The two-photon absorption property of stilbazolium derivative with A–π–D–π–A structure: Influence by counter-anion and aggregation

This paper reported two stilbazolium derivatives with differdent counter-anion (OPVBr and OPVOH). The two stilbazolium derivatives have a quadrupoles (A–π–D–π–A) structure, in which pyridinium cation was used as electron-accept group and dibutoxy benzene as electron-donor group. Their linear optical properties were investigated through UV–vis and fluorescence spectral analysis. Two-photon laser induced fluorescence measurements have shown that OPVOH have a small TPA cross section (35 GM), while OPVBr have a large TPA cross section (904 GM). The TPA cross-sections value of OPVBr is increased with the concentration increasing due to the enhancement of intermolecular π–π stacking interaction.