Boric acid, trimethyl ester
- Formula: C3H9BO3
- Molecular weight: 103.913
- IUPAC Standard InChIKey: WRECIMRULFAWHA-UHFFFAOYSA-N
- CAS Registry Number: 121-43-7
- 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: Trimethoxyborane; Boric acid (H3BO3), trimethyl ester; Borester O; Methyl borate; Trimethoxyborine; Trimethoxyboron; Trimethyl borate; B(OCH3)3; Methyl borate, ((MeO)3B); Trimethylester kyseliny borite; UN 2416; NSC 777
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Condensed phase 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 by: Eugene S. Domalski and Elizabeth D. Hearing
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
45.39 | 298.15 | Hansen and Hughes, 1959 | T = 273 to 453 K. Cp(liq) = 0.75534 + 0.0012419t Btu/lb*K (0 to 180°C). Cp value calculated from equation. |
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
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- + C3H9BO3 = (F- • C3H9BO3)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 42.0 ± 4.0 | kcal/mol | IMRB | 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 |
ΔrG° | 34.0 ± 3.0 | kcal/mol | IMRB | 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 |
By formula: CN- + C3H9BO3 = (CN- • C3H9BO3)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 19.6 ± 1.0 | kcal/mol | IMRE | Larson, Szulejko, et al., 1988 | gas phase; B,M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 35. | cal/mol*K | N/A | Larson, Szulejko, et al., 1988 | gas phase; switching reaction,Thermochemical ladder(CN-)H2O, Entropy change calculated or estimated; Payzant, Yamdagni, et al., 1971; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 10.70 ± 0.50 | kcal/mol | IMRE | Larson, Szulejko, et al., 1988 | gas phase; B,M |
Gas phase ion energetics data
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
Data compiled as indicated in comments:
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 195.0 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 187.2 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.0 | PE | Kroner, Nolle, et al., 1973 | LLK |
10.62 | EI | Lappert, Litzow, et al., 1970 | RDSH |
10.8 ± 0.3 | EI | Wada and Kiser, 1964 | RDSH |
8.9 ± 0.2 | EI | Law and Margrave, 1956 | RDSH |
10.40 | PE | Kroner, Nolle, et al., 1973 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
B+ | 31.6 ± 1.0 | ? | EI | Law and Margrave, 1956 | RDSH |
BO2+ | 17.5 ± 0.3 | ? | EI | Wada and Kiser, 1964 | RDSH |
BO3+ | 13.2 ± 0.3 | ? | EI | Wada and Kiser, 1964 | RDSH |
BO3+ | 12.7 ± 1.0 | ? | EI | Law and Margrave, 1956 | RDSH |
CHO+ | 19.1 ± 0.3 | ? | EI | Wada and Kiser, 1964 | RDSH |
CH3+ | 13.6 ± 0.5 | ? | EI | Law and Margrave, 1956 | RDSH |
CH3O+ | 12.7 ± 0.2 | ? | EI | Wada and Kiser, 1964 | RDSH |
C2H5BO2+ | 13.2 ± 0.2 | ? | EI | Wada and Kiser, 1964 | RDSH |
C2H6BO+ | 16.6 ± 0.3 | ? | EI | Wada and Kiser, 1964 | RDSH |
C2H6BO2+ | 13.0 ± 0.2 | CH3O | EI | Wada and Kiser, 1964 | RDSH |
C2H6BO2+ | 9.6 ± 0.2 | CH3O | EI | Law and Margrave, 1956 | RDSH |
C2H6BO3+ | 12.1 ± 0.2 | CH3 | EI | Wada and Kiser, 1964 | RDSH |
References
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry 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.
Hansen and Hughes, 1959
Hansen, C.E.; Hughes, R.L.,
Thermal properties of methyl borate, U.S. Dept. Comm., Off. Tech. Serv.,
P. B. Report, 1959, No. 150-307, 45pp. [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]
Larson, Szulejko, et al., 1988
Larson, J.W.; Szulejko, J.E.; McMahon, T.B.,
Gas Phase Lewis Acid-Base Interactions. An Experimental Determination of Cyanide Binding Energies From Ion Cyclotron Resonance and High-Pressure Mass Spectrometric Equilibrium Measurements.,
J. Am. Chem. Soc., 1988, 110, 23, 7604, https://doi.org/10.1021/ja00231a004
. [all data]
Payzant, Yamdagni, et al., 1971
Payzant, J.D.; Yamdagni, R.; Kebarle, P.,
Hydration of CN-, NO2-, NO3-, and HO- in the gas phase,
Can. J. Chem., 1971, 49, 3308. [all data]
Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,
Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,
J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018
. [all data]
Kroner, Nolle, et al., 1973
Kroner, J.; Nolle, D.; Noth, H.,
Photoelektronenspektroskopische untersuchungen an bor-verbindungen, I Orbitalreihenfolgen und ladungsdichten in methylthiound methoxyborane,
Z. Naturforsch. B:, 1973, 28, 416. [all data]
Lappert, Litzow, et al., 1970
Lappert, M.F.; Litzow, M.R.; Pedley, J.B.; Riley, P.N.K.; Spalding, T.R.; Tweedale, A.,
Bonding studies of compounds of boron and the group IV elements. Part III.First ionisation potentials of some simple boron compounds by electron impact and by a new empirical molecular orbital method,
J. Chem. Soc. A, 1970, 2320. [all data]
Wada and Kiser, 1964
Wada, Y.; Kiser, R.W.,
A mass spectrometric study of trimethyl borate,
J. Phys. Chem., 1964, 68, 1588. [all data]
Law and Margrave, 1956
Law, R.W.; Margrave, J.L.,
Mass spectrometer appearance potentials for positive ion fragments from BF3, B(CH3)3, B(C2H5)3, B(OCH3)3, and HB(OCH3)2,
J. Chem. Phys., 1956, 25, 1086. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Cp,liquid Constant pressure heat capacity of liquid 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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