language: de

Einfluß von Substituenten auf die Fluoreszenzquantenausbeute bei Donator-Akzeptor-substituierten trans-Stilbenen *

D. Gloyna **, A. Kawski und I. Gryczynski
Lumineszenz-Forschungsgruppe , Institut für Physik der Universität Gdansk,
Gdansk , Polen
Z. Naturforsch. 35 a, 1192-1196 (1980);

[eingegangen am 18. Juli 1980]

[Influence of Substüuents on Fluorescence Quantum Yields of Donor-Acceptor-Substüuted-trans - Stilbene8]

For 4'-acceptor substituted 4-dimethylaminostilbenes 1 the fluorescence quantum yield tpt increases in n-heptane and toluene with decreasing acceptor interaction ( i.e. with decreasing polarity in the Sx-state ). At the same time, the lifetimes Tf w change with q % so that k^ remains approximately constant. Changes in pt for compounds 1 result from a strong change of the rate constant t p of radiationless deactivation. This is interpreted in terms of the decreased stabilization of the Si-state occurring with the increase in the polarity of the investigated compounds in non-polar solvents, and remains in good agreement with the calculations carried out previously.

1. Einleitung