Photoreductive Electron Transfers in Nanoarchitectonics Organization Between a Diketopyrrolopyroleplatinum(II)-Containing Organometallic Polymer and Various Electron Acceptors

2022 ◽  
Author(s):  
Gabriel Marineau-Plante ◽  
Malak Qassab ◽  
Adrien Schlachter ◽  
Mélodie Nos ◽  
Muriel Durandetti ◽  
...  
Keyword(s):  
Electron Acceptors ◽  
Organometallic Polymer ◽  
Electron Transfers

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

The influence of potassium dichromate on dissimilatory reduction of sulfate and nitrate ions by bacteria Desulfovibrio sp.

2017 ◽  
Vol 28 (1-2) ◽  
pp. 84-95
Author(s):  
O. M. Moroz ◽  
S. O. Hnatush ◽  
Ch. I. Bohoslavets ◽  
T. M. Hrytsun’ ◽  
B. M. Borsukevych
Keyword(s):  
Electron Acceptor ◽  
Potassium Dichromate ◽  
Anaerobic Respiration ◽  
Sulfate Reducing Bacteria ◽  
Negative Influence ◽  
Electron Acceptors ◽  
Metal Compounds ◽  
Nitrate Ions ◽  
Sulfate Reducing ◽  
Reducing Bacteria

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.

Photoconductivity in Vacuum Deposited Films of Silicon-Based Polymers

1996 ◽  
Vol 444 ◽  
Author(s):  
H. Okumoto ◽  
M. Shimomura ◽  
N. Minami ◽  
Y. Tanabe
Keyword(s):  
Charge Transfer ◽  
Chemical Modification ◽  
Electronic Transport ◽  
Hole Transport ◽  
Electron Acceptors ◽  
Oxygen Atmosphere ◽  
Dangling Bonds ◽  
Silicon Based ◽  
Deposited Films

AbstractSilicon-based polymers with σconjugated electrons have specific properties; photoreactivity for microlithography and photoconductivity for hole transport materials. To explore the possibility of combining these two properties to develop photoresists with electronic transport capability, photoconductivity of polysilanes is investigated in connection with their photoinduced chemical modification. Increase in photocurrent is observed accompanying photoreaction of poly(dimethylsilane) vacuum deposited films. This increase is found to be greatly enhanced in oxygen atmosphere. Such changes of photocurrent can be explained by charge transfer to electron acceptors from Si dangling bonds postulated to be formed during photoreaction.

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.

Do We Need to Re-write the Electro-Optical Rule Book for Non-Fullerene Electron Acceptors?

2020 ◽  
Author(s):  
Paul Meredith ◽  
Ardalan Armin ◽  
Oskar Sandberg ◽  
Stefan Zeiske ◽  
Wei Li ◽  
...  
Keyword(s):  
Electron Acceptors

Природные материалы для сорбционной очистки хром- и кадмийсодержащих инфильтратов полигонов ТБО

2019 ◽  
pp. 13-19
Author(s):  
A. Safonov ◽  
N. Andriushchenko ◽  
N. Popova ◽  
K. Boldyrev
Keyword(s):  
Sorption Capacity ◽  
Electron Acceptors ◽  
Bacterial Cells ◽  
Maximum Sorption Capacity ◽  
Sorption Material ◽  
Maximum Sorption ◽  
Properties Of Materials ◽  
Solid Waste Landfills ◽  
Sorption Characteristics

Проведен анализ сорбционных характеристик природных материалов (вермикулит, керамзит, перлит, цеолит Трейд ) при очистке кадмий- и хромсодержащих сточных вод с высокой нагрузкой по ХПК. Установлено, что цеолит обладает максимальными сорбционными характеристиками для Cd и Cr и наименьшим биологическим обрастанием. При использовании вермикулита и керамзита или смесей на их основе можно ожидать увеличения сорбционной емкости для Cd и Сr при микробном обрастании, неизбежно происходящем в условиях контакта с водами, загрязненными органическими соединениями и биогенами. При этом биообрастание может повысить иммобилизационную способность материалов для редоксзависимых металлов за счет ферментативных ресурсов бактериальных клеток, использующих их в качестве акцепторов электронов. Эффект микробного обрастания разнонаправленно изменял параметры материалов: для Cr в большинстве случаев уменьшение и для Cd значительное увеличение. При этом дополнительным эффектом иммобилизации Cr является его биологическое восстановление биопленками. Варьируя состав сорбционного материала, можно подбирать смеси, оптимально подходящие для очистки вод инфильтратов с полигонов твердых бытовых отходов с высокой нагрузкой по ХПК и биогенным элементам как при использовании in situ, так и в системах на поверхности.The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, Trade zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.

Conformational Stability, FMO, NMR, MEP and NBO Analysis of 2,5-Di-methyl-2,5-bis(methylthio)-1,4-dithiane and Dimethoxy compounds by DFT Approach

2021 ◽  
Vol 17 ◽  
Author(s):  
Nasrin Masnabadi
Keyword(s):  
Computational Methods ◽  
Electrostatic Potential ◽  
Conformational Stability ◽  
Nbo Analysis ◽  
Dft Methods ◽  
Geometrical Properties ◽  
Stereoelectronic Effect ◽  
Nmr Parameters ◽  
Electron Transfers ◽  
Stability Energy

Abstract: Conformational behaviors of 2,5-dimethoxy-2,5-dimethyl-1,4-dithiane (compound 1) and 2,5-dimethyl-2,5-bis (methylthio)-1,4-dithiane (compound 2) investigated by computational methods including B3LYP/6-311+G** and M06-2X/6-311+G** levels of theory and NBO analysis. The stereoelectronic effect of axial, axial (ax, ax) and equatorial, equa-torial (eq, eq) conformations were studied using NBO analysis. Using NBO analysis, the values of the stereoelectronic effects were calculated through the energy of stability associated with the electron transfers of compounds 1 and 2. The results showed that the eq, eq conformations of the studied compounds were more stable than their corresponding ax, ax conformations, and LP2X→σS1-C2 and LP2S→σ*C2-X electron transfers play important roles in the conformational be-havior of the studied compounds. The main purpose of the present work was to study the effects of stereoelectronic inter-actions and steric on the conformational superiority of the di-methoxy (compound 1) and di-thiomethyl compounds (com-pound 2). Thus, the values of resonance stability energy, non-diagonal elements, and orbital populations were investigated. Also, active electrophilic and nucleophilic centers were identified using fronting orbitals analysis obtained by DFT methods. The electrostatic potential maps of the title compounds were investigated at the B3LYP/6-311+G* level of theory. All of the NMR parameters and geometrical properties of both compounds were determined in this study.

scholarly journals Helarchaeota and co-occurring sulfate-reducing bacteria in subseafloor sediments from the Costa Rica Margin

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rui Zhao ◽  
Jennifer F. Biddle
Keyword(s):  
Costa Rica ◽  
Metabolic Pathways ◽  
Phylogenetic Analyses ◽  
Sulfate Reducing Bacteria ◽  
Sulfate Reducing ◽  
Hydrocarbon Emission ◽  
Costa Rica Margin ◽  
Reducing Bacteria ◽  
Electron Transfers ◽  
Deep Sediments

AbstractDeep sediments host many archaeal lineages, including the Asgard superphylum which contains lineages predicted to require syntrophic partnerships. Our knowledge about sedimentary archaeal diversity and their metabolic pathways and syntrophic partners is still very limited. We present here new genomes of Helarchaeota and the co-occurring sulfate-reducing bacteria (SRB) recovered from organic-rich sediments off Costa Rica Margin. Phylogenetic analyses revealed three new metagenome-assembled genomes (MAGs) affiliating with Helarchaeota, each of which has three variants of the methyl-CoM reductase-like (MCR-like) complex that may enable them to oxidize short-chain alkanes anaerobically. These Helarchaeota have no multi-heme cytochromes but have Group 3b and Group 3c [NiFe] hydrogenases, and formate dehydrogenase, and therefore have the capacity to transfer the reducing equivalents (in the forms of hydrogen and formate) generated from alkane oxidation to external partners. We also recovered five MAGs of SRB affiliated with the class of Desulfobacteria, two of which showed relative abundances (represented by genome coverages) positively correlated with those of the three Helarchaeota. Genome analysis suggested that these SRB bacteria have the capacity of H2 and formate utilization and could facilitate electron transfers from other organisms by means of these reduced substances. Their co-occurrence and metabolic features suggest that Helarchaeota may metabolize synergistically with some SRB, and together exert an important influence on the carbon cycle by mitigating the hydrocarbon emission from sediments to the overlying ocean.

Highly efficient fused ring electron acceptors based on a new undecacyclic core

2021 ◽  
Author(s):  
Chun-Ru Wang ◽  
Fuwen Zhao ◽  
Dan He ◽  
Jingming Xin ◽  
Huotian Zhang ◽  
...  
Keyword(s):  
Extinction Coefficient ◽  
Energy Levels ◽  
Electron Acceptors ◽  
Highly Efficient ◽  
Fused Ring ◽  
Nanoscale Morphology

Two FREAs, IUIC-O and IUIC-T, based on an undecacyclic core were developed. IUIC-T having higher extinction coefficient, affords aligned energy levels with PBDB-T, finer nanoscale morphology and more orderly molecular...

Electron transfers in graphitized HZSM-5 zeolite

2020 ◽  
Author(s):  
Alain Moissette ◽  
Isabelle Gener-Batonneau ◽  
Matthieu Hureau ◽  
Ludovic Pinard ◽  
Hervé Vezin ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Zeolite P ◽  
Electron Transfers

In the present work, we report the electron transfers occurring after ionization of the guest molecule of t-stilbene incorporated in graphitized HZSM-5 zeolite and we compare these results with the...

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