Synthesis of multi-porphyrin dendrimer as artificial light-harvesting antennae

2009 ◽  
Vol 13 (07) ◽  
pp. 787-793 ◽  
Author(s):  
Woo-Dong Jang ◽  
Chi-Hwa Lee ◽  
Myung-Seok Choi ◽  
Makiko Osada
Keyword(s):  
Energy Transfer ◽  
High Efficiency ◽  
Inner Core ◽  
Light Harvesting ◽  
Energy Transfer Efficiency ◽  
Fluorescence Measurement ◽  
Free Base ◽  
H Nmr ◽  
Light Harvesting Antenna ◽  
Tof Ms

To mimic bacterial light-harvesting antenna complexes, a series of dendritic multiporphyrin arrays, n PZn-PFB (n = 2, 4; cone-shaped dendrimers, n = 8, 16; star-shaped dendrimers), were synthesized and characterized by 1H NMR and MALDI-TOF-MS spectroscopy. Photoinduced energy-transfer efficiency (ΦET) from peripheral Zn porphyrin ( PZn ) units to an inner core free-base porphyrin ( PFB ) in the dendrimers was evaluated by fluorescence measurement. Both star- and cone-shaped multi-porphyrin arrays exhibited significantly high efficiency energy transfer from the photoexcited PZn units to the energy-accepting PFB , where the star-shaped dendrimers, 8PZn-PFB (94%) and 16PZn-PFB (88%), had a slightly higher efficiency than those of the cone-shaped dendrimers, 2PZn-PFB (92%) and 4PZn-PFB (80%), respectively.

scholarly journals A photosynthetic antenna complex foregoes unity carotenoid-to-bacteriochlorophyll energy transfer efficiency to ensure photoprotection

2020 ◽  
Vol 117 (12) ◽  
pp. 6502-6508 ◽  
Author(s):  
Dariusz M. Niedzwiedzki ◽  
David J. K. Swainsbury ◽  
Daniel P. Canniffe ◽  
C. Neil Hunter ◽  
Andrew Hitchcock
Keyword(s):  
Energy Transfer ◽  
Transient Absorption ◽  
Light Harvesting ◽  
Protein Complexes ◽  
Fluorescence Emission ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Light Harvesting Complexes ◽  
Antenna Complex ◽  
Pigment Protein Complexes

Carotenoids play a number of important roles in photosynthesis, primarily providing light-harvesting and photoprotective energy dissipation functions within pigment–protein complexes. The carbon–carbon double bond (C=C) conjugation length of carotenoids (N), generally between 9 and 15, determines the carotenoid-to-(bacterio)chlorophyll [(B)Chl] energy transfer efficiency. Here we purified and spectroscopically characterized light-harvesting complex 2 (LH2) fromRhodobacter sphaeroidescontaining theN= 7 carotenoid zeta (ζ)-carotene, not previously incorporated within a natural antenna complex. Transient absorption and time-resolved fluorescence show that, relative to the lifetime of the S1state of ζ-carotene in solvent, the lifetime decreases ∼250-fold when ζ-carotene is incorporated within LH2, due to transfer of excitation energy to the B800 and B850 BChlsa. These measurements show that energy transfer proceeds with an efficiency of ∼100%, primarily via the S1→ Qxroute because the S1→ S0fluorescence emission of ζ-carotene overlaps almost perfectly with the Qxabsorption band of the BChls. However, transient absorption measurements performed on microsecond timescales reveal that, unlike the nativeN≥ 9 carotenoids normally utilized in light-harvesting complexes, ζ-carotene does not quench excited triplet states of BChla, likely due to elevation of the ζ-carotene triplet energy state above that of BChla. These findings provide insights into the coevolution of photosynthetic pigments and pigment–protein complexes. We propose that theN≥ 9 carotenoids found in light-harvesting antenna complexes represent a vital compromise that retains an acceptable level of energy transfer from carotenoids to (B)Chls while allowing acquisition of a new, essential function, namely, photoprotective quenching of harmful (B)Chl triplets.

scholarly journals Enhancement of Energy Transfer Efficiency with Structural Control of Multichromophore Light‐Harvesting Assembly

2020 ◽  
Vol 7 (20) ◽  
pp. 2001623
Author(s):  
Inhwan Oh ◽  
Hosoowi Lee ◽  
Tae Wu Kim ◽  
Chang Woo Kim ◽  
Sunhong Jun ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Structural Control ◽  
Light Harvesting ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency

scholarly journals Excitation energy transfer and equilibration process in LHCII studied by multidimensional electronic spectroscopy

2019 ◽  
Vol 205 ◽  
pp. 09038
Author(s):  
Thanh Nhut Do ◽  
Adriana Huerta-Viga ◽  
Cheng Zhang ◽  
Parveen Akhtar ◽  
Pawei J. Nowakowski ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Light Harvesting ◽  
Electronic Spectroscopy ◽  
Excitation Energy Transfer ◽  
Phenomenological Analysis ◽  
Two Dimensional ◽  
Light Harvesting Complex ◽  
Light Harvesting Complex Ii ◽  
Equilibration Process ◽  
Light Harvesting Antenna

Light-harvesting complex II (LHCII) – the light-harvesting antenna of Photosystem II – is a naturally abundant system that plays an important role in photosynthesis. In this study, we present a phenomenological analysis of the excitonic energy transfer in LHCII using ultrafast two-dimensional electronic spectroscopy, that we find compares well with previous theoretical and experimental results.

Influence of Phospholipid Composition on Self-Assembly and Energy-Transfer Efficiency in Networks of Light-Harvesting 2 Complexes

2013 ◽  
Vol 117 (36) ◽  
pp. 10395-10404 ◽  
Author(s):  
Ayumi Sumino ◽  
Takehisa Dewa ◽  
Tomoyasu Noji ◽  
Yuki Nakano ◽  
Natsuko Watanabe ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Self Assembly ◽  
Light Harvesting ◽  
Phospholipid Composition ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency

scholarly journals Marine Cyanobacteria Tune Energy Transfer Efficiency in their Light-harvesting Antennae by Modifying Pigment Coupling

2019 ◽  
Author(s):  
Yuval Kolodny ◽  
Hagit Zer ◽  
Mor Propper ◽  
Shira Yochelis ◽  
Yossi Paltiel ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Light Harvesting ◽  
Vertical Mixing ◽  
Photosynthetic Apparatus ◽  
Emission Spectra ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Transfer Energy ◽  
Harvesting Process

AbstractPhotosynthetic organisms regulate energy transfer to fit to changes in environmental conditions. The biophysical principles underlying the flexibility and efficiency of energy transfer in the light-harvesting process are still not fully understood. Here we examine how energy transfer is regulatedin-vivo. We compare different acclimation states of the photosynthetic apparatus in a marine cyanobacterial species that is well adapted to vertical mixing of the ocean water column and identify a novel acclimation strategy for photosynthetic life under low light intensities. Antennae rods extend, as expected, increasing light absorption. Surprisingly, in contrast to what was known for plants and predicted by classic calculations, these longer rods transfer energy fasteri.e.more efficiently. The fluorescence lifetime and emission spectra dependence on temperature, at the range of 4-300K, suggests that energy transfer efficiency is tuned by modifying the energetic coupling strength between antennae pigments.

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