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.

ABSORPTION SPECTRA OF ETHYLENE AND ETHYLENE-d4 IN THE VACUUM ULTRAVIOLET. II

1956 ◽  
Vol 34 (7) ◽  
pp. 643-652 ◽  
Author(s):  
P. G. Wilkinson
Keyword(s):  
Absorption Spectra ◽  
Vacuum Ultraviolet ◽  
Stable Equilibrium ◽  
Equilibrium Configuration ◽  
Rydberg States ◽  
Torsional Oscillator ◽  
Potential Barriers ◽  
First Order ◽  
Stretching Vibration ◽  
Vibrational Constants

The absorption spectra of ethylene and ethylene-d4 have been investigated in the 1300 Å to 1500 Å region using the first order of a 21-ft. vacuum grating spectrograph. Vibrational constants for the v2(ag) stretching vibration and the v4(au) twisting vibration have been determined for each of the observed five Rydberg states. The torsional oscillator–rotator treatment has been applied to the observed twisting data, and potential barriers hindering free rotation of 500 to 1200 cm−1 were obtained. It is concluded that the stable equilibrium configuration of the Rydberg states is not of D2h symmetry but is probably bent or staggered.

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.

VIBRATIONAL ISOTOPE SHIFTS OF ABSORPTION BANDS OF N2 IN THE SPECTRAL REGION 720–830 Å

1964 ◽  
Vol 42 (6) ◽  
pp. 1087-1096 ◽  
Author(s):  
Masaru Ogawa
Keyword(s):  
Absorption Spectra ◽  
Spectral Region ◽  
Normal Incidence ◽  
Rydberg Series ◽  
Absorption Bands ◽  
Isotope Shifts ◽  
Previous Assignment ◽  
Vibrational Constants ◽  
Concave Grating

Using a normal-incidence vacuum spectrograph with a 3-meter concave grating, the absorption spectra of 14N2 and 15N2 in the 720–830 Å region have been investigated. From the vibrational isotope shifts, it has been confirmed that the previous assignment given by Ogawa and Tanaka for the Rydberg series converging to the A2Πu state of N2+ was correct. The observed series limits converging to the [Formula: see text] state of 15N2+ are 134735(0,0), 136540(1,0), 138320(2,0), and 140070(3,0) cm−1. The observed vibrational isotope shifts at the series limits in both Rydberg series converging to the A2Πu and the X2Σg+ states of N2+ agree with those values calculated from the known vibrational constants of the A2Πu, and the X2Σg+ states of 14N2+ and the X1Σg+ state of 14N2. In addition to the Rydberg series, four new progressions have been identified tentatively. The observed vibrational quanta of the upper states of these progressions are almost the same, and are, moreover, almost the same as those of the A2Πu state of N2+.

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 Vacuum Ultraviolet Absorption of Dense Plasmas with Resonance Series of Be, B, C, N, Mg, Al and Si

1972 ◽  
Vol 14 ◽  
pp. 531-531
Author(s):  
G. Mehlman-Balloffet ◽  
J. M. Esteva
Keyword(s):  
Vacuum Ultraviolet ◽  
Extreme Ultraviolet ◽  
Light Element ◽  
Numerical Data ◽  
Normal Incidence ◽  
Electron Excitation ◽  
Rydberg Series ◽  
Dense Plasmas ◽  
Continuous Background ◽  
Ionization Limit

AbstractAbsorption spectra of light elements were observed in the vacuum ultraviolet with an original technique described in an earlier paper (Mehlman-Balloffet and Esteva, 1969). The method utilizes a two-vacuum spark mounting: one of the sparks is emitting the continuous background, the other one generates the absorbing plasma. Several light element have been successsively introduced in the spark anode. For all of them new autoionizing levels have been observed in Rydberg series of resonances exhibiting the asymmetric ‘Beutler-Fano’ profile.In the beryllium and magnesium spectra three new series corresponding to two-electron excitation process have been identified while for boron, carbon, nitrogen, aluminium and silicon the resonances observed correspond to single subshell electron excitation such as: 2s22p2P0 → 2s2p(3P0)np2De for the case of boron.All these series lie in the photoionization continuum of the absorbing atomic species and usually between the first and second ionization limit. This means that they were observed with a normal incidence grating spectrograph in the spectral range 500–1500 Å. In the extreme ultraviolet some other transitions involving inner-shell electron excitation were observed. In the beryllium spectra a series lying between 100 and 110 Å was identified while, the magnesium spectra exhibited only isolated resonances in the 220-265 Å range together with an inner-shell 2p electron photoioniation continuum.A complete description of experimental results with numerical data is being submitted for publication (Esteva and Mehlman-Balloffet, 1972).

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.

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.

THE VACUUM ULTRAVIOLET ABSORPTION SPECTRUM OF DIAZOMETHANE

1964 ◽  
Vol 42 (6) ◽  
pp. 1242-1255 ◽  
Author(s):  
A. J. Merer
Keyword(s):  
Excited States ◽  
Vacuum Ultraviolet ◽  
Ultraviolet Absorption ◽  
Electronic Transitions ◽  
Ultraviolet Absorption Spectrum ◽  
Rydberg Series ◽  
Coriolis Interaction ◽  
Out Of Plane ◽  
Symmetry Species ◽  
Vibrational Bands

Ultraviolet absorption spectra of CH2N2 and CD2N2 between 2000 Å and 1350 Å have been photographed. Many electronic transitions occur in this region, including a Rydberg series (first reported by Herzberg) which gives the first I.P. of diazomethane as 8.999 ± 0.001 ev. Examination of a band system at 1900 Å has shown that it contains three close-lying electronic transitions, with origins within 200 cm−1. Of the upper states, the two outermost, D and F, are shown by rotational analysis to be of the same symmetry species 1B1, while the third, E, lying between them, seems to be responsible for large perturbations observed in the K structures. By inference, this third state must be 1B2, in Coriolis interaction with the two 1B1 states. Various vibrational bands of this 1900 Å group have been assigned; among these are a number of vibrationally forbidden bands involving one and three quanta of the out-of-plane CH2 bending frequency, ν6. There is strong evidence that the molecule remains planar in these excited states.

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