Determination of Excited-State Energies and Dynamics in the B Band of the Bacterial Reaction Center with 2D Electronic Spectroscopy

2012 ◽  
Vol 3 (17) ◽  
pp. 2487-2492 ◽  
Author(s):  
Gabriela S. Schlau-Cohen ◽  
Eleonora De Re ◽  
Richard J. Cogdell ◽  
Graham R. Fleming
Keyword(s):  
Excited State ◽  
Reaction Center ◽  
Electronic Spectroscopy ◽  
Bacterial Reaction Center

scholarly journals Primary processes in the bacterial reaction center probed by two-dimensional electronic spectroscopy

2018 ◽  
Vol 115 (14) ◽  
pp. 3563-3568 ◽  
Author(s):  
Andrew Niedringhaus ◽  
Veronica R. Policht ◽  
Riley Sechrist ◽  
Arkaprabha Konar ◽  
Philip D. Laible ◽  
...  
Keyword(s):  
Excited State ◽  
Reaction Center ◽  
Charge Separation ◽  
Purple Bacteria ◽  
Electronic Spectroscopy ◽  
Reaction Centers ◽  
Purple Bacterium ◽  
Absorption Bands ◽  
Sequential Reaction ◽  
Special Pair

In the initial steps of photosynthesis, reaction centers convert solar energy to stable charge-separated states with near-unity quantum efficiency. The reaction center from purple bacteria remains an important model system for probing the structure–function relationship and understanding mechanisms of photosynthetic charge separation. Here we perform 2D electronic spectroscopy (2DES) on bacterial reaction centers (BRCs) from two mutants of the purple bacterium Rhodobacter capsulatus, spanning the Qy absorption bands of the BRC. We analyze the 2DES data using a multiexcitation global-fitting approach that employs a common set of basis spectra for all excitation frequencies, incorporating inputs from the linear absorption spectrum and the BRC structure. We extract the exciton energies, resolving the previously hidden upper exciton state of the special pair. We show that the time-dependent 2DES data are well-represented by a two-step sequential reaction scheme in which charge separation proceeds from the excited state of the special pair (P*) to P+HA− via the intermediate P+BA−. When inhomogeneous broadening and Stark shifts of the B* band are taken into account we can adequately describe the 2DES data without the need to introduce a second charge-separation pathway originating from the excited state of the monomeric bacteriochlorophyll BA*.

scholarly journals Dynamic band-shift signal in two-dimensional electronic spectroscopy: A case of bacterial reaction center

2021 ◽  
Vol 154 (11) ◽  
pp. 115102
Author(s):  
Eglė Bukartė ◽  
David Paleček ◽  
Petra Edlund ◽  
Sebastian Westenhoff ◽  
Donatas Zigmantas
Keyword(s):  
Reaction Center ◽  
Electronic Spectroscopy ◽  
Two Dimensional ◽  
Band Shift ◽  
Bacterial Reaction Center

Electronic Interactions in the Bacterial Reaction Center Revealed by Two-Color 2D Electronic Spectroscopy

2018 ◽  
Vol 9 (18) ◽  
pp. 5219-5225 ◽  
Author(s):  
Arkaprabha Konar ◽  
Riley Sechrist ◽  
Yin Song ◽  
Veronica R. Policht ◽  
Philip D. Laible ◽  
...  
Keyword(s):  
Reaction Center ◽  
Electronic Spectroscopy ◽  
Bacterial Reaction Center ◽  
Electronic Interactions

scholarly journals Polydopamine/Ethylenediamine Nanoparticles Embedding a Photosynthetic Bacterial Reaction Center for Efficient Photocurrent Generation

2021 ◽  
pp. 2000303
Author(s):  
Gabriella Buscemi ◽  
Danilo Vona ◽  
Roberta Ragni ◽  
Roberto Comparelli ◽  
Massimo Trotta ◽  
...  
Keyword(s):  
Reaction Center ◽  
Bacterial Reaction Center ◽  
Photocurrent Generation

scholarly journals Excitonic structure and charge separation in the heliobacterial reaction center probed by multispectral multidimensional spectroscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yin Song ◽  
Riley Sechrist ◽  
Hoang H. Nguyen ◽  
William Johnson ◽  
Darius Abramavicius ◽  
...  
Keyword(s):  
Reaction Center ◽  
Charge Separation ◽  
Electronic Spectroscopy ◽  
Spectroscopic Studies ◽  
Primary Electron ◽  
Reaction Centers ◽  
Separation Mechanism ◽  
Photosynthetic Reaction Centers ◽  
Density Analysis ◽  
Function Relationship

AbstractPhotochemical reaction centers are the engines that drive photosynthesis. The reaction center from heliobacteria (HbRC) has been proposed to most closely resemble the common ancestor of photosynthetic reaction centers, motivating a detailed understanding of its structure-function relationship. The recent elucidation of the HbRC crystal structure motivates advanced spectroscopic studies of its excitonic structure and charge separation mechanism. We perform multispectral two-dimensional electronic spectroscopy of the HbRC and corresponding numerical simulations, resolving the electronic structure and testing and refining recent excitonic models. Through extensive examination of the kinetic data by lifetime density analysis and global target analysis, we reveal that charge separation proceeds via a single pathway in which the distinct A0 chlorophyll a pigment is the primary electron acceptor. In addition, we find strong delocalization of the charge separation intermediate. Our findings have general implications for the understanding of photosynthetic charge separation mechanisms, and how they might be tuned to achieve different functional goals.

Nanomolar Determination of Nitrofurans in Water via Excited-State Inter-Ligand Proton Transfer

2021 ◽  
pp. 338905
Author(s):  
Xiaojun Zhang ◽  
Lina Zhao ◽  
Xiaomeng Jin ◽  
Zijun Zhang ◽  
Yuxin Li
Keyword(s):  
Excited State ◽  
Proton Transfer
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