Trimethylsilyl fluoride


Reaction thermochemistry data

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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

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Individual Reactions

Fluorine anion + Trimethylsilyl fluoride = (Fluorine anion • Trimethylsilyl fluoride)

By formula: F- + C3H9FSi = (F- • C3H9FSi)

Quantity Value Units Method Reference Comment
Δr160. ± 8.4kJ/molIMRELarson and McMahon, 1985gas 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
Δr<230. ± 42.kJ/molIMRBMurphy and Beauchamp, 1977gas phase; B
Quantity Value Units Method Reference Comment
Δr92.J/mol*KN/ALarson and McMahon, 1985gas phase; switching reaction,Thermochemical ladder(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M
Quantity Value Units Method Reference Comment
Δr132. ± 8.4kJ/molIMRELarson and McMahon, 1985gas 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- + Hydrogen cation = Trimethylsilyl fluoride

By formula: C3H8FSi- + H+ = C3H9FSi

Quantity Value Units Method Reference Comment
Δr1625. ± 20.kJ/molG+TSAllison and McMahon, 1990gas phase; Between H2O, HO.; B
Quantity Value Units Method Reference Comment
Δr1591. ± 19.kJ/molIMRBAllison and McMahon, 1990gas phase; Between H2O, HO.; B

Gas phase ion energetics data

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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 ± 0.04PIMurphy and Beauchamp, 1977, 2LLK
10.55 ± 0.06EIHess, Lampe, et al., 1965RDSH
11.0PERoberge, Sandorfy, et al., 1978Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C2H6FSi+10.70 ± 0.04CH3PIMurphy and Beauchamp, 1977, 2LLK
C2H6FSi+11.11 ± 0.05CH3EIHess, Lampe, et al., 1965RDSH
C3H9Si+11.7 ± 0.5F-?EIHess, Lampe, et al., 1965RDSH

De-protonation reactions

C3H8FSi- + Hydrogen cation = Trimethylsilyl fluoride

By formula: C3H8FSi- + H+ = C3H9FSi

Quantity Value Units Method Reference Comment
Δr1625. ± 20.kJ/molG+TSAllison and McMahon, 1990gas phase; Between H2O, HO.; B
Quantity Value Units Method Reference Comment
Δr1591. ± 19.kJ/molIMRBAllison and McMahon, 1990gas phase; Between H2O, HO.; B

Gas Chromatography

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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

Normal alkane RI, non-polar column, temperature ramp

View large format table.

Column type Active phase I Reference Comment
CapillaryOV-101437.Zenkevich, 200525. m/0.20 mm/0.10 μm, N2/He, 6. K/min; Tstart: 50. C; Tend: 250. C

Normal alkane RI, non-polar column, custom temperature program

View large format table.

Column type Active phase I Reference Comment
CapillarySE-52416.van Langenhove and Schamp, 1986Column length: 100. m; Column diameter: 0.50 mm; Program: not specified

References

Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Gas Chromatography, 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]

Zenkevich, 2005
Zenkevich, I.G., Experimentally measured retention indices., 2005. [all data]

van Langenhove and Schamp, 1986
van Langenhove, H.; Schamp, N., Identification of Volatiles in the Head Space of Acid-Treated Phosphate Rock by Gas Chromatography-Mass Spectromety, J. Chromatogr., 1986, 351, 65-75, https://doi.org/10.1016/S0021-9673(01)83473-7 . [all data]


Notes

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