Push–Pull Azo‐Chromophores Containing Two Fused Pentatomic Heterocycles and Their Nonlinear Optical Properties

Abstract

AbstractWe have developed procedures for the synthesis of push–pull azo‐chromophores containing the s‐triazolo[3,4‐b]thiadiazole heterocycle compatible with the presence of electron‐acceptor groups (nitrophenyl group) as substituents on both the triazole and thiadiazole rings. The linear and non‐linear optical properties of the synthesized chromophores have been characterized by the EFISH technique, electro‐optical absorption spectroscopy and DFT calculations. The combined results indicate a significant modulation of the properties of the chromophores depending on the substitution pattern on the heterobicycle. Fast UV‐driven trans → cis and slower thermally driven cis → trans isomerizations around the N=N bond were observed and characterized for the chromophores. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)