Extended BODIPYs as Red-NIR Laser Radiation Sources with Emission from 610 nm to 750 nm

Herein, we report the synthetic access to a set of & pi;-extended BODIPYs featuring a penta-arylated (phenyl and/or thiophene) dipyrrin framework. We take advantage of the full chemoselective control of 8-methylthio-2,3,5,6-tetrabromoBODIPY when we conduct the Liebeskind-Srogl cross-coupling (LSCC) to functionalize exclusively the meso-position, followed by the tetra-Suzuki reaction to arylate the halogenated sites. All these laser dyes display absorption and emission bands in the red edge of the visible spectrum reaching the near-infrared with thiophene functionalization. The emission efficiency, both fluorescence and laser, of the polyphenylBODIPYs can be enhanced upon decoration of the peripheral phenyls with electron donor/acceptor groups at para positions. Alternatively, the polythiopheneBODIPYs show an astonishing laser performance despite the charge transfer character of the emitting state. Therefore, these BODIPYs are suitable as a palette of stable and bright laser sources covering the spectral region from 610 nm to 750 nm.

Automated summary

In this study, a synthetic method for a new set of π-extended BODIPY derivatives was reported, which involved the selective functionalization of the meso-position and the halogenated sites using the Liebeskind-Srogl cross-coupling and Suzuki reactions. All these laser dyes exhibited absorption and emission bands in the red edge of the visible spectrum, with the thiophene-containing compounds showing the highest emission efficiency. The fluorescence and laser efficiency of the polyphenylBODIPYs could be further enhanced by decorating the peripheral phenyls with electron donor/acceptor groups. Surprisingly, the polythiopheneBODIPYs demonstrated excellent laser performance despite their charge transfer character. Thus, these BODIPY derivatives offer a palette of stable and bright laser sources covering the spectral range from 610 nm to 750 nm.