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
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Henry's Law data
  • Ion clustering data
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • 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

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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis

Enthalpy of vaporization

Entropy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

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

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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
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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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.

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]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Russell, Osborne, et al., 1942
Russell, H., Jr.; Osborne, D.W.; Yost, D.M., The heat capacity, entropy, heats of fusion, transition, and vaporization and vapor pressures of methyl mercaptan, J. Am. Chem. Soc., 1942, 64, 165-169. [all data]

Morris, Lanum, et al., 1960
Morris, J.C.; Lanum, W.J.; Helm, R.V.; Haines, W.E.; Cook, G.L.; Ball, J.S., Purification and Properties of Ten Organic Sulfur Compounds, J. Chem. Eng. Data, 1960, 5, 112-6. [all data]

Teets, 1934
Teets, D.E., The Relation of the Melting Point to the Number of Carbon Atoms in a Series of Normal Mercaptans, J. Am. Chem. Soc., 1934, 56, 1143. [all data]

Ellis and Reid, 1932
Ellis, L.M.; Reid, E.E., The Preparation and Properties of A Double Series of Aliphatic Mercaptans, J. Am. Chem. Soc., 1932, 54, 1674. [all data]

Timmermans and Mattaar, 1921
Timmermans, J.; Mattaar, J.F., Freezing points of orgainic substances VI. New experimental determinations., Bull. Soc. Chim. Belg., 1921, 30, 213. [all data]

Russell, Osborne, et al., 1942, 2
Russell, H.; Osborne, D.W.; Yost, D.M., The Heat Capacity, Entropy, Heats of Fusion, Transition and Vaporization and Vapor Pressures of Methyl Mercaptan, J. Am. Chem. Soc., 1942, 64, 165-9. [all data]

Berthoud and Brum, 1924
Berthoud, A.; Brum, R., Physical Properties of Some Organic Compounds., J. Chim. Phys. Phys.-Chim. Biol., 1924, 21, 143-60. [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Dykyj, Svoboda, et al., 1999
Dykyj, J.; Svoboda, J.; Wilhoit, R.C.; Frenkel, M.L.; Hall, K.R., Vapor Pressure of Chemicals: Part A. Vapor Pressure and Antoine Constants for Hydrocarbons and Sulfur, Selenium, Tellurium and Hydrogen Containing Organic Compounds, Springer, Berlin, 1999, 373. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [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]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  S°liquid	Entropy of liquid at standard conditions
  T	Temperature
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH(+) ion,0K	Enthalpy of formation of positive ion at 0K
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ΔvapS	Entropy of vaporization
  ρc	Critical density

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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