Home Symbol which looks like a small house Up Solid circle with an upward pointer in it

Methylene

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.


Gas phase ion energetics data

Go To: Top, 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 - S.G. Lias

Data compiled as indicated in comments:
B - J.E. Bartmess
LLK - S.G. Lias, R.D. Levin, and S.A. Kafafi
RDSH - H.M. Rosenstock, K. Draxl, B.W. Steiner, and J.T. Herron

View reactions leading to CH2+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)10.396 ± 0.003eVN/AN/AL
Quantity Value Units Method Reference Comment
Deltaf(+) ion1370. ± 10.kJ/molN/AN/A 
Quantity Value Units Method Reference Comment
DeltafH(+) ion,0K1380. ± 10.kJ/molN/AN/A 

Electron affinity determinations

EA (eV) Method Reference Comment
0.6520 ± 0.0060LPESLeopold, Murray, et al., 1985Singlet-triplet splitting of CH2 = 9.0 kcal; B
<0.600 ± 0.030PDFeldman, Rackwitz, et al., 1977B
0.210 ± 0.015LPESEngelking, Corderman, et al., 1981Hot band problem; B
0.208 ± 0.031LPESZittel, Ellison, et al., 1976Hot band problem, singlet-triplet splitting = 19.5 kcal; B
>0.90 ± 0.40EIAEThynne and MacNiel, 1971From CH2=CH2; B

Ionization energy determinations

IE (eV) Method Reference Comment
10.35 ± 0.15EIReineke and Strein, 1976LLK
10.5 ± 0.2EINiehaus, 1967RDSH
10.396 ± 0.003SHerzberg, 1961RDSH

De-protonation reactions

CH- + Hydrogen cation = Methylene

By formula: CH- + H+ = CH2

Quantity Value Units Method Reference Comment
Deltar1615.2 ± 1.8kJ/molD-EAKasdan, Herbst, et al., 1975gas phase; B
Quantity Value Units Method Reference Comment
Deltar1586.9 ± 2.2kJ/molH-TSKasdan, Herbst, et al., 1975gas 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.

Leopold, Murray, et al., 1985
Leopold, D.G.; Murray, K.K.; Miller, A.E.S.; Lineberger, W.C., Methylene: A study of the X3B1 and the 1A1 states by photoelectron spectroscopy of CH2- and CD2-, J. Chem. Phys., 1985, 83, 4849. [all data]

Feldman, Rackwitz, et al., 1977
Feldman, D.; Rackwitz, R.; Kaiser, H.J.; Heincke, E., Photodetachment bei einigen neagtiven molekulionen: P2-, As2-, CH2-, CH3-, S3-, Z. Naturforsch. A:, 1977, 32, 600. [all data]

Engelking, Corderman, et al., 1981
Engelking, P.E.; Corderman, R.R.; Wenddoski, J.J.; Ellison, G.B.; O'Niel, V.S.; Lineberger, W.C., Laser photoelectron spectroscopy of CH2-, and the singlet-triplet splitting in methylene, J. Chem. Phys., 1981, 74, 5460. [all data]

Zittel, Ellison, et al., 1976
Zittel, P.F.; Ellison, G.B.; O'Neil, S.V.; Herbst, E.; Lineberger, W.C.; Reinhardt, W.P., Laser photoelectron spectrometry of CH2-. Singlet-triplet splitting and electron affinity of CH21, J. Am. Chem. Soc., 1976, 98, 3731. [all data]

Thynne and MacNiel, 1971
Thynne, J.C.J.; MacNiel, K.A.G., Negative ion formation by ethylene and 1,1-difluoroethylene, J. Phys. Chem., 1971, 75, 2584. [all data]

Reineke and Strein, 1976
Reineke, W.; Strein, K., Erzeugung eines methylenhaltigen Molekularstrahls durch Pyrolyse von Keten, Ber. Bunsen-Ges. Phys. Chem., 1976, 80, 343. [all data]

Niehaus, 1967
Niehaus, A., Anregung und Dissoziation von Molekulen beim Elektronenbeschuss. Messung der Bildungswahrscheinlichkeit fur neutrale Fragmente als Funktion der Elektronenenergie., Z. Naturforsch., 1967, 22a, 690. [all data]

Herzberg, 1961
Herzberg, G., The ionization potential of CH2, Can J. Phys., 1961, 39, 1511. [all data]

Kasdan, Herbst, et al., 1975
Kasdan, A.; Herbst, E.; Lineberger, W.C., Laser photoelectron spectrometry of CH2-, Chem. Phys. Lett., 1975, 31, 78. [all data]


Notes

Go To: Top, Gas phase ion energetics data, References