Methane, diazo-


Gas phase 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Δfgas51.3kcal/molKinLaufer and Okabe, 1971Heat of formation at 0 K
Δfgas49.3 ± 2.3kcal/molIonPaulett and Ettinger, 1963Mass spectra

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

View reactions leading to CH2N2+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)8.999 ± 0.001eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)205.3kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity197.6kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
9.00PEBastide and Maier, 1976LLK
8.999 ± 0.001SMerer, 1964RDSH
9.03 ± 0.05EIPaulett and Ettinger, 1963, 2RDSH
9.2 ± 0.3EIBerkowitz and Wexler, 1962RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
CHN2+14.8 ± 0.1HEIPaulett and Ettinger, 1963, 2RDSH
CH2+12.3 ± 0.1N2EIPaulett and Ettinger, 1963, 2RDSH

De-protonation reactions

CHN2- + Hydrogen cation = Methane, diazo-

By formula: CHN2- + H+ = CH2N2

Quantity Value Units Method Reference Comment
Δr371.4 ± 2.2kcal/molG+TSClifford, Wenthold, et al., 1998gas phase; Lit values of DfH(H2CNN) range from 71 (78BEN) to 51 ( Laufer and Okabe, 1972). Here we use the computational ( Dixon, de Jong, et al., 2005) agreeing with G3MP2B3; B
Quantity Value Units Method Reference Comment
Δr364.1 ± 2.0kcal/molIMREClifford, Wenthold, et al., 1998gas phase; Lit values of DfH(H2CNN) range from 71 (78BEN) to 51 ( Laufer and Okabe, 1972). Here we use the computational ( Dixon, de Jong, et al., 2005) agreeing with G3MP2B3; B
Δr365.0 ± 4.0kcal/molIMRBDePuy, Van Doren, et al., 1989gas phase; Near HF, between H2O2 & acetone. G2 calculations( Gordon and Kass, 1997) give ΔHf(CH2N2)=63.1 kcal/mol; B

References

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Laufer and Okabe, 1971
Laufer, A.H.; Okabe, H., Heat of formation and bond dissociation energy of diazomethane by a photodissociation method, J. Am. Chem. Soc., 1971, 93, 4137-7140. [all data]

Paulett and Ettinger, 1963
Paulett, G.S.; Ettinger, R., Mass spectra and appearance potentials of diazirine and diazomethane, J. Chem. Phys., 1963, 39, 825-827. [all data]

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]

Bastide and Maier, 1976
Bastide, J.; Maier, J.P., Electronic states of the radical cations of the 1,3-dipoles: HCNO, CH2N2, and N3H, studied by photoelectron spectroscopy, Chem. Phys., 1976, 12, 177. [all data]

Merer, 1964
Merer, A.J., The vacuum ultraviolet absorption spectrum of diazomethane, Can. J. Phys., 1964, 42, 1242. [all data]

Paulett and Ettinger, 1963, 2
Paulett, G.S.; Ettinger, R., Mass spectra and appearance potentials of diazirine and diazomethane, J. Chem. Phys., 1963, 39, 825. [all data]

Berkowitz and Wexler, 1962
Berkowitz, J.; Wexler, S., On the ionization potential of the CH2 radical, J. Chem. Phys., 1962, 37, 1476. [all data]

Clifford, Wenthold, et al., 1998
Clifford, E.P.; Wenthold, P.G.; Lineberger, W.C.; Peterssom, G.A.; Broaddus, K.M.; Kass, S.R.; Kato, S., Properties of Diazocarbene [CNN] and the diazomethyl Radical [HCNN] via Ion Chemistry and Spectroscopy, J. Phys. Chem. A, 1998, 102, 36, 7100, https://doi.org/10.1021/jp9802735 . [all data]

Laufer and Okabe, 1972
Laufer, A.H.; Okabe, H., J. Phys. Chem., 1972, 76, 3504. [all data]

Dixon, de Jong, et al., 2005
Dixon, D.A.; de Jong, W.A.; Peterson, K.A.; McMahon, T.B., Methyl cation affinities of rare gases and nitrogen and the heat of formation of diazomethane, J. Phys. Chem. A, 2005, 109, 18, 4073-4080, https://doi.org/10.1021/jp044561e . [all data]

DePuy, Van Doren, et al., 1989
DePuy, C.H.; Van Doren, J.M.; Gronert, S.; Kass, S.R.; Motell, E.L.; Ellison, G.B.; Bierbaum, V.M., Gas-Phase Negative-Ion Chemistry of Diazomethane, J. Org. Chem., 1989, 54, 8, 1846, https://doi.org/10.1021/jo00269a020 . [all data]

Gordon and Kass, 1997
Gordon, M.S.; Kass, S.R., CHN2-: A biradical anion and a potentially new type of reactive intermediate (vol 99, pg 6548, 1995), J. Phys. Chem. A, 1997, 101, 42, 7922-7922, https://doi.org/10.1021/jp972321b . [all data]


Notes

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