Carbon anion
- Formula: C2-
- Molecular weight: 24.0219
- IUPAC Standard InChI: InChI=1S/CH3/h1H3/q-1
- IUPAC Standard InChIKey: LGRLWUINFJPLSH-UHFFFAOYSA-N
- CAS Registry Number: 50802-47-6
- Chemical structure:
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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
| Symbol | Meaning |
|---|---|
| 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) |
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | 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
| 1 | Constants 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. |
| 2 | Small perturbations by a 4Σu+. |
| 3 | Dv= +[1.0(v+1/2) + 0.08(v+1.2)2]E-7. |
| 4 | The 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. |
| 5 | Fragments of absorption bands. |
| 6 | From D00(C2) and the electron affinities of C2 and of C(=1.268 eV). |
| 7 | Photodetachment threshold Feldman, 1970. |
References
Go To: Top, Constants of diatomic molecules, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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
Go To: Top, Constants of diatomic molecules, References
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