Diffusionless Electron Transfer of Xanthene Dyes in Nonpolar and Weakly Polar Donor- and Acceptor-Solvents

1991 ◽  
Vol 20 (4) ◽  
pp. 645-648 ◽  
Author(s):  
Klaus Kemnitz ◽  
Keitaro Yoshihara
Keyword(s):  
Electron Transfer ◽  
Xanthene Dyes ◽  
Donor And Acceptor

Zur Theorie der Elektronenübergangsreaktionen in molekularen Komplexen / Theory of Electron Transfer Reactions in Molecular Complexes

1974 ◽  
Vol 29 (6) ◽  
pp. 880-887 ◽  
Author(s):  
P. P. Schmidt
Keyword(s):  
Activation Energy ◽  
Electron Transfer ◽  
Charge Transfer ◽  
Rate Constant ◽  
Reaction Rate ◽  
Charge Transfer Complex ◽  
Rate Theory ◽  
Transfer Step ◽  
Donor And Acceptor ◽  
Inner Sphere

This paper reports a theory of the inner sphere-type electron transfer reaction. Inner sphere reactions, as opposed to the outer sphere variety, require that the solvate or ligand shells surrounding the electron donor and acceptor species undergo considerable change in the course of the electron transfer. In this paper we assume that the electron transfer step takes place in a molecular complex which exists in equilibrium with the reactants. The electron transfer step occurs as a non-radiative charge transfer-type transition. In this manner we treat the charge transfer kinetics, in particular, the evaluation of the reaction rate constant, in the same manner as is usual for non-radiative problems. The analysis leading to the rate constant expression is based on Yamamoto’s general chemical reaction rate theory. The rate constant expressions obtained are quite general, they hold for any degree of strength of coupling between subsystems comprising the entire system. The activation energy, in the Arrhenius form for the rate constant, shows a dependence on the energy (work) of formation of the intermediate charge transfer complex, on vibrational shift energies associated with the molecular motions of the ligands, and on solvent repolarization energies. The activation energy also shows an important dependence on coupling terms which link the vibrations of the molecular inner shell with the polarization states of the (assumed) dielectric continuum which surrounds the charge transfer participants. The approach we take in developing this theory we believe points the way towards the development of a more complete theory capable of accounting for the dynamics of the molecular reorganization leading to the intermediate charge transfer complex as well as accounting for the electron transfer step itself.

scholarly journals Recent advances in twisted intramolecular charge transfer (TICT) fluorescence and related phenomena in materials chemistry

2016 ◽  
Vol 4 (14) ◽  
pp. 2731-2743 ◽  
Author(s):  
Shunsuke Sasaki ◽  
Gregor P. C. Drummen ◽  
Gen-ichi Konishi
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Transfer Process ◽  
Intramolecular Charge Transfer ◽  
Materials Chemistry ◽  
Single Bond ◽  
Electron Transfer Process ◽  
Twisted Intramolecular Charge Transfer ◽  
Recent Advances ◽  
Donor And Acceptor

Twisted intramolecular charge transfer (TICT) is an electron transfer process that occurs upon photoexcitation in molecules that usually consist of a donor and acceptor part linked by a single bond.

THE MECHANISM AND PROPERTIES OF ELECTRON TRANSFER IN THE BIOLOGICAL ORGANISM

2013 ◽  
Vol 27 (21) ◽  
pp. 1350090 ◽  
Author(s):  
XIAO-FENG PANG
Keyword(s):  
Electron Transfer ◽  
Finite Temperature ◽  
Energy Transport ◽  
Atp Hydrolysis ◽  
Interaction Strength ◽  
Reduction Reaction ◽  
Oxidation Reduction ◽  
Donor And Acceptor ◽  
Protein Molecules ◽  
Oxidation Reduction Reaction

The mechanism and properties of electron transfer along protein molecules at finite temperature T ≠ 0 in the life systems are studied using nonlinear theory of bio-energy transport and Green function method, in which the electrons are transferred from donors to acceptors in virtue of the supersound soliton excited by the energy released in ATP hydrolysis. The electron transfer is, in essence, a process of oxidation–reduction reaction. In this study we first give the Hamiltonian and wavefunction of the system and find out the soliton solution of the dynamical equation in the protein molecules with finite temperature, and obtain the dynamical coefficient of the electron transfer. The results show that the speed of the electron transfer is related to the velocity of motion of the soliton, distribution of electrons in the donor and acceptor as well as the interaction strength among them. We finally concluded the changed rule of electric current, arising from the electron transfer, with increasing time. These results are useful in molecular and chemical biology.

97 Study on electron transfer through RNA/DNA duplex using pyrene and 5-bromouracil as an electron donor and acceptor pair

2013 ◽  
Vol 31 (sup1) ◽  
pp. 61-62
Author(s):  
Tadao Takada ◽  
Kenji Maie ◽  
Yumiko Otsuka ◽  
Tomohiro Saeki ◽  
Yuta Takamatsu ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Donor ◽  
Dna Duplex ◽  
Acceptor Pair ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor

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 Electron migration in DNA matrix: an electron transfer reaction

1998 ◽  
Vol 23 (0) ◽  
pp. 99-109 ◽  
Author(s):  
Cecília Dominical POY ◽  
Marinônio Lopes CORNÉLIO
Keyword(s):  
Electron Transfer ◽  
Methyl Viologen ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Dna Bases ◽  
Base Pairs ◽  
Dna Molecule ◽  
A Value ◽  
Donor And Acceptor ◽  
Electron Migration

This paper brings an active and provocative area of current research. It describes the investigation of electron transfer (ET) chemistry in general and ET reactions results in DNA in particular. Two DNA intercalating molecules were used: Ethidium Bromide as the donor (D) and Methyl-Viologen as the acceptor (A), the former intercalated between DNA bases and the latter in its surface. Using the Perrin model and fluorescence quenching measurements the distance of electron migration, herein considered to be the linear spacing between donor and acceptor molecule along the DNA molecule, was obtained. A value of 22.6 (± 1.1) angstroms for the distance and a number of 6.6 base pairs between donor and acceptor were found. In current literature the values found were 26 angstroms and almost 8 base pairs. DNA electron transfer is considered to be mediated by through-space interactions between the p-electron-containing base pairs.

scholarly journals Distal [FeS]-Cluster Coordination in [NiFe]-Hydrogenase Facilitates Intermolecular Electron Transfer

2017 ◽  
Author(s):  
Alexander Petrenko ◽  
Matthias Stein
Keyword(s):  
Electron Transfer ◽  
Density Functional ◽  
Electric Energy ◽  
Reorganization Energy ◽  
Outer Sphere ◽  
Intermolecular Electron Transfer ◽  
Sulfur Cluster ◽  
Donor And Acceptor ◽  
Marcus Equation ◽  
Hydrogenase Enzyme

Biohydrogen is a versatile energy carrier for the generation of electric energy from renewable sources. Hydrogenases can be used in enzymatic fuel cells to oxidize dihydrogen. The rate of electron transfer (ET) at the anodic side between the [NiFe]-hydrogenase enzyme distal iron–sulfur cluster and the electrode surface can be described by the Marcus equation. All parameters for the Marcus equation are accessible from Density Functional Theory (DFT) calculations. The distal cubane FeS-cluster has a three-cysteine and one-histidine coordination [Fe4S4](His)(Cys)3 first ligation sphere. The reorganization energy (inner- and outer-sphere) is almost unchanged upon a histidine-to-cysteine substitution. Differences in rates of electron transfer between the wild-type enzyme and an all-cysteine mutant can be rationalized by a diminished electronic coupling between the donor and acceptor molecules in the [Fe4S4](Cys)4 case. The fast and efficient electron transfer from the distal iron–sulfur cluster is realized by a fine-tuned protein environment, which facilitates the flow of electrons. This study enables the design and control of electron transfer rates and pathways by protein engineering.

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

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