tonkyn_1989#
R. G. Tonkyn, J. W. Winniczek and M. G. White, “Rotationally resolved photoionization of O2+ near threshold”, Chem. Phys. Lett. 164, 137 (1989)
Source record · Catalogue · Review register
DOI: 10.1016/0009-2614(89)85005-5
Source kind: measurement
Recorded technique: Delayed pulsed-field ionisation of high Rydberg states (n >= 100, within about 10 cm^-1 of each threshold) with coherent VUV light (UV near 308 nm tripled in a pulsed argon jet; bandwidth 2.1 cm^-1, about 1e9 photons per pulse) in a time-of-flight photoelectron spectrometer; O2 from a 40 um nozzle 3 cm from the interaction region; field-ionisation pulse 0.3-3 V after 250-2000 ns delay. The energy scale was calibrated against the ionisation potential of Xe (Yoshino & Freeman 1985) present in trace amounts. The rotational structure of the X 2Pi_g <- X 3Sigma_g- (0,0) ionising transition was fitted with Buckingham, Orr & Sichel’s rotationally resolved cross sections and the literature rotational and spin-orbit constants (Huber & Herzberg), which ‘did not require any refinement’ (pp. 138-140).
Materials in structured entries: O2
Dataset quantities: ionization_energy
Contents: 2 datasets; 0 formulas.
Curation notes#
PDF pages 1-6 = journal pages 137-142. Identity checked on the first page. Oxygen only.
THE IONISATION ENERGY (pp. 137, 140, 141): the fit gave ‘T0 = 97348 +- 2 cm^-1’ (p. 140), ‘which we define as the energy for the transition X 2Pi_g, F1(v = 0, J = 1/2) <- X 3Sigma_g-, F2(v = 0, J = 1)’ (p. 141). By the paper’s footnote #1 (p. 140), F1 is the Omega = 1/2 spin-orbit component of the ion (K = J - 1/2), so the final level is O2+ X 2Pi_(1/2)g, v+ = 0, J+ = 1/2; the initial level is the neutral’s F2 (J = N) level with J = 1, i.e. N = 1. The confidence level of +-2 cm^-1 is not stated. In eV (not printed; hc = 1.239841984e-4 eV cm): 97348 cm^-1 = 12.069614 eV (+-0.00025 eV).
OTHER FIT RESULTS (p. 140): intensity coefficients (C1, C2, C3, C4) = (0.16, 1.0, 0.87, 0.86); rotational temperature 220 +- 20 K; effective linewidth 3.0 +- 0.3 cm^-1. The authors say the temperature and C_i ‘cannot be considered to accurately reflect the populations’, only ‘a qualitative description’ (p. 141). The M branches require an important l = 3 partial wave (p. 141).
THE ACCEPTED VALUE THEN (pp. 138, 141): ‘97362 +- 9 cm^-1 obtained by Samson and Gardner [16] from high resolution photoelectron spectroscopy’, by modelling the rotational contour of the v+ = 0 photoelectron band; recorded as a reproduced value. Tonkyn et al.’s branch intensities contradict Samson and Gardner’s (P, R):Q = 0 (p. 141).
NOT EXTRACTED: the unlabelled table (p. 140, tbl_3a97762d1a0c): the Delta K branch designations of a 2Pi <- 3Sigma ionising transition for each photoelectron l and lambda (l = 0: O-R (F1’), P-S (F2’); l = 1: N-S, O-T; l = 2: M-T, N-U; l = 3: L-U, M-V; branches L ... V are Delta K = -5 ... +5). Branch labels, not values. The xenon field-ionisation study (Fig. 1) and the spectra (Figs. 2-3) are figures only.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
tonkyn_1989/ie_O2#
{
"id": "ie_O2",
"material": "O2",
"table": "text",
"quantity": "ionization_energy",
"unit": "cm-1",
"abscissa": "label",
"use": "primary",
"parameters": {
"kind": "adiabatic",
"final_state": "X 2Pi_(1/2)g (F1, Omega = 1/2), v+ = 0, J+ = 1/2",
"initial_state": "X 3Sigma_g- F2, v = 0, J = 1 (N = 1)"
},
"uncertainty": {
"column": true,
"level": "not stated"
}
}
1 inline points in the source record.
pp. 137, 140, 141: ‘97348 +- 2 cm^-1, which we define as the energy for the transition X 2Pi_g, F1(v = 0, J = 1/2) <- X 3Sigma_g-, F2(v = 0, J = 1)’. F1 is Omega = 1/2 (footnote #1, p. 140). Calibrated against the Xe ionisation potential. = 12.069614 eV. Level of +-2 not stated.
tonkyn_1989/samson_1975_O2#
{
"id": "samson_1975_O2",
"material": "O2",
"table": "text",
"quantity": "ionization_energy",
"unit": "cm-1",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"J. A. Samson and J. L. Gardner, Can. J. Phys. 53, 1948 (1975)"
],
"parameters": {
"kind": "adiabatic",
"final_state": "X 2Pi_g (v+ = 0)"
},
"uncertainty": {
"column": true,
"level": "not stated"
}
}
1 inline points in the source record.
pp. 138 and 141: ‘the presently accepted value of 97362 +- 9 cm^-1 obtained by Samson and Gardner [16] from high resolution photoelectron spectroscopy’, from a rotational-contour model of the v+ = 0 band. The levels it refers to are not stated here.
Formulas#
No formulas are recorded.
Corrections#
No dataset errata are recorded in this source record.
Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.