Intramolecular charge transfer and enhanced quadratic optical non-linearities in push pull polyenes

Push-pull polyenes, which have an electron-donating group (D) and an electron-withdrawing group (A) grafted on opposite ends of a conjugated polyenic chain, are of particular interest as model compounds for long-distance intramolecular charge transfer (ICT), as well as potent non-linear optical chromophores. Several series of push-pull polyenes of increasing length, combining aromatic donor moieties and various acceptor groups, have been prepared and studied. Their linear and non-linear optical properties have been investigated by performing electro-optical absorption measurements (FOAM) and electric-field-induced second-harmonic generation (EFISH) experiments in solution.