A new A3B zinc(II)-porphyrin ligand and its ruthenium(II) complex: Synthesis, photophysical properties and photocatalytic applications

Porphyrins and metalloporphyrins (or porphyrin coordination complexes) have been wildly investigated as photocatalysts in recent years. Herein we synthesized two new A(3)B porphyrins, a new asymmetric A(3)B zinc-porphyrin ligand with peripheral chelate group (pyridine dicarboxylate), and a ruthenium(II) complex of the porphyrin ligand. Their photo-physical properties were characterized and investigated by UVVis and fluorescent emission. The modeling of the molecular structures was optimized by DFT theoretical calculation. All porphyrin compounds exhibited strong absorbance at the Soret bands and Q bands. The free base of porphyrin possessed a higher quantum yield and a longer life time than the other two zincporphyrins and ruthenium-porphyrin in terms of fluorescence. Furthermore, the ruthenium-porphyrin complex can be used as a promising photocatalyst under visible light for two kinds of organic reactions: ketone-related oxidative aminothiocyanation (above 90% yield) and indole-related oxidative thiocyanation (around 80% yield) with a remarkable low amount (0.1 mmol %). (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Porphyrins and metalloporphyrins have been widely studied as photocatalysts. In this study, two new A(3)B porphyrins were synthesized and their photo-physical properties were characterized. The results showed strong absorbance at the Soret and Q bands, with potential applications in photocatalysis.