Author/Authors :
Cornil، نويسنده , , J. and Beljonne، نويسنده , , D. and Shuia، نويسنده , , Z. and Hagler، نويسنده , , T.W. and Campbell، نويسنده , , I. and Bradley، نويسنده , , D.D.C. and Brédas، نويسنده , , J.L. and Spangler، نويسنده , , C.W. and Müllen، نويسنده , , K.، نويسنده ,
Abstract :
We present a joint experimental and theoretical investigation of the optical absorption spectra of phenylene vinylene oligomers. The vibronic structure, which is clearly observed in the experimental spectra, is well described by a simple model based on the Frank-Condon approximation but requires the use of at least two effective modes coupled to the electronic states. Using a fitting procedure, we deduce the displacement of the 1Bu excited state potential energy curve relative to that of the ground state and compare it to the results of recent Hartree-Fock semi-empirical calculations. Such information is of prime importance in the description of the frequency-dependent linear as well as nonlinear optical responses.
