The resonance Raman excitation profiles (RREPs) of the v1 and v2 vibrations of fucoxanthin in acetone and toluene solvents have been studied. Fucoxanthin, which is a predominant pigment in marine seaweed and phytoplankton, has several structural differences from carotenoids for which excitation prof
Excitation profile of the resonance Raman effect of uranyl nitrate in acetone
β Scribed by Ken Ohwada; Akira Takahashi; Ginji Fujisawa
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 520 KB
- Volume
- 52
- Category
- Article
- ISSN
- 1386-1425
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β¦ Synopsis
The resonance Raman spectra of uranyl nitrate in acetone were measured at room temperature, using ten output lines (528.7, 514.5, 501.7, 496.5, 488.0, 476.5, 472.7, 465.8, 457.9 and 454.5 nm) of an argon-ion laser. The excitation profile of the resonance Raman effect has been obtained by plotting the relative intensities of the uranyl symmetric stretching vibration at 863 cm-1 against the laser exciting wavelengths. It is however pointed out that the resonance Raman effect in acetone is not so large in comparison with that in dimethyl sulfoxide (DMSO). The observed excitation profile is found to resemble to the vibronic structure of the electronic absorption spectrum but not completely superimpose on it. Such a discrepancy is qualitatively explained by the interference effect which occurs noticeably in the uranyl nitrate DMSO system. Structure in the Raman excitation profile is briefly discussed on the basis of the Albrecht theory. Lastly, the equilibrium conformation of the uranyl ion in the excited electronic state is clarified through consideration of the scattering intensities of the uranyl symmetric stretching vibration depending on the wavelengths of laser exciting lines.
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