Thioether-Substituted Hexa-peri-hexabenzocoronenes

The synthesis of novel mono-, di-, tri-, tetra-, and hexafluorinated hexa-peri-hexabenzocoronenes (HBCs) and their conversion into their thioether-substituted analogs is reported. The substitution reaction with the corresponding thiolates was performed microwave-assisted to significantly reduce the reaction time. With increasing amount of fluorination or thioether-substituents, a decreasing extinction coefficient can be observed for the HBCs. Successive addition of thioether-moieties leads to a bathochromic shift of the absorption and emission bands, whereas the nature of the attached thioether does not affect the optoelectronical properties. To further tune the electronic environment of the HBC core, a successive oxidation to the corresponding sulfone as well as the formation of the sulfonium salts were performed. With that, the electron-donating thioethers were transformed into electron-withdrawing substituents, resulting in an inversed electron demand in the periphery of the core. The so obtained compounds showed decreased extinction coefficients and a broadening of the absorption and emission bands.

Automated summary

The synthesis of novel fluorinated hexa-peri-hexabenzocoronenes (HBCs) and their thioether-substituted analogs was reported, with the reaction time significantly reduced by using microwave assistance. Increasing fluorination or thioether-substituents led to a decrease in the extinction coefficient of the HBCs. Addition of thioether-moieties caused a shift in absorption and emission bands, while the nature of the thioether did not affect the optoelectronic properties. Oxidation to sulfone and formation of sulfonium salts further modified the electronic environment of the HBC core, resulting in decreased extinction coefficients and broadening of absorption and emission bands.