A Dyad as Photocatalyst for Light-Driven Sulfide Oxygenation with Water As the Unique Oxygen Atom Source

Abstract

With the objective to convert light energy into chemical oxidation energy, a ruthenium-based dyad constituted of the assembly of a photosensitizer and a catalytic fragment was synthesized. Upon irradiation with blue LEDs, and in the presence of an electron acceptor, the complex is able to catalyze selective sulfide oxygenation involving an oxygen atom transfer from water to the substrate. Electrochemical and photophysical studies highlighted a proton-coupled electron transfer (PCET) to access to a high valent oxidant Ru(IV) oxo species.

Photoassisted Oxidation of Sulfides Catalyzed by Artificial Metalloenzymes Using Water as an Oxygen Source

“…This could indicate that the insertion of 1-Mn into the hydrophobic pocket of Xln10A [18] hinders the electron transfer from the manganese center to the photo-activated ruthenium complex. The results observed in the presence of 1-Mn-Xln10A are, however, comparable to those obtained under the same conditions for the oxidation of thioanisole catalyzed by an Mn-corrole complex and Mn-corrole-BSA artificial metalloenzyme, which respectively lead to the chemoselective formation of the corresponding sulfoxide with 32 ± 3 and 21 ± 7 TON ( [22,23].…”

Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated IrIII Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

“…The group of traditional 1 O 2 PSs comprises different families of organic compounds such as porphyrins, phthalocyanines, fullerene derivatives, and organic dyes (e.g., Rose Bengal, Methylene Blue), but most of them undergo degradation on irradiation and cannot be easily modified to modulate their photophysical properties. On the contrary, Ru II polypyridyl complexes and bis‐cyclometalated Ir III compounds have proved to combine efficient 1 O 2 (or O 2 .− ) photosensitizing abilities or photoredox catalytic activity along with high photostability and a modular structure that can be readily modified, and they are emerging as ideal candidates for use as PSs in the photocatalytic oxidation of organic substrates and biomolecules …”

H2 generation and sulfide to sulfoxide oxidation with H2O and sunlight with a model photoelectrosynthesis cell

“…(3), has been described in the literature using [Ru(bpy) 3 [17,18]. As before, dyad systems with catalytic and photosensitizer units in the same molecule have shown good turnover numbers (TN) for the oxidation of a large variety of substrates, such as alcohols, sulfides and alkenes [19][20][21][22][23][24][25][26].…”