Trimethylsilyl fluoride
- Formula: C3H9FSi
- Molecular weight: 92.1875
- IUPAC Standard InChIKey: CTIKAHQFRQTTAY-UHFFFAOYSA-N
- CAS Registry Number: 420-56-4
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: Silane, fluorotrimethyl-; Fluorotrimethylsilane; Trimethylfluorosilane; Trimethylsilicon fluoride; (CH3)3SiF; Ffluorotrimethylsilane
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Reaction thermochemistry data
Go To: Top, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), 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:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
By formula: F- + C3H9FSi = (F- • C3H9FSi)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 38.2 ± 2.0 | kcal/mol | IMRE | Larson and McMahon, 1985 | gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M |
ΔrH° | <54. ± 10. | kcal/mol | IMRB | Murphy and Beauchamp, 1977 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 22. | cal/mol*K | N/A | Larson and McMahon, 1985 | gas phase; switching reaction,Thermochemical ladder(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 31.6 ± 2.0 | kcal/mol | IMRE | Larson and McMahon, 1985 | gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M |
C3H8FSi- + =
By formula: C3H8FSi- + H+ = C3H9FSi
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 388.5 ± 4.7 | kcal/mol | G+TS | Allison and McMahon, 1990 | gas phase; Between H2O, HO.; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 380.2 ± 4.6 | kcal/mol | IMRB | Allison and McMahon, 1990 | gas phase; Between H2O, HO.; B |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry data, Ion clustering data, Mass spectrum (electron ionization), 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:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.31 ± 0.04 | PI | Murphy and Beauchamp, 1977, 2 | LLK |
10.55 ± 0.06 | EI | Hess, Lampe, et al., 1965 | RDSH |
11.0 | PE | Roberge, Sandorfy, et al., 1978 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C2H6FSi+ | 10.70 ± 0.04 | CH3 | PI | Murphy and Beauchamp, 1977, 2 | LLK |
C2H6FSi+ | 11.11 ± 0.05 | CH3 | EI | Hess, Lampe, et al., 1965 | RDSH |
C3H9Si+ | 11.7 ± 0.5 | F-? | EI | Hess, Lampe, et al., 1965 | RDSH |
De-protonation reactions
C3H8FSi- + =
By formula: C3H8FSi- + H+ = C3H9FSi
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 388.5 ± 4.7 | kcal/mol | G+TS | Allison and McMahon, 1990 | gas phase; Between H2O, HO.; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 380.2 ± 4.6 | kcal/mol | IMRB | Allison and McMahon, 1990 | gas phase; Between H2O, HO.; B |
Ion clustering data
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: F- + C3H9FSi = (F- • C3H9FSi)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 38.2 ± 2.0 | kcal/mol | IMRE | Larson and McMahon, 1985 | gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M |
ΔrH° | <54. ± 10. | kcal/mol | IMRB | Murphy and Beauchamp, 1977 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 22. | cal/mol*K | N/A | Larson and McMahon, 1985 | gas phase; switching reaction,Thermochemical ladder(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 31.6 ± 2.0 | kcal/mol | IMRE | Larson and McMahon, 1985 | gas phase; These relative affinities are ca. 10 kcal/mol weaker than threshold values (see Wenthold and Squires, 1995) for donors greater than ca. 27 kcal/mol in free energy. This discrepancy has not yet been resolved, though the stronger value appears preferable.; B,M |
Mass spectrum (electron ionization)
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering 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: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | R.W.CRAWFORD UNIV. OF CALIFORNIA, LIVERMORE, CALIFORNIA, USA |
NIST MS number | 776 |
References
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Larson and McMahon, 1985
Larson, J.W.; McMahon, T.B.,
Fluoride and chloride affinities of the main group oxides, fluorides, oxofluorides, and alkyls. Quantitative scales of lewis acidities from ICR halide exchange equilibria,
J. Am. Chem. Soc., 1985, 107, 766. [all data]
Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R.,
Bond dissociation energies of F2(-) and HF2(-). A gas-phase experimental and G2 theoretical study,
J. Phys. Chem., 1995, 99, 7, 2002, https://doi.org/10.1021/j100007a034
. [all data]
Murphy and Beauchamp, 1977
Murphy, M.K.; Beauchamp, J.L.,
Methyl and Fluorine Substituent Effects on the Gas Phase Lewis Acidities of Silanes by ICR Spectroscopy,
J. Am. Chem. Soc., 1977, 99, 15, 4992, https://doi.org/10.1021/ja00457a017
. [all data]
Arshadi, Yamdagni, et al., 1970
Arshadi, M.; Yamdagni, R.; Kebarle, P.,
Hydration of Halide Negative Ions in the Gas Phase. II. Comparison of Hydration Energies for the Alkali Positive and Halide Negative Ions,
J. Phys. Chem., 1970, 74, 7, 1475, https://doi.org/10.1021/j100702a014
. [all data]
Allison and McMahon, 1990
Allison, C.E.; McMahon, T.B.,
How Strong is the Si=C Bond in Fluoro- and Methyl Substituted Silaethylenes? An Experimental Determination of Pi Bond Strengths,
J. Am. Chem. Soc., 1990, 112, 5, 1672, https://doi.org/10.1021/ja00161a002
. [all data]
Murphy and Beauchamp, 1977, 2
Murphy, M.K.; Beauchamp, J.L.,
Photoionization mass spectrometry of the fluoromethylsilanes (CH3)n F4-nSi (n = 1-4),
J. Am. Chem. Soc., 1977, 99, 2085. [all data]
Hess, Lampe, et al., 1965
Hess, G.G.; Lampe, F.W.; Sommer, L.H.,
An electron impact study of ionization and dissociation of trimethylsilanes,
J. Am. Chem. Soc., 1965, 87, 5327. [all data]
Roberge, Sandorfy, et al., 1978
Roberge, R.; Sandorfy, C.; Matthews, J.I.; Strausz, O.P.,
The far ultraviolet HeI photoelectron spectra of alkyl and fluorine substituted silane derivatives,
J. Chem. Phys., 1978, 69, 5105. [all data]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, Mass spectrum (electron ionization), References
- Symbols used in this document:
AE Appearance energy ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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