ON THE sp2 CONFIGURATIONS AND CONFIGURATION-MIXING IN THE FIRST SPECTRA OF INDIUM (In I) AND THALLIUM (Tl I)

1966 ◽  
Vol 44 (8) ◽  
pp. 1745-1752 ◽  
Author(s):  
W. R. S. Garton ◽  
W. H. Parkinson ◽  
E. M. Reeves
Keyword(s):  
Ionization Potential ◽  
Absorption Spectra ◽  
Fano Resonances ◽  
Mixing Effects ◽  
Configuration Mixing ◽  
First Ionization Potential

Several aspects of configuration-mixing effects in the spectra of In I and Tl I are discussed, and evidence supporting an earlier conclusion that sp22D in In I lies above the first ionization potential is given. Experiments on the absorption spectra of shock-heated In and Tl vapors have revealed the weak In I [Formula: see text] transition and a new Tl I doublet [Formula: see text]. The profile of the Tl I [Formula: see text] autoionization feature has been obtained by experiments with a furnace and scanning monochromator, and the result is compared with the theory of Beutler–Fano resonances.

scholarly journals The absorption spectra of hexatriene and divinyl acetylene in the vacuum ultra-violet

1946 ◽  
Vol 185 (1001) ◽  
pp. 182-191 ◽  
Keyword(s):  
Double Bond ◽  
Ionization Potential ◽  
Absorption Spectra ◽  
Wave Length ◽  
Ultra Violet ◽  
Ionization Potentials ◽  
A Value ◽  
Integral Graphs ◽  
First Ionization Potential ◽  
Vacuum Ultra Violet

The absorption spectra of hexatriene and divinyl acetylene have been investigated in the region 2700-1200 A. In both molecules the longest wave-length regions of absorption are the strongest and these are interpreted as N → V 1 intravalence shell transitions. The spectra appear to be consistent with a value of about 8·2 V for the first ionization potential of hexatriene. Calculations based oh certain features of the spectra give reasonable values for the double-bond resonance integral. Graphs are given which enable the first regions of absorption and the ionization potentials of the higher polyenes to be predicted.

scholarly journals The absorption spectra of benzene derivatives in the vacuum ultra-violet. I

1947 ◽  
Vol 191 (1024) ◽  
pp. 22-31 ◽  
Keyword(s):  
Ionization Potential ◽  
Absorption Spectra ◽  
Ultra Violet ◽  
Benzene Derivatives ◽  
Rydberg Series ◽  
First Ionization Potential ◽  
Vacuum Ultra Violet

New photographs of the far ultra-violet spectrum of benzene are presented. The absorption from 2000 to 1800A ( λ max , c . 1980A) is regarded not as a part of the much stronger absorp­tion of peak at 1790A but as due to a separate transition. Sharp bands lying at 1790A represent the first member of a previously reported Rydberg series. The spectra of toluene, xylene, monochloro-and o -dichlorobenzene, bromobenzene, iodoben-zene and pyridine are briefly described, and the shifts relative to benzene are discussed. Two Rydberg series were observed for toluene, converging to a first ionization potential of 8.77 ± 0.05 V.

The far ultra-violet absorption spectra of the hydrides and deuterides of sulphur, selenium and tellurium and of the methyl derivatives of hydrogen sulphide

1950 ◽  
Vol 201 (1067) ◽  
pp. 600-609 ◽  
Keyword(s):  
Ionization Potential ◽  
Absorption Spectra ◽  
Ground State ◽  
Lone Pair ◽  
Ultra Violet ◽  
General Nature ◽  
Rydberg Series ◽  
Group Vi ◽  
Methyl Derivatives ◽  
First Ionization Potential

The absorption spectra in the vacuum ultra-violet of the hydrides and deuterides of sulphur, selenium and tellurium, and methyl mercaptan and dimethyl sulphide are described. Well-developed Rydberg series leading to the following ionization potentials have been found: H 2 S, 10.47V; MeSH, 9.44V; H 2 Se, 9.88V; H 2 Te, 9.14V. In the case of one series for H 2 Se fifteen members of the series were observed. The spectra of the deuterides are almost identical with those of the hydrides, showing that virtually every band in the spectra is due to a separate electronic transition. This and the general nature of the rotational fine structure show the transitions concerned to be those of an electron from a non-bonding ground-state orbital, i.e. from the p lone-pair ground-state orbital. The nature of the upper orbitals of the various series is also interpreted and shown to provide explanations of certain peculiarities of the observations. The quantity I(X) — J(H 2 X), where X is a group VI element, or I ( Y ) — I ( HY), where Y is a group VII element, is shown to be positive and comparatively large when X or Y lies in the first period of the periodic table, but to change sign and to remain almost constant at a small negative value as one passes to elements in later periods. A plot of I (H 2 X)against the first ionization potential of the corresponding inert gas is linear. Extrapolation enables the first ionization potential of H 2 Po to be predicted at 8.6V. A similar plot for the halogen acids, if assumed linear, yields a predicted first ionization potential for HF of 17.0±0.7V.

The 1650-1350 Å absorption spectrum of nitrogen dioxide

1962 ◽  
Vol 267 (1330) ◽  
pp. 395-407 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Nitrogen Dioxide ◽  
Ionization Potential ◽  
Ground State ◽  
Band System ◽  
Anharmonic Constant ◽  
Rydberg Transitions ◽  
First Ionization Potential

An analysis of the 1650-1350 Å band system of nitrogen dioxide has been carried out. A pattern of band spacings and intensities is found that is complex but regular. It is shown that this pattern is qualitatively, and to a large extent quantitatively, just what would be expected for a transition in which the shape of the molecule changes from bent to linear. The transition is a parallel one and the upper state has 2 Σ + u symmetry. The symmetrical stretching frequency is increased from its ground-state value to ca. 1420 cm -1 in the upper state. The upper-state bending frequency is ca. 600 cm -1 . The N — O length is decreased from its groundstate value, probably to 1·1(3) Å. The upper state resembles closely the ground state of NO + 2 . The transition is to be classed as one of the Rydberg transitions leading to the first ionization potential of NO 2 ; and the orbital to which the odd electron is transferred in the transition is (pσ) in type. The anharmonic constant g 22 for the linear upper state is found to be 2·(3) cm -1 . Other Rydberg transitions may well be present in the region, but have not been definitely identified.

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