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].

Difluorosilylene

Formula: SiF2 (g, singlet)

CAS RN: 13966-66-0

ATcT ID: 13966-66-0*2

SMILES: F[Si]F

InChI: InChI=1S/F2Si/c1-3-2

InChIKey: MGNHOGAVECORPT-UHFFFAOYSA-N

Hills Formula: F2Si1

2D Image:

Aliases: SiF2; Difluorosilylene; Silicon difluoride; Silylene difluoride

Relative Molecular Mass: 66.08231 ± 0.00030

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-629.1	-630.0	± 1.3	kJ/mol

3D Image of SiF2 (g, singlet)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of SiF2 (g, singlet)

The 20 contributors listed below account only for 81.4% of the provenance of Δ_fH° of SiF2 (g, singlet).
A total of 34 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
27.3	8510.5	SiF2 (g, singlet) → Si (g) + 2 F (g)	Δ_rH°(0 K) = 294.7 ± 0.5 kcal/mol	Feller 1999a, Feller 1999a
25.4	8532.5	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.6 ± 0.5 kcal/mol	Feller 1999a, Feller 1999a
4.0	8491.1	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
2.8	8532.4	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.90 ± 1.50 kcal/mol	Ruscic W1RO
2.4	8532.2	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.13 ± 1.60 kcal/mol	Ruscic G4
2.1	8532.1	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.71 ± 1.72 kcal/mol	Ruscic G3X
1.7	8512.5	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.814 ± 0.040 eV	Ruscic W1RO
1.5	8532.6	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 155.17 ± 2 kcal/mol	Ricca 1998, est unc
1.5	8521.4	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 105.55 ± 1.50 kcal/mol	Ruscic W1RO
1.5	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
1.3	8532.3	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.84 ± 2.16 kcal/mol	Ruscic CBS-n
1.3	8521.2	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 105.00 ± 1.60 kcal/mol	Ruscic G4
1.1	8521.1	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 104.74 ± 1.72 kcal/mol	Ruscic G3X
1.1	8491.3	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
1.0	8434.2	Si (cr,l) → Si (g)	Δ_rG°(1525 K) = 231.1 ± 2.0 kJ/mol	Batdorf 1959, 3rd Law
1.0	8512.1	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.78 ± 0.05 (×1.044) eV	Westwood 1974
0.9	8584.1	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
0.8	8521.5	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 105.66 ± 2 kcal/mol	Ricca 1998, est unc
0.8	8548.1	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
0.8	8522.5	SiF4 (g) + SiF2 (g, singlet) → 2 SiF3 (g)	Δ_rH°(0 K) = 251.42 ± 4.6 kJ/mol	Guo 2023

Top 10 species with enthalpies of formation correlated to the Δ_fH° of SiF2 (g, singlet)

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	Difluorosilylene	SiF2 (g)	-629.1	-630.0	± 1.3	kJ/mol	66.08231 ± 0.00030	13966-66-0*0
100.0	Difluorosilylene	SiF2 (g, triplet)	-314.3	-314.9	± 1.3	kJ/mol	66.08231 ± 0.00030	13966-66-0*1
40.8	Trifluorosilyl	SiF3 (g)	-993.0	-996.0	± 1.3	kJ/mol	85.08071 ± 0.00030	14835-14-4*0
39.9	Difluorosilyliumyl	[SiF2]+ (g)	416.0	415.3	± 2.0	kJ/mol	66.08176 ± 0.00030	37300-76-8*0
39.4	Fluorosilylidyne	SiF (g, quartet)	297.19	298.41	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*2
39.4	Fluorosilylidyne	SiF (g)	-60.32	-58.48	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*0
39.4	Fluorosilylidyne	SiF (g, doublet)	-60.32	-58.48	± 0.62	kJ/mol	47.08390 ± 0.00030	11128-24-8*1
38.6	Difluorosilylene anion	[SiF2]- (g)	-652.8	-653.1	± 3.4	kJ/mol	66.08285 ± 0.00030	145089-80-1*0
36.9	Silicon	Si (g)	450.34	454.68	± 0.56	kJ/mol	28.08550 ± 0.00030	7440-21-3*0
36.9	Silicon anion	Si- (g)	316.28	319.26	± 0.56	kJ/mol	28.08605 ± 0.00030	14337-02-1*0

Most Influential reactions involving SiF2 (g, singlet)

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	8519.1	SiF2 (g, singlet) → SiF2 (g, triplet)	Δ_rH°(0 K) = 26319.478 ± 0.012 cm-1	Harper 1998
1.000	8518.1	SiF2 (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0 ± 0 cm-1	Ruscic W1RO, Ruscic G4, Ruscic CBS-n
0.411	8514.5	[SiF2]- (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0.242 ± 0.050 eV	Ruscic W1RO
0.333	8510.5	SiF2 (g, singlet) → Si (g) + 2 F (g)	Δ_rH°(0 K) = 294.7 ± 0.5 kcal/mol	Feller 1999a, Feller 1999a
0.328	8532.5	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.6 ± 0.5 kcal/mol	Feller 1999a, Feller 1999a
0.276	8514.3	[SiF2]- (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0.299 ± 0.061 eV	Ruscic G4
0.241	8522.5	SiF4 (g) + SiF2 (g, singlet) → 2 SiF3 (g)	Δ_rH°(0 K) = 251.42 ± 4.6 kJ/mol	Guo 2023
0.234	8512.5	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.814 ± 0.040 eV	Ruscic W1RO
0.142	8514.2	[SiF2]- (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0.239 ± 0.085 eV	Ruscic G3X
0.137	8512.1	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.78 ± 0.05 (×1.044) eV	Westwood 1974
0.121	8514.4	[SiF2]- (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0.198 ± 0.092 eV	Ruscic CBS-n
0.070	8512.3	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.881 ± 0.073 eV	Ruscic G4
0.049	8521.4	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 105.55 ± 1.50 kcal/mol	Ruscic W1RO
0.047	8514.1	[SiF2]- (g) → SiF2 (g, singlet)	Δ_rH°(0 K) = 0.10 ± 0.10 (×1.477) eV	Kawamata 1996
0.043	8512.2	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.898 ± 0.093 eV	Ruscic G3X
0.043	8521.2	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 105.00 ± 1.60 kcal/mol	Ruscic G4
0.038	8512.4	SiF2 (g, singlet) → [SiF2]+ (g)	Δ_rH°(0 K) = 10.812 ± 0.099 eV	Ruscic CBS-n
0.037	8521.1	SiF3 (g) → SiF2 (g, singlet) + F (g)	Δ_rH°(0 K) = 104.74 ± 1.72 kcal/mol	Ruscic G3X
0.036	8532.4	SiF2 (g, singlet) → SiF (g, doublet) + F (g)	Δ_rH°(0 K) = 154.90 ± 1.50 kcal/mol	Ruscic W1RO
0.032	8522.4	SiF4 (g) + SiF2 (g, singlet) → 2 SiF3 (g)	Δ_rH°(0 K) = 60.01 ± 3.00 kcal/mol	Ruscic W1RO

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.