Nonlinear Optical Thin Film Device from a Chiral Octopolar Phenylacetylene Liquid Crystal

摘要

A set of chiral discotic phenylacetylenes have beennsynthesized by 3-fold Sonogashira coupling between differentnethynylbenzenes and triiodobenzenes. The resultant bulk materialsnare fully characterized by polarized optical microscopy (POM),ndifferential scanning calorimetry (DSC), and X-ray diffraction. Thenoctopolar nature of the target compounds is studied by UV−visnabsorption spectroscopy and hyper-Raleigh scattering in solution.nOptimization of the donor−acceptor substitution yields both highnhyperpolarizability values and appreciable mesomorphic properties. Ansimple thin film device for second harmonic generation has beennprepared from the nitro-substituted liquid crystalline derivative.