Tuning the optical properties of pyrimidine-thiophene derivatives via molecular engineering

Abstract

The development of dual-state emission luminogens (DSEgens), which exhibit strong emission in solution and aggregated states, holds great promise for various practical applications due to their persistent fluorescence signals. This study proposes a straightforward synthetic approach for utilizing pyrimidine-thiophene derivatives as a template for synthesizing DSEgens. By incorporating different chromophores such as carbazole, triphenylamine, and tetraphenyl ethylene, we successfully synthesized three DSEgens with well-defined π-conjugation and non-planar structures through molecular engineering. SNS-TPE is particularly noteworthy for its strong emission in solution, solid, and aggregated states, exhibiting fluorescence quantum yields of 0.75 in the solution state and 0.25 in the solid state. Additionally, theoretical calculations and single crystal analysis reveal that the intramolecular charge transfer effect and enhanced molecular planarity are the primary factors contributing to their DSE properties. Our study offers a simple template and design strategy for constructing multifunctional DSEgens.