Carbon anion


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

Carbon anion + Hydrogen cation = C2H

By formula: C2- + H+ = C2H

Quantity Value Units Method Reference Comment
Δr>349.0 ± 3.6kcal/molD-EAArnold, Bradforth, et al., 1991gas phase
Δr<375.8 ± 2.3kcal/molG+TSSchiff and Bohme, 1975gas phase; No reaction with acetylene
Quantity Value Units Method Reference Comment
Δr>341.7 ± 3.8kcal/molH-TSArnold, Bradforth, et al., 1991gas phase
Δr<368.5 ± 2.0kcal/molIMRBSchiff and Bohme, 1975gas phase; No reaction with acetylene

Constants of diatomic molecules

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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: Klaus P. Huber and Gerhard H. Herzberg

Data collected through July, 1976

Symbols used in the table of constants
SymbolMeaning
State electronic state and / or symmetry symbol
Te minimum electronic energy (cm-1)
ωe vibrational constant – first term (cm-1)
ωexe vibrational constant – second term (cm-1)
ωeye vibrational constant – third term (cm-1)
Be rotational constant in equilibrium position (cm-1)
αe rotational constant – first term (cm-1)
γe rotation-vibration interaction constant (cm-1)
De centrifugal distortion constant (cm-1)
βe rotational constant – first term, centrifugal force (cm-1)
re internuclear distance (Å)
Trans. observed transition(s) corresponding to electronic state
ν00 position of 0-0 band (units noted in table)
Diatomic constants for 12C2-
StateTeωeωexeωeyeBeαeγeDeβereTrans.ν00
a 4Σu+ (19448) (1074) 1 (25)  (1.135) 1 (0.0035)    (1.573)  
B 2Σu+ 18390.88 1968.73 Z 14.433 -0.324 1.87745 2 0.01776 -0.00037 0.00000684 3  1.22330 B ↔ X 4 V 18483.98 Z
missing citation
A 2Πu 5           A ← X 
Lineberger and Patterson, 1972
X 2Σg+ 0 1781.04 Z 11.585 -0.027 1.74685 0.0167  0.00000669  1.26821  

Notes

1Constants derived Bondybey and Brus, 1975 from the perturbations Herzberg and Lagerqvist, 1968 in B 2Σu+. Ab initio calculations by Barsuhn, 1974 and Thulstrup and Thulstrup, 1974 independently predict the existence of a 4Σu+ state slightly above B 2Σu+ with re and ωe values near those derived from the perturbations.
2Small perturbations by a 4Σu+.
3Dv= +[1.0(v+1/2) + 0.08(v+1.2)2]E-7.
4The spectrum was observed in flash discharges in CH4 Herzberg and Lagerqvist, 1968, behind reflected shock waves [fel ~ 0.017 Cathro and Mackie, 1973], and in rare gas matrices Milligan and Jacox, 1969, Frosch, 1971, Bondybey and Nibler, 1972, missing citation, Brus and Bondybey, 1975. Conclusive proof that it belongs to C2- was supplied by two-photon photodetachment spectroscopy Lineberger and Patterson, 1972. Franck-Condon factors Singh and Maheshwari, 1971.
5Fragments of absorption bands.
6From D00(C2) and the electron affinities of C2 and of C(=1.268 eV).
7Photodetachment threshold Feldman, 1970.

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.

Arnold, Bradforth, et al., 1991
Arnold, D.W.; Bradforth, S.E.; Kitsopoulos, T.N.; Neumark, D.M., Vibrationally Resolved Spectra of C2-C11 by Anion Photoelectron Spectroscopy, J. Chem. Phys., 1991, 95, 12, 8753, https://doi.org/10.1063/1.461211 . [all data]

Schiff and Bohme, 1975
Schiff, H.I.; Bohme, D.K., Flowing afterglow studies at York University, Int. J. Mass Spectrom. Ion Phys., 1975, 16, 167. [all data]

Lineberger and Patterson, 1972
Lineberger, W.C.; Patterson, T.A., Two photon photodetachment spectroscopy: the C2--2Σ states, Chem. Phys. Lett., 1972, 13, 40. [all data]

Bondybey and Brus, 1975
Bondybey, V.E.; Brus, L.E., Photophysics of C2-(B2Σu+) in rare gas lattices: vibrational relaxation through intermediate a4Σu+ levels, J. Chem. Phys., 1975, 63, 2223. [all data]

Herzberg and Lagerqvist, 1968
Herzberg, G.; Lagerqvist, A., A new spectrum associated with diatomic carbon, Can. J. Phys., 1968, 46, 2363. [all data]

Barsuhn, 1974
Barsuhn, J., Nonempirical calculations on the electronic spectrum of the molecular ion C2-, J. Phys. B:, 1974, 7, 155. [all data]

Thulstrup and Thulstrup, 1974
Thulstrup, P.W.; Thulstrup, E.W., A theoretical investigation of the low-lying states of the C2- ion, Chem. Phys. Lett., 1974, 26, 144. [all data]

Cathro and Mackie, 1973
Cathro, W.S.; Mackie, J.C., Oscillator strength of the C2-B2Σ - X2Σ transition: a shock-tube determination, J. Chem. Soc. Faraday Trans. 2, 1973, 69, 237. [all data]

Milligan and Jacox, 1969
Milligan, D.E.; Jacox, M.E., Studies of the photoproduction of electrons in inert solid matrices. The electronic spectrum of the species C2-, J. Chem. Phys., 1969, 51, 1952. [all data]

Frosch, 1971
Frosch, R.P., C2 and C2- spectra produced by the X irradiation of acetylene in rare-gas matrices, J. Chem. Phys., 1971, 54, 2660. [all data]

Bondybey and Nibler, 1972
Bondybey, V.; Nibler, J.W., Laser excited fluorescence studies of matrix isolated C2-, J. Chem. Phys., 1972, 56, 4719. [all data]

Brus and Bondybey, 1975
Brus, L.E.; Bondybey, V.E., Molecular ions and electron transport in rare gas lattices: C2- formation mechanism and X2Σg+ = B2Σu+ spectroscopy, J. Chem. Phys., 1975, 63, 3123. [all data]

Singh and Maheshwari, 1971
Singh, I.D.; Maheshwari, R.C., Isotope/effect on Franck-Condon factors & r-centroids for the new (1Σu+-1Σg+) system of isotopic C2 molecule, Indian J. Pure Appl. Phys., 1971, 9, 296. [all data]

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


Notes

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