Photophysics and Photochemistry of Bifluorophore Systems

N. Vasil'eva and I. Sokolova
Department of Photonics of Molecules
Siberian Physical-Technical Institute under Tomsk State University
Revolution sq., 1
634050 Tomsk
Russia

E-mail: root@eccspti.tomsk.su

SUMMARY

Theoretical and experimental studies of photophysical and photochemical processes for nonconjugate bichromophores, i.e. molecules of two different monofluorophores coupled by (CH₂)_n-bridge, are present. Our investigations have shown that bichromophores are more complex molecular systems, than a mere sum two nonconjugate fluorophores. Bichromophore is a unified system - "supermolecule" with the unified system of molecular orbitals largely belonging to separate fragments, but on the other hand, unified molecular orbitals. It was obtained after optical excitation in the donor absorption band there develop fast internal conversion processes with the result that the molecule is found in the S₁*-state localized on the acceptor fragment. Thus the energy transfer from the donor fragment to the acceptor that may be interpreted as the internal conversion process.