Photophysical characterization of trans-4, 4′-disubstituted stilbenes Academic Article uri icon

abstract

  • 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 ( Φ f ) and fluorescence lifetimes ( τ f ) 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 ν-constants. In addition, we experimentally observed the appearance of a second emitting state which is close energetically to the lowest exited singlet state 1 t ∗ in cases of strong donor-acceptor substituents in polar solvents.

publication date

  • January 1, 1997