Borane, trimethyl-

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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 + Borane, trimethyl- = (Fluorine anion • Borane, trimethyl-)

By formula: F- + C3H9B = (F- • C3H9B)

Quantity Value Units Method Reference Comment
Δr58.50kcal/molIMRBMurphy and Beauchamp, 1977gas phase; MeSiF3>Me3B>SF4; B
Δr47.2 ± 2.0kcal/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
Quantity Value Units Method Reference Comment
Δr25.cal/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
Δr39.7 ± 2.0kcal/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

C3H8B- + Hydrogen cation = Borane, trimethyl-

By formula: C3H8B- + H+ = C3H9B

Quantity Value Units Method Reference Comment
Δr366.2 ± 6.1kcal/molG+TSMurphy and Beauchamp, 1976gas phase; Between AsH3,PH3; value altered from reference due to change in acidity scale; B
Quantity Value Units Method Reference Comment
Δr358.9 ± 6.0kcal/molIMRBMurphy and Beauchamp, 1976gas phase; Between AsH3,PH3; value altered from reference due to change in acidity scale; B

References

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Murphy and Beauchamp, 1977
Murphy, M.K.; Beauchamp, J.L., Fluorine and Alkyl Substituent Effects on Gas-Phase Lewis Acidities of Boranes by ICR Spectroscopy, Inorg. Chem., 1977, 16, 2437. [all data]

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]

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]

Murphy and Beauchamp, 1976
Murphy, M.K.; Beauchamp, J.L., Acid-base properties and gas-phase ion chemistry of (CH3)3B, J. Am. Chem. Soc., 1976, 98, 1433. [all data]


Notes

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