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Methane, iodo-

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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

Quantity Value Units Method Reference Comment
IE (evaluated)9.54 ± 0.02eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)691.7kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity665.5kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
0.110 ± 0.020LPESKim, Kelley, et al., 1999B
0.30 ± 0.20NBIEMoutinho, Aten, et al., 1974Stated electron affinity is the Vertical Detachment Energy; B

Ionization energy determinations

IE (eV) Method Reference Comment
9.54 ± 0.05EIHolmes and Lossing, 1991LL
9.54PECarlson, Gerard, et al., 1988LL
10.86SBaig, Connerade, et al., 1982LBLHLM
9.54PEKimura, Katsumata, et al., 1981LLK
9.538EQLias and Ausloos, 1978LLK
9.54PIPECOMintz and Baer, 1976LLK
9.53 ± 0.01PITsai, Baer, et al., 1975LLK
9.538SHochmann, Templet, et al., 1975LLK
9.54PEBoschi and Salahub, 1974LLK
9.48 ± 0.03EIJohnstone and Mellon, 1972LLK
9.538SBoschi and Salahub, 1972LLK
9.52PEBrogli and Heilbronner, 1971LLK
10.14PEBrogli and Heilbronner, 1971LLK
9.50PERagle, Stenhouse, et al., 1970RDSH
9.54PEPotts, Lempka, et al., 1970RDSH
9.534 ± 0.005TEBaer, Peatman, et al., 1969RDSH
9.538 ± 0.003SPrice, 1936RDSH
9.53PEUtsunomiya, Kobayashi, et al., 1980Vertical value; LLK
9.9PEDromey and Peel, 1974Vertical value; LLK
9.51PEUehara, Saito, et al., 1973Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
CH+21.2 ± 0.2?EIReed and Snedden, 1956RDSH
CH2+14.6 ± 0.2HIEITsuda and Hamill, 1964RDSH
CH2I+12.78HEIHolmes, Lossing, et al., 1988LL
CH2I+12.08 ± 0.09HEIMartin, Lampe, et al., 1966RDSH
CH3+12.18IPITraeger and McLoughlin, 1981LLK
CH3+12.24 ± 0.01IPIPECOMintz and Baer, 1976LLK
CH3+12.25 ± 0.03IPITsai, Baer, et al., 1975LLK
CH3+12.07 ± 0.07IEIJohnstone and Mellon, 1972LLK
CH3+12.260 ± 0.013IPINicholson, 1970RDSH
CH3+12.22IEILossing and Semeluk, 1970RDSH
I+12.9 ± 0.05CH3EITsuda, Melton, et al., 1964RDSH

De-protonation reactions

CH2I- + Hydrogen cation = Methane, iodo-

By formula: CH2I- + H+ = CH3I

Quantity Value Units Method Reference Comment
Δr1616. ± 21.kJ/molG+TSIngemann and Nibbering, 1985gas phase; B
Quantity Value Units Method Reference Comment
Δr1587. ± 20.kJ/molIMRBIngemann and Nibbering, 1985gas phase; B


Go To: Top, 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.

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, . [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, . [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]

Tsuda, Melton, et al., 1964
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]


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