Methane, iodo-

• Formula: CH₃I
• Molecular weight: 141.9390
• IUPAC Standard InChI: InChI=1S/CH3I/c1-2/h1H3 Copy

  
• IUPAC Standard InChIKey: INQOMBQAUSQDDS-UHFFFAOYSA-N Copy
• CAS Registry Number: 74-88-4
• 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.
• Isotopologues:
  • iodo(2H3)methane
• Other names: Iodomethane; Methyl iodide; CH3I; Halon 10001; Iodometano; Iodure de methyle; Jod-methan; Joodmethaan; Methyljodid; Methyljodide; Metylu jodek; Monoioduro di metile; Rcra waste number U138; UN 2644; Methyl iodine; Monoiodomethane; NSC 9366
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• Information on this page:
  • Gas phase thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Vibrational and/or electronic energy levels
• 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

Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, 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

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

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

CH₂I^- +  =

By formula: CH₂I^- + H⁺ = CH₃I

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

Gas Chromatography

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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

Kovats' RI, non-polar column, isothermal

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Kovats' RI, polar column, isothermal

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Van Den Dool and Kratz RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, custom temperature program

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Normal alkane RI, polar column, custom temperature program

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References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, Notes

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

Golden, Walsh, et al., 1965
Golden, D.M.; Walsh, R.; Benson, S.W., The thermochemistry of the gas phase equilibrium I₂ + CH₄ «=» CH₃I + HI and the heat of formation of the methyl radical, J. Am. Chem. Soc., 1965, 87, 4053-4057. [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]

Goy and Pritchard, 1965
Goy, C.A.; Pritchard, H.O., Kinetics and thermodynamics of the reaction between iodine and methane and the heat of formation of methyl iodide, J. Phys. Chem., 1965, 69, 3040-3041. [all data]

Carson, Carter, et al., 1961
Carson, A.S.; Carter, W.; Pedley, J.B., The thermochemistry of reductions caused by lithium aluminium hydride I. The C-I bond dissociation energy in CH₃I, Proc. Roy. Soc. London A, 1961, 260, 550-557. [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]

Kim, Kelley, et al., 1999
Kim, J.; Kelley, J.A.; Ayotte, P.; Nielsen, S.B.; Weddle, G.H.; Johnson, M.A., Preparation and photoelectron spectrum of the CH3I- anion: Rare gas cluster mediated synthesis of an ion-radical complex, J. Am. Soc. Mass Spectrom., 1999, 10, 9, 810-814, https://doi.org/10.1016/S1044-0305(99)00057-4 . [all data]

Moutinho, Aten, et al., 1974
Moutinho, A.M.C.; Aten, J.A.; Los, J., Chemi-ionization in alkali-methylhalogen collisions, Chem. Phys., 1974, 5, 84. [all data]

Holmes and Lossing, 1991
Holmes, J.L.; Lossing, F.P., Ionization energies of homologous organic compounds and correlation with molecular size, Org. Mass Spectrom., 1991, 26, 537. [all data]

Carlson, Gerard, et al., 1988
Carlson, T.A.; Gerard, P.; Pullen, B.P.; Grimm, F.A., Autoionization from the ione-pair orbitals of molecules containing iodine, J. Chem. Phys., 1988, 89, 1464. [all data]

Baig, Connerade, et al., 1982
Baig, M.A.; Connerade, J.P.; Hormes, J., Autoionisation resonances in the 4p(Π) spectrum of methyl bromide, J. Phys. B:, 1982, 15, 5. [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]

Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J., eIonization energies of organic compounds by equilibrium measurements, J. Am. Chem. Soc., 1978, 100, 6027. [all data]

Mintz and Baer, 1976
Mintz, D.M.; Baer, T., Kinetic energy release distributions for the dissociation of internal energy selected CH₃I⁺ and CD₃I⁺ ions, J. Chem. Phys., 1976, 65, 2407. [all data]

Tsai, Baer, et al., 1975
Tsai, B.P.; Baer, T.; Werner, A.S.; Lin, S.F., A photoelectron-photoion coincidence study of the ionization and fragment appearance potentials of bromo- and iodomethanes, J. Phys. Chem., 1975, 79, 570. [all data]

Hochmann, Templet, et al., 1975
Hochmann, P.; Templet, P.H.; Wang, H.-t.; McGlynn, S.P., Molecular Rydberg transitions. I. Low-energy Rydberg transitions in methyl halides, J. Chem. Phys., 1975, 62, 2588. [all data]

Boschi and Salahub, 1974
Boschi, R.A.A.; Salahub, D.R., The high resolution photoelectron spectra of some iodoalkanes, iodocycloalkanes, iodoalkenes, and fluoroiodohydrocarbons, Can. J. Chem., 1974, 52, 1217. [all data]

Johnstone and Mellon, 1972
Johnstone, R.A.W.; Mellon, F.A., Electron-impact ionization and appearance potentials, J. Chem. Soc. Faraday Trans. 2, 1972, 68, 1209. [all data]

Boschi and Salahub, 1972
Boschi, R.A.; Salahub, D.R., The far ultra-violet spectra of some 1-iodoalkanes, Mol. Phys., 1972, 24, 289. [all data]

Brogli and Heilbronner, 1971
Brogli, F.; Heilbronner, E., The competition between spin orbit coupling and conjugation in alkyl halides and its repercussion on their photoelectron spectra, Helv. Chim. Acta, 1971, 54, 1423. [all data]

Ragle, Stenhouse, et al., 1970
Ragle, J.L.; Stenhouse, I.A.; Frost, D.C.; McDowell, C.A., Valence-shell ionization potentials of halomethanes by photoelectron spectroscopy. I. CH₃Cl, CH₃Br, CH₃I. Vibrational frequencies and vibronic interaction in CH₃Br⁺ and CH₃Cl⁺, J. Chem. Phys., 1970, 53, 178. [all data]

Potts, Lempka, et al., 1970
Potts, A.W.; Lempka, H.J.; Streets, D.G.; Price, W.C., Photoelectron spectra of the halides of elements in groups III, IV, V and VI, Phil. Trans. Roy. Soc. (London), 1970, A268, 59. [all data]

Baer, Peatman, et al., 1969
Baer, T.; Peatman, W.B.; Schlag, E.W., Photoionization resonance studies with a steradiancy analyzer. II.The photoionization of CH₃I, Chem. Phys. Lett., 1969, 4, 243. [all data]

Price, 1936
Price, W.C., The far ultraviolet absorption spectra and ionization potentials of the alkyl halides. Part I, J. Chem. Phys., 1936, 4, 539. [all data]

Utsunomiya, Kobayashi, et al., 1980
Utsunomiya, C.; Kobayashi, T.; Nagakura, S., Photoelectron angular distribution measurements for some aliphatic alcohols, amines, halides, Bull. Chem. Soc. Jpn., 1980, 53, 1216. [all data]

Dromey and Peel, 1974
Dromey, R.G.; Peel, J.B., Photoelectron spectroscopic correlation of the molecular orbitals of the alkanes and alkyl iodides, J. Mol. Struct., 1974, 23, 53. [all data]

Uehara, Saito, et al., 1973
Uehara, Y.; Saito, N.; Yonezawa, T., Ionization potentials of trifluoromethyl and methyl halides by photoelectron spectroscopy and calculations by extended Hucket and CNDO/2 methods, Chem. Lett., 1973, 495. [all data]

Reed and Snedden, 1956
Reed, R.I.; Snedden, W., Studies in electron impact methods. Part 6.-The formation of the methine and carbon ions, J. Chem. Soc. Faraday Trans., 1956, 55, 876. [all data]

Tsuda and Hamill, 1964
Tsuda, S.; Hamill, W.H., Structure in ionization efficiency curves near threshold from alkanes and alkyl halides, J. Chem. Phys., 1964, 41, 2713. [all data]

Holmes, Lossing, et al., 1988
Holmes, J.L.; Lossing, F.P.; McFarlane, R.A., Stabilization energy and positional effects in halogen-substituted alkyl ions., Int. J. Mass Spectrom. Ion Phys., 1988, 86, 209. [all data]

Martin, Lampe, et al., 1966
Martin, R.H.; Lampe, F.W.; Taft, R.W., An electron-impact study of ionization and dissociation in methoxy- and halogen- substituted methanes, J. Am. Chem. Soc., 1966, 88, 1353. [all data]

Traeger and McLoughlin, 1981
Traeger, J.C.; McLoughlin, R.G., Absolute heats of formation for gas phase cations, J. Am. Chem. Soc., 1981, 103, 3647. [all data]

Nicholson, 1970
Nicholson, A.J.C., Determination of bond dissociation energies from photoionization efficiency curves in Recent Developments in Mass Spectrometroscopy, ed. K Ogata and T. Hayakawa, Univ. Park Press, Baltimore, MD, 1970, 745. [all data]

Lossing and Semeluk, 1970
Lossing, F.P.; Semeluk, G.P., Free radicals by mass spectrometry. XLII.Ionization potentials and ionic heats of formation for C₁-C₄ alkyl radicals, Can. J. Chem., 1970, 48, 955. [all data]

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Tsuda, S.; Melton, C.E.; Hamill, W.H., Ionization- efficiency curves for molecular and fragment ions from methane and the methyl halides, J. Chem. Phys., 1964, 41, 689. [all data]

Ingemann and Nibbering, 1985
Ingemann, S.; Nibbering, N.M.M., Gas-phase acidity of CH₃X [X = P(CH₃)₂, SCH₃, F, Cl, Br, I] compounds, J. Chem. Soc. Perkin Trans. 2, 1985, 837. [all data]

Castello and Gerbino, 1988
Castello, G.; Gerbino, T.C., Effect of Temperature on the Gas Chromatographic Separation of Halogenated Compounds on Polar and Non-Polar Stationary Phases, J. Chromatogr., 1988, 437, 33-45, https://doi.org/10.1016/S0021-9673(00)90369-8 . [all data]

Riedo, Fritz, et al., 1976
Riedo, F.; Fritz, D.; Tarján, G.; Kováts, E.Sz., A tailor-made C₈₇ hydrocarbon as a possible non-polar standard stationary phase for gas chromatography, J. Chromatogr., 1976, 126, 63-83, https://doi.org/10.1016/S0021-9673(01)84063-2 . [all data]

Hively and Hinton, 1968
Hively, R.A.; Hinton, R.E., Variation of the retention index with temperature on squalane substrates, J. Gas Chromatogr., 1968, 6, 4, 203-217, https://doi.org/10.1093/chromsci/6.4.203 . [all data]

Rohrschneider, 1966
Rohrschneider, L., Eine methode zur charakterisierung von gaschromatographischen trennflüssigkeiten, J. Chromatogr., 1966, 22, 6-22, https://doi.org/10.1016/S0021-9673(01)97064-5 . [all data]

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Helmig, D.; Pollock, W.; Greenberg, J.; Zimmerman, P., Gas chromatography mass spectrometry analysis of volatile organic trace gases at Mauna Loa Observatory, Hawaii, J. Geophys. Res., 1996, 101, D9, 14697-14710, https://doi.org/10.1029/96JD00212 . [all data]

Helmig and Greenberg, 1995
Helmig, D.; Greenberg, J., Artifact formation from the use of potassium-iodide-based ozone traps during atmospheric sampling of trace organic gases, J. Hi. Res. Chromatogr., 1995, 18, 1, 15-18, https://doi.org/10.1002/jhrc.1240180105 . [all data]

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Zenkevich, I.G., Encyclopedia of Chromatography. Derivatization of Acids for GC Analysis, Marcel Dekker, Inc., New York - Basel, 2001, 221. [all data]

Flanagan, Streete, et al., 1997
Flanagan, R.J.; Streete, P.J.; Ramsey, J.D., Volatile Substance Abuse, UNODC Technical Series, No 5, United Nations, Office on Drugs and Crime, Vienna International Centre, PO Box 500, A-1400 Vienna, Austria, 1997, 56, retrieved from http://www.odccp.org/pdf/technical_series₁997-01-01₁.pdf. [all data]

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Strete, P.J.; Ruprah, M.; Ramsey, J.D.; Flanagan, R.J., Detection and identification of volatile substances by headspace capillary gas chromatography to aid the diagnosis of acute poisoning, Analyst, 1992, 117, 7, 1111-1127, https://doi.org/10.1039/an9921701111 . [all data]

Ramsey and Flanagan, 1982
Ramsey, J.D.; Flanagan, R.J., Detection and Identification of Volatile Organic Compounds in Blood by Headspace Gas Chromatography as an Aid to the Diagnosis of Solvent Abuse, J. Chromatogr., 1982, 240, 2, 423-444, https://doi.org/10.1016/S0021-9673(00)99622-5 . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, References

• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  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

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