Two-photon absorption dye based on 2,5-bis(phenylacrylonitrile)thiophene with aggregration enhanced fluorescence

This paper reports the synthesis and characterization of a 2,5-bis(phenylacrylonitrile) thiophene based two-photon dye, designed to show enhancement in fluorescence quantum yield in nanoaggregated form. Strong solvatochromism has been observed and explained by the favoritism of locally excited (LE) or internal charge transfer (ICT) state depending on the solvent polarity. Aqueous dispersions of nanoparticles have been prepared and investigated regarding their optical properties which were correlated to the LE and ICT state and the molecular structure of the aggregates. (C) 2016 Optical Society of America