Integrating CuO−Fe₂O₃ Nanocomposites and Supramolecular Assemblies of Phenazine for Visible‐Light Photoredox Catalysis

Abstract

A photoredox catalytic ensemble consisting of CuO‐Fe2O3 nanocomposites and oligomeric derivative of phenazine has been developed. The prepared system acts as an efficient photoredox catalyst for C−N bond formation reaction via SET mechanism under ‘green’ conditions (aerial environment, mixed aqueous media, recyclable), requiring less equivalents of base and amine substrate. The present study demonstrates the significant role of supramolecular assemblies as photooxidants and reductants upon irradiation and their important contribution towards the activation of the metallic centre through energy transfer and electron transfer pathways. The potential of oligomer 4: CuO‐Fe2O3 has also been explored for C−C bond formation reactions via the Sonogashira protocol.

Phenazine‐based supramolecular photosensitizing assemblies: A “smart” selectivity control on catalytic activity of Pd(II) nanoparticles

“…The THF solution of PPA exhibits absorption bands at 314 nm due to π–π* transitions of phenazine moiety and at 435 nm due to intramolecular charge transfer state. [ 23 ] Upon adding the water fraction (up to 99%) in the THF solution, the absorbance of the band at 314 nm decreases and a shift of 25 nm is observed in the absorption band at 435 nm (Figure 1A). The fluorescence spectrum of PPA in THF exhibits an emission band at 502 nm (Φ f = 0.19) when excited at 435 nm.…”