Porphyrins as Promising Photocatalysts for Red-Light-Induced Functionalizations of Biomolecules

Abstract

Red-light enables deeper material penetration, which is important for biological applications and has consequences for chemical synthesis. Therefore, the search for new photocatalysts that absorb in this region is crucial. Despite the undeniable utility of porphyrins in blue-and green-light-induced energy-and electron-transfer processes, they are also perfectly suited for redlight applications. Herein, we describe free-base porphyrins as photoredox catalysts for red-light-induced organic transformations. They can act as both photooxidants and photoreductants and can accomplish the synthesis of biaryls once merged with Pd-catalysis. The developed methodology holds promise for broader applications, as the heme-based protoporphyrin is used as a photocatalyst and reactions can be realized in aqueous conditions.

Sensitizer-controlled photochemical reactivityviaupconversion of red light

“…The development of new red or near-infrared light absorbing catalysts could potentially give access to new photochemical applications with low-energy input light. 31,79,120,151,[157][158][159][160][161][162][163][164] Furthermore, recent interest in triplet-triplet annihilation upconversion will likely promote the development of more sophisticated systems with lower threshold irradiation intensities that permit more effective excitation by LEDs, higher photochemical quantum yields and larger pseudo anti-Stokes shis, 34,76,78,96,100,104,165 resulting in more efficient setups for applications in photo(redox) catalysis in the future. 166,167 We hope that the concepts and proof-of-principle reactions presented herein can serve as useful inspiration for future catalytic applications with red and near-infrared light.…”

Intelligent Identification of Early Esophageal Cancer by Band-Selective Hyperspectral Imaging

“…The longer the wavelength, the deeper the penetration [ 53 ]. The red light is absorbed differently by heme in blood vessels based on the difference in depth [ 54 ]. As a result, the microvessels in the superficial mucosa tissue will be brown, and blood vessels in the submucosal tissue will be green, thereby creating a strong sense of hierarchy that is advantageous to identifying lesions of the mucosal tissue.…”

Optical and Electrophysical Properties of Vinylidene Fluoride/Hexafluoropropylene Ferroelectric Copolymer Films: Effect of Doping with Porphyrin Derivatives

“…Among the numerous dyes, porphyrin derivatives are widely used as photosensitizers due to their outstanding photophysical properties. The combination of the intense absorption in the visible spectral range and pronounced fluorescence and photochemical activity, resulting in the photoinduced generation of different reactive oxygen species, makes porphyrin derivatives efficient photovoltaic dyes [ 13 , 14 , 15 , 16 , 17 ], optical sensors, and fluorescent imaging agents [ 18 , 19 , 20 , 21 ], and efficient visible light photocatalysts [ 22 , 23 ] and photosensitizers in photodynamic therapy [ 24 , 25 , 26 , 27 , 28 ].…”