Lanthanide Photocatalysis DOI
Yusen Qiao, Eric J. Schelter

Accounts of Chemical Research, Journal Year: 2018, Volume and Issue: 51(11), P. 2926 - 2936

Published: Oct. 18, 2018

ConspectusThe use of earth-abundant, cheap, potent, and readily available lanthanide photocatalysts provides an opportunity to complement or even replace rare precious metal photosensitizers. Moreover, photosensitizers have been demonstrated for the generation a variety reactive species, including aryl radicals, alkyl others, by single-electron-transfer (SET) hydrogen atom transfer (HAT) pathways under mild reaction conditions. Some unprecedented reducing power from their photoexcited states, achieving activation challenging organic substrates that not otherwise activated reported transition-metal In this Account, we describe our recent advances in rational design strategic application photo(redox)catalysis. Our research goals include understanding photophysics luminophores incorporating them into new photocatalysis. Among lanthanides, focused on cerium because doublet 4f → 5d excitation emission, which affords good conservation energy without losses through spin-state changes, as well large natural abundance element. We performed structural, spectroscopic, computational, reactivity studies demonstrate luminescent Ce(III) guanidinate–amide complexes can mediate photocatalytic C(sp3)–C(sp3) bond forming reactions. Taking advantage strong excited states cerium–halogen enthalpies, determined reactive, excited-state metalloradical abstracts chloride anion benzyl generate radical. To control predict reactivities, also photophysical photochemical series mixed-ligand guanidinate–aryloxide establish structure–property relationship photocatalysts. discovered emission color is directly related ligand type rigidity coordination sphere photoluminescent quantum yield correlated variation steric encumbrance around centers. The low reduction potentials (E1/2* ≈ −2.1 −2.9 V versus Cp2Fe0/+) relatively fast quenching rates (kq 107 M–1 s–1) toward halides enabled participate C(sp2)–C(sp2) reactions either inner-sphere outer-sphere SET processes. simple, air-stable ultraviolet A photoreductant, hexachlorocerate(III) ([CeIIICl6]3–). This complex potent photoreductant −3.45 exhibits kinetics 109–1010 organohalogens. [CeIVCl6]2− redox partner act photo-oxidant though (presumably) long-lived chloride-to-cerium(IV) charge state (ε = ∼6000 cm–1), was used turnover dechlorination Miyuara borylation With [CeIIICl6]3–, achieved efficient photoinduced dehalogenation unactivated chlorides with broad substrate scope, formally two-photon cycles where both Ce(IV) Lanthanide photoredox catalysis now being applied several contexts dehydrogenation amines, alkoxy-radical-mediated C–C cleavage amination alkanols, C–H alkanes. Overall, simple photocatalysis expected find practical applications synthesis, pharmaceutical development, small molecule activation.

Language: Английский

Photoredox-Catalyzed C–H Functionalization Reactions DOI

Natalie Holmberg‐Douglas,

David A. Nicewicz

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1925 - 2016

Published: Sept. 29, 2021

The fields of C–H functionalization and photoredox catalysis have garnered enormous interest utility in the past several decades. Many different scientific disciplines relied on strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, fine chemical synthesis. In this Review, we highlight use reactions. We separate review into inorganic/organometallic catalysts organic-based catalytic systems. Further subdivision by reaction class─either sp2 or sp3 functionalization─lends perspective tactical for these methods synthetic applications.

Language: Английский

Citations

661
Copper’s rapid ascent in visible-light photoredox catalysis DOI Open Access
Asik Hossain, Aditya Bhattacharyya, Oliver Reiser

et al.

Science, Journal Year: 2019, Volume and Issue: 364(6439)

Published: May 2, 2019

Visible-light photoredox catalysis offers a distinct activation mode complementary to thermal transition metal catalyzed reactions. The vast majority of processes capitalizes on precious ruthenium(II) or iridium(III) complexes that serve as single-electron reductants oxidants in their photoexcited states. As low-cost alternative, organic dyes are also frequently used but general suffer from lower photostability. Copper-based photocatalysts rapidly emerging, offering not only economic and ecological advantages otherwise inaccessible inner-sphere mechanisms, which have been successfully applied challenging transformations. Moreover, the combination conventional with copper(I) copper(II) salts has emerged an efficient dual catalytic system for cross-coupling

Language: Английский

Citations

577
Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry DOI
Laura Buglioni, Fabian Raymenants, Aidan Slattery

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 2752 - 2906

Published: Aug. 10, 2021

Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing plethora opportunities to synthetic organic chemists. However, performing photochemical transformation can be quite challenge because various issues related the delivery photons. These challenges barred widespread adoption steps industry. past decade, several technological innovations led more reproducible, selective, and scalable photoinduced reactions. Herein, we provide comprehensive overview these exciting advances, including flow chemistry, high-throughput experimentation, reactor design scale-up, combination photo- electro-chemistry.

Language: Английский

Citations

544
Direct Methane Conversion under Mild Condition by Thermo-, Electro-, or Photocatalysis DOI Creative Commons
Xianguang Meng,

Xiaoju Cui,

N. Pethan Rajan

et al.

Chem, Journal Year: 2019, Volume and Issue: 5(9), P. 2296 - 2325

Published: May 27, 2019

Language: Английский

Citations

474
Photoactive Complexes with Earth-Abundant Metals DOI
Oliver S. Wenger

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(42), P. 13522 - 13533

Published: Oct. 11, 2018

In this invited Perspective, recent developments and possible future directions of research on photoactive coordination compounds made from nonprecious transition metal elements will be discussed. The focus is conceptually new, structurally well-characterized complexes with excited-state lifetimes between 10 ps 1 ms in fluid solution for applications photosensitizing, light-harvesting, luminescence catalysis. key considered herein are Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, W Ce various oxidation states equipped diverse ligands, giving access to long-lived excited via a range fundamentally different types electronic transitions. Research performed area over the past five years demonstrated that much broader spectrum than what was long relevant exhibits useful photophysics photochemistry.

Language: Английский

Citations

466
Visible light-driven organic photochemical synthesis in China DOI
Yiyun Chen, Liang‐Qiu Lu, Da‐Gang Yu

et al.

Science China Chemistry, Journal Year: 2018, Volume and Issue: 62(1), P. 24 - 57

Published: Dec. 21, 2018

Language: Английский

Citations

433
Rare earth elements: Mendeleev’s bane, modern marvels DOI Open Access
Thibault Cheisson, Eric J. Schelter

Science, Journal Year: 2019, Volume and Issue: 363(6426), P. 489 - 493

Published: Feb. 1, 2019

The rare earths (REs) are a family of 17 elements that exhibit pronounced chemical similarities as group, while individually expressing distinctive and varied electronic properties. These atomistic properties extraordinarily useful motivate the application REs in many technologies devices. From their discovery to present day, major challenge faced by chemists has been separation RE elements, which evolved from tedious crystallization highly engineered solvent extraction schemes. increasing incorporation dependence technology have raised concerns about sustainability motivated recent studies for improved separations achieve circular economy.

Language: Английский

Citations

416
A Critical Review on Energy Conversion and Environmental Remediation of Photocatalysts with Remodeling Crystal Lattice, Surface, and Interface DOI
Jinming Luo, Shuqu Zhang, Meng Sun

et al.

ACS Nano, Journal Year: 2019, Volume and Issue: 13(9), P. 9811 - 9840

Published: July 31, 2019

Solar energy is a renewable resource that can supply our needs in the long term. A semiconductor photocatalysis capable of utilizing solar has appealed to considerable interests for recent decades, owing ability aim at environmental problems and produce renewal energy. Much effort been put into synthesis highly efficient photocatalyst promote its real application potential. Hence, we reviewed most advanced methods strategies terms (i) broadening light absorption wavelengths, (ii) design active reaction sites, (iii) control electron–hole (e–-h+) recombination, while these three processes could be influenced by remodeling crystal lattice, surface, interface. Additionally, individually examined their current applications conversion (i.e., hydrogen evolution, CO2 reduction, nitrogen fixation, oriented synthesis) remediation air purification wastewater treatment). Overall, this review, particularly focused on photocatalytic activity with simultaneous decontamination further enriched mechanism proposing electron flow substance conversion. Finally, review offers prospects photocatalysts following vital (distinct) aspects: large-scale preparation photocatalysts, development sustainable systems, optimization process practical application.

Language: Английский

Citations

406
New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry DOI Creative Commons
Jinjian Liu, Lingxiang Lu, Devin Wood

et al.

ACS Central Science, Journal Year: 2020, Volume and Issue: 6(8), P. 1317 - 1340

Published: July 16, 2020

As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern synthetic innovation. In this regard, photochemistry electrochemistry-both considered as niche fields for decades-have seen an explosive renewal interest recent years gradually have become a cornerstone organic chemistry. Outlook article, we examine current state-of-the-art areas electrochemistry photochemistry, well nascent area electrophotochemistry. These techniques employ external stimuli activate molecules imbue privileged control reaction progress selectivity that is challenging traditional chemical methods. Thus, they provide alternative entries known reactive intermediates enable distinct strategies were previously unimaginable. Of many hallmarks, electro- are often classified "green" technologies, promoting reactions under mild conditions without necessity potent wasteful oxidants reductants. This reviews most growth these with special emphasis on conceptual advances given rise enhanced accessibility tools trade.

Language: Английский

Citations

381
Generation of Alkyl Radicals: From the Tyranny of Tin to the Photon Democracy DOI Creative Commons
Stefano Crespi, Maurizio Fagnoni

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(17), P. 9790 - 9833

Published: Aug. 6, 2020

Alkyl radicals are key intermediates in organic synthesis. Their classic generation from alkyl halides has a severe drawback due to the employment of toxic tin hydrides point that "flight tyranny tin" radical processes was considered for long time an unavoidable issue. This review summarizes main alternative approaches unstabilized radicals, using photons as traceless promoters. The recent development photochemical and photocatalyzed enabled discovery plethora new precursors, opening world chemistry broader community, thus allowing era photon democracy.

Language: Английский

Citations

364