CH3 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 by: John E. Bartmess

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Individual Reactions

CH3- + Hydrogen cation = Methane

By formula: CH3- + H+ = CH4

Quantity Value Units Method Reference Comment
Δr1743.6 ± 2.9kJ/molD-EAEllison, Engelking, et al., 1978gas phase
Δr1749. ± 15.kJ/molCIDTGraul and Squires, 1990gas phase
Δr>1691.1 ± 0.42kJ/molG+TSBohme, Lee-Ruff, et al., 1972gas phase
Δr1735.5kJ/molN/ACheck, Faust, et al., 2001gas phase; FeBr3; ; ΔS(EA)=9.3
Quantity Value Units Method Reference Comment
Δr1709.8 ± 3.3kJ/molH-TSEllison, Engelking, et al., 1978gas phase
Δr1715. ± 15.kJ/molH-TSGraul and Squires, 1990gas phase
Δr>1657.3kJ/molIMRBBohme, Lee-Ruff, et al., 1972gas phase
Δr1704.1kJ/molN/ACheck, Faust, et al., 2001gas phase; FeBr3; ; ΔS(EA)=9.3

(CH3- • 4294967295Methylene) + Methylene = CH3-

By formula: (CH3- • 4294967295CH2) + CH2 = CH3-

Quantity Value Units Method Reference Comment
Δr397.4 ± 3.3kJ/molN/AEllison, Engelking, et al., 1978gas phase

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 compiled by: John E. Bartmess

Protonation reactions

CH3- + Hydrogen cation = Methane

By formula: CH3- + H+ = CH4

Quantity Value Units Method Reference Comment
Δr1743.6 ± 2.9kJ/molD-EAEllison, Engelking, et al., 1978gas phase
Δr1749. ± 15.kJ/molCIDTGraul and Squires, 1990gas phase
Δr>1691.1 ± 0.42kJ/molG+TSBohme, Lee-Ruff, et al., 1972gas phase
Δr1735.5kJ/molN/ACheck, Faust, et al., 2001gas phase; FeBr3; ; ΔS(EA)=9.3
Quantity Value Units Method Reference Comment
Δr1709.8 ± 3.3kJ/molH-TSEllison, Engelking, et al., 1978gas phase
Δr1715. ± 15.kJ/molH-TSGraul and Squires, 1990gas phase
Δr>1657.3kJ/molIMRBBohme, Lee-Ruff, et al., 1972gas phase
Δr1704.1kJ/molN/ACheck, Faust, et al., 2001gas phase; FeBr3; ; ΔS(EA)=9.3

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 = 645 ± 240 gas Ellison, Engelking, et al., 1978

State:   X


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

a1 1 CH3 stretch 3206.25 gas PD Mitchell, Conklin, et al., 2003
2 Umbrella 460 ± 40 gas PE Ellison, Engelking, et al., 1978

Additional references: Jacox, 1994, page 129

Notes

dPhotodissociation threshold

References

Go To: Top, Reaction thermochemistry data, 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.

Ellison, Engelking, et al., 1978
Ellison, G.B.; Engelking, P.C.; Lineberger, W.C., An experimental determination of the geometry and electron affinity of CH3, J. Am. Chem. Soc., 1978, 100, 2556. [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]

Bohme, Lee-Ruff, et al., 1972
Bohme, D.K.; Lee-Ruff, E.; Young, L.B., Acidity order of selected bronsted acids in the gas phase at 300K, J. Am. Chem. Soc., 1972, 94, 5153. [all data]

Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S., Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements, J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l . [all data]

Mitchell, Conklin, et al., 2003
Mitchell, S.E.; Conklin, P.M.; Farley, J.W., First observation of autodetachment lifetimes of methide, CH[sub 3][sup -], J. Chem. Phys., 2003, 118, 24, 11017, https://doi.org/10.1063/1.1574017 . [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]


Notes

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