scholarly journals Electron transfer across a thermal gradient

2016 ◽  
Vol 113 (34) ◽  
pp. 9421-9429 ◽  
Author(s):  
Galen T. Craven ◽  
Abraham Nitzan
Keyword(s):  
Electron Transfer ◽  
Heat Transport ◽  
Single Point ◽  
State Theory ◽  
Free Energy Surface ◽  
Donor And Acceptor ◽  
Transfer Channel ◽  
Different Temperatures ◽  
Donor Acceptor ◽  
Open Electron

Charge transfer is a fundamental process that underlies a multitude of phenomena in chemistry and biology. Recent advances in observing and manipulating charge and heat transport at the nanoscale, and recently developed techniques for monitoring temperature at high temporal and spatial resolution, imply the need for considering electron transfer across thermal gradients. Here, a theory is developed for the rate of electron transfer and the associated heat transport between donor–acceptor pairs located at sites of different temperatures. To this end, through application of a generalized multidimensional transition state theory, the traditional Arrhenius picture of activation energy as a single point on a free energy surface is replaced with a bithermal property that is derived from statistical weighting over all configurations where the reactant and product states are equienergetic. The flow of energy associated with the electron transfer process is also examined, leading to relations between the rate of heat exchange among the donor and acceptor sites as functions of the temperature difference and the electronic driving bias. In particular, we find that an open electron transfer channel contributes to enhanced heat transport between sites even when they are in electronic equilibrium. The presented results provide a unified theory for charge transport and the associated heat conduction between sites at different temperatures.

scholarly journals Electronics Communication and Photoinduced Intramolecular Electron Transfer in Hybrid Ru(II)-Re(I) Complexes Using Eigenstate-Based and Diabatic-State-Based Models

2021 ◽  
Author(s):  
Rangsiman Ketkaew
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reduction Reaction ◽  
Vital Role ◽  
Energy Curve ◽  
Intramolecular Electron Transfer ◽  
Oxidation Reduction ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Adiabatic State

Photoinduced intramolecular electron transfer (PIET) plays a vital role in the efficiency of electronics communication in transition metal complexes catalysing oxidation-reduction reaction. In this work, we theoretically calculate the rate of electron transfer(ET) in Ru(II)-BL-Ru(I) hybrid complexes; where BL is bridging ligand. A brief concept of ET in the basis of Marcus theory, which is extended to address a variety of different type of ET, is provided. We show that, in the case of Ru(II)-BL-Ru(I) complex, ET involves a non-adiabatic state which thanks to a fast electronics communication between donor and acceptor connected by BL and becomes rigid complex. Single electron transferring in Ru(II)-BL-Ru(I) complex governed by PIET constructed by potential energy curve as change of structural transformation over time-evolution. We also investigate the mechanism of PIET involving a redox reaction in excited state, wherein the oxidation state of Ru(II) (donor) and Ru(I) (acceptor) changes. To access non-adiabatic state of Ru(II)-BL-Ru(I), we use constrained density functional theory to allow ground state calculation to be performed along with geometry constraints. We also systematically study the role of distance of donor-acceptor separation on kinetics of PIET

scholarly journals Electronics Communication and Photoinduced Intramolecular Electron Transfer in Hybrid Ru(II)-Re(I) Complexes Using Eigenstate-Based and Diabatic-State-Based Models

2021 ◽  
Author(s):  
Rangsiman Ketkaew
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reduction Reaction ◽  
Vital Role ◽  
Energy Curve ◽  
Intramolecular Electron Transfer ◽  
Oxidation Reduction ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Adiabatic State

Photoinduced intramolecular electron transfer (PIET) plays a vital role in the efficiency of electronics communication in transition metal complexes catalysing oxidation-reduction reaction. In this work, we theoretically calculate the rate of electron transfer(ET) in Ru(II)-BL-Ru(I) hybrid complexes; where BL is bridging ligand. A brief concept of ET in the basis of Marcus theory, which is extended to address a variety of different type of ET, is provided. We show that, in the case of Ru(II)-BL-Ru(I) complex, ET involves a non-adiabatic state which thanks to a fast electronics communication between donor and acceptor connected by BL and becomes rigid complex. Single electron transferring in Ru(II)-BL-Ru(I) complex governed by PIET constructed by potential energy curve as change of structural transformation over time-evolution. We also investigate the mechanism of PIET involving a redox reaction in excited state, wherein the oxidation state of Ru(II) (donor) and Ru(I) (acceptor) changes. To access non-adiabatic state of Ru(II)-BL-Ru(I), we use constrained density functional theory to allow ground state calculation to be performed along with geometry constraints. We also systematically study the role of distance of donor-acceptor separation on kinetics of PIET

scholarly journals Electronics Communication and Photoinduced Intramolecular Electron Transfer in Hybrid Ru(II)-Re(I) Complexes Using Eigenstate-Based and Diabatic-State-Based Models

2021 ◽  
Author(s):  
Rangsiman Ketkaew
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Reduction Reaction ◽  
Vital Role ◽  
Energy Curve ◽  
Intramolecular Electron Transfer ◽  
Oxidation Reduction ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Adiabatic State

Photoinduced intramolecular electron transfer (PIET) plays a vital role in the efficiency of electronics communication in transition metal complexes catalysing oxidation-reduction reaction. In this work, we theoretically calculate the rate of electron transfer(ET) in Ru(II)-BL-Ru(I) hybrid complexes; where BL is bridging ligand. A brief concept of ET in the basis of Marcus theory, which is extended to address a variety of different type of ET, is provided. We show that, in the case of Ru(II)-BL-Ru(I) complex, ET involves a non-adiabatic state which thanks to a fast electronics communication between donor and acceptor connected by BL and becomes rigid complex. Single electron transferring in Ru(II)-BL-Ru(I) complex governed by PIET constructed by potential energy curve as change of structural transformation over time-evolution. We also investigate the mechanism of PIET involving a redox reaction in excited state, wherein the oxidation state of Ru(II) (donor) and Ru(I) (acceptor) changes. To access non-adiabatic state of Ru(II)-BL-Ru(I), we use constrained density functional theory to allow ground state calculation to be performed along with geometry constraints. We also systematically study the role of distance of donor-acceptor separation on kinetics of PIET

Ion-Mediated Electron Transfer in a Supramolecular Donor-Acceptor Ensemble

Science ◽  
2010 ◽  
Vol 329 (5997) ◽  
pp. 1324-1327 ◽  
Author(s):  
Jung Su Park ◽  
Elizabeth Karnas ◽  
Kei Ohkubo ◽  
Ping Chen ◽  
Karl M. Kadish ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ion Binding ◽  
Acceptor Pair ◽  
Initial Oxidation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Back Electron Transfer ◽  
Donor And Acceptor ◽  
Mediated Electron Transfer ◽  
Donor Acceptor

Ion binding often mediates electron transfer in biological systems as a cofactor strategy, either as a promoter or as an inhibitor. However, it has rarely, if ever, been exploited for that purpose in synthetic host-guest assemblies. We report here that strong binding of specific anions (chloride, bromide, and methylsulfate but not tetrafluoroborate or hexafluorophosphate) to a tetrathiafulvalene calix[4]pyrrole (TTF-C4P) donor enforces a host conformation that favors electron transfer to a bisimidazolium quinone (BIQ2+) guest acceptor. In contrast, the addition of a tetraethylammonium cation, which binds more effectively than the BIQ2+ guest in the TTF-C4P cavity, leads to back electron transfer, restoring the initial oxidation states of the donor and acceptor pair. The products of these processes were characterized via spectroscopy and x-ray crystallography.

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals A carbon membrane-mediated CdSe and TiO2 nanofiber film for enhanced photoelectrochemical degradation of methylene blue

RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 11872-11881
Author(s):  
Xinye Zhang ◽  
Xueyue Zhang ◽  
Keting Feng ◽  
Xiaoyun Hu ◽  
Jun Fan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Electron Transfer ◽  
Carbon Membrane ◽  
Carrier Transfer ◽  
Tio2 Nanofiber ◽  
Transfer Channel ◽  
Nanofiber Film ◽  
Degradation Ability

A CdSe/C/TiO2 nanofiber film was prepared for enhanced photoelectrochemical degradation ability, and carbon membrane as a carrier-transfer-channel could promote electron transfer.

scholarly journals Supramolecular Systems Containing B–N Frustrated Lewis Pairs of Tris(pentafluorophenyl)borane and Triphenylamine Derivatives

2021 ◽  
Vol 03 (02) ◽  
pp. 174-183
Author(s):  
P. Chidchob ◽  
S. A. H. Jansen ◽  
S. C. J. Meskers ◽  
E. Weyandt ◽  
N. P. van Leest ◽  
...  
Keyword(s):  
Materials Science ◽  
Supramolecular Polymers ◽  
Frustrated Lewis Pairs ◽  
Paramagnetic Resonance ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Noncovalent Polymers ◽  
Electron Paramagnetic ◽  
Supramolecular Polymerization ◽  
Lewis Pairs

The introduction of a chemical additive to supramolecular polymers holds high potential in the development of new structures and functions. In this regard, various donor- and acceptor-based molecules have been applied in the design of these noncovalent polymers. However, the incorporation of boron–nitrogen frustrated Lewis pairs in such architectures is still rare despite their many intriguing properties in catalysis and materials science. The limited choices of suitable boron derivatives represent one of the main limitations for the advancement in this direction. Here, we examine the use of the commercially available tris(pentafluorophenyl)borane with various triphenylamine derivatives to create supramolecular B–N charge transfer systems. Our results highlight the importance of a proper balance between the donor/acceptor strength and the driving force for supramolecular polymerization to achieve stable, long-range ordered B–N systems. Detailed analyses using electron paramagnetic resonance and optical spectroscopy suggest that tris(pentafluorophenyl)borane displays complex behavior with the amide-based triphenylamine supramolecular polymers and may interact in dimers or larger chiral aggregates, depending on the specific structure of the triphenylamines.

Photoelectrochemical properties of supramolecular composites of an anionic zinc chlorin and Li+@C60 on SnO2

2014 ◽  
Vol 18 (10n11) ◽  
pp. 982-990 ◽  
Author(s):  
Kei Ohkubo ◽  
Yuki Kawashima ◽  
Kentaro Mase ◽  
Hayato Sakai ◽  
Taku Hasobe ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Photovoltaic Cells ◽  
Lithium Ion ◽  
Transparent Electrode ◽  
Supramolecular Complex ◽  
Photoelectrochemical Properties ◽  
Triplet Excited State ◽  
Optically Transparent ◽  
Donor Acceptor

An electron donor–acceptor supramolecular complex was formed between an anionic zinc chlorin carboxylate ( ZnCh -) and lithium-ion-encapsulated [60]fullerene ( Li +@ C 60) by an electrostatic interaction in benzonitrile ( PhCN ). Photoinduced electron transfer in the supramolecular complex of ZnCh -/ Li +@ C 60 resulted in the formation of the charge-separated state via electron transfer from the triplet excited state of ZnCh - to Li +@ C 60. We report herein photovoltaic cells using ZnCh -/ Li +@ C 60 nanoclusters, which are assembled on the optically transparent electrode (OTE) of nanostructured SnO 2 (OTE/ SnO 2). The photoelectrochemical behavior of the nanostructured SnO 2 film of supramolecular nanoclusters of ZnCh - and Li +@ C 60 denoted as OTE/ SnO 2/( ZnCh -/ Li +@ C 60)n is significantly higher than the single component films of ZnCh - or Li +@ C 60 clusters, denoted as OTE/ SnO 2/( ZnCh -)n or OTE/ SnO 2/( Li +@ C 60)n.

scholarly journals The effects of temperature on aberrant ascus frequencies at the Buff locus in Sordaria brevicollis

1975 ◽  
Vol 26 (2) ◽  
pp. 127-135 ◽  
Author(s):  
A. F. Ahmad
Keyword(s):  
Single Point ◽  
Different Temperatures ◽  
Effects Of Temperature

SUMMARYSingle-point crosses using five allelic spore colour mutants at the buff locus were carried out at different temperatures. The data suggest (i) that fixed or preferred opening points in the DNA, required for initiation of recombination events, are available more often at higher than at lower temperatures, (ii) opening points at or beyond both proximal and distal ends of the buff locus respond similarly to variations in temperature, and (iii) the correction pattern seems to be independent of temperature at the buff locus in S. brevicollis.

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