scholarly journals On the Ionization Potential of Molecular Oxygen

1975 ◽  
Vol 53 (19) ◽  
pp. 1948-1952 ◽  
Author(s):  
James A. R. Samson ◽  
J. L. Gardner
Keyword(s):  
High Resolution ◽  
Ionization Potential ◽  
Molecular Oxygen ◽  
Dissociation Energy ◽  
Electron Spectroscopy ◽  
Rotational Structure ◽  
Appearance Potential ◽  
A Value ◽  
Vibrational Bands

The ionization potential of O2 has been measured by the technique of high resolution photo-electron spectroscopy taking into account the influence of rotational structure on the shape of the vibrational bands. A value of 12.071 ± 0.001 eV (1027.1 ± 0.1 Å) was found for the ionization potential. This value leads to a dissociation energy of D0(O2+X2Πg) = 6.661 ± 0.001 eV. A lowering of the ionization potential caused by a branch head when ΔN = −2 gave an appearance potential for ionization of 12.068 ± 0.001 eV (1027.4 ± 0.1 Å).

THE ELECTRONIC EMISSION SPECTRUM AND MOLECULAR CONSTANTS OF IODINE MONOFLUORIDE

1966 ◽  
Vol 44 (2) ◽  
pp. 337-352 ◽  
Author(s):  
R. A. Durie
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Dissociation Energy ◽  
Band System ◽  
Vibrational Analysis ◽  
Rotational Structure ◽  
Molecular Constants ◽  
Present Evidence ◽  
Halogen Compounds ◽  
Concave Grating

Observation by the author (Durie 1951) of a well-developed band system in the emission from an iodine–fluorine flame provided the first evidence for the existence of iodine monofluoride (IF), the last of the six possible diatomic inter-halogen compounds to be detected. The spectrum, which lies in the region 4 300 to 7 600 Å, has since been photographed under high resolution using a 21-ft concave grating spectrograph. The rotational structure of the bands is shown to be consistent with an A3Π0+ → X1Σ transition in the IF molecule. A rotational and vibrational analysis of the bands has been carried out and the molecular constants evaluated for IF. The results are as follows:[Formula: see text]The present evidence relating to the value of the dissociation energy of IF is discussed.

Emission Spectrum of the PO Molecule. Part II.2Σ–2Σ Transitions

1971 ◽  
Vol 49 (24) ◽  
pp. 3180-3200 ◽  
Author(s):  
R. D. Verma ◽  
M. N. Dixit ◽  
S. S. Jois ◽  
S. Nagaraj ◽  
S. R. Singhal
Keyword(s):  
Emission Spectrum ◽  
Ionization Potential ◽  
Dissociation Energy ◽  
Ground State ◽  
Rydberg States ◽  
Electronic States ◽  
Electronic Transitions ◽  
A Value ◽  
Upper Limit ◽  
First Ionization Potential

Rotational structure of emission bands of the PO molecule in the region 5300–3800 Å is analyzed. The spectrum is attributed to 5 electronic transitions A2Σ+–B2Σ+, F2Σ+–B2Σ+, G2Σ+–B2Σ+, H2Σ+–B2Σ+, and I2Σ+–B2Σ+, where F, G, H, and I are the new electronic states and A and B are the upper states of the well-known γ and β bands respectively. Practically all the new 2Σ states are found to be perturbed. A qualitative account of these perturbations together with a deperturbation of certain levels is given. A number of cases of predissociation are also observed. This predissociation is attributed to the presence of 4Πi, and A′2Σ+ states, which dissociate to the ground state atomic products. From this an upper limit of the dissociation energy of the ground state of PO is determined to be D0 = 49 536 cm−1. The A, D, E, G, H, and I states of this molecule are assigned as Rydberg states corresponding to the σ4s, π4p, δ3d, σ4p, σ3d, and σ5s orbitals, respectively. From them a value of 67 570 cm−1 is evaluated for the first ionization potential of PO. All the electronic states established for this molecule are described in terms of electron configurations.

Autoionization resonances in the Eu I absorption spectrum and a new determination of the ionization potential

1975 ◽  
Vol 342 (1628) ◽  
pp. 149-156 ◽  
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Ionization Potential ◽  
Wavelength Region ◽  
Rydberg Series ◽  
A Value ◽  
Ionization Limit ◽  
The Eu

The absorption spectrum of europium has been studied at high resolution in the wavelength region between 2200 and 2100 Å. Two Rydberg series were found converging towards the 9 S 4 and 7 S 3 levels of the configuration 4f 7 6s in Eu II. The first series is perturbed near the series limit and the second shows strong autoionization features. A value of 45734.9 ± 0.2 cm -1 is deduced for the first ionization limit.

A new predissociated 2Σ+ state of the BeCl molecule

1977 ◽  
Vol 55 (6) ◽  
pp. 582-588 ◽  
Author(s):  
M. Carleer ◽  
B. Burtin ◽  
R. Colin
Keyword(s):  
Excited State ◽  
High Resolution ◽  
Dissociation Energy ◽  
Intensity Distribution ◽  
Internuclear Distance ◽  
Ground State ◽  
Thermochemical Data ◽  
Molecular Constants ◽  
Equilibrium Internuclear Distance ◽  
A Value

Ten bands belonging to a new B2Σ+–X2Σ+ system of the BeCl molecule have been discovered in emission between 1990 and 2175 Å. The bands of both isotopes Be35Cl and Be37Cl have been photographed at high resolution and the most intense ones have been rotationally analyzed. Only three levels of the excited state have been observed and they present vibrational and rotational perturbations. The principal molecular constants of the new B2Σ+ state of Be35Cl are: v00 = 48 827.6, ΔG1/2 = 925.5, ΔG3/2 = 1212.7, Be = 0.7751, De = 3.5 × 10−6 cm−1, and the equilibrium internuclear distance is 1.7422 Å. The unusual intensity distribution in the bands can be tentatively interpreted as the result of an inverse predissociation which leads to a value of D″0 = 27 800 ± 500 cm−1 (3.45 ± 0.06 eV) for the dissociation energy of the ground state of the BeCl molecule. This value is at variance with thermochemical data.

The absorption spectrum of SO and the flash photolysis of sulphur dioxide and sulphur trioxide

1959 ◽  
Vol 249 (1259) ◽  
pp. 498-512 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Energy ◽  
Sulphur Dioxide ◽  
Flash Photolysis ◽  
Ultra Violet ◽  
Vibrationally Excited ◽  
A Value ◽  
Continuous Absorption ◽  
Sulphur Trioxide ◽  
Normal Spectrum

The flash photolysis of sulphur dioxide under adiabatic conditions results in the complete temporary disappearance of its spectrum , which then slowly regains its original intensity over a period of several milliseconds. Simultaneously with the disappearance of the sulphur dioxide spectrum a continuous absorption appears in the far ultra-violet and fades slowly as the sulphur dioxide reappears. It is shown that the effect of the flash is thermal rather than photochemical, and the possibility of the existence of an isomer of sulphur dioxide at high temperatures is discussed; the disappearance of the normal spectrum on flashing is explained in this way. Several previously unrecorded bands of SO observed in the photolysis indicate that the vibrational numbering of its spectrum should be revised by the addition of 2 to the present values of v' . This leads to a value of the dissociation energy of 123.5 kcal. In formation about the levels v' = 4, 5 and 6 has also been obtained. The isothermal flash photolysis of sulphur trioxide results in the appearance of vibrationally excited SO, and the primary photochemical step in this reaction is discussed.

Re-analysis of the (100), (001), and (020) rotational structure of SO2 on the basis of high resolution FTIR spectra

2013 ◽  
Vol 130 ◽  
pp. 220-232 ◽  
Author(s):  
O.N. Ulenikov ◽  
G.A. Onopenko ◽  
O.V. Gromova ◽  
E.S. Bekhtereva ◽  
V.-M. Horneman
Keyword(s):  
High Resolution ◽  
Ftir Spectra ◽  
Rotational Structure
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