Synthesis and optical properties of a carbazole-containing novel oligomer

We report on the synthesis and optical properties of a novel oligomer (oligo(2-{2-but-l-enyl-6-[2-(9-decyl-6-formyl-9H-carbazol-3-yl)-vinyl]-pyran-4-ylidenel}-malononitrile)) (Olg(Cz-Pyr-CN)) with an average degree of polymerization three. The molecule was designed to have push-pull structure and was synthesized by Knovenagel condensation reaction. The resulting Olg(Cz-Pyr-CN) was characterized by means of H-1 NMR spectroscopy and IR spectroscopy. The initial decomposition temperature (T-id) of Olg(Cz-Pyr-CN) appeared at 372 degrees C. The alignment order parameter of the poled Olg(Cz-Pyr-CN) film was 0.31, The electro-optic (EO) coefficients (r(33)) and their NLO properties were evaluated by simple reflection and the Maker fringe method. The EO coefficients of Olg(Cz-Pyr-CN) was found to be 28.7 pm/V at 632.8 nm. (c) 2007 Elsevier B.V. All rights reserved.