Photocatalysis: A Green Tool for Redox Reactions

Synlett ◽  
2021 ◽  
Author(s):  
Shoubhik Das ◽  
Robin Cauwenbergh
Keyword(s):  
Redox Reactions ◽  
Organic Dyes ◽  
Photophysical Properties ◽  
Value Added ◽  
Research Area ◽  
Redox Processes ◽  
Redox Potentials ◽  
Photoredox Catalysis ◽  
Reduction And Oxidation

AbstractReduction-and-oxidation (redox) reactions are one of the most utilized approaches for the synthesis of value-added compounds. With the growing awareness of green chemistry, researchers have searched for new and sustainable pathways for performing redox reactions. From this, a new field has gained tremendous attention, namely photoredox catalysis. Here, molecules can be easily oxidized or reduced with the use of one of Nature’s biggest resources: visible light. This tutorial paper gives the basics of photoredox catalysis along with limited examples to encourage further research in this blooming research area.1 Introduction2 Redox Chemistry3 Photochemistry3.1 Laws of Photochemistry3.2 Principles3.3 Examples4 Photoredox Catalysis4.1 General Principles4.2 Classification of Redox Processes4.3 Other Mechanistic Considerations4.4 Stern–Volmer Plots4.5 Photophysical Properties4.6 Redox Potentials5 Photocatalysts5.1 Metal-Based Photocatalysts5.2 Organic Dyes5.3 Semiconductors6 Dual Catalysis7 Conclusions

A Critical Evaluation of the Redox Properties of Uranium, Neptunium and Plutonium Ions in Acidic Aqueous Solutions

1999 ◽  
Vol 71 (9) ◽  
pp. 1771-1807 ◽  
Author(s):  
Sorin Kihara ◽  
Zenko Yoshida ◽  
Hisao Aoyagi ◽  
Kohji Maeda ◽  
Osamu Shirai ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Redox Reactions ◽  
Critical Evaluation ◽  
Redox Properties ◽  
Redox Processes ◽  
Redox Potentials ◽  
Electrode Processes ◽  
Reversible Redox ◽  
Reduction Mechanisms ◽  
Current Potential

Standard redox potentials, E0s, and redox processes of U, Np and Pu ions in acidic aqueous solutions are reviewed and evaluated critically. The E0sof reversible redox processes, MO22+/MO2+ and M4+/M3+ (M: U, Np or Pu) adopted are those proposed mainly by Riglet et al. on the basis of the precise correction of formal potentials, E0's, according to the improved theoretical approach to estimate the activity coefficient. Electrode processes of the U, Np and Pu ions are discussed in terms of current-potential curves, measured so far by polarography, voltammetry or flow coulometry. Special attention is payed to the irreversible MO2+/M4+ reactions. Disproportionation reactions of MO2+ are also discussed. New substances are introduced as intermediates during reductions of MO2+ to M4+ or disproportionations of MO2+.CONTENTSIntroductionStandard redox potentials for uranium, neptunium and plutonium ions in acidic aqueous solutions2.1 Evaluation of E0 from E0' determined by electrochemical measurements2.2 Temperature dependence of E0Redox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by polarography or voltammetry3.1 Uranium3.2 Neptunium3.3 Plutonium3.4 Disproportionation of NpO2+, PuO2+, Np4+ and Pu4+3.5 Reduction of MO2+ and reduction intermediatesRedox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by flow coulometry4.1 Electrode processes of the uranium, neptunium and plutonium ions investigated by flow coulometry at the column electrode at the column electrode4.2 Disproportionation of MO2+ during the electrolysis by flow coulometry4.3 Reduction mechanisms of MO2+ (M = Np or Pu) and reduction intermediates investigated by flow coulometryConclusionsList of abbreviationsAppendixReferences

Redox Reactions of Bio Molecule for Nano-bio Battery

2006 ◽  
Vol 915 ◽  
Author(s):  
Kwang Min Shin ◽  
Sang Jun Park ◽  
Seong Gil Yoon ◽  
Chang Kee Lee ◽  
Su Ryon Shin ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Energy Storage ◽  
Metal Oxide ◽  
Redox Reactions ◽  
Methyl Viologen ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Redox Potentials ◽  
Inorganic Elements ◽  
Reduction And Oxidation

AbstractMetal oxide nanoparticles within the protein ferritin can act as an energy storage source in nano-bio batteries containing ferrous ferritin and a reconstituted ferritin cage containing different inorganic elements, such as Co, Mn, Ni, and Pt. These components were introduced as two ferritin half-cells with different redox potentials existing between the ferrous ferritin and the reconstituted ferritin. The reduction of ferritin was analyzed in a solution containing 3-[N-morpholino] propanesulfonic acid buffer and oxidized methyl viologen using cyclic voltammetry. The reduction and oxidation peaks of the methyl viologen occurred at potentials of −300 and −100 mV, respectively, and the reduction and the oxidation peaks of the released Fe occurred at potentials of −300 and −100 mV, respectively. The reduction of ferritin was influenced by the pH of the ferritin solution.

scholarly journals [Cu(bcp)DPEPhos]+: a Versatile and Efficient Copper-Based Photoredox Catalyst and Photosensitizer

SynOpen ◽  
2021 ◽  
Author(s):  
Samuel Oger ◽  
Hajar Baguia ◽  
Tuan-Anh Phan ◽  
Titouan Teunens ◽  
Jérôme Beaudelot ◽  
...  
Keyword(s):  
Excited States ◽  
Copper Complex ◽  
Copper Complexes ◽  
Organic Dyes ◽  
Iridium Complexes ◽  
Chemical Transformations ◽  
Redox Potentials ◽  
Photoredox Catalysis ◽  
Radical Species ◽  
The Core

The development of photoredox catalysis has recently enabled the design of remarkably powerful synthetic tools now commonly used in a wide array of chemical transformations, and notably for the generation of radical species under mild, safe and environmentally friendly conditions. This field is largely dominated by ruthenium and iridium complexes, the main alternative to the use of these photocatalysts mostly relying on the use of organic dyes, which poses problems not only in terms of cost - therefore strongly limiting synthetic applications of photocatalysis - but also, more importantly, for the design of new light-mediated transformations. Much less attention has been devoted to the use of copper complexes in photoredox catalysis, despite their strong potential not only as cheaper catalysts but also for the activation of a broader range of substrates. Most copper complexes are indeed known to be poor photocatalysts, mostly due to their short-lived excited states and low redox potentials. Over the last decade, one copper-based copper complex has however emerged as a remarkably efficient and general photoredox catalyst, which is at the core of this Spotlight that highlights its applications as a photosensitizer and its potential.

Photophysical Properties and Redox Potentials of Photosensitizers for Organic Photoredox Transformations

Synlett ◽  
2021 ◽  
Author(s):  
Thomas S. Teets ◽  
Yanyu Wu ◽  
Dooyoung Kim
Keyword(s):  
Organic Chemistry ◽  
Excited State ◽  
Ground State ◽  
Rational Design ◽  
Photocatalytic Performance ◽  
Photophysical Properties ◽  
Redox Potentials ◽  
Photoredox Catalysis ◽  
Organic Transformations ◽  
Synthetic Organic Chemistry

AbstractPhotoredox catalysis has proven to be a powerful tool in synthetic organic chemistry. The rational design of photosensitizers with improved photocatalytic performance constitutes a major advancement in photoredox organic transformations. This review summarizes the fundamental ground-state and excited-state photophysical and electrochemical attributes of molecular photosensitizers, which are important determinants of their photocatalytic reactivity.

Modulation in Ru and Cu nanoparticles contents over CuAlPO-5 in synergistic enhancement in the selective reduction and oxidation of biomass-derived furan based alcohols and carbonyls

2021 ◽  
Author(s):  
Abhinav Kumar ◽  
Rajaram Bal ◽  
Rajendra Srivastava
Keyword(s):  
Selective Reduction ◽  
Value Added ◽  
Cu Nanoparticles ◽  
Platform Chemicals ◽  
Synergistic Enhancement ◽  
Reduction And Oxidation ◽  
Significant Attention ◽  
Lignocellulose Biomass

Furfural (FAL) and 5-hydroxymethylfurfural (HMF) are important and sustainable platform chemicals. They are produced from lignocellulose biomass and attract significant attention as precursors for producing value-added chemicals and fuels. The...

scholarly journals Using internal electrostatic fields to manipulate the valence manifolds of copper complexes

2021 ◽  
Author(s):  
Alexander B. Weberg ◽  
Samuel P. McCollom ◽  
Laura M. Thierer ◽  
Michael R. Gau ◽  
Patrick J. Carroll ◽  
...  
Keyword(s):  
Coordination Sphere ◽  
Copper Complexes ◽  
Photophysical Properties ◽  
Redox Potentials ◽  
Electrostatic Effects ◽  
Electrostatic Fields ◽  
Secondary Coordination Sphere

Secondary coordination sphere electrostatic effects tune the valence manifolds of copper centers, impacting molecular geometries, photophysical properties, and redox potentials.

scholarly journals Diketopyrrolopyrrole Fluorescent Probes, Photophysical and Biological Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 44
Author(s):  
Muhammad Aminu Auwalu ◽  
Shanshan Cheng
Keyword(s):  
Quantum Yield ◽  
Fluorescent Probes ◽  
Organic Dyes ◽  
Tumor Therapy ◽  
Research Area ◽  
Research Field ◽  
Review Article ◽  
Biological Applications ◽  
Chemistry Research ◽  
Cancer Tumor

Biological applications of fluorescent probes are rapidly increasing in the supramolecular chemistry research field. Several organic dyes are being utilized currently in developing and advancing this attractive research area, of which diketopyrrolopyrrole (DPP) organic dyes show an exceptional photophysical features (high-fluorescence quantum yield (FQY), good photochemical and thermal stability) that are essential properties for biological applications. Great efforts have been made in recent years towards developing novel fluorescent DPPs by different chemists for such applications, and some positive results have been reported. As a result, this review article gives an account of the progress that has so far been made very recently, mainly within the last decade, in that we selectively focus on and discuss more from 2015 to present on some recent scholarly achievements of fluorescent DPPs: quantum yield, aggregation-induced emission (AIE), solid-state emission, bio-imaging, cancer/tumor therapy, mitochondria staining and some polymeric fluorescent DPPs. Finally, this review article highlights researchers working on luminescent DPPs and the future prospects in some key areas towards designing DPP-based fluorescent probes in order to boost their photophysical and biological applications more effectively.

MetallaPhotoredox Catalysis with Organic Dyes

2021 ◽  
Author(s):  
Pier Giorgio Cozzi ◽  
Andrea Gualandi ◽  
Michele Anselmi ◽  
Francesco Calogero ◽  
Simone Potenti ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Organic Reactions ◽  
Photoredox Catalysis

The use of organic dyes to promote organic reactions by photoredox catalysis is continuosly expanding, and was recently reviewed by Nicewicz. The synthesis of new dyes, their application in flow...

Structures and properties of hemiquinone-substituted oxoporphyrinogens

2009 ◽  
Vol 13 (01) ◽  
pp. 60-69 ◽  
Author(s):  
Jonathan P. Hill ◽  
Katsuhiko Ariga ◽  
Francis D'Souza
Keyword(s):  
Physical Properties ◽  
Redox Reactions ◽  
Photophysical Properties ◽  
Electron Acceptors ◽  
Substitution Pattern ◽  
X Ray ◽  
X Ray Crystallography ◽  
Guest Binding ◽  
Structures And Properties

The structure and physical properties of a series of N-substituted, hemiquinone-substituted oxoporphyrinogens is presented and discussed. Structures of the compounds are dictated by the nature of the substituent, with the substitution pattern being in turn dictated by regioselectivity of N-alkylation. X-ray crystallography and other aggregation properties of the compounds are discussed. Redox reactions are also strongly influenced by N-substitution and substituent identity. Also presented are properties related to guest binding and photophysical properties of oligochromophoric host-guest complexes, involving oxoporphyrinogen, N-substituted with porphyrins and appropriately substituted fullerene guest electron acceptors.

Music Neurotechnology for Sound Synthesis: Sound Synthesis with Spiking Neuronal Networks

Leonardo ◽  
2009 ◽  
Vol 42 (5) ◽  
pp. 439-442 ◽  
Author(s):  
Eduardo R. Miranda ◽  
John Matthias
Keyword(s):  
Cortical Neurons ◽  
Neuronal Networks ◽  
Research Area ◽  
Sound Synthesis ◽  
Ongoing Research ◽  
Computer Interfaces ◽  
Engineering Sciences ◽  
New Research ◽  
Sound Files

Music neurotechnology is a new research area emerging at the crossroads of neurobiology, engineering sciences and music. Examples of ongoing research into this new area include the development of brain-computer interfaces to control music systems and systems for automatic classification of sounds informed by the neurobiology of the human auditory apparatus. The authors introduce neurogranular sampling, a new sound synthesis technique based on spiking neuronal networks (SNN). They have implemented a neurogranular sampler using the SNN model developed by Izhikevich, which reproduces the spiking and bursting behavior of known types of cortical neurons. The neurogranular sampler works by taking short segments (or sound grains) from sound files and triggering them when any of the neurons fire.

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