Absorption spectra in the vacuum ultraviolet and the ionization potentials of naphthalene and naphthalene-d8 molecules

1968 ◽  
Vol 21 (9) ◽  
pp. 2153 ◽  
Author(s):  
JG Angus ◽  
BJ Christ ◽  
GC Morris
Keyword(s):  
Ionization Potential ◽  
Absorption Spectra ◽  
Vacuum Ultraviolet ◽  
Ionization Potentials ◽  
Rydberg Series ◽  
Quantum Defects ◽  
Rydberg Transitions

The vapour absorption spectra of naphthalene and naphthalene-d8 were obtained photographically and photoelectrically from 50000 to 70000 cm-1. A series of Rydberg transitions and possibly two π*-π systems are observed. Each of the five Rydberg series converges to an ionization potential of 65620 � 40 cm-l, i.e. 8.136 � 0.005 eV (C10H8), and 65640 � 60 cm-l, i.e. 8.138 � 0.008 eV (C10D8). The quantum defects of the series are (0.94, 0.88, 0.82, 0.67, 0.53) � 0.01. The significance of these results is discussed.

scholarly journals The absorption spectra of the cyclic dienes in the vacuum ultra-violet

1941 ◽  
Vol 179 (977) ◽  
pp. 201-214 ◽  
Keyword(s):  
Electronic Structure ◽  
Double Bond ◽  
Ionization Potential ◽  
Absorption Spectra ◽  
Ultra Violet ◽  
Ionization Potentials ◽  
Rydberg Series ◽  
Cyclic Dienes ◽  
Vacuum Ultra Violet ◽  
Marked Tendency

The absorption spectra of cyclohexadiene, cyclopentadiene, pyrrole, thiophene and furan have been investigated in the vacuum ultra-violet. The spectra obtained are due to the excitation of a π electron from the conjugated double-bond electrons (X 2 1 x 2 2 )• The ionization potentials of the molecules deduced from Rydberg series are respectively 8.4, 8.58, 8.9, 8.91 and 9.01V, these values referring to the outer X 2 shell of π electrons. A second less certain ionization potential of about 10.8V was obtained for furan. Some discussion of the electronic structure of the molecules on the basis of their spectra is given, and it is concluded that only in furan is there marked tendency towards homocyclic conjugation. It is also concluded that ‘hyperconjugation’ does not play so large a part in the interpretation of the spectra of cyclohexadiene and cyclopentadiene as previously supposed.

The photoabsorption of chlorodifluoroethenes in the vacuum ultraviolet

1985 ◽  
Vol 63 (7) ◽  
pp. 1949-1954 ◽  
Author(s):  
Eckart Rühl ◽  
Hans-Werner Jochims ◽  
Helmut Baumgärtel
Keyword(s):  
Energy Range ◽  
Ionization Potential ◽  
Gas Phase ◽  
Absorption Spectra ◽  
Photon Energy ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Absorption Bands ◽  
Broad Absorption ◽  
Cis And Trans

The gas phase absorption spectra of 2-chloro-1,1-difluoroethene, cis- and trans-1-chloro-1,2-difluoroethene have been measured in the photon energy range from 6.5 to 25 eV. The π → π* transition is assigned to bands centered around 7.17 – 7.20 eV for all three isomers. Four Rydberg series are observed in all the spectra, converging to the π ionization potential: two np-type Rydberg series, one ns, and one nd series are assigned. The convergence limits are: 9.84 eV (2-chloro-1,1-difluoroethene), 9.86 eV (trans-1-chloro-1,2-difluoroethene), and 9.85 eV (trans-1-chloro-1,2-difluoroethene). In the case of 2-chloro-1,1-difluoroethene four additional Rydberg series are found converging to the nCl ionization potential. The convergence limit of these series is 12.15 eV.Above 12 eV broad absorption bands dominate the spectra.

ABSORPTION SPECTRA OF BENZENE AND BENZENE-d6 IN THE VACUUM ULTRAVIOLET

1956 ◽  
Vol 34 (6) ◽  
pp. 596-615 ◽  
Author(s):  
P. G. Wilkinson
Keyword(s):  
Absorption Spectra ◽  
Vacuum Ultraviolet ◽  
Stable Equilibrium ◽  
Normal Incidence ◽  
Rydberg Series ◽  
First Order ◽  
Jahn Teller ◽  
Vibrational Bands ◽  
Vibrational Constants ◽  
Rydberg Transitions

The absorption spectra of benzene and benzene-d6 have been photographed from 1300 Å to 1850 Å in the first order of a 21-ft. normal incidence vacuum spectrograph. The band analysis resulted in the identification of four Rydberg series (over one hundred vibrational bands) in each molecule, converging to ionization potentials of 9.247 ev. (benzene) and 9.251 ev. (benzene-d6). Progressions of the ν2, ν18, and ν20 vibrations are associated with most of the 31 observed Rydberg transitions, and vibrational constants are tabulated for each. The strong intensity and the unusual length of the upper state ν18 (e2g) progression in comparison with the ν2(a1g) progression are interpreted in terms of the Jahn–Teller theorem, and it is concluded that the stable equilibrium nuclear configuration in the Rydberg states is of D2h symmetry.

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.

The absorption spectrum of Ag I in the vacuum ultraviolet

1978 ◽  
Vol 361 (1706) ◽  
pp. 379-398 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Synchrotron Radiation ◽  
Variational Method ◽  
Theoretical Prediction ◽  
Ab Initio ◽  
Absorption Spectra ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Hartree Fock ◽  
Doubly Excited

The absorption spectrum of Ag I between 550 Å and 1590 Å has been investigated by using synchrotron radiation as the source of continuum. Over 50 new transitions are reported, nearly all of which can be classified into Rydberg series due to excitation of one electron from the 4d subshell. Identifications are made by comparison with previous studies of the arc spectrum as well as with absorption spectra of related elements. Ab initio Hartree-Fock calculations have revealed the importance of treating 5s 5p 1 P based levels by a separate variational method. Doubly excited configurations are also found, but, in contrast to a previous theoretical prediction, double vacancy production within the 4d subshell is not found to be significant for Ag I.

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.

Vacuum ultraviolet spectrum of the iodine molecule

1970 ◽  
Vol 48 (9) ◽  
pp. 1055-1079 ◽  
Author(s):  
Putcha Venkateswarlu
Keyword(s):  
Vacuum Ultraviolet ◽  
Rydberg States ◽  
Rydberg Series ◽  
Molecular Ion ◽  
Similar Series ◽  
Common Limit ◽  
The Common ◽  
Ionization Limit ◽  
Rydberg Transitions ◽  
Concave Grating

The absorption spectrum of iodine has been photographed in the higher orders of a 10.7 m concave grating spectrograph in the region 1950–1200 Å. A number of band systems has been obtained, most of which correspond to Rydberg transitions. The limit of the Rydberg series leading to the 2Π3/2g state of the molecular ion has been recorded and the corresponding ionization potential is found to be 75 814 ± 10 cm−1. Five series have been found which terminate at this common limit. They represent transitions from the ground state to [σg2πu4Πg32Π3/2g]np σu Π1u, [σg2πu4πg32Π3/2g]np πu Σ+ (0u+), [σg2πu4πg32Π3/2g]nf σu Π1u, [σg2πu4πg32Π3/2g]nf πu, Σ+(0u+), and [σg2πu4πg32Π3/2g]nf δu Π1u states respectively, where n takes the running values 6, 7, 8, … etc. for the first three series and 4, 5, 6, … etc. for the last two series. The series limit of the bands corresponding to the molecules with ν″ = 1 has been found to be at 75 600 ± 10 cm−1. The first few members of similar series corresponding to transitions to different states involving the common [σg2πu4πg32Π1/2g] core have been identified and the ionization limit of these series is estimated to be at 80 895 ± 50 cm−1. Some of the remaining band systems obtained have been found to be very likely due to transitions to the Rydberg states involving molecular ion cores like [σg2πu 3πg42Π3/2u], [σg2πu3πg42Π1/2u], and [σg2πu4πg2σu2Σu+]. Three of the observed band systems do not appear to involve Rydberg states and their upper levels are very likely the 1Π(1u), 3Π(1u), and 3Π(0u+) states arising from the configuration σgπu3πg4σu2. The positions of these levels are at 64 956, 62 844, and 61 847 cm−1, the corresponding vibrational frequencies being 145, 144, and 109 cm−1 respectively.

Electron energy-loss spectra of some triatomic molecules

1971 ◽  
Vol 322 (1551) ◽  
pp. 535-554 ◽  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Vacuum Ultraviolet ◽  
Rydberg Series ◽  
Triatomic Molecules ◽  
Forbidden Transition ◽  
Quantum Defects ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra ◽  
Transition Behaviour

Electron energy-loss spectra in the range 3 to 20 eV of CO 2 , N 2 O, COS, CS 2 , SO 2 are reported. Rydberg series are compared with those identified in vacuum ultraviolet absorption spectra, and a number of new lowest members and new series are reported. The quantum defects of these are discussed in terms of the orbitals of the active electrons. CO 2 levels have been studied with variable scattering angle, the progressions around 15 eV showing characteristic forbidden transition behaviour, and being tentatively assigned as π 3 g σ g 1 II g and π 3 g σ g 3 II g . The generalized oscillator strength of CO 2 D ~ 11.09 eV shows a discrepancy from that reported by Lassettre & Shiloff (1965).

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.

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