Methanethiol

• Formula: CH₄S
• Molecular weight: 48.107
• IUPAC Standard InChI: InChI=1S/CH4S/c1-2/h2H,1H3 Copy

  
• IUPAC Standard InChIKey: LSDPWZHWYPCBBB-UHFFFAOYSA-N Copy
• 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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• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Ion clustering data
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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
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)

 +  =

By formula: CH₃S^- + H⁺ = CH₄S

CH₃S^- +  =

By formula: CH₃S^- + H⁺ = CH₄S

(CH₆N⁺ • 2) +  = (CH₆N⁺ •  • 2)

By formula: (CH₆N⁺ • 2C₂H₃N) + CH₄S = (CH₆N⁺ • CH₄S • 2C₂H₃N)

Free energy of reaction

 +  = ( • )

By formula: Cl^- + CH₄S = (Cl^- • CH₄S)

 +  = ( • )

By formula: C₂H₃O₂^- + CH₄S = (C₂H₃O₂^- • CH₄S)

(CH₆N⁺ • ) +  = (CH₆N⁺ •  • )

By formula: (CH₆N⁺ • C₂H₃N) + CH₄S = (CH₆N⁺ • CH₄S • C₂H₃N)

CH₆N⁺ +  = (CH₆N⁺ • )

By formula: CH₆N⁺ + CH₄S = (CH₆N⁺ • CH₄S)

 +  =  + 

By formula: HI + CH₃IS = CH₄S + I₂

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 evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to CH₄S⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

 +  =

By formula: CH₃S^- + H⁺ = CH₄S

CH₃S^- +  =

By formula: CH₃S^- + H⁺ = CH₄S

Mass spectrum (electron ionization)

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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

Spectrum

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Additional Data

UV/Visible spectrum

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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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, Notes

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

Good, Lacina, et al., 1961
Good, W.D.; Lacina, J.L.; McCullough, J.P., Methanethiol and carbon disulfide: Heats of combustion and formation by rotating-bomb calorimetry, J. Phys. Chem., 1961, 65, 2229-2231. [all data]

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]

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]

Nourbakhsh, Norwood, et al., 1991
Nourbakhsh, S.; Norwood, K.; Yin, H.-M.; Liao, C.-L.; Ng, C.Y., Vacuum ultraviolet photodissociation and photoionization studies of CH₃SH and SH, J. Chem. Phys., 1991, 95, 946. [all data]

Kutina, Edwards, et al., 1982
Kutina, R.; Edwards, A.; Goodman, G.; Berkowitz, J., Photoionization mass spectrometry of CH₃SH, CD₃SH, and CH₃SD: Heats of formation of CH₃S⁺ (CH₂SH⁺), CH₂S⁺, CH₂S, and HCS⁺, J. Chem. Phys., 1982, 77, 5508. [all data]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]

Ogata, Onizuka, et al., 1973
Ogata, H.; Onizuka, H.; Nihei, Y.; Kamada, H., The photoelectron spectra of alcohols, mercaptans and amines, Bull. Chem. Soc. Jpn., 1973, 46, 3036. [all data]

Ogata, Onizuka, et al., 1972
Ogata, H.; Onizuka, H.; Nihei, Y.; Kamada, H., On the first bands of the photoelectron spectra of amines, alcohols, and mercaptans, Chem. Lett., 1972, 895. [all data]

Kroto and Suffolk, 1972
Kroto, H.W.; Suffolk, R.J., The photoelectron spectrum of an unstable species in the pyrolysis products of dimethyldisulphide, Chem. Phys. Lett., 1972, 15, 545. [all data]

Frost, Herring, et al., 1972
Frost, D.C.; Herring, F.G.; Katrib, A.; McDowell, C.A.; McLean, R.A.N., Photoelectron spectra of CH₃SH, (CH₃)₂S, C₆H₅SH, and C₆H₅CH₂SH; the bonding between sulfur and carbon, J. Phys. Chem., 1972, 76, 1030. [all data]

Akopyan, Sergeev, et al., 1970
Akopyan, M.E.; Sergeev, Yu.L.; Vilesov, F.I., Photionization in vapors of aliphatic sulfides. I. Methymercaptan, dimethyl and diethyl sulfides, High Energy Chem., 1970, 4, 265, In original 305. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Price, Teegan, et al., 1950
Price, W.C.; Teegan, J.P.; Walsh, A.D., The far ultra-violet absorption spectra of the hydrides and deuterides of sulphur, selenium and tellurium and of the methyl derivatives of hydrogen sulphide, Proc. Roy. Soc. (London), 1950, A201, 600. [all data]

Cradock and Whiteford, 1972
Cradock, S.; Whiteford, R.A., Photoelectron spectra of the methyl, silyl and germyl derivatives of the group VI elements, J. Chem. Soc. Faraday Trans. 2, 1972, 68, 281. [all data]

Bock, Wagner, et al., 1972
Bock, H.; Wagner, G.; Kroner, J., Photoelektronenspektren und molekuleigenschaften, XIV. Die delokalisation des schwefel-elektronenpaar in CH₃S-substituierten aromaten, Chem. Ber., 1972, 105, 3850. [all data]

Ruska and Franklin, 1969
Ruska, W.E.W.; Franklin, J.L., Ion-molecule reactions in hydrogen sulfide, methanethiol and 2-thiapropane, Intern. J. Mass Spectrom. Ion Phys., 1969, 3, 221. [all data]

Holmes, Lossing, et al., 1983
Holmes, J.L.; Lossing, F.P.; Terlouw, J.K.; Burgers, P.C., Novel gas-phase ions. The radical cations [CH₂XH]⁺. (X = F, Cl, Br, I, OH, NH², SH) and [CH₂CH₂NH₃]⁺., Can. J. Chem., 1983, 61, 2305. [all data]

Taft, Martin, et al., 1965
Taft, R.W.; Martin, R.H.; Lampe, F.W., Stabilization energies of substituted methyl cations. The effect of strong demand on the resonance order, J. Am. Chem. Soc., 1965, 87, 2490. [all data]

Bol'shakov, et al., 1969
Bol'shakov, G.F., et al., Ultraviolet spectra of heteroorganic compounds, 1969, 83. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, References

• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  T	Temperature
  ΔfH(+) ion,0K	Enthalpy of formation of positive ion at 0K
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  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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