Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials

2019 ◽  
Author(s):  
Hyunwoo Kim ◽  
Hyungjun Kim ◽  
Tristan Lambert ◽  
Song Lin
Keyword(s):  
Radical Anion ◽  
Aryl Radicals ◽  
Reduction Potentials ◽  
High Reduction ◽  
Very High ◽  
Excited Radical ◽  
Reducing Potential

We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of –3.2 V vs. SCE, which can be used to activate substrates with very high reduction potentials (<i>E</i><sub>red</sub> ~ –1.9 to –2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.<br>

scholarly journals Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials

2019 ◽  
Author(s):  
Hyunwoo Kim ◽  
Hyungjun Kim ◽  
Tristan Lambert ◽  
Song Lin
Keyword(s):  
Radical Anion ◽  
Aryl Radicals ◽  
Reduction Potentials ◽  
High Reduction ◽  
Very High ◽  
Excited Radical ◽  
Reducing Potential

We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of –3.2 V vs. SCE, which can be used to activate substrates with very high reduction potentials (<i>E</i><sub>red</sub> ~ –1.9 to –2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.<br>

scholarly journals Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials

2019 ◽  
Author(s):  
Hyunwoo Kim ◽  
Hyungjun Kim ◽  
Tristan Lambert ◽  
Song Lin
Keyword(s):  
Radical Anion ◽  
Aryl Radicals ◽  
Reduction Potentials ◽  
High Reduction ◽  
Very High ◽  
Excited Radical ◽  
Reducing Potential

We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of –3.2 V vs. SCE, which can be used to activate substrates with very high reduction potentials (<i>E</i><sub>red</sub> ~ –1.9 to –2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.<br>

scholarly journals Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides

2021 ◽  
Author(s):  
Jinhui Xu ◽  
Jilei Cao ◽  
Xiangyang Wu ◽  
Han Wang ◽  
Xiaona Yang ◽  
...  
Keyword(s):  
Limited Range ◽  
Redox Potentials ◽  
Aryl Chlorides ◽  
Aryl Radicals ◽  
Reduction Potentials ◽  
Anion Form ◽  
Donor Acceptor ◽  
High Reduction ◽  
Very High ◽  
Excited Radical

Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis, and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 V to +1.79 V. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN<sup>•</sup><sup>−</sup>*, which can be used to activate reductively recalcitrant aryl chlorides (E<sub>red </sub>≈ -1.9 to -2.9 V) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes, respectively.

scholarly journals Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides

2021 ◽  
Author(s):  
Jinhui Xu ◽  
Jilei Cao ◽  
Xiangyang Wu ◽  
Han Wang ◽  
Xiaona Yang ◽  
...  
Keyword(s):  
Limited Range ◽  
Redox Potentials ◽  
Aryl Chlorides ◽  
Aryl Radicals ◽  
Reduction Potentials ◽  
Anion Form ◽  
Donor Acceptor ◽  
High Reduction ◽  
Very High ◽  
Excited Radical

Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis, and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 V to +1.79 V. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN<sup>•</sup><sup>−</sup>*, which can be used to activate reductively recalcitrant aryl chlorides (E<sub>red </sub>≈ -1.9 to -2.9 V) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes, respectively.

Phosphoryl- and Phosphonium-Bridged Viologens as Stable Two- and Three-Electron Acceptors for Organic Electrodes

2020 ◽  
Author(s):  
Colin R. Bridges ◽  
Andryj M. Borys ◽  
Vanessa Béland ◽  
Joshua R. Gaffen ◽  
Thomas Baumgartner
Keyword(s):  
Molecular Weight ◽  
Organic Molecules ◽  
Electrode Materials ◽  
High Energy ◽  
Electron Acceptors ◽  
Low Molecular Weight ◽  
Reduction Potentials ◽  
Organic Electrode ◽  
High Reduction ◽  
High Specific Energy

Low molecular weight organic molecules that can accept multiple electrons at high<br>reduction potentials are sought after as electrode materials for high-energy sustainable batteries. To date their synthesis has been difficult, and organic scaffolds for electron donors significantly outnumber electron acceptors. Herein, we report two highly electron deficient phosphaviologen derivatives from a phosphorus-bridged 4,4-bipyridine and characterize their electrochemical properties. Phosphaviologen sulfide (PVS) and P-methyl phosphaviologen (PVM) accept two and three electrons at high reduction potentials, respectively. PVM can reversibly accept 3 electrons between 3-3.6 V vs. Li/Li+ with an equivalent molecular weight of 102 g/(mol e-) (262 mAh/g), making it a promising scaffold for sustainable organic electrode materials having high specific energy densities.

scholarly journals Intermolecular oxyarylation of olefins with aryl halides and TEMPOH catalyzed by the phenolate anion under visible light

2020 ◽  
Vol 11 (27) ◽  
pp. 6996-7002
Author(s):  
Kangjiang Liang ◽  
Qian Liu ◽  
Lei Shen ◽  
Xipan Li ◽  
Delian Wei ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
Aryl Halides ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Strong Reduction ◽  
Aryl Radicals ◽  
Reduction Potentials

The phenolate anion was developed as a new photocatalyst with strong reduction potentials (−3.16 V vs. SCE) to reduction of aryl halides to aryl radicals through single electron transfer.

scholarly journals Characterization of a Tricationic Trigonal Bipyramidal Iron(IV) Cyanide Complex, with a Very High Reduction Potential, and Its Iron(II) and Iron(III) Congeners

2011 ◽  
Vol 50 (7) ◽  
pp. 2885-2896 ◽  
Author(s):  
Jason England ◽  
Erik R. Farquhar ◽  
Yisong Guo ◽  
Matthew A. Cranswick ◽  
Kallol Ray ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Cyanide Complex ◽  
Trigonal Bipyramidal ◽  
High Reduction ◽  
Very High

Characterizing the Shear Deformation during Asymmetric Rolling

2008 ◽  
Vol 584-586 ◽  
pp. 327-332 ◽  
Author(s):  
Yun Long Chen ◽  
Ai Dang Shan ◽  
Jian Hua Jiang ◽  
Yi Ding
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Shear Deformation ◽  
Room Temperature ◽  
Pure Aluminum ◽  
Asymmetric Rolling ◽  
Metallic Material ◽  
Side Face ◽  
High Reduction ◽  
Very High

Asymmetric rolling has been considered as a possible way to obtain severe plastic deformation (SPD) since it will give an extra shear deformation to the processed materials during rolling. Previous researches have confirmed such a shear deformation. Very recently, the method of inserting-block is used to characterize the shear deformation through direct observation, but when the reduction is more than 70%, the lineation scratched on the side face of internal mark becomes vague and illegible. In order to directly observe the shear deformation of metallic material with large reduction, the internal mark method is employed in this research and asymmetric rolling was performed with pure aluminum and iron at room temperature. In severe plastic deformation, the shear deformation caused by asymmetric rolling was clearly observed and measured through employing internal mark method. Remarkable extra shear deformation during asymmetric rolling was confirmed. Very high equivalent strains were achieved when sheet samples were asymmetrically rolled to high reduction ratio. These strain values fall into the range of SPD.

scholarly journals Efficacy of spirotetramat in the control of the currant-sowthistle (Hyperomyzus lactucae l.) on blackcurrant plantations in Poland

2013 ◽  
Vol 21 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Barbara H. Łabanowska ◽  
Mirosław Korzeniowski ◽  
Tomasz Gasparski
Keyword(s):  
Single Treatment ◽  
Dose Rates ◽  
High Reduction ◽  
Very High

ABSTRACT Spirotetramat applied as Movento 100 SC at dose rates: 0.7 and 1.0 L·ha-1 in a single treatment just after blossom resulted in a very high reduction of currant-sowthistle aphid - Hyperomyzus lactucae L. (Aphidoidea, Aphididae) on blackcurrants ‘Ojebyn’ and ‘Titania’. The results obtained with this pesticide applied at both tested dose rates: 0.7 and 1.0 L·ha-1 were comparable. The efficacy of spirotetramat at 7th day after treatment was similar or slightly poorer compared to standard insecticides, but at 21st day after treatment a higher reduction of aphids than with reference insecticides such as pirimicarb (Pirimor 500 WG at the rate 0.75 kg·ha-1), thiacloprid (Calypso 480 SC 0.15 L·ha-1) and thiamethoxam (Actara 25 WG at the rate 0.1 kg·ha-1) was recorded. With regard to environment safety and biodiversity it must be underlined that on plants treated with Movento 100 SC, high populations of Coccinellidae (both larvae and beetles), Syrphidae (larvae) and Phytoseiidae were noted.

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