Borane, trimethyl-
- Formula: C3H9B
- Molecular weight: 55.915
- IUPAC Standard InChI: InChI=1S/C3H9B/c1-4(2)3/h1-3H3
- IUPAC Standard InChIKey: WXRGABKACDFXMG-UHFFFAOYSA-N
- CAS Registry Number: 593-90-8
- Chemical structure:
This structure is also available as a 2d Mol file - Other names: Trimethylborane; Trimethylboron; (CH3)3B
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Reaction thermochemistry data
Go To: Top, 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- + C3H9B = (F- • C3H9B)
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 58.50 | kcal/mol | IMRB | Murphy and Beauchamp, 1977 | gas phase; MeSiF3>Me3B>SF4; B |
| ΔrH° | 47.2 ± 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 |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrS° | 25. | 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° | 39.7 ± 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 |
C3H8B- + =
By formula: C3H8B- + H+ = C3H9B
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 366.2 ± 6.1 | kcal/mol | G+TS | Murphy and Beauchamp, 1976 | gas phase; Between AsH3,PH3; value altered from reference due to change in acidity scale; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 358.9 ± 6.0 | kcal/mol | IMRB | Murphy and Beauchamp, 1976 | gas phase; Between AsH3,PH3; value altered from reference due to change in acidity scale; B |
References
Go To: Top, Reaction thermochemistry data, Notes
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
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
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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