scholarly journals Quantum electrodynamical theory of high-efficiency excitation energy transfer in laser-driven nanostructure systems

2016 ◽  
Vol 94 (8) ◽  
Author(s):  
Dilusha Weeraddana ◽  
Malin Premaratne ◽  
Sarath D. Gunapala ◽  
David L. Andrews
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
High Efficiency ◽  
Excitation Energy Transfer ◽  
Nanostructure Systems

Photosynthesis

2009 ◽  
pp. 573-587
Author(s):  
Julia Adolphs
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Reaction Center ◽  
High Efficiency ◽  
Excitation Energy Transfer ◽  
Photosynthetic Reaction Center ◽  
Photochemical Reactions ◽  
Light Harvesting Complexes ◽  
Transition Energies ◽  
Local Transition

This chapter introduces the theory of optical spectra and excitation energy transfer of light harvesting complexes in photosynthesis. The light energy absorbed by protein bound pigments in these complexes is transferred via an exciton mechanism to the photosynthetic reaction center where it drives the photochemical reactions. The protein holds the pigments in optimal orientation for excitation energy transfer and creates an energy sink by shifting the local transition energies of the pigments. In this way, the excitation energy is directed with high efficiency (close to 100 %) to the reaction center. In the present chapter, this energy transfer is studied theoretically. Based on crystal structure data, the excitonic couplings are calculated taking into account also the polarizability of the protein. The local transition energies are obtained by two independent methods and are used to predict the orientation of the FMO protein relative to the reaction center.

scholarly journals Uphill energy transfer mechanism for photosynthesis in the Antarctic alga

2021 ◽  
Author(s):  
Makiko Kosugi ◽  
Masato Kawasaki ◽  
Yutaka Shibata ◽  
Kojiro Hara ◽  
Shinichi Takaichi ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
High Efficiency ◽  
Light Harvesting ◽  
Red Light ◽  
Excitation Energy Transfer ◽  
Energy Transfer Mechanism ◽  
Light Harvesting Complex ◽  
Prasiola Crispa

Abstract Prasiola crispa, a major green alga in Antarctica, forms layered colonies for survival under the severe terrestrial conditions of Antarctica, which include severe cold, drought, and strong sunlight. As a result of these conditions, the surface cells of P. crispa and other Antarctic organisms face high risk of photodamage. Cells of deeper layer escape from photodamage at the sacrifice of photosynthetic active radiation except infrared. P. crispa achieves effective photosynthesis by low energy far-red light for photosystem II excitation with high efficiency similar to that of visible light. Here, we identified a far-red light-harvesting complex of photosystem II in P. crispa, Pc-frLHC, and proposed a molecular mechanism of uphill excitation energy transfer based on its cryogenic electron-microscopy structure. While Pc-frLHC is associated with photosystem II, it is evolutionarily related to the light-harvesting complex of photosystem I. Pc-frLHC forms a ring-shaped homo-undecamer in which all chlorophyll a molecules are energetically connected and contains chlorophyll a trimers. It seems that the trimers are long-wavelength-absorbing chlorophylls for far-red light at 708 nm, and further absorbance extension is accomplished by Davydov-splitting in dimeric chlorophylls. The chlorophyll network should enable a highly efficient entropy-driven uphill excitation energy transfer using far-red light up to 725 nm.

THEORY OF EXCITATION-ENERGY TRANSFER PROCESSES INVOLVING OPTICALLY FORBIDDEN EXCITON STATES IN ANTENNA SYSTEMS OF PHOTOSYNTHESIS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3637-3640
Author(s):  
KOICHIRO MUKAI ◽  
SHUJI ABE ◽  
HITOSHI SUMI
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Reaction Center ◽  
High Efficiency ◽  
Purple Bacteria ◽  
Excitation Energy Transfer ◽  
Light Harvesting Complex ◽  
Transfer Processes ◽  
Photosynthetic Purple Bacteria ◽  
Antenna Systems

The rate of excitation-energy transfer (EET) within the light-harvesting complex (LH) and from LH to the reaction center (RC) of photosynthetic purple bacteria is calculated, based on a formula for EET between molecular aggregates. We show that optically forbidden exciton states participate in EET processes through mulitpole EET interactions with the help of disorder. In the antenna systems of photosynthesis, high efficiency of energy transfer is implemented by these EET processes involving optically forbidden exciton states.

scholarly journals An Effective Potential for Frenkel Excitons

2020 ◽  
Author(s):  
Bartosz Błasiak ◽  
Wojciech Bartkowiak ◽  
Robert Władysław Góra
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Efficient Method ◽  
Effective Potential ◽  
Excitation Energy Transfer ◽  
Computationally Efficient ◽  
Frenkel Excitons

Excitation energy transfer (EET) is a ubiquitous process in life and materials sciences. Here, a new and computationally efficient method of evaluating the electronic EET couplings between interacting chromophores is...

scholarly journals Excitation Energy Transfer from Rhodamine 6G to Photochromic Fulgide

2014 ◽  
Vol 26 (23) ◽  
pp. 8229-8233
Author(s):  
Rabab Sharaf Jassas ◽  
Samy Abdullah El-Daly ◽  
Abdullah M. Asiri ◽  
Salman A Khan
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Rhodamine 6G ◽  
Excitation Energy Transfer
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