The first absorption band for H2O: Interpretation of the absorption spectrum using time dependent pictures

1988 ◽  
Vol 89 (9) ◽  
pp. 5607-5613 ◽  
Author(s):  
Niels E. Henriksen ◽  
Jinzhong Zhang ◽  
Dan G. Imre
1999 ◽  
Vol 19 (1-4) ◽  
pp. 71-74 ◽  
Author(s):  
Xuming Zheng ◽  
David Lee Phillips

We have obtained A-band absorption resonance Raman spectra of 1-chloro-2- iodoethane in cyclohexane solution. We have done preliminary time-dependent wavepacket calculations to simulate the resonance Raman intensities and absorption spectrum in order to learn more about the short-time photodissociation dynamics. We compare our preliminary results for 1-chloro-2-iodoethane with previous resonance Raman results for iodoethane and find that there appears to be more motion along non- C—I stretch modes for 1-chloro-2-iodoethane than for iodoethane. This is consistent with results of TOF photofragment spectroscopy experiments which indicate much more internal excitation of the photoproducts from 1-chloro-2-iodoethane photodissociation than the photoproducts from iodoethane photodissociation.


1994 ◽  
Vol 14 (1-3) ◽  
pp. 155-160 ◽  
Author(s):  
Tatsuhisa Kato

Absorption spectra are detected for C60− and C602− produced electrolytically in solution at room temperature. Theoretical analysis of the spectrum of C60− by CNDO/S calculations gives an interpretation of the characteristic near-IR bands, the weak visible bands, and the strong bands in the UV region. The emission spectrum of C60− is a mirror image of the near-IR absorption band, and the detection of the emission reconfirms our original assignment of the absorption spectrum. The nature of the spectrum of C602− is characterized by a similar orbital picture to that of C60−. Further laser experiments of significance are proposed.


1949 ◽  
Vol 27b (7) ◽  
pp. 610-615 ◽  
Author(s):  
H. W. Lemon ◽  
C. K. Cross

The infrared absorption spectrum of methyl isolinoleate, separated from the methyl esters of hydrogenated linseed oil fatty acids, has a well defined absorption band with maximum absorption at about 968 cm.−1 As an identical band was found in the spectra of fatty acids or esters after isomerization with selenium, it is attributed to the presence of double bonds with a trans-configuration. It was found that the same band was present in the spectra of samples taken during hydrogenation of oils, and that its intensity increased to a maximum, then decreased as hydrogenation proceeded. It is concluded that hydrogenation is accompanied by a cis-to-trans change in some of the double bonds of the fatty acids, and that methyl isolinoleate has at least one double bond with a trans-configuration.


1980 ◽  
Vol 45 (2) ◽  
pp. 307-320 ◽  
Author(s):  
Miloš Titz ◽  
Antonín Novák ◽  
Viktor Řehák

Absorption, fluorescence excitation and APF spectra of cryptocyanine have been measured. Dipole moment of the respective S1 excited state has been estimated from shifts of the marked maximum of the first absorption band in various solvents. On the basis of quantum-chemical calculations carried out by the PPP method in the approximation of quasi-real geometry we have received the optimum model of π-electronic structure of the cryptocyanine molecule and therefrom the theoretical electronic singlet spectrum inclusive character of the S0 - S1 transition.


1972 ◽  
Vol 38 (298) ◽  
pp. 721-724 ◽  
Author(s):  
E. R. Vance ◽  
B. W. Anderson

SummaryLow Ceylon zircons showing an optical absorption band at 5200 Å appear to have suffered more radiation damage than other low Ceylon zircons. Very heavy fission-fragment irradiation failed to lower the density of each of two low Ceylon zircons significantly, although the specimens were rendered completely amorphous. Further fission-fragment irradiation experiments indicated that low Ceylon zircons showing a previously reported anomalous absorption spectrum have been heated late in their geological histories.


2004 ◽  
Vol 19 (4) ◽  
pp. 1203-1207 ◽  
Author(s):  
Yan Wang ◽  
Chaoyang Tu ◽  
Changcang Huang ◽  
Zhenyu You

Yb3+-doped single-crystal Ca3Y2(BO3)4 with dimension φ20 × 55 mm was grown by the Czochralski method. The structure of it was determined by x-ray diffraction. It belongs to the orthorhombic system, space group Pnma, with the following parameters: a= 7.1690(4), b = 15.4758(8), c = 8.5587(6) Å, V = 949.55(10)Å3, Mr = 537.51, Z = 2, Dc = 3.8 g/cm3, (MoKa) = 0.71073 Å, F(000) = 508, μ = 6.927 mm-1, final R = 0.0670, and wR = 0.1542 for 2975 independent reflections. The structure of Yb:Ca3Y2(BO3)4 is made up of three set of M-oxygen distorted polyhedrons, and three set of BO3 planar triangles. Ca2+ and Y3+ ions occupy three M sites statistically. Yb3+ ions substitute Y3+ ions to enter these three lattices. The adsorption and emission spectra were measured. It exhibits a broad absorption band ranging from 850 to 1000 nm in the absorption spectrum, which is well matched with the emission wavelength of a laser diode. A broad emission spectrum ranging from 927.95 to 1102.7 nm was observed under the excitation of 895 nm.


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