Energy Transfer between Subunits of Photosystem II Dimer Observed by Femtosecond Transient Absorption

2016 ◽  
Author(s):  
Yusuke Yoneda ◽  
Tetsuro Katayama ◽  
Yutaka Nagasawa ◽  
Hiroshi Miyasaka ◽  
Yasufumi Umena
Keyword(s):  
Energy Transfer ◽  
Photosystem Ii ◽  
Transient Absorption ◽  
Femtosecond Transient Absorption

Femtosecond Transient Absorption Studies of Energy Transfer within Chromophore-Labeled Dendrimers

2001 ◽  
Vol 105 (7) ◽  
pp. 1307-1312 ◽  
Author(s):  
Frederik V. R. Neuwahl ◽  
Roberto Righini ◽  
Alex Adronov ◽  
Patrick R. L. Malenfant ◽  
Jean M. J. Fréchet
Keyword(s):  
Energy Transfer ◽  
Transient Absorption ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

Unveiling excited state energy transfer and charge transfer in a host/guest coordination cage

2018 ◽  
Vol 20 (4) ◽  
pp. 2205-2210 ◽  
Author(s):  
Rui-Ling Zhang ◽  
Yang Yang ◽  
Song-Qiu Yang ◽  
Ke-Li Han
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
State Energy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Dynamic Processes ◽  
Excited State Energy ◽  
Femtosecond Transient Absorption ◽  
Femtosecond Transient Absorption Spectroscopy ◽  
Excited State Dynamic

Ultrafast excited-state dynamic processes, charge and energy transfer in a HGCT system are unveiled by using femtosecond transient absorption spectroscopy.

scholarly journals Femtosecond visible transient absorption spectroscopy of chlorophyll-f-containing photosystem II

2020 ◽  
Vol 117 (37) ◽  
pp. 23158-23164
Author(s):  
Noura Zamzam ◽  
Rafal Rakowski ◽  
Marius Kaucikas ◽  
Gabriel Dorlhiac ◽  
Sefania Viola ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Photosystem Ii ◽  
Charge Separation ◽  
Transient Absorption ◽  
Spectral Feature ◽  
Cation Radical ◽  
Stimulated Emission ◽  
Transient Absorption Spectroscopy ◽  
Long Wavelength

The recently discovered, chlorophyll-f-containing, far-red photosystem II (FR-PSII) supports far-red light photosynthesis. Participation and kinetics of spectrally shifted far-red pigments are directly observable and separated from that of bulk chlorophyll-a. We present an ultrafast transient absorption study of FR-PSII, investigating energy transfer and charge separation processes. Results show a rapid subpicosecond energy transfer from chlorophyll-a to the long-wavelength chlorophylls-f/d. The data demonstrate the decay of an ∼720-nm negative feature on the picosecond-to-nanosecond timescales, coinciding with charge separation, secondary electron transfer, and stimulated emission decay. An ∼675-nm bleach attributed to the loss of chl-a absorption due to the formation of a cation radical, PD1+•, is only fully developed in the nanosecond spectra, indicating an unusually delayed formation. A major spectral feature on the nanosecond timescale at 725 nm is attributed to an electrochromic blue shift of a FR-chlorophyll among the reaction center pigments. These time-resolved observations provide direct experimental support for the model of Nürnberg et al. [D. J. Nürnberg et al., Science 360, 1210–1213 (2018)], in which the primary electron donor is a FR-chlorophyll and the secondary donor is chlorophyll-a (PD1 of the central chlorophyll pair). Efficient charge separation also occurs using selective excitation of long-wavelength chlorophylls-f/d, and the localization of the excited state on P720* points to a smaller (entropic) energy loss compared to conventional PSII, where the excited state is shared over all of the chlorin pigments. This has important repercussions on understanding the overall energetics of excitation energy transfer and charge separation reactions in FR-PSII.

Single-molecule spectroscopy and femtosecond transient absorption studies on the excitation energy transfer process in ApcE(1–240) dimers

2015 ◽  
Vol 17 (20) ◽  
pp. 13387-13396 ◽  
Author(s):  
Saran Long ◽  
Meng Zhou ◽  
Kun Tang ◽  
Xiao-Li Zeng ◽  
Yingli Niu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Single Molecule ◽  
Transfer Process ◽  
Transient Absorption ◽  
Energy Transfer Process ◽  
Excitation Energy Transfer ◽  
Single Molecule Spectroscopy ◽  
Femtosecond Transient Absorption ◽  
Absorption Studies

The red-shifted absorption of ApcE dimers results from extending chromophore conformation, which does not depend on strong exction coupling.

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