-3*0

SMILES: c1ccc2c(c1)C=C[CH+]2

InChI: InChI=1S/C9H7/c1-2-5-9-7-3-6-8(9)4-1/h1-7H/q+1

InChIKey: GGKQYPHNJHXVCL-UHFFFAOYSA-N

Hills Formula: C9H7

2D Image:

Aliases: [C6H4(CHCHCH)]+; Indenylium; 1H-Inden-1-ylium; Indenyl cation; Indenyl ion (1+); 1H-Inden-1-yl cation; 1H-Inden-1-yl ion (1+); Indenocarbonium; 885019-53-4

Relative Molecular Mass: 115.1513 ± 0.0072

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
1030.2	1010.7	± 2.0	kJ/mol

3D Image of [C6H4(CHCHCH)]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [C6H4(CHCHCH)]+ (g)

The 20 contributors listed below account only for 77.2% of the provenance of Δ_fH° of [C6H4(CHCHCH)]+ (g).
A total of 40 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
19.9	7125.6	C6H4(CHCHCH2) (g) → [C6H4(CHCHCH)]+ (g, singlet) + H (g)	Δ_rH°(0 K) = 11.016 ± 0.040 eV	Ruscic W1RO
7.2	7115.6	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 7.572 ± 0.040 eV	Ruscic W1RO
5.9	7125.3	C6H4(CHCHCH2) (g) → [C6H4(CHCHCH)]+ (g, singlet) + H (g)	Δ_rH°(0 K) = 11.028 ± 0.073 eV	Ruscic G4
5.6	7125.5	C6H4(CHCHCH2) (g) → [C6H4(CHCHCH)]+ (g, singlet) + H (g)	Δ_rH°(0 K) = 11.054 ± 0.075 eV	Ruscic CBS-n
5.1	7115.1	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 7.53 ± 0.02 (×2.378) eV	Hemberger 2010a, est unc
3.9	7116.1	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, triplet)	Δ_rH°(0 K) = 8.10 ± 0.02 eV	Hemberger 2010a, est unc
3.6	7125.2	C6H4(CHCHCH2) (g) → [C6H4(CHCHCH)]+ (g, singlet) + H (g)	Δ_rH°(0 K) = 11.010 ± 0.093 eV	Ruscic G3X
3.2	7125.4	C6H4(CHCHCH2) (g) → [C6H4(CHCHCH)]+ (g, singlet) + H (g)	Δ_rH°(0 K) = 11.063 ± 0.099 eV	Ruscic CBS-n
2.5	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
2.2	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
2.2	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
2.2	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
2.0	7115.5	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 7.597 ± 0.075 eV	Ruscic CBS-n
1.8	7124.3	C6H4(CHCHCH2) (g) + CH(CHCHCHCH) (g) → C6H4(CHCHCH) (g) + CH2(CHCHCHCH) (g)	Δ_rH°(0 K) = -1.79 ± 1.00 kcal/mol	Ruscic CBS-n
1.7	7122.5	[C6H4(CHCHCH)]+ (g, singlet) → [C6H4(CHCHCH)]+ (g, triplet)	Δ_rH°(0 K) = 4447 ± 420 cm-1	Ruscic W1RO
1.6	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
1.6	7115.3	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 7.660 ± 0.073 (×1.164) eV	Ruscic G4
1.5	7122.2	[C6H4(CHCHCH)]+ (g, singlet) → [C6H4(CHCHCH)]+ (g, triplet)	Δ_rH°(0 K) = 4315 ± 450 cm-1	Ruscic G4
1.4	7122.4	[C6H4(CHCHCH)]+ (g, singlet) → [C6H4(CHCHCH)]+ (g, triplet)	Δ_rH°(0 K) = 3960 ± 455 cm-1	Ruscic CBS-n
1.3	7115.2	C6H4(CHCHCH) (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 7.561 ± 0.093 eV	Ruscic G3X

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [C6H4(CHCHCH)]+ (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
100.0	Indenylium	[C6H4(CHCHCH)]+ (g, singlet)	1030.2	1010.7	± 2.0	kJ/mol	115.1513 ± 0.0072	12203-21-3*2
60.3	Indenylium	[C6H4(CHCHCH)]+ (g, triplet)	1081.2	1061.6	± 2.2	kJ/mol	115.1513 ± 0.0072	12203-21-3*1
59.0	Indenyl	C6H4(CHCHCH) (g)	299.2	279.2	± 1.6	kJ/mol	115.1519 ± 0.0072	71551-80-9*0
58.9	Indenide	[C6H4(CHCHCH)]- (g)	125.3	105.3	± 1.6	kJ/mol	115.1524 ± 0.0072	12128-54-0*0
34.9	Indene	C6H4(CHCHCH2) (g)	183.77	159.88	± 0.72	kJ/mol	116.1598 ± 0.0072	95-13-6*0
34.5	Indene cation	[C6H4(CHCHCH2)]+ (g)	969.94	946.70	± 0.73	kJ/mol	116.1593 ± 0.0072	42949-13-3*0
20.6	Indene	C6H4(CHCHCH2) (cr,l)	117.22	109.93	± 0.85	kJ/mol	116.1598 ± 0.0072	95-13-6*500
17.5	Cyclopentadienyl	CH(CHCHCHCH) (g)	275.59	262.48	± 0.80	kJ/mol	65.0932 ± 0.0040	2143-53-5*0
17.4	Cyclopentadienylium	[CH(CHCHCHCH)]+ (g)	1088.68	1075.82	± 0.80	kJ/mol	65.0927 ± 0.0040	29661-18-5*0
14.5	Cyclopentadienide	[CH(CHCHCHCH)]- (g)	101.15	88.18	± 0.96	kJ/mol	65.0937 ± 0.0040	12127-83-2*0

Most Influential reactions involving [C6H4(CHCHCH)]+ (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
1.000	7121.1	[C6H4(CHCHCH)]+ (g) → [C6H4(CHCHCH)]+ (g, singlet)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic W1RO, Ruscic G4, 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. 1.172 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.