MeO anion


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

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Individual Reactions

CH3O- + Hydrogen cation = Methyl Alcohol

By formula: CH3O- + H+ = CH4O

Quantity Value Units Method Reference Comment
Δr382. ± 2.kcal/molAVGN/AAverage of 6 values; Individual data points
Quantity Value Units Method Reference Comment
Δr376.02 ± 0.62kcal/molH-TSNee, Osterwalder, et al., 2006gas phase; B
Δr376.04 ± 0.55kcal/molH-TSOsborn, Leahy, et al., 1998gas phase; B
Δr374.0 ± 2.0kcal/molIMREBartmess, Scott, et al., 1979gas phase; The acidity is 1.2 kcal/mol stronger than that from the D-EA cycle, due to the multi-compound fit for the acidity scale.; value altered from reference due to change in acidity scale; B
Δr374.6 ± 2.1kcal/molH-TSHaas and Harrison, 1993gas phase; Both metastable and 50 eV collision energy.; B
Δr375.10 ± 0.60kcal/molTDEqMeot-ner and Sieck, 1986gas phase; Experimental entropy: 21.5 eu, 0.6 less than H2O; B

CH3O- + Methyl Alcohol = (CH3O- • Methyl Alcohol)

By formula: CH3O- + CH4O = (CH3O- • CH4O)

Quantity Value Units Method Reference Comment
Δr29.3 ± 1.0kcal/molTDAsPaul and Kebarle, 1990gas phase; B,M
Δr28.80 ± 0.30kcal/molTDAsMeot-ner and Sieck, 1986gas phase; B,M
Δr29.4 ± 2.5kcal/molTDAsCaldwell, Rozeboom, et al., 1984gas phase; Reanchored to average data from Paul and Kebarle, 1990 and Meot-ner and Sieck, 1986.; value altered from reference due to change in acidity scale; B
Δr19.0 ± 2.0kcal/molN/AMoylan, Dodd, et al., 1985gas phase; B
Quantity Value Units Method Reference Comment
Δr31.8cal/mol*KPHPMSPaul and Kebarle, 1990gas phase; M
Δr26.7cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr20.30kcal/molIMREMustanir, Matsuoka, et al., 2006gas phase; B
Δr19.8 ± 1.0kcal/molTDAsPaul and Kebarle, 1990gas phase; B
Δr20.80 ± 0.50kcal/molTDAsMeot-ner and Sieck, 1986gas phase; B
Δr20.3 ± 1.6kcal/molTDAsCaldwell, Rozeboom, et al., 1984gas phase; Reanchored to average data from Paul and Kebarle, 1990 and Meot-ner and Sieck, 1986.; value altered from reference due to change in acidity scale; B

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
19.1296.FAMacKay and Bohme, 1978gas phase; From thermochemical cycle,switching reaction(CH3O-)H2O; Meot-Ner(Mautner), 1986; M

CH3O- + Water = (CH3O- • Water)

By formula: CH3O- + H2O = (CH3O- • H2O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr25.3 ± 2.2kcal/molCIDTDeTuri and Ervin, 1999gas phase; B
Δr23.9kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M,B,M
Quantity Value Units Method Reference Comment
Δr22.9cal/mol*KPHPMSMeot-ner and Sieck, 1986gas phase; M
Δr22.9cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr17.00 ± 0.30kcal/molTDAsMeot-ner and Sieck, 1986gas phase; B

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
15.4296.FAMacKay and Bohme, 1978gas phase; From thermochemical cycle,switching reaction(OH-)H2O, DG>; Meot-Ner(Mautner), 1986; M

(CH3O- • 4294967295Formaldehyde) + Formaldehyde = CH3O-

By formula: (CH3O- • 4294967295CH2O) + CH2O = CH3O-

Quantity Value Units Method Reference Comment
Δr39.90 ± 0.51kcal/molN/ANee, Osterwalder, et al., 2006gas phase; B
Δr40.8 ± 1.1kcal/molTherOsborn, Leahy, et al., 1998gas phase; B
Δr41.8 ± 2.2kcal/molTherBartmess, Scott, et al., 1979gas phase; The acidity is 1.2 kcal/mol stronger than that from the D-EA cycle, due to the multi-compound fit for the acidity scale.; value altered from reference due to change in acidity scale; B

(CH3O- • 2Water) + Water = (CH3O- • 3Water)

By formula: (CH3O- • 2H2O) + H2O = (CH3O- • 3H2O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr14.8kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr24.4cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
7.9296.FAMacKay and Bohme, 1978gas phase; From thermochemical cycle,switching reaction(OH-)3H2O; Meot-Ner(Mautner), 1986; M

(CH3O- • Water) + Water = (CH3O- • 2Water)

By formula: (CH3O- • H2O) + H2O = (CH3O- • 2H2O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr19.2kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr25.3cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
8.2296.FAMacKay and Bohme, 1978gas phase; From thermochemical cycle,switching reaction(OH-)2H2O; Meot-Ner(Mautner), 1986; M

CH3O- + Methanol-D4 = C2H4D7O2-

By formula: CH3O- + CD4O = C2H4D7O2-

Quantity Value Units Method Reference Comment
Δr28.3 ± 1.0kcal/molIMREChabinyc and Brauman, 2000gas phase; Original dG=19.4 at 350K; dS based on symmetry alone.; B
Quantity Value Units Method Reference Comment
Δr20.7 ± 1.0kcal/molIMREChabinyc and Brauman, 2000gas phase; Original dG=19.4 at 350K; dS based on symmetry alone.; B

(CH3O- • Water • Methyl Alcohol) + Water = (CH3O- • 2Water • Methyl Alcohol)

By formula: (CH3O- • H2O • CH4O) + H2O = (CH3O- • 2H2O • CH4O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr15.2kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr27.7cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

(CH3O- • 2Methyl Alcohol) + Water = (CH3O- • Water • 2Methyl Alcohol)

By formula: (CH3O- • 2CH4O) + H2O = (CH3O- • H2O • 2CH4O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr13.8kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr25.0cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

(CH3O- • Methyl Alcohol) + Water = (CH3O- • Water • Methyl Alcohol)

By formula: (CH3O- • CH4O) + H2O = (CH3O- • H2O • CH4O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr17.8kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr25.9cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

(CH3O- • 3Water) + Water = (CH3O- • 4Water)

By formula: (CH3O- • 3H2O) + H2O = (CH3O- • 4H2O)

Bond type: Hydrogen bond (negative ion to hydride)

Quantity Value Units Method Reference Comment
Δr11.0kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr20.0cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

CH3O- + Fluoroform = C2H4F3O-

By formula: CH3O- + CHF3 = C2H4F3O-

Quantity Value Units Method Reference Comment
Δr23.5 ± 1.0kcal/molIMREChabinyc and Brauman, 1998gas phase; B
Quantity Value Units Method Reference Comment
Δr16.6 ± 1.0kcal/molIMREChabinyc and Brauman, 1998gas phase; B

(CH3O- • Water) + Methyl Alcohol = (CH3O- • Methyl Alcohol • Water)

By formula: (CH3O- • H2O) + CH4O = (CH3O- • CH4O • H2O)

Free energy of reaction

ΔrG° (kcal/mol) T (K) Method Reference Comment
13.7296.FAMacKay and Bohme, 1978gas phase; From thermochemical cycle,switching reaction(CH3O-)2H2O; Meot-Ner(Mautner), 1986; M

CH3O- + Boron trifluoride = (CH3O- • Boron trifluoride)

By formula: CH3O- + BF3 = (CH3O- • BF3)

Quantity Value Units Method Reference Comment
Δr>22.0 ± 2.0kcal/molIMRBBlair, Isolani, et al., 1973gas phase; MeOH..MeO- + BF3 ->. Computations indicate dHaff ca. 80 kcal/mol; B

(CH3O- • 2Methyl Alcohol) + Methyl Alcohol = (CH3O- • 3Methyl Alcohol)

By formula: (CH3O- • 2CH4O) + CH4O = (CH3O- • 3CH4O)

Quantity Value Units Method Reference Comment
Δr15.0kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr26.3cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

(CH3O- • 3Methyl Alcohol) + Methyl Alcohol = (CH3O- • 4Methyl Alcohol)

By formula: (CH3O- • 3CH4O) + CH4O = (CH3O- • 4CH4O)

Quantity Value Units Method Reference Comment
Δr11.4kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr22.4cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

(CH3O- • Methyl Alcohol) + Methyl Alcohol = (CH3O- • 2Methyl Alcohol)

By formula: (CH3O- • CH4O) + CH4O = (CH3O- • 2CH4O)

Quantity Value Units Method Reference Comment
Δr21.4kcal/molPHPMSMeot-Ner(Mautner), 1986gas phase; n; M
Quantity Value Units Method Reference Comment
Δr27.8cal/mol*KPHPMSMeot-Ner(Mautner), 1986gas phase; n; M

CH3O- + Trifluorophenylsilane = C7H8F3OSi-

By formula: CH3O- + C6H5F3Si = C7H8F3OSi-

Quantity Value Units Method Reference Comment
Δr76.6 ± 5.9kcal/molCIDTKrouse, Lardin, et al., 2003gas phase; B

Vibrational and/or electronic energy levels

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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: Marilyn E. Jacox

State:   ?


 Energy 
 (cm-1
 Med.   Transition   λmin 
 (nm) 
 λmax 
 (nm) 
 References

Td = 12655 ± 15 gas Engleking, Ellison, et al., 1978
Osborn, Leahy, et al., 1998, 2
Ramond, Davico, et al., 2000
Nee, Osterwalder, et al., 2006

State:   X


Vib. 
sym. 
 No.   Approximate 
 type of mode 
 cm-1   Med.   Method   References

a1 3 1113 gas TPE Nee, Osterwalder, et al., 2006
e 6 1120 gas TPE Nee, Osterwalder, et al., 2006

Additional references: Jacox, 1994, page 242; Jacox, 2003, page 260; Oakes, Harding, et al., 1985

Notes

dPhotodissociation threshold

References

Go To: Top, Reaction thermochemistry 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.

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]

Paul and Kebarle, 1990
Paul, G.J.C.; Kebarle, P., Thermodynamics of the Association Reactions OH- - H2O = HOHOH- and CH3O- - CH3OH = CH3OHOCH3- in the Gas Phase, J. Phys. Chem., 1990, 94, 12, 5184, https://doi.org/10.1021/j100375a076 . [all data]

Caldwell, Rozeboom, et al., 1984
Caldwell, G.; Rozeboom, M.D.; Kiplinger, J.P.; Bartmess, J.E., Anion-alcohol hydrogen bond strengths in the gas phase, J. Am. Chem. Soc., 1984, 106, 4660. [all data]

Moylan, Dodd, et al., 1985
Moylan, C.R.; Dodd, J.A.; Brauman, J.I., Electron photodetachment spectroscopy of Sslvated anions. A probe of structure and energetics, Chem. Phys. Lett., 1985, 118, 38. [all data]

Meot-Ner(Mautner), 1986
Meot-Ner(Mautner), M., Comparative Stabilities of Cationic and Anionic Hydrogen-Bonded Networks. Mixed Clusters of Water-Methanol, J. Am. Chem. Soc., 1986, 108, 20, 6189, https://doi.org/10.1021/ja00280a014 . [all data]

Mustanir, Matsuoka, et al., 2006
Mustanir; Matsuoka, M.; Mishima, M.; Koch, H., Stability of complexes of phenylacetylides and benzyl alkoxides with methanol in the gas phase. Acid-base correlation in the ionic hydrogen-bond strength, Bull. Chem. Soc. Japan, 2006, 79, 7, 1118-1125, https://doi.org/10.1246/bcsj.79.1118 . [all data]

MacKay and Bohme, 1978
MacKay, G.I.; Bohme, D.K., Proton-Transfer Reactions in Nitromethane at 297K, Int. J. Mass Spectrom. Ion Phys., 1978, 26, 4, 327, https://doi.org/10.1016/0020-7381(78)80052-7 . [all data]

DeTuri and Ervin, 1999
DeTuri, V.F.; Ervin, K.M., Competitive threshold collision-induced dissociation: Gas-phase acidities and bond dissociation energies for a series of alcohols, J. Phys. Chem. A, 1999, 103, 35, 6911-6920, https://doi.org/10.1021/jp991459m . [all data]

Chabinyc and Brauman, 2000
Chabinyc, M.L.; Brauman, J.I., Unusual ionic hydrogen bonds: Complexes of acetylides and fluoroform, J. Am. Chem. Soc., 2000, 122, 36, 8739-8745, https://doi.org/10.1021/ja000806z . [all data]

Chabinyc and Brauman, 1998
Chabinyc, M.L.; Brauman, J.I., Acidity, basicity, and the stability of hydrogen bonds: Complexes of RO-+HCF3, J. Am. Chem. Soc., 1998, 120, 42, 10863-10870, https://doi.org/10.1021/ja9817592 . [all data]

Blair, Isolani, et al., 1973
Blair, L.K.; Isolani, P.C.; Riveros, J.M., Formation, reactivity, and relative stability of clustered alkoxide ions by ICR spectroscopy, J. Am. Chem. Soc., 1973, 95, 1057. [all data]

Krouse, Lardin, et al., 2003
Krouse, I.H.; Lardin, H.A.; Wenthold, P.G., Gas-phase ion chemistry and ion thermochemistry of phenyltrifluorosilane, Int. J. Mass Spectrom., 2003, 227, 3, 303-314, https://doi.org/10.1016/S1387-3806(03)00080-0 . [all data]

Engleking, Ellison, et al., 1978
Engleking, P.C.; Ellison, G.B.; Lineberger, W.C., Laser photodetachment electron spectrometry of methoxide, deuteromethoxide, and thiomethoxide: Electron affinities and vibrational structure of CH3O, and CH3S, J. Chem. Phys., 1978, 69, 1826. [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]

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

Oakes, Harding, et al., 1985
Oakes, J.M.; Harding, L.B.; Ellison, G.B., The photoelectron spectroscopy of HO2-, J. Chem. Phys., 1985, 83, 5400. [all data]


Notes

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