Synthesis and Spectral Properties of Push–Pull Dyes Based on Isobenzofuran Scaffolds

Abstract

A new class of push−pull dyes based on the reactive isobenzofuran core have been synthesized. The new dyes have a smaller HOMO−LUMO gap than a related class of dyes based on benzofurazan and allow for isolation of structural factors that contribute to environmental sensitivity. Experimental and theoretical evidence implicate different photophysical processes are responsible for a reversal of emissive behavior that is observed between isobenzofuran and benzofurazan analogues.

Revisiting the non-fluorescence of nitroaromatics: presumption versus reality

“…For this reason, three features that affect both the absorption and fluorescence properties must be considered. 93,94 Moreover, modification at the 2-position with heteroatoms from group 16 other than oxygen does not significantly affect the chromophore character. 93,95 To study the influence of nitrogen atoms, the NBD chromophore was compared with the analogous structure based on an electron-rich core (Fig.…”

“…While the fluorescence is strong in the majority of solvents, it slightly decreases in acetonitrile and alcohols, and significantly dims in water (Table 10). 93,96 Conversely, the NBD with a methoxy group, 30 , shows very weak fluorescence.…”

“…Both spectroscopic and computational studies suggest that, for NBD, the ISC relaxation pathway is not typical, even in nonpolar solvents. 93…”

Polarity Mapping of Cells and Embryos by Improved Fluorescent Solvatochromic Pyrene Probe

“…30,31 Nile Red operates in a more suitable range of wavelengths than Laurdan, but its photostability and solvatochromism are limited. A number of new solvatochromic dyes were developed to overcome the limitation of these dyes, notably push-pull fluorophores based on anthracene, 32 fluorene, 33 pyrene, 34 isobenzofuran, 35 DCDHF family, 36 phenyl-furane, 17 diphenylamino derivatives, 37,38 dioxaborine, 25 etc. Some of these were applied successfully to study lipid droplets 14,17,25,[37][38][39][40] and biomembranes.…”

Highly selective staining and quantification of intracellular lipid droplets with a compact push–pull fluorophore based on benzothiadiazole

“…In the context of benzothiadiazoles, push-pull substitution patterns (such as the one exhibited by CBD-Fluor) can red-shift spectral features while maintaining a small size. 26,[28][29][30][31] Spectral characteristics of CBD-Fluor are ideal for LD imaging The compact and polar structure of CBD-Fluor compared to other polycyclic aromatic dyes has the potential to improve solubility in water in order to diminish non-specific staining and disruption of native interactions. Despite this compact structure, however, CBD-Fluor emits similarly to larger cellimaging dyes such as Nile Red, BODIPY, and fluorescein (>400 nm, Fig.…”