Wave-Function Symmetry Control of Electron-Transfer Pathways within a Charge-Transfer Chromophore

2020 ◽  
Vol 11 (19) ◽  
pp. 8399-8405
Author(s):  
Bruno M. Aramburu-Trošelj ◽  
Ivana Ramírez-Wierzbicki ◽  
Franco Scarcasale ◽  
Paola S. Oviedo ◽  
Luis M. Baraldo ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Wave Function ◽  
Charge Transfer ◽  
Electron Transfer Pathways ◽  
A Charge

scholarly journals Electron transfer dynamics and excited state branching in a charge-transfer platinum(ii) donor–bridge-acceptor assembly

2014 ◽  
Vol 43 (47) ◽  
pp. 17677-17693 ◽  
Author(s):  
Paul A. Scattergood ◽  
Milan Delor ◽  
Igor V. Sazanovich ◽  
Oleg V. Bouganov ◽  
Sergei A. Tikhomirov ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
A Charge

Luminescence and reactivity of a charge-transfer excited iron complex with nanosecond lifetime

Science ◽  
2018 ◽  
Vol 363 (6424) ◽  
pp. 249-253 ◽  
Author(s):  
Kasper Skov Kjær ◽  
Nidhi Kaul ◽  
Om Prakash ◽  
Pavel Chábera ◽  
Nils W. Rosemann ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Room Temperature ◽  
Iron Complex ◽  
Transfer Reactions ◽  
Carbene Ligands ◽  
Doublet Ground State ◽  
A Charge ◽  
Bimolecular Quenching ◽  
Metal Charge Transfer

Iron’s abundance and rich coordination chemistry are potentially appealing features for photochemical applications. However, the photoexcitable charge-transfer states of most iron complexes are limited by picosecond or subpicosecond deactivation through low-lying metal-centered states, resulting in inefficient electron-transfer reactivity and complete lack of photoluminescence. In this study, we show that octahedral coordination of iron(III) by two mono-anionic facialtris-carbene ligands can markedly suppress such deactivation. The resulting complex [Fe(phtmeimb)2]+, where phtmeimb is {phenyl[tris(3-methylimidazol-1-ylidene)]borate}−, exhibits strong, visible, room temperature photoluminescence with a 2.0-nanosecond lifetime and 2% quantum yield via spin-allowed transition from a doublet ligand-to-metal charge-transfer (2LMCT) state to the doublet ground state. Reductive and oxidative electron-transfer reactions were observed for the2LMCT state of [Fe(phtmeimb)2]+in bimolecular quenching studies with methylviologen and diphenylamine.

Increasing the Yield of Photoinduced Charge Separation through Parallel Electron Transfer Pathways

1999 ◽  
Vol 03 (01) ◽  
pp. 32-44 ◽  
Author(s):  
NYANGENYA I. MANIGA ◽  
JOHN P. SUMIDA ◽  
SIMON STONE ◽  
ANA L. MOORE ◽  
THOMAS A. MOORE ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Quantum Yield ◽  
Charge Separation ◽  
Charge Recombination ◽  
Final State ◽  
Photoinduced Charge Separation ◽  
Electron Transfer Pathways ◽  
Artificial Photosynthetic ◽  
A Charge ◽  
Photoinduced Charge

A strategy for increasing the yield of long-lived photoinduced charge separation in artificial photosynthetic reaction centers which is based on multiple electron transfer pathways operating in parallel has been investigated. Excitation of the porphyrin moiety of a carotenoid ( C )–porphyrin ( P )–naphthoquinone (Q) molecular triad leads to the formation of a charge-separated state C ·+– P – Q ·− with an overall quantum yield of 0.044 in benzonitrile solution. Photoinduced electron transfer from the porphyrin first excited singlet state gives C – P ·+– Q ·− with a quantum yield of ~1.0. However, electron transfer from the carotenoid to the porphyrin radical cation to form the final state does not compete well with charge recombination of C – P ·+– Q ·−, reducing the yield. The related pentad C 3– P – Q features carotenoid, porphyrin and quinone moieties closely related to those in the triad. Excitation of this molecule gives a C ·+– P ( C 2)– Q ·− state with a quantum yield of 0.073. The enhanced yield is ascribed to the fact that three electron donation pathways operating in parallel compete with charge recombination. The yield does not increase by the statistically predicted factor of three owing to small differences in thermodynamic driving force between the two compounds.

scholarly journals Electron Transfer Pathways and Dynamics in Drosophila Cryptochrome - the Role of Protein Electrostatics

2019 ◽  
Vol 205 ◽  
pp. 10009 ◽  
Author(s):  
Martin Richter ◽  
Benjamin P. Fingerhut
Keyword(s):  
Amino Acids ◽  
Electron Transfer ◽  
Charge Transfer ◽  
Charge Separation ◽  
Quantum Dynamics ◽  
Protein Electrostatics ◽  
Charged Amino Acids ◽  
Electron Transfer Pathways ◽  
Dynamics Simulations

Dissipative quantum dynamics simulations reveal a branching of charge separation dynamics in Drosophila Cryptochrome due to subtle balanced energetics within the enzyme. In silico mutations of charged amino acids provide control over charge transfer directionality.

Complex reactions

1996 ◽  
Author(s):  
Wolfgang Schmickler
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Electrode Surface ◽  
Electrochemical Reactions ◽  
Charge Transfer Reaction ◽  
Electron Transfer Reactions ◽  
The Past ◽  
Rate Determining Step ◽  
The Subject ◽  
A Charge

In the past two chapters we have already encountered examples of reactions involving several steps, and introduced the notion of rate determining step. Here we will elaborate on the subject of complex reactions, introduce another concept; the electrochemical reaction order, and consider a few other examples. The simplest type of complex electrochemical reactions consists of two steps, at least one of which must be a charge-transfer reaction. We now consider two consecutive electron-transfer reactions of the type: . . . Red ⇌ Int + e- ⇌ Ox + 2e- . . .(11.1) such as: Tl+ ⇌Tl2+ + e- ⇌ Tl3+ + 2e- . . . (11.2) For simplicity we assume that the intermediate stays at the electrode surface, and does not diffuse to the bulk of the solution.

Charge Transfer Modeling for Charge-Coupled Devices

1997 ◽  
Vol 490 ◽  
Author(s):  
James P. Lavine ◽  
Eric G. Stevens ◽  
Edmund K. Banghart ◽  
Eugene A. Trabka ◽  
Bruce C. Burkey ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Random Walk ◽  
Charge Transfer ◽  
Three Dimensional ◽  
Electron Motion ◽  
Charge Coupled Device ◽  
Charge Coupled Devices ◽  
Spatial Dimensions ◽  
Random Walk Simulation ◽  
A Charge

ABSTRACTThe three-dimensional Poisson's equation is solved by iterative methods and the resulting electric field is used in Newton's equation to simulate electron transfer in a charge-coupled device (CCD). The time dependence of charge transfer is studied through a random walk simulation of Newton's equation. Potential obstacles of the order of 0.03 V are seen to slow charge transfer. Electron motion is also followed in two spatial dimensions through Newton's equation in order to probe a more varied set of potential obstacles.

Coherent control of electrons in molecules

1996 ◽  
Vol 74 (6) ◽  
pp. 988-994 ◽  
Author(s):  
Andre D. Bandrauk ◽  
Hengtai Yu ◽  
Eric E. Aubanel
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Ab Initio Calculations ◽  
Coherent Control ◽  
Laser Excitation ◽  
Electronic States ◽  
Level System ◽  
Key Words Laser ◽  
Laser Control ◽  
A Charge

Coherent superposition of electronic states can be achieved by simultaneous laser excitation at different frequencies. As an example, the three-level system is examined in order to demonstrate the possibility of phase control of electron transfer in molecules. Ab initio calculations are used to illustrate the principle in a charge transfer molecule DMBAN, 4-(N,N-dimethylamino)benzonitrile. Key words: laser control, charge transfer electrons.

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