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
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
  • Switch to SI units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References, Notes

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

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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:
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, Mass spectrum (electron ionization), 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 (atm)
    T = temperature (K)

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), 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)

 +  =

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

Mass spectrum (electron ionization)

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 compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), 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]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,liquid	Constant pressure heat capacity of liquid
  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°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
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.