Dendronized tricyanopyrroline‐based chromophores in nonlinear optical active host polymer

Abstract

We synthesized new nonlinear optical (NLO) chromophores containing a 3,5-bis(3,5-bisbenzyloxy-benzyloxy)-benzoate dendron. Tricyanopyrroline (TCP)-based chromophores were designed and prepared by virtue of its strong electron withdrawing property. A soluble polyimide containing 6-({4-[2-(1-allyl-4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-vinyl]-phenyll-butyl-amino)-hexanoyl group in the side chain was also prepared as an NLO active host polymer. A benzoate dendron was tethered at two different binding positions of the chromophore to yield two different guest molecules. Thin-film composites of these dendronized chromophores dissolved in the NLO active polyimide host were employed to fabricate the electro-optic (EO) samples. The EO properties of new NLO polyimides containing dendronized chromophores were compared with those of the sample with nondendronized plain chromophores. The effect of a bulky dendron on the EO properties was investigated using an in situ reflection technique.