Intensities of Electronic Transitions in Molecular Spectra IX. Calculations on the Long Wave‐Length Halogen Spectra

1940 ◽  
Vol 8 (3) ◽  
pp. 234-243 ◽  
Author(s):  
Robert S. Mulliken
1979 ◽  
Vol 34 (5) ◽  
pp. 664-666 ◽  
Author(s):  
M. Zander ◽  
R. B. Zellerhoff

Abstract9,9′-Dianthryl disulphide is the first example studied for a diaryl disulphide whose uv/vis absorption spectrum exhibits a distinct vibrational structure whereas the formerly investigated spectra of diphenyl disulphide and the isomeric dinaphthyl disulphides are characterized by the complete lack of vibrational structure. Different interpretations have been given in the literature for this particular property of the diphenyl disulphide and dinaphthyl disulphide spectra. The long wave-length region of the dianthryl disulphide spectrum is interpreted with the assumption of three electronic transitions. Two of them are localized in the anthracene or dithio anthracene chromophore, respectively, whereas the third transition is assumed to be non-localized including the whole system with the S-S bridge acting as a conjugative (butadienoid) link. This assignment is consistent with a pπ-model without pπ/dπ-participation in agreement with results of photoelectron spectral investigations on disulphides reported in the literature.


This study of the thallium fluoride spectrum was undertaken as part of a detailed investigation into the molecular spectra of the series of heavy diatomic fluorides HgF, TlF, PbF and BiF. Whereas the spectra of PbF (Rochester 1936) and BiF (Howell 1936), of which analyses have already been published, contain no very unusual features the TlF spectrum is particularly rich in them, so that it has seemed desirable to extend the original investigation in order to include the other halides of thallium. The absorption spectrum of the fluoride has already been examined by Boizova and Butkow (1936), their findings being summarized below: 1— A continuum at 2200 A appears when the absorption tube is at a temperature of 155° C. Its long-wave edge moves towards the red with increase of temperature, being at 2700 for the unsaturated vapour and at 3400 for the saturated vapour when the temperature is 280° C. They attributed this continuum to the dissociation of Tl 2 F 2 . Tl 2 F 2 → 2TlF + kinetic energy.


1973 ◽  
Vol 17 (02) ◽  
pp. 61-71
Author(s):  
H. S. Chen ◽  
C. C. Mei

Exciting forces and moments due to plane incident waves on a stationary platform are studied in this paper. The platform is a vertical cylinder with a finite draft and elliptical cross section. The mathematical solution to the diffraction problem is obtained on the basis of the linearized long wave approximation. Numerical results via Mathieu functions are presented for a shiplike body with beam-to-length ratio Various draft-to-depth ratios and angles of incidence are considered. Results have been checked with the limiting case of a circular cylinder for the long-wave length range. Aside from its own practical interest, the present theory provides a basis for comparison with other approximate theories of slender-body type and serves as a prelude to the corresponding calculations for arbitrary wavelengths.


2005 ◽  
Vol 13 (14) ◽  
pp. 5192 ◽  
Author(s):  
Nian Ji ◽  
Mengkun Liu ◽  
Jihao Zhou ◽  
Zhifang Lin ◽  
S. T. Chui

2007 ◽  
Vol 4 (3) ◽  
pp. 387-392
Author(s):  
Baghdad Science Journal

The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.72) at the same thickness & concentration of the sample.


2003 ◽  
Vol 770 ◽  
Author(s):  
D. Kuritsyn ◽  
A. Kozanecki ◽  
H. Przybylińska ◽  
W. Jantsch

AbstractWe study sensitization of the 4I13/2 – 4I15/2 Er3+ luminescence at 1.54 μm in silicon-rich silicon oxide (SRSO) in the whole range of blue-green pump wavelengths. We show that, in general, defects due to excess Si in silica act as luminescence sensitizers. They cause a wide excitation band with a long wave length limit of 600 nm. For monochromatic excitation the maximum luminescence yield is still smaller than for resonant excitation within the 4f shell of Er without additional Si. The large enhancement of the excitation cross section for electrical excitation reported in the literature is plausible, however, as the wide excitation band makes good use of the wide energy distribution of hot carriers. We suggest that the dominant factors, which limit the excitation efficiency of Er3+, are distance dependence of the transfer rate and little spectral overlap of the interacting states.


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