Selected ATcT [1, 2] enthalpy of formation based on version 1.148 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.140 to include species relevant to a recent study of the role of atmospheric methanediol[4].

Disilene cation

Formula: [SiH2SiH2]+ (g)

CAS RN: 108492-63-3

ATcT ID: 108492-63-3*0

SMILES: [SiH2]=[SiH2+]

InChI: InChI=1S/H4Si2/c1-2/h1-2H2/q+1

InChIKey: HVEZKWVGYFPQFX-UHFFFAOYSA-N

Hills Formula: H4Si2+

2D Image:

Aliases: [SiH2SiH2]+; Disilene cation; Disilene ion (1+); SiH2SiH2+

Relative Molecular Mass: 60.20221 ± 0.00066

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
1069.3	1060.3	± 2.0	kJ/mol

3D Image of [SiH2SiH2]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [SiH2SiH2]+ (g)

The 20 contributors listed below account only for 61.6% of the provenance of Δ_fH° of [SiH2SiH2]+ (g).
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
9.6	8328.5	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.128 ± 0.040 eV	Ruscic W1RO
6.4	8316.1	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.09 ± 0.03 eV	Ruscic 1991e
6.1	8328.1	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.10 ± 0.05 eV	Ruscic 1991d
4.9	8198.1	Si (cr,l) + 2 F2 (g) → SiF4 (g)	Δ_rH°(298.15 K) = -385.98 ± 0.19 kcal/mol	Wise 1963, Wise 1963, Wise 1962
3.6	8316.5	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.061 ± 0.040 eV	Ruscic W1RO
3.5	8291.1	SiH3SiH3 (g) → 2 Si (cr,l) + 3 H2 (g)	Δ_rH°(298.15 K) = -19.1 ± 0.6 (×1.61) kcal/mol	Gunn 1961, est unc
3.2	8342.5	SiH3SiH3 (g) → [SiH3SiH]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.706 ± 0.040 eV	Ruscic W1RO
3.0	8255.1	SiH4 (g) → Si (cr,l) + 2 H2 (g)	Δ_rH°(298.15 K) = -8.3 ± 0.5 kcal/mol	Gunn 1961, Gurvich TPIS, est unc
2.9	8328.3	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.133 ± 0.073 eV	Ruscic G4
2.2	8141.2	Si (cr,l) → Si (g)	Δ_rG°(1525 K) = 231.1 ± 2.0 kJ/mol	Batdorf 1959, 3rd Law
1.9	546.1	SiF4 (g) + 2 H2O (cr,l) → Si (cr,l) + O2 (g) + 4 HF (aq, 5 H2O)	Δ_rH°(298.15 K) = 899.77 ± 1.20 kJ/mol	Paulechka 2020, Vorobev 1960, Hummel 1959, Johnson 1987, Good 1964, Good 1964, Johnson 1973
1.7	8328.2	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.131 ± 0.093 eV	Ruscic G3X
1.7	8341.4	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -13.33 ± 0.90 kcal/mol	Ruscic W1RO
1.6	8288.8	SiH3SiH3 (g) → 2 Si (g) + 6 H (g)	Δ_rH°(0 K) = 503.09 ± 0.30 kcal/mol	Karton 2011, Karton 2007b
1.5	8328.4	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.086 ± 0.099 eV	Ruscic CBS-n
1.4	8371.4	Si(HSiH3) (g, triplet) → [Si(HSiH3)]+ (g)	Δ_rH°(0 K) = 7.288 ± 0.040 eV	Ruscic W1RO
1.4	8176.6	SiO2 (cr,l) + Si (cr,l) → 2 SiO (g)	Δ_rG°(1618 K) = 37.94 ± 0.29 kcal/mol	Ramstad 1961, 3rd Law, Gurvich TPIS
1.4	8341.2	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -12.94 ± 1.00 kcal/mol	Ruscic G4
1.3	8198.3	Si (cr,l) + 2 F2 (g) → SiF4 (g)	Δ_rH°(298.15 K) = -1615.78 ± 0.46 (×3.292) kJ/mol	Johnson 1986, Johnson 1986
1.2	8168.10	SiO (g) → Si (g) + O (g)	Δ_rH°(0 K) = 190.23 ± 0.30 kcal/mol	Karton 2011

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [SiH2SiH2]+ (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
68.9	Disilene	SiH2SiH2 (g, singlet)	288.6	280.0	± 1.8	kJ/mol	60.20276 ± 0.00066	15435-77-5*2
68.9	Disilene	SiH2SiH2 (g)	288.6	280.0	± 1.8	kJ/mol	60.20276 ± 0.00066	15435-77-5*0
67.0	1-Disilanylium-1-yl	[SiH3SiH]+ (g)	1124.0	1116.4	± 2.2	kJ/mol	60.20221 ± 0.00066	108492-64-4*0
66.6	mu-Hydrotrihydrodisilicon cation	[Si(HSiH3)]+ (g)	1160.0	1151.9	± 2.6	kJ/mol	60.20221 ± 0.00066	497967-55-20
62.4	Silylsilylene	SiH3SiH (g)	317.2	309.4	± 2.0	kJ/mol	60.20276 ± 0.00066	50420-90-1*0
62.4	Silylsilylene	SiH3SiH (g, singlet)	317.2	309.4	± 2.0	kJ/mol	60.20276 ± 0.00066	50420-90-1*2
61.1	Disilane	SiH3SiH3 (g)	92.0	75.9	± 1.3	kJ/mol	62.21864 ± 0.00073	1590-87-0*0
58.3	Silane	SiH4 (g)	42.66	33.04	± 0.63	kJ/mol	32.11726 ± 0.00041	7803-62-5*0
57.7	mu-Hydrotrihydrodisilicon	SiH2(HSiH) (g)	317.7	307.6	± 2.2	kJ/mol	60.20276 ± 0.00066	497967-56-3*0
55.8	Disilanyl	SiH3SiH2 (g)	242.5	230.5	± 1.6	kJ/mol	61.21070 ± 0.00069	73151-72-1*0

Most Influential reactions involving [SiH2SiH2]+ (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
0.263	8375.4	[Si(HSiH3)]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -22.45 ± 0.90 kcal/mol	Ruscic W1RO
0.262	8316.1	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.09 ± 0.03 eV	Ruscic 1991e
0.213	8375.2	[Si(HSiH3)]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -21.18 ± 1.00 kcal/mol	Ruscic G4
0.202	8341.4	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -13.33 ± 0.90 kcal/mol	Ruscic W1RO
0.176	8375.1	[Si(HSiH3)]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -20.87 ± 1.10 kcal/mol	Ruscic G3X
0.163	8341.2	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -12.94 ± 1.00 kcal/mol	Ruscic G4
0.161	8328.5	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.128 ± 0.040 eV	Ruscic W1RO
0.147	8316.5	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.061 ± 0.040 eV	Ruscic W1RO
0.135	8341.1	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -12.93 ± 1.10 kcal/mol	Ruscic G3X
0.126	8375.3	[Si(HSiH3)]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -20.87 ± 1.30 kcal/mol	Ruscic CBS-n
0.103	8328.1	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.10 ± 0.05 eV	Ruscic 1991d
0.096	8341.3	[SiH3SiH]+ (g) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = -12.65 ± 1.30 kcal/mol	Ruscic CBS-n
0.048	8328.3	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.133 ± 0.073 eV	Ruscic G4
0.044	8316.3	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.150 ± 0.073 eV	Ruscic G4
0.029	8328.2	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.131 ± 0.093 eV	Ruscic G3X
0.027	8316.2	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.151 ± 0.093 eV	Ruscic G3X
0.026	8328.4	SiH3SiH3 (g) → [SiH2SiH2]+ (g) + H2 (g)	Δ_rH°(0 K) = 10.086 ± 0.099 eV	Ruscic CBS-n
0.024	8316.4	SiH2SiH2 (g, singlet) → [SiH2SiH2]+ (g)	Δ_rH°(0 K) = 8.105 ± 0.099 eV	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. 1.148 of the Thermochemical Network (2023); available at ATcT.anl.gov
4		T. L. Nguyen, J. Peeters, J.-F. Müller, A. Perera, D. H. Bross, B. Ruscic, and J. F. Stanton, Methanediol from Cloud-Processed Formaldehyde is Only a Minor Source of Atmospheric Formic Acid Natl. Acad. Sci. 120, e2304650120/1-8 (2023) [DOI: 10.1073/pnas.2304650120]
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.