Methylidyne

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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.

Quantity Value Units Method Reference Comment
Δfgas594.13kJ/molReviewChase, 1998Data last reviewed in December, 1967
Quantity Value Units Method Reference Comment
gas,1 bar183.04J/mol*KReviewChase, 1998Data last reviewed in December, 1967

Gas Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 298. to 1100.1100. to 6000.
A 32.9421030.15367
B -16.710568.455112
C 24.18595-1.969644
D -7.7847090.154270
E -0.065198-4.980090
F 584.6303576.6891
G 226.5138209.3531
H 594.1280594.1280
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in December, 1967 Data last reviewed in December, 1967

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, 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 - 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 CH+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)10.64 ± 0.01eVN/AN/AL

Electron affinity determinations

EA (eV) Method Reference Comment
1.260 ± 0.020N/AGoebbert, 2012B
1.2380 ± 0.0078LPESKasdan, Herbst, et al., 1975B
0.740 ± 0.050PDFeldman, 1970B
2.60 ± 0.30EIAELocht and Momigny, 1970From CH4,C2H2,C2H4; B

Ionization energy determinations

IE (eV) Method Reference Comment
10.64EVALHuber and Herzberg, 1979LLK
10.64 ± 0.01SHerzberg and Johns, 1969RDSH

De-protonation reactions

Carbon anion + Hydrogen cation = Methylidyne

By formula: C- + H+ = CH

Quantity Value Units Method Reference Comment
Δr1529.4 ± 0.71kJ/molD-EAScheer, Bilodeau, et al., 1998gas phase; Given: 1.262119(20) eV; B
Quantity Value Units Method Reference Comment
Δr1506.2 ± 1.1kJ/molH-TSScheer, Bilodeau, et al., 1998gas phase; Given: 1.262119(20) eV; B

References

Go To: Top, Gas phase thermochemistry data, 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.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Goebbert, 2012
Goebbert, D.J., Photoelectron imaging of CH-, Chem. Phys. Lett., 2012, 551, 19-25, https://doi.org/10.1016/j.cplett.2012.08.065 . [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]

Feldman, 1970
Feldman, D., Photoablosung von Elektronen bei einigen Stabilen Negativen Ionen, Z. Naturfor., 1970, 25A, 621. [all data]

Locht and Momigny, 1970
Locht, R.; Momigny, J., Mass Spectrometric Determination of the Electron Affinities of Radicals, Chem. Phys. Lett., 1970, 6, 4, 273, https://doi.org/10.1016/0009-2614(70)85072-2 . [all data]

Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G., Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979, ,1. [all data]

Herzberg and Johns, 1969
Herzberg, G.; Johns, J.W.C., New spectra of the CH molecule, Astrophys. J., 1969, 158, 399. [all data]

Scheer, Bilodeau, et al., 1998
Scheer, M.; Bilodeau, R.C.; Brodie, C.A.; Haugen, H.K., Systematic study of the stable states of C-, Si-, Ge-, and Sn- via infrared laser spectroscopy, Phys. Rev. A, 1998, 58, 4, 2844-2856, https://doi.org/10.1103/PhysRevA.58.2844 . [all data]


Notes

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