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7969721 
Journal Article 
Peculiarities in the photophysical properties of some 6-styryl-2,4-disubstituted pyrylium salts 
Nikolov, P; Metzov, S 
2000 
Yes 
Journal of Photochemistry and Photobiology A: Chemistry
ISSN: 1010-6030
EISSN: 1873-2666 
135 
1 
13-25 
English 
WOS:000087791600003 
The absorption and fluorescence characteristics of some 6-styryl-2,4-disubstituted pyrylium salts in cyclohexane, acetonitrile and ethanol are reported. The UV-VIS absorption spectra are dominated by two well separated bands. The absorption band in the spectral region of 320-400nm for all investigated compounds is strongly localized on the corresponding pyrylium fragment of the molecule, while the longest wavelength absorption band with maximum in the region of 420-530nm depends on the presence of different substituents in 6-position of the pyrylium fragment. The excitation in the second absorption band (320-400nm) brings rise to two different emissions, denoted in the text as 'L' and 'D' bands. The analysis of the experimental data, based on a comparison with the spectral properties of model compounds, show that 'D' band is connected with the whole conjugated system of the investigated 6-styryl-2,4-disubstituted pyrylium salts, while 'L' band with maximum 400-450nm is a local emission from the corresponding pyrylium fragment of the molecule. 2000 Elsevier Science S.A. 
electronic spectra; fluorescence; local emission; 6-styryl-2,4-disubstituted pyrylium salts