Hyper-Rayleigh scattering of thiophene-incorporated polyene chromophores with pi-configuration locking

Abstract

The hyper-Rayleigh scattering (HRS) technique is used to determine and compare the first hyperpolarizabilities (beta) of thiophene-incorporated polyene chromophores with and without a configuration locked trans-triene bridge, To ensure the purity of the HRS signal, special attention is paid to its dependence on the fundamental intensity and the spectral content of the scattered radiation including the two-photon absorption induced fluorescence. From the HRS results, it is found that the configuration-locked trans-triene bridge enhances the beta values of the chromophores studied, The beta-enhancement is more pronounced when the electron acceptor CHC(CN)(2) in the chromophores is replaced with C-2(CN)(3). (C) 1997 Elsevier Science B.V.