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

Abstract

Abstract For 4'-acceptor substituted 4-dimethylaminostilbenes 1 the fluorescence quantum yield φ f increases in n-heptane and toluene with decreasing acceptor interaction (i.e. with decreasing polarity in the S 1 -state). At the same time, the lifetimes τ f w change with φ f so that k f n remains approximately constant. Changes in φ f for compounds 1 result from a strong change of the rate constant k tp 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.