Synthesis of New Symmetrically Substituted Stilbenes with Large Multi-Photon Absorption Cross Section and Strong Two-Photon-Induced Blue Fluorescence

Abstract

Abstract Efficient Ti-catalyzed reductive coupling methodology was first employed to synthesize three new chromophores, whose chemical structures have been characterized by IR, 1H NMR, MS spectra, and elemental analyses. These dye solutions exhibit the linear transmission of ca. 90% at wavelengths ≥ 500 nm at the concentrations of 0.005–0.0005 mol dm−3. Pumped by ca. 700 nm laser irradiation, they possess large two-photon absorption cross sections of 44.5 × 40−48–62.0 × 10−48 cm4 s photon−1, and strong up-conversion blue fluorescence occuring at 437–452 nm. A large three-photon absorption cross section of 27.3 × 10−76 cm6 s2 photon−1 has also observed for one of these dyes under ca. 990 nm laser irradiation.