Methanethiol
- Formula: CH4S
- Molecular weight: 48.107
- IUPAC Standard InChI:
- InChI=1S/CH4S/c1-2/h2H,1H3
- Download the identifier in a file.
- IUPAC Standard InChIKey: LSDPWZHWYPCBBB-UHFFFAOYSA-N
- CAS Registry Number: 74-93-1
- 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: Methyl mercaptan; Mercaptomethane; CH3SH; Methyl sulfhydrate; Methyl thioalcohol; Mercaptan methylique; Methaanthiol; Methanthiol; Methvtiolo; Methylmercaptaan; Metilmercaptano; Rcra waste number U153; Thiomethanol; UN 1064; Methanethiole
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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
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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- + CH4S = (F- CH4S)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 143. ± 8.4 | kJ/mol | IMRE | Larson and McMahon, 1983 | 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 |
![]() | 97.1 | J/mol*K | N/A | Larson and McMahon, 1983 | gas phase; switching reaction(F-)H2O, Entropy change calculated or estimated; Arshadi, Yamdagni, et al., 1970; M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 114. ± 8.4 | kJ/mol | IMRE | Larson and McMahon, 1983 | 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 |
---|---|---|---|---|---|
![]() | 1496. ± 8.4 | kJ/mol | D-EA | Schwartz, Davico, et al., 2000 | gas phase; B |
![]() | 1496. ± 8.4 | kJ/mol | D-EA | Moran and Ellison, 1988 | gas phase; B |
![]() | 1493. ± 9.2 | kJ/mol | G+TS | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 1467. ± 8.4 | kJ/mol | IMRE | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
CH3S- + =
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 1654. ± 11. | kJ/mol | G+TS | Kass, Guo, et al., 1990 | gas phase; Acidity between D2O and Me2NH.; B |
![]() | 1638. ± 32. | kJ/mol | D-EA | Kass, Guo, et al., 1990 | gas phase; Between O2 and SO2. Explains bad anchor in McIver Jr. and Fukuda, 1982; B |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 1624. ± 10. | kJ/mol | IMRB | Kass, Guo, et al., 1990 | gas phase; Acidity between D2O and Me2NH.; B |
By formula: (CH6N+ 2C2H3N) + CH4S = (CH6N+
CH4S
2C2H3N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 33. | kJ/mol | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 84. | J/mol*K | N/A | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; Entropy change calculated or estimated; M |
Free energy of reaction
![]() |
T (K) | Method | Reference | Comment |
---|---|---|---|---|
10. | 270. | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; Entropy change calculated or estimated; M |
By formula: Cl- + CH4S = (Cl- CH4S)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 65. ± 13. | kJ/mol | IMRB | Staneke, Groothuis, et al., 1995 | gas phase; Chloride affinity comparable to that of CHCl3; B |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 45. ± 13. | kJ/mol | IMRB | Staneke, Groothuis, et al., 1995 | gas phase; Chloride affinity comparable to that of CHCl3; B |
By formula: C2H3O2- + CH4S = (C2H3O2- CH4S)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 62.3 ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B,M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 95.4 | J/mol*K | PHPMS | Meot-ner, 1988 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 34. ± 4.2 | kJ/mol | TDAs | Meot-ner, 1988 | gas phase; B |
By formula: (CH6N+ C2H3N) + CH4S = (CH6N+
CH4S
C2H3N)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 41. | kJ/mol | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 83.7 | J/mol*K | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; M |
By formula: CH6N+ + CH4S = (CH6N+ CH4S)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | 56.1 | kJ/mol | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
![]() | 92.5 | J/mol*K | PHPMS | Meot-Ner (Mautner) and Sieck, 1985 | gas phase; M |
By formula: HI + CH3IS = CH4S + I2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
![]() | -12.0 ± 2.3 | kJ/mol | Eqk | Shum and Benson, 1983 | gas phase; ALS |
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.
Larson and McMahon, 1983
Larson, J.W.; McMahon, T.B.,
Strong hydrogen bonding in gas-phase anions. An ion cyclotron resonance determination of fluoride binding energetics to bronsted acids from gas-phase fluoride exchange equilibria measurements,
J. Am. Chem. Soc., 1983, 105, 2944. [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]
Schwartz, Davico, et al., 2000
Schwartz, R.L.; Davico, G.E.; Lineberger, W.C.,
Negative-ion photoelectron spectroscopy of CH3S-,
J. Electron Spectros. Rel. Phenom., 2000, 108, 1-3, 163-168, https://doi.org/10.1016/S0368-2048(00)00125-0
. [all data]
Moran and Ellison, 1988
Moran, S.; Ellison, G.B.,
Photoelectron Spectroscopy of Sulfur Ions,
J. Phys. Chem., 1988, 92, 7, 1794, https://doi.org/10.1021/j100318a021
. [all data]
Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr.,
The gas phase acidity scale from methanol to phenol,
J. Am. Chem. Soc., 1979, 101, 6047. [all data]
Kass, Guo, et al., 1990
Kass, S.R.; Guo, H.-Z.; Dahlke, G.D.,
The Thiomethyl Anion: Formation, Reactivity, and Thermodynamic Properties,
J. Am. Soc. Mass Spectrom., 1990, 1, 5, 366, https://doi.org/10.1016/1044-0305(90)85016-F
. [all data]
McIver Jr. and Fukuda, 1982
McIver Jr.; Fukuda, E.K.,
Equilibrium Electron Affinities,
Lec. Notes in Chem., 1982, 31, 165. [all data]
Meot-Ner (Mautner) and Sieck, 1985
Meot-Ner (Mautner), M.; Sieck, L.W.,
The Ionic Hydrogen Bond and Ion Solvation. 4. SH+ O and NH+ S Bonds. Correlations with Proton Affinity. Mutual Effects of Weak and Strong Ligands in Mixed Clusters,
J. Phys. Chem., 1985, 89, 24, 5222, https://doi.org/10.1021/j100270a021
. [all data]
Staneke, Groothuis, et al., 1995
Staneke, P.O.; Groothuis, G.; Ingemann, S.; Nibbering, N.M.M.,
Formation, stability and structure of radical anions of chloroform, tetrachloromethane and fluorotrichloromethane in the gas phase,
Int. J. Mass Spectrom. Ion Proc., 1995, 142, 1-2, 83, https://doi.org/10.1016/0168-1176(94)04127-S
. [all data]
Meot-ner, 1988
Meot-ner, M.,
Ionic Hydrogen Bond and Ion Solvation. 6. Interaction Energies of the Acetate Ion with Organic Molecules. Comparison of CH3COO- with Cl-, CN-, and SH-,
J. Am. Chem. Soc., 1988, 110, 12, 3854, https://doi.org/10.1021/ja00220a022
. [all data]
Shum and Benson, 1983
Shum, L.G.S.; Benson, S.W.,
Thermochemnistry and kinetics of the reaction of methyl mercaptan with iodine,
Int. J. Chem. Kinet., 1983, 15, 433-453. [all data]
Notes
Go To: Top, Reaction thermochemistry data, References
- Symbols used in this document:
T Temperature rG°
Free energy of reaction at standard conditions rH°
Enthalpy of reaction at standard conditions rS°
Entropy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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