Faculty Opinions recommendation of Nitrite, an electron donor for anoxygenic photosynthesis.

AbstractAlthough an important fraction of the world’s lakes remains ice-covered during a large proportion of the year, little is known about the microorganisms that govern the biogeochemical processes occurring under-ice along the stratigraphic redox gradients. Reconstructed genomes provide evidence for anoxygenic photosynthesis involving fixation of carbon using reduced sulphur and iron as an electron donor in the anoxic zone of the sampled lake systems. In addition to anoxygenic photosynthesis, our molecular data reveals novel chemolithoautotrophic organisms and supports the existence of methanotrophs in bottom anoxic waters. Reconstructed genomes matched methanotrophs related to Methylobacter tundripaludum, phototrophic Chloroflexi and Chlorobia, as well as lithoautotrophic genomes affiliated to the Betaproteobacteria class and Planctomycetes phylum. Based on our in-depth characterization, complex metabolic interactomes emerge unique to each lake’s redox tower and with sulfur, iron and carbon cycling tightly intertwined through chemolithotrophy and anoxygenic photosynthesis.

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Nitrite, an Electron Donor for Anoxygenic Photosynthesis

Science ◽

10.1126/science.1139478 ◽

2007 ◽

Vol 316 (5833) ◽

pp. 1870-1870 ◽

Cited By ~ 60

Author(s):

B. M. Griffin ◽

J. Schott ◽

B. Schink

Keyword(s):

Electron Donor ◽

Anoxygenic Photosynthesis

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Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

10.26434/chemrxiv.11912073 ◽

2020 ◽

Author(s):

José Tiago Menezes Correia ◽

Gustavo Piva da Silva ◽

Camila Menezes Kisukuri ◽

Elias André ◽

Bruno Pires ◽

...

Keyword(s):

Electron Donor ◽

Functional Group ◽

Photoexcited Electron ◽

One Pot ◽

Quaternary Centers ◽

Metal Free ◽

Acceptor Complex ◽

Catalyst Free ◽

Donor Acceptor ◽

Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

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Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

10.26434/chemrxiv.12170136.v2 ◽

2020 ◽

Author(s):

Vishwanath R.S ◽

Masa-aki Haga ◽

Takumi Watanabe ◽

Emilia Witkowska Nery ◽

Martin Jönsson-Niedziolka

Keyword(s):

Redox Potential ◽

Organic Phase ◽

Electron Donor ◽

Ion Transfer ◽

Neutral Complex ◽

Pyridine Ligand ◽

Electrochemical Testing ◽

Ru Complex ◽

Three Phase ◽

Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

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Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

10.26434/chemrxiv.12170136.v1 ◽

2020 ◽

Author(s):

Vishwanath R.S ◽

Masa-aki Haga ◽

Takumi Watanabe ◽

Emilia Witkowska Nery ◽

Martin Jönsson-Niedziolka

Keyword(s):

Redox Potential ◽

Organic Phase ◽

Electron Donor ◽

Ion Transfer ◽

Neutral Complex ◽

Pyridine Ligand ◽

Electrochemical Testing ◽

Ru Complex ◽

Three Phase ◽

Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

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Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

10.26434/chemrxiv.12170136 ◽

2020 ◽

Author(s):

Vishwanath R.S ◽

Masa-aki Haga ◽

Takumi Watanabe ◽

Emilia Witkowska Nery ◽

Martin Jönsson-Niedziolka

Keyword(s):

Redox Potential ◽

Organic Phase ◽

Electron Donor ◽

Ion Transfer ◽

Neutral Complex ◽

Pyridine Ligand ◽

Electrochemical Testing ◽

Ru Complex ◽

Three Phase ◽

Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [RuII(LR)(L)]0 (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [RuII(LR)(L)]0 shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl−. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

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The Effect of Mixtures of Xenobiotics and Primary Electron Donor on the Anaerobic Biotransformation of High Concentrations of Chlorinated Aliphatics

Water Science & Technology ◽

10.2166/wst.1992.0392 ◽

1992 ◽

Vol 26 (1-2) ◽

pp. 117-126 ◽

Cited By ~ 5

Author(s):

J. B. Hughes ◽

G. F. Parkin

Keyword(s):

Electron Donor ◽

Mixed Effects ◽

Primary Electron ◽

Primary Electron Donor ◽

Loading Rates ◽

Chlorinated Aliphatics ◽

Anaerobic Biotransformation ◽

Transformation Rates ◽

High Concentrations ◽

Effect Of Feeding

Results are presented from experiments addressing the anaerobic biotransfoimation of high concentrations of three chlorinated aliphatics, dichloromethane (DCM), chloroform (CF), and 1,1,1-trichloroethane (TCA), when fed alone and in mixtures. Experiments were conducted to address the effect of feeding mixtures of these compounds on the transformation rates of individual components in the mixture, and to assess the effect of acetate loading rates on the extent of transformation of the chlorinated aliphatics. Feeding mixtures of chlorinated aliphatics caused decreased transformation of TCA, increased the transformation of DCM, and had mixed effects on CF transformation. The systems fed higher acetate loading rates demonstrated an increased ability to transform the chlorinated aliphatics.

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Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions

Water Science & Technology ◽

10.2166/wst.1996.0235 ◽

1996 ◽

Vol 34 (10) ◽

pp. 25-33 ◽

Cited By ~ 3

Author(s):

Cheng Jiayang ◽

Makram T. Suidan ◽

Albert D. Venosa

Keyword(s):

Electron Donor ◽

Chemical Reduction ◽

Sulfide Minerals ◽

Sulfide Concentration ◽

Magnesium Ions ◽

High Concentration ◽

Anoxic Conditions ◽

High Affinity ◽

Iron Nickel ◽

Abiotic Reduction

Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

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