Morphology, Linear and Nonlinear Optical Response of Octopolar Chromophores Embedded in a Silica Sonogel Matrix

In this work, a liquid crystalline octopolar molecule 1,3,5-tris(ethynylphenyl)benzene-(1) was successfully embedded as dopant chromophore within a SiO2 based sonogel network in order to prepare stable solid state hybrid materials with intense second harmonic generation (SHG). This recently synthesized octopolar compound exhibit a centrosymmetric C 3 -symmetry structure, which is constituted by an electron-rich core and electron-poor periphery groups. The sonogel method, induced by energetic ultrasonic (US) waves applied at the TEOS/H2O reactant mixture interface has proven to be a suitable route in the manufacture of monolithic hybrid systems suitable for optical characterizations. The octopolar-based hybrid samples were comprehensively studied in their morphology, spectroscopic, linear and second-order nonlinear optical (NLO) properties, according to several characterization techniques: epimicroscopy, AFM, UV-Vis- and fluorescence (PL) spectroscopies, and the NLO-SHG-technique. Epimicroscopy, photolumin...