Difluorosilane
- Formula: F2H2Si
- Molecular weight: 68.0982
- IUPAC Standard InChI: InChI=1S/F2H2Si/c1-3-2/h3H2
- IUPAC Standard InChIKey: PUUOOWSPWTVMDS-UHFFFAOYSA-N
- CAS Registry Number: 13824-36-7
- Chemical structure:
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Gas phase thermochemistry data
Go To: Top, Phase change data, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | -189.00 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1976 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 62.648 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1976 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = A + B*t + C*t2 + D*t3 +
E/t2
H° − H°298.15= A*t + B*t2/2 +
C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 −
E/(2*t2) + G
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 298. to 1200. | 1200. to 6000. |
|---|---|---|
| A | 5.907890 | 24.52849 |
| B | 34.37340 | 0.692661 |
| C | -24.77170 | -0.134875 |
| D | 6.740459 | 0.009070 |
| E | -0.104087 | -3.093421 |
| F | -192.4340 | -203.7210 |
| G | 60.00509 | 82.12729 |
| H | -189.0000 | -189.0000 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in June, 1976 | Data last reviewed in June, 1976 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
AC - William E. Acree, Jr., James S. Chickos
Enthalpy of vaporization
| ΔvapH (kcal/mol) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 4.76 | 159. | Emel«65533»us and Maddock, 1944 | Based on data from 151. to 167. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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| Temperature (K) | A | B | C | Reference | Comment |
|---|---|---|---|---|---|
| 126.5 to 195.3 | 3.97626 | 657.142 | -30.551 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Phase change data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 11. ± 1. | EI | Farber and Srivastava, 1977 | |
| 12.2 | PE | Chadwick, Cornford, et al., 1972 | |
| 12.85 | PE | Chadwick, Cornford, et al., 1972 | Vertical value |
| 12.85 | PE | Frost, Herring, et al., 1971 | Vertical value |
| 12.9 ± 0.1 | PE | Cradock and Whiteford, 1971 | Vertical value |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Chase, 1998
Chase, M.W., Jr.,
NIST-JANAF Themochemical Tables, Fourth Edition,
J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]
Emel«65533»us and Maddock, 1944
Emel«65533»us, H.J.; Maddock, A.G.,
77. Derivatives of monosilane. Part III. The fluoromonosilanes,
J. Chem. Soc., 1944, 293, https://doi.org/10.1039/jr9440000293
. [all data]
Stull, 1947
Stull, Daniel R.,
Vapor Pressure of Pure Substances. Organic and Inorganic Compounds,
Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022
. [all data]
Farber and Srivastava, 1977
Farber, M.; Srivastava, R.D.,
Mass spectrometric determination of the heats of formation of the silane fluorides,
Chem. Phys. Lett., 1977, 51, 307. [all data]
Chadwick, Cornford, et al., 1972
Chadwick, D.; Cornford, A.B.; Frost, D.C.; Herring, F.G.; Katrib, A.; McDowell, C.A.; McLean, R.A.N.,
Photoelectron spectra of some dihalocompounds
in Electron spectroscopy, ed. D.A. Shirley (North-Holland Publixhing Co, Amsterdam), 1972, 453. [all data]
Frost, Herring, et al., 1971
Frost, D.C.; Herring, F.G.; Katrib, A.; McLean, R.A.N.; Drake, J.E.; Westwood, N.P.C.,
Photoelectron spectra and bonding in some halosilanes,
Can. J. Chem., 1971, 49, 4033. [all data]
Cradock and Whiteford, 1971
Cradock, S.; Whiteford, R.A.,
Photo-electron spectra of the mono and dihalo silanes and germanes,
J. Chem. Soc. Faraday Trans., 1971, 67, 3425. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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