NLO chromophores containing dihydrobenzothiazolylidene and dihydroquinolinylidene donors with an azo linker: Synthesis and optical properties

We report the synthesis of a series of nonlinear optical chromophores containing either - a dihydrobenzothiazolylidene or dihydroquinolinylidene donor with an azo linker. The results demonstrate the versatility of coupling a diazonium salt to a donor-methylidene nucleus in order to access novel materials with good thermal stabilities and high nonlinear optical responses. From hyper-Raleigh scattering studies it was found that the use of the well-known TCF acceptor yields the best performing chromophores, one of which has a dynamic first hyperpolarizability of 1900 x 10(-30) esu at 800 nm. The results from this study suggest the use of pro-aromatic donors such as dihydrobenzothiazolylidene or dihydroquinolinylidene results in compounds with higher nonlinear optical responses than those containing donors based on either indoline or aniline. (C) 2013 Elsevier Ltd. All rights reserved.