Methoxy radical

• Formula: CH₃O
• Molecular weight: 31.0339
• IUPAC Standard InChI: InChI=1S/CH3O/c1-2/h1H3 Copy

  
• IUPAC Standard InChIKey: GRVDJDISBSALJP-UHFFFAOYSA-N Copy
• CAS Registry Number: 2143-68-2
• 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.
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• Information on this page:
  • Gas phase ion energetics data
  • Vibrational and/or electronic energy levels
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Gas phase ion energetics data

Go To: Top, Vibrational and/or electronic energy levels, 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:
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

View reactions leading to CH₃O⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

Anion protonation reactions

CH₃O^- +  =

By formula: CH₃O^- + H⁺ = CH₄O

Vibrational and/or electronic energy levels

Go To: Top, 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 by: Marilyn E. Jacox

State:   A

State:   X

Additional references: Jacox, 1994, page 236; Jacox, 1998, page 271; Jacox, 2003, page 257; Radford and Russell, 1977; Inoue, Akimoto, et al., 1979; Russell and Radford, 1980; Endo, Saito, et al., 1984; Fuke, Ozawa, et al., 1986; Agrawalla and Setser, 1986; Wantuck, Oldenborg, et al., 1987; Lin, Lee, et al., 1988; Momose, Endo, et al., 1988; Suto, Ye, et al., 1988; Geers, Kappert, et al., 1990; Powers, Pushkarsky, et al., 1997, 2; Applegate, Pushkarsky, et al., 1999; Liu, Chen, et al., 2009, 2

Notes

References

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, Notes

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

Ruscic and Berkowitz, 1991
Ruscic, B.; Berkowitz, J., Photoionization mass spectrometric studies of the isomeric transient species CD₂OH and CD₃O, J. Chem. Phys., 1991, 95, 4033. [all data]

Lias, Bartmess, et al., 1988
Lias, S.G.; Bartmess, J.E.; Liebman, J.F.; Holmes, J.L.; Levin, R.D.; Mallard, W.G., Gas-phase ion and neutral thermochemistry, J. Phys. Chem. Ref. Data, Suppl. 1, 1988, 17, 1-861. [all data]

Griffiths and Harris, 1987
Griffiths, W.J.; Harris, F.M., Ionization energies of CH₃O and CH₃S radicals measured by charge-inversion energy-loss spectrometry, Chem. Phys. Lett., 1987, 142, 7. [all data]

Dyke, 1987
Dyke, J.M., Properties of gas-phase ions, J. Chem. Soc. Faraday Trans., 1987, 83, 69. [all data]

Kuo, Zhang, et al., 1994
Kuo, S.-C.; Zhang, Z.; Klemm, R.B.; Liebman, J.F.; Stief, L.J.; Nesbitt, F.L., Photoionization of hydroxymethyl (CD₂OH and CD₃O) radicals: Photoion efficiency spectra, ionization energies and thermochemistry, J. Phys. Chem., 1994, 98, 4026. [all data]

Nee, Osterwalder, et al., 2006
Nee, M.J.; Osterwalder, A.; Zhou, J.; Neumark, D.M., Slow electron velocity-map imaging photoelectron spectra of the methoxide anion, J. Chem. Phys., 2006, 125, 1, 014306, https://doi.org/10.1063/1.2212411 . [all data]

Osborn, Leahy, et al., 1998
Osborn, D.L.; Leahy, D.J.; Kim, E.H.; deBeer, E.; Neumark, D.M., Photoelectron spectroscopy of CH3O- and CD3O-, Chem. Phys. Lett., 1998, 292, 4-6, 651-655, https://doi.org/10.1016/S0009-2614(98)00717-9 . [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]

Haas and Harrison, 1993
Haas, M.J.; Harrison, A.G., The Fragmentation of Proton-Bound Cluster Ions and the Gas-Phase Acidities of Alcohols, Int. J. Mass Spectrom. Ion Proc., 1993, 124, 2, 115, https://doi.org/10.1016/0168-1176(93)80003-W . [all data]

Meot-ner and Sieck, 1986
Meot-ner, M.; Sieck, L.W., Relative acidities of water and methanol, and the stabilities of the dimer adducts, J. Phys. Chem., 1986, 90, 6687. [all data]

Style and Ward, 1953
Style, D.W.G.; Ward, J.C., Fluorescent spectra from ethyl nitrate. Part 1.?Supposed emissions from alkoxy radicals and NO2, Trans. Faraday Soc., 1953, 49, 999, https://doi.org/10.1039/tf9534900999 . [all data]

Ohbayashi, Akimoto, et al., 1977
Ohbayashi, K.; Akimoto, H.; Tanaka, I., Emission spectra of methoxyl, ethoxyl, and isopropoxyl radicals, J. Phys. Chem., 1977, 81, 8, 798, https://doi.org/10.1021/j100523a023 . [all data]

Wendt and Hunziker, 1979
Wendt, H.R.; Hunziker, H.E., Electronic absorption spectrum of CH3O, J. Chem. Phys., 1979, 71, 12, 5202, https://doi.org/10.1063/1.438296 . [all data]

Inoue, Akimoto, et al., 1980
Inoue, G.; Akimoto, H.; Okuda, M., Spectroscopy of the CH3O A 2A1--X 2E system by laser-excited fluorescence method, J. Chem. Phys., 1980, 72, 3, 1769, https://doi.org/10.1063/1.439291 . [all data]

Powers, Hopkins, et al., 1981
Powers, E.; Hopkins, J.B.; Smalley, R.E., Laser production of jet-cooled radicals. Methoxy and methoxy-argon, J. Phys. Chem., 1981, 85, 19, 2711, https://doi.org/10.1021/j150619a003 . [all data]

Carrick, Brossard, et al., 1985
Carrick, P.G.; Brossard, S.D.; Engelking, P.C., Experimental observation of the spin-orbit splitting in methoxy, J. Chem. Phys., 1985, 83, 4, 1995, https://doi.org/10.1063/1.449338 . [all data]

Brossard, Carrick, et al., 1986
Brossard, S.D.; Carrick, P.G.; Chappell, E.L.; Hulegaard, S.C.; Engelking, P.C., The 2A1--2E electronic spectrum of methoxy, CH3O: Vibrational progressions, and spin-orbit and Jahn--Teller couplings, J. Chem. Phys., 1986, 84, 5, 2459, https://doi.org/10.1063/1.450364 . [all data]

Garland, 1988
Garland, N.L., and D. R. Crosley, 1988, J. Phys. Chem. 92, 5322. [all data]

Foster, Misra, et al., 1988
Foster, S.C.; Misra, P.; Lin, T.-Y.; Damo, C.P.; Carter, C.C.; Miller, T.A., Free jet-cooled laser-induced fluorescence spectrum of methoxy. 1. Vibronic analysis of the ~A and ~X states, J. Phys. Chem., 1988, 92, 21, 5914, https://doi.org/10.1021/j100332a014 . [all data]

Liu, Damo, et al., 1989
Liu, X.; Damo, C.P.; Lin, T.-Y.D.; Foster, S.C.; Misra, P.; Yu, L.; Miller, T.A., Free jet-cooled laser-induced fluorescence spectrum of methoxy radical. 2. Rotational analysis of the ~A2A1 .tautm. ~X2E electronic transition, J. Phys. Chem., 1989, 93, 6, 2266, https://doi.org/10.1021/j100343a016 . [all data]

Kappert and Temps, 1989
Kappert, J.; Temps, F., Rotationally resolved laser-induced fluorescence excitation studies of CH3O, Chem. Phys., 1989, 132, 1-2, 197, https://doi.org/10.1016/0301-0104(89)80088-6 . [all data]

Liu, Foster, et al., 1990
Liu, X.; Foster, S.C.; Williamson, J.M.; Yu, L.; Miller, T.A., The spin-rotation interactions in the methoxy radical, Mol. Phys., 1990, 69, 2, 357, https://doi.org/10.1080/00268979000100251 . [all data]

Lee, Wann, et al., 1993
Lee, Y.-Y.; Wann, G.-H.; Lee, Y.-P., Vibronic analysis of the A→X laser-induced fluorescence of jet-cooled methoxy (CH3O) radical, J. Chem. Phys., 1993, 99, 12, 9465, https://doi.org/10.1063/1.465481 . [all data]

Geers, Kappert, et al., 1994
Geers, A.; Kappert, J.; Temps, F.; Wiebrecht, J.W., Rotation--vibration state resolved unimolecular dynamics of highly vibrationally excited CH3O (X 2E). I. Observed stimulated emission pumping spectra, J. Chem. Phys., 1994, 101, 5, 3618, https://doi.org/10.1063/1.467547 . [all data]

Osborn, Leahy, et al., 1995
Osborn, D.L.; Leahy, D.J.; Ross, E.M.; Neumark, D.M., Study of the predissociation of by fast beam photofragment translational spectroscopy, Chem. Phys. Lett., 1995, 235, 5-6, 484, https://doi.org/10.1016/0009-2614(95)00151-S . [all data]

Powers, Pushkarsky, et al., 1997
Powers, D.E.; Pushkarsky, M.B.; Miller, T.A., Rovibronic analysis of the laser induced fluorescence excitation spectrum of the jet-cooled methoxy radical, J. Chem. Phys., 1997, 106, 17, 6863, https://doi.org/10.1063/1.473712 . [all data]

Liu, Chen, et al., 2009
Liu, J.; Chen, M.-W.; Melnik, D.; Yi, J.T.; Miller, T.A., The spectroscopic characterization of the methoxy radical. I. Rotationally resolved A [sup 2]A[sub 1]--X [sup 2]E electronic spectra of CH[sub 3]O, J. Chem. Phys., 2009, 130, 7, 074302, https://doi.org/10.1063/1.3072104 . [all data]

Chiang, Hsu, et al., 1989
Chiang, S.-Y.; Hsu, Y.-C.; Lee, Y.-P., Laser-induced emission of CH3O in solid argon, J. Chem. Phys., 1989, 90, 1, 81, https://doi.org/10.1063/1.456471 . [all data]

Temps, 1995
Temps, F., VIBRATIONAL SPECTROSCOPY, INTRAMOLECULAR DYNAMICS AND STATE SPECIFIC UNIMOLECULAR DISSOCIATION OF, Adv. Ser. Phys. Chem., 1995, 4, 375. [all data]

Ebata, Yanagishita, et al., 1982
Ebata, T.; Yanagishita, H.; Obi, K.; Tanaka, I., Ã→X fluorescence spectra of CH3O and C2H5O generated by the Arf laser photolysis of alkyl nitrites, Chem. Phys., 1982, 69, 1-2, 27, https://doi.org/10.1016/0301-0104(82)88129-9 . [all data]

Han, Utkin, et al., 2002
Han, J.-X.; Utkin, Yu.G.; Chen, H.-B.; Burns, L.A.; Curl, R.F., High-resolution infrared spectra of the C-H asymmetric stretch vibration of jet-cooled methoxy radical (CH[sub 3]O), J. Chem. Phys., 2002, 117, 14, 6538, https://doi.org/10.1063/1.1507116 . [all data]

Han, Hu, et al., 2007
Han, J.; Hu, S.; Chen, H.; Utkin, Y.; Brown, J.M.; Curl, R.F., Jet-cooled infrared spectrum of methoxy in the CH stretching region, Phys. Chem. Chem. Phys., 2007, 9, 28, 3725, https://doi.org/10.1039/b700502d . [all data]

Osborn, Leahy, et al., 1998, 2
Osborn, D.L.; Leahy, D.J.; Kim, E.H.; de Beer, E.; Neumark, D.M., Photoelectron spectroscopy of CH3O- and CD3O-, Chem. Phys. Lett., 1998, 292, 4-6, 651, https://doi.org/10.1016/S0009-2614(98)00717-9 . [all data]

Ramond, Davico, et al., 2000
Ramond, T.M.; Davico, G.E.; Schwartz, R.L.; Lineberger, W.C., Vibronic structure of alkoxy radicals via photoelectron spectroscopy, J. Chem. Phys., 2000, 112, 3, 1158, https://doi.org/10.1063/1.480767 . [all data]

Geers, Kappert, et al., 1993
Geers, A.; Kappert, J.; Temps, F.; Sears, T.J., Stimulated emission pumping spectroscopy of CH3O (X 2E, ν6): New observations on the Jahn--Teller effect, J. Chem. Phys., 1993, 98, 5, 4297, https://doi.org/10.1063/1.465036 . [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]

Jacox, 1998
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement A, J. Phys. Chem. Ref. Data, 1998, 27, 2, 115-393, https://doi.org/10.1063/1.556017 . [all data]

Jacox, 2003
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules: supplement B, J. Phys. Chem. Ref. Data, 2003, 32, 1, 1-441, https://doi.org/10.1063/1.1497629 . [all data]

Radford and Russell, 1977
Radford, H.E.; Russell, D.K., Spectroscopic detection of methoxy (CH3O), J. Chem. Phys., 1977, 66, 5, 2222, https://doi.org/10.1063/1.434142 . [all data]

Inoue, Akimoto, et al., 1979
Inoue, G.; Akimoto, H.; Okuda, M., Laser-induced fluorescence spectra of CH3O, Chem. Phys. Lett., 1979, 63, 2, 213, https://doi.org/10.1016/0009-2614(79)87002-5 . [all data]

Russell and Radford, 1980
Russell, D.K.; Radford, H.E., Analysis of the LMR spectra of methoxy, CH3O, J. Chem. Phys., 1980, 72, 4, 2750, https://doi.org/10.1063/1.439423 . [all data]

Endo, Saito, et al., 1984
Endo, Y.; Saito, S.; Hirota, E., The microwave spectrum of the methoxy radical CH3O, J. Chem. Phys., 1984, 81, 1, 122, https://doi.org/10.1063/1.447375 . [all data]

Fuke, Ozawa, et al., 1986
Fuke, K.; Ozawa, K.; Kaya, K., Electronic spectra and predissociation of jet-cooled CH3O and CH3O-Ar in the Ã2A1 state, Chem. Phys. Lett., 1986, 126, 2, 119, https://doi.org/10.1016/S0009-2614(86)80023-9 . [all data]

Agrawalla and Setser, 1986
Agrawalla, B.S.; Setser, D.W., Infrared chemiluminescence and laser-induced fluorescence studies of energy disposal by reactions of fluorine and chlorine atoms with hydrogen sulfide, deuterium sulfide, hydrogen selenide, water, water-d2, and methanol, J. Phys. Chem., 1986, 90, 11, 2450, https://doi.org/10.1021/j100402a039 . [all data]

Wantuck, Oldenborg, et al., 1987
Wantuck, P.J.; Oldenborg, R.C.; Baughcum, S.L.; Winn, K.R., Collisional quenching of methoxy(A2A1) radical, J. Phys. Chem., 1987, 91, 12, 3253, https://doi.org/10.1021/j100296a030 . [all data]

Lin, Lee, et al., 1988
Lin, S.-R.; Lee, Y.-P.; Nee, J.B., Radiative lifetime and quenching of the A 2A1 state of the CH3O radical, J. Chem. Phys., 1988, 88, 1, 171, https://doi.org/10.1063/1.454633 . [all data]

Momose, Endo, et al., 1988
Momose, T.; Endo, Y.; Hirota, E.; Shida, T., The submillimeter-wave spectrum of the 13CH3O radical, J. Chem. Phys., 1988, 88, 9, 5338, https://doi.org/10.1063/1.454593 . [all data]

Suto, Ye, et al., 1988
Suto, M.; Ye, C.; Lee, L.C., CH3O(A--X) fluorescence from photodissociation of dimethyl ether, J. Chem. Phys., 1988, 89, 10, 6555, https://doi.org/10.1063/1.455378 . [all data]

Geers, Kappert, et al., 1990
Geers, A.; Kappert, J.; Temps, F.; Wiebrecht, J.W., Stimulated-emission pumping spectroscopy of highly excited states of CH_3O (X~ ^2E): zero-order vibrational states at 3000 cm^-1 ≤ 9000 cm^-1, J. Opt. Soc. Am. B, 1990, 7, 9, 1935, https://doi.org/10.1364/JOSAB.7.001935 . [all data]

Powers, Pushkarsky, et al., 1997, 2
Powers, D.E.; Pushkarsky, M.B.; Miller, T.A., Vibrational mode and frequency dependence of the photofragmentation of the methoxy radical, J. Chem. Phys., 1997, 106, 17, 6878, https://doi.org/10.1063/1.473713 . [all data]

Applegate, Pushkarsky, et al., 1999
Applegate, B.E.; Pushkarsky, M.B.; Miller, T.A., Spectral Analysis and Photofragmentation Dynamics of the Perdeuteromethoxy Radical, J. Phys. Chem. A, 1999, 103, 11, 1538, https://doi.org/10.1021/jp984141n . [all data]

Liu, Chen, et al., 2009, 2
Liu, J.; Chen, M.-W.; Melnik, D.; Miller, T.A.; Endo, Y.; Hirota, E., The spectroscopic characterization of the methoxy radical. II. Rotationally resolved A [sup 2]A[sub 1]-X [sup 2]E electronic and X [sup 2]E microwave spectra of the perdeuteromethoxy radical CD[sub 3]O, J. Chem. Phys., 2009, 130, 7, 074303, https://doi.org/10.1063/1.3072105 . [all data]

Notes

Go To: Top, Gas phase ion energetics data, Vibrational and/or electronic energy levels, References

• Symbols used in this document:
  

  AE	Appearance energy
  IE (evaluated)	Recommended ionization energy
  ΔfH(+) ion,0K	Enthalpy of formation of positive ion at 0K
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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