The photoabsorption of chlorodifluoroethenes in the vacuum ultraviolet

1985 ◽  
Vol 63 (7) ◽  
pp. 1949-1954 ◽  
Author(s):  
Eckart Rühl ◽  
Hans-Werner Jochims ◽  
Helmut Baumgärtel

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.

2018 ◽  
Vol 122 (27) ◽  
pp. 5832-5847 ◽  
Author(s):  
Sydney Leach ◽  
Nykola C. Jones ◽  
Søren V. Hoffmann ◽  
Sun Un

1968 ◽  
Vol 21 (9) ◽  
pp. 2153 ◽  
Author(s):  
JG Angus ◽  
BJ Christ ◽  
GC Morris

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.


1989 ◽  
Vol 44 (1) ◽  
pp. 17-20 ◽  
Author(s):  
G. Hagenow ◽  
H.-W. Jochims ◽  
J. Sawatzki ◽  
R. Minkwitz ◽  
H. Baumgärtel

Abstract The ionization potential of CH3SCF3 and the appearance potentials of fragment ions have been measured in the photon energy range 9 -19 eV using synchrotron, radiation. From these results thermochemical data of CH3SCF3, CH3SCF3+ and fragment ions have been evaluated.


In connexion with studies of the electronic structure of disordered systems, we enquire whether there exist exciton states in simple liquids. We report the results of a vacuum ultraviolet spectroscopic study of liquid argon and of liquid krypton doped with xenon. Experimental evidence was obtained for Wannier-Mott type impurity states in liquids which have no parentage in the excited states of the isolated atoms constituting the dense fluid. The absorption spectra of the doped liquid rare gases were monitored in the region 160 to 120 nm. The following experimental results are reported: (a) In the Xe/Ar liquid two absorption bands corresponding to the 1 S 0 → 3 P 1 and to the 1 S 0 → 1 P 1 transitions (or alternatively to the n = 1 Wannier states) were identified at 141 nm (8.80eV)† and at 123nm (10.1 eV). An additional line was observed at 127 nm (9.76eV). (b) In the Xe/Kr liquid three absorption bands were observed at 144.5 nm (8.59 eV), 125.5 nm (9.89 eV) and 129 nm (9.6 eV). (c) The absorption spectra of the doped liquids were compared with the spectra of 1 cm thick doped solid rare-gas crystals. From these results we conclude that: (a) The 127 nm (9.76 eV) band in the Xe/Ar liquid system and the 129 nm (9.61 eV) band in the Xe/Kr liquid system cannot be attributed to a perturbed ‘atomic’ state and are assigned to the n = 2 Wannier state in the liquid. (b) Line broadening of exciton states in the liquid can be accounted for by a simple scattering model. (c) Preliminary information on band gaps in liquid rare gases were obtained from the spectroscopic data. (d) The effect of liquid-solid phase transition on the line broadening of exciton states is consistent with electron mobility data in these systems.


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.


2020 ◽  
Vol 27 (5) ◽  
pp. 1388-1394
Author(s):  
Z. P. Sun ◽  
Z. H. Liu ◽  
Z. T. Liu ◽  
W. L. Liu ◽  
F. Y. Zhang ◽  
...  

The vacuum ultraviolet beamline BL03U with a photon energy range from 7 eV upwards has been constructed at the 3.5 GeV Shanghai Synchrotron Radiation Facility. Equipped with an APPLE-Knot undulator, this beamline is dedicated to angle-resolved photoemission spectroscopy. An energy-resolving power of higher than 4.6 × 104 has been achieved in the photon energy range 21.6–48 eV, which is almost the same as the theoretical estimation.


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 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.


1965 ◽  
Vol 43 (2) ◽  
pp. 256-267 ◽  
Author(s):  
G. R. Cook ◽  
M. Ogawa

Absolute photo-ionization coefficients and ionization efficiencies of N2 have been measured in the 734–805 Å region using a 1-meter Seya–Namioka scanning vacuum monochromator with the Hopfield helium continuum as a background light source.The ion-current spectrum obtained has been compared with the absorption spectrum observed photographically. Nearly all of the absorption bands with higher energies than the first ionization potential showed ion-current peaks, indicating pre-ionization. However, their ionization efficiencies showed strong fluctuations whose magnitudes decreased toward the shorter wavelengths. The spectral regions with the lowest absorption coefficients (180–340 cm−1) beyond the first ionization potential showed the highest efficiencies, the values of which were about 80%. Efficiencies of bands with m[Formula: see text] of the Ogawa–Tanaka Rydberg series were much larger than those of the corresponding bands of the Worley third Rydberg series. The progressions (1) and (2) had a rather high efficiency of 70% which increased slightly with an increase of the vibrational quantum numbers of the upper electronic states.


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