Langmuir–Blodgett film and second harmonic generation of a new type of amphiphilic non-linear optical bis-chromophore complex dye

Abstract
A bivalent zinc complex anion: bis(2-thione-1,3-dithiol-4,5-dimercapto)zinc, has been chosen to balance several non-linear optical (NLO) dye cations in the design and synthesis of a series of novel bis-chromophore complex dyes. The Langmuir film-forming properties of these new NLO complex dyes at the air/water interface, the stability and second-order non-linear optical properties of the monolayer and Langmuir–Blodgett multilayer films were investigated. Results show that both the film-forming properties and NLO coefficiencies were improved greatly when the zinc complex anion was incorporated into four types of NLO-active organic dyes.