Strong multiphoton absorption properties of one styrylpyridinium salt in a highly polar solvent

Abstract

Multiphoton absorption (MPA) effects have become useful for real applications as well as conceptual predictions. However, most of organic molecules exhibit small Stokes shift and reduced MPA in the highly polar solvents, which may seriously hinder their related applications. In this work, one styrylpyridinium salt has been synthesized, which exhibits outstanding properties such as bright red fluorescence at the wavelength of 626 nm in a highly polar solvent (DMSO). Importantly, it is noted that the material also exhibits strong two- and three-photon absorption action cross-section (δ_2PA = 597 GM and δ_3PA = 18 × 10^-80 cm⁶∙s²∙photon^-2, respectively), which can be excited in near-infrared (NIR) window I (650-900 nm) and NIR window II (1000-1450 nm). Meanwhile, two-photon in vitro bioimaging and MPA induced optical limiting behavior have been successfully demonstrated based on the chromophore.

Thermally activated delayed fluorescence organic dots for two-photon fluorescence lifetime imaging

“…Although numerous fluorescent dyes have been reported to be nontoxic to cells, most suffer from the limitation of short fluorescence lifetimes (in the nanosecond range). 7,8 Therefore, conventional organic dyes cannot overcome most autofluorescent backgrounds in biological systems. To extend the lifetime of fluorescent dyes and avoid the toxic effects of heavy-metal complexes on cells, organic fluorescent dyes with long fluorescence lifetimes are highly desirable.…”