Synthesis, spectroscopic characterization and one and two-photon absorption properties of pi-expanded thiophene and truxene BODIPYs dyes

A series of BODIPY derivatives with different thiophene and truxene substituents were synthesized by Knoevenagel condensation or Sonogashira coupling reaction and were characterized by 1H and 13C NMR spectroscopy and HRMS. Their photophysical and electrochemical properties have been investigated by UV-vis absorption spectroscopy, steady-state and time-resolved fluorescence spectroscopy, two-photon excited spectroscopy and cyclic voltammetry. These conjugated dyes exhibit excellent one-photon photophysical properties in red to nearinfrared region, including large extinction coefficients and high fluorescence quantum yields in methylene chloride solutions. They also exhibit remarkable two-photon absorption cross section sigma 2.