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Difluoromethane

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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
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)12.71eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)148.3kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity140.9kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
12.70PEPullen, Carlson, et al., 1970RDSH
12.72PEBrundle, Robin, et al., 1970RDSH
13.27EIHarshbarger, Robin, et al., 1973Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
CF+18.8?EILifshitz and Long, 1965RDSH
CF2+14.8 ± 0.4H2EISteele, 1964RDSH
CHF+17.7?EILifshitz and Long, 1965RDSH
CHF2+13.11HEILossing, 1972LLK
CHF2+13.14 ± 0.02HEIMartin, Lampe, et al., 1966RDSH
CHF2+13.1HEILifshitz and Long, 1965RDSH
CH2F+14.06FEILossing, 1972LLK
CH2F+15.28FEILifshitz and Long, 1965RDSH

De-protonation reactions

CHF2- + Hydrogen cation = Difluoromethane

By formula: CHF2- + H+ = CH2F2

Quantity Value Units Method Reference Comment
Deltar389.0 ± 3.5kcal/molCIDTGraul and Squires, 1990gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict «DELTA»Hacid = 399 kcal/mol; B
Quantity Value Units Method Reference Comment
Deltar381.2 ± 3.6kcal/molH-TSGraul and Squires, 1990gas phase; G2 calculations( Lee, Dyke, et al., 1998) predict «DELTA»Hacid = 399 kcal/mol; B
Deltar379.0 ± 6.0kcal/molIMRBSullivan, 1977gas phase; B

References

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, https://doi.org/10.1063/1.556018 . [all data]

Pullen, Carlson, et al., 1970
Pullen, B.P.; Carlson, T.A.; Moddeman, W.E.; Schweitzer, G.K.; Bull, W.E., Photoelectron spectra of methane, silane, germane, methyl fluoride, difluoromethane, and trifluoromethane, J. Chem. Phys., 1970, 53, 768. [all data]

Brundle, Robin, et al., 1970
Brundle, C.R.; Robin, M.B.; Basch, H., Electronic energies and electronic structures of the fluoromethanes, J. Chem. Phys., 1970, 53, 2196. [all data]

Harshbarger, Robin, et al., 1973
Harshbarger, W.R.; Robin, M.B.; Lassettre, E.N., The electron impact spectra of the fluoromethanes, J. Electron Spectrosc. Relat. Phenom., 1973, 1, 319. [all data]

Lifshitz and Long, 1965
Lifshitz, C.; Long, F.A., Appearance potentials and mass spectra of fluorinated ethylenes. II. Heats offormation of fluorinated species and their positive ions, J. Phys. Chem., 1965, 69, 3731. [all data]

Steele, 1964
Steele, W.C., Appearance potentials of the difluoromethylene positive ion, J. Phys. Chem., 1964, 68, 2359. [all data]

Lossing, 1972
Lossing, F.P., Free radicals by mass spectrometry. XLIV. Ionization potentials bond dissociation energies for chloro-and fluoromethyl radicals, Bull. Soc. Chim. Belg., 1972, 81, 125. [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]

Graul and Squires, 1990
Graul, S.T.; Squires, R.R., Gas-Phase Acidities Derived from Threshold Energies for Activated Reactions, J. Am. Chem. Soc., 1990, 112, 7, 2517, https://doi.org/10.1021/ja00163a007 . [all data]

Lee, Dyke, et al., 1998
Lee, E.P.F.; Dyke, J.M.; Mayhew, C.A., Study of the OH-+CH2F2 reaction by selected ion flow tube experiments and ab initio calculations, J. Phys. Chem. A, 1998, 102, 43, 8349-8354, https://doi.org/10.1021/jp982224y . [all data]

Sullivan, 1977
Sullivan, S.A., Thesis, Cal. Inst. Tech. thesis,, 1977. [all data]


Notes

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