Perspective for Uranyl Photo-Redox Catalysis

The application of the uranyl salts as the powerful photo-redox catalysts in chemical transformations is backward in comparison with their advances in thermo-catalysis and structural chemistry. In fact, the uranyl cations (UO22+) have been proven as ideal photo-redox catalysts in visible-light-driven chemical reactions. The excited state of uranyl cations (*UO22+), quenching by organic substrates via hydrogen atom transfer (HAT) or single electron transfer (SET), possesses a long-lived fluorescence lifetime up to microseconds and high oxidizing ability [Eo = +2.6 V vs standard hydrogen electrode (SHE)], which were excited with visible-light irradiation through ligand-to-metal charge transfer (LMCT). Interestingly, the ground state and excited state of uranyl cations (UO22+) are chemical inert toward oxygen molecules, preventing undesired transformations from active oxygen species. This review summarizes recent advances in photo-redox transformations enabled by uranyl salts.

Metallophthalocyanines as Catalysts in Aerobic Oxidation

The first remarkable property associated to metallophthalocyanines (MPcs) was their chemical “inertness”, which made and make them very attractive as stable and durable industrial dyes. Nevertheless, their rich redox chemistry was also explored in the last decades, making available a solid and detailed knowledge background for further studies on the suitability of MPcs as redox catalysts. An overlook of MPcs and their catalytic activity with dioxygen as oxidants will be discussed here with a special emphasis on the last decade. The mini-review begins with a short introduction to phthalocyanines, from their structure to their main features, going then through the redox chemistry of metallophthalocyanines and their catalytic activity in aerobic oxidation reactions. The most significant systems described in the literature comprise the oxidation of organosulfur compounds such as thiols and thiophenes, the functionalization of alkyl arenes, alcohols, olefins, among other substrates.

A silicon-based hybrid photocathode modified with an N5-chelated nickel catalyst in a noble-metal-free biomimetic photoelectrochemical cell for solar-driven unbiased overall water splitting

Modification of the surface of semiconductor-based photoelectrodes with molecular redox catalysts gives a way to realize atom-efficient catalysis for photoelectrochemical (PEC) H2 and O2 evolution. However, the diversity of immobilized...

Organo-Redox-Catalysis for the difunctionalization of alkenes and oxidative Ritter reactions by C-H functionalization

Transition metals are the dominant catalysts for redox-reactions between peroxides and organic substrates. Here, we show that triarylamines can act as organic redox-catalysts, enabling oxidative difunctionalization reactions of alkenes and...