Absorption and emission spectra of twenty trans-4,4′-disubstituted stilbenes have been measured in four solvents: cyclohexane (CH), chlorobenzene (CB), 2-butanone (methylethyl ketone, MEK) and dimethylsulfoxide (DMSO) at room temperature. Fluorescence quantum yields (Φf) and fluorescence lifetimes (τf) have been measured for these stilbenes. The lifetimes and quantum yields of fluorescence were found to be dependent on the donor-acceptor properties of the substituents and correlate with the Hammett σ-constants. In addition, we experimentally observed the appearance of a second emitting state which is close energetically to the lowest exited singlet state 1t* in cases of strong donor-acceptor substituents in polar solvents.
|Number of pages||10|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|State||Published - 1 Jan 1997|
- Fluorescence lifetimes
- Fluorescence quantum yields
- Photophysical characterization
- Trans-4,4′-disubstituted stilbenes