ISSN:
1573-4994
Keywords:
Bichromophore
;
intramolecular electronic energy transfer
;
photophysical processes
;
internal conversion process
;
process of singlet–triplet conversion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Results of experimental and theoretical research for three bichromophore molecules, trans-stilbene-CH2-coumarin 120 (I), 4-methylumbelliferone-CH2-UC 17, and 4-(3-fluoro)-methylumbelliferone-CH2-UC 17 (II, III), are presented. Schemes of photophysical processes in the bichromophore molecules based on quantum chemical calculations by the INDO method and theory of radiationless transitions in polyatomic organic molecules are suggested. After optical excitation to the strong donor absorption band, the fast internal conversion processes develop there. As a result, the molecule is found in the S 1 * -state localized on the acceptor moiety. It is shown that a mechanism of intramolecular transfer energy in bichromophores different from that proposed by Förster may be realized. Excitation energy, initially located on D, will be transferred from the donor moiety to the acceptor chromophore in convenience of the internal conversion process. The intramolecular electronic energy transfer from energy donor to energy acceptor may be interpreted as the internal conversion process. The rate constants of internal conversion are calculated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1020527505660
Permalink
