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.

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.

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 Voltage-induced long-range coherent electron transfer through organic molecules

2019 ◽  
Vol 116 (13) ◽  
pp. 5931-5936 ◽  
Author(s):  
Karen Michaeli ◽  
David N. Beratan ◽  
David H. Waldeck ◽  
Ron Naaman
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Charge Transport ◽  
Molecular Orbital ◽  
Organic Semiconductors ◽  
Electronic States ◽  
Long Distance ◽  
Damage Repair ◽  
Limited Temperature ◽  
Voltage Dependent

Biological structures rely on kinetically tuned charge transfer reactions for energy conversion, biocatalysis, and signaling as well as for oxidative damage repair. Unlike man-made electrical circuitry, which uses metals and semiconductors to direct current flow, charge transfer in living systems proceeds via biomolecules that are nominally insulating. Long-distance charge transport, which is observed routinely in nucleic acids, peptides, and proteins, is believed to arise from a sequence of thermally activated hopping steps. However, a growing number of experiments find limited temperature dependence for electron transfer over tens of nanometers. To account for these observations, we propose a temperature-independent mechanism based on the electric potential difference that builds up along the molecule as a precursor of electron transfer. Specifically, the voltage changes the nature of the electronic states away from being sharply localized so that efficient resonant tunneling across long distances becomes possible without thermal assistance. This mechanism is general and is expected to be operative in molecules where the electronic states densely fill a wide energy window (on the scale of electronvolts) above or below the gap between the highest-occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). We show that this effect can explain the temperature-independent charge transport through DNA and the strongly voltage-dependent currents that are measured through organic semiconductors and peptides.

Vibronic and electronic states of doubly charged H2S studied by Auger and charge transfer spectroscopy and by ab initio calculations

1990 ◽  
Vol 93 (2) ◽  
pp. 918-931 ◽  
Author(s):  
A. Cesar ◽  
H. Ågren ◽  
A. Naves de Brito ◽  
S. Svensson ◽  
L. Karlsson ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electronic States ◽  
Doubly Charged

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.

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