Efficiency of Intramolecular Charge Separation from the Second Excited State: Suppression of the Hot Charge Recombination by Electron Transfer to the Secondary Acceptor

2013 ◽  
Vol 117 (45) ◽  
pp. 11479-11489 ◽  
Author(s):  
Serguei V. Feskov ◽  
Anatoly I. Ivanov
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Separation ◽  
Charge Recombination ◽  
Hot Charge Recombination

Corrole–ferrocene and corrole–anthraquinone dyads: synthesis, spectroscopy and photochemistry

2015 ◽  
Vol 17 (40) ◽  
pp. 26607-26620 ◽  
Author(s):  
Jaipal Kandhadi ◽  
Venkatesh Yeduru ◽  
Prakriti R. Bangal ◽  
Lingamallu Giribabu
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Charge Recombination ◽  
Transfer Rates ◽  
Donor Acceptor

Two different donor–acceptor systems based on corrole–ferrocene (Cor–Fc) and corrole–anthraquinone (Cor–AQ) have been designed and synthesized. Excited state properties of these dyads indicates intramolecular photoinduced electron transfer (PET) take place in these dyads and the electron-transfer rates (kET) was found to be ∼1011s−1. The charge separation (CS) and charge recombination (CR) are found to be identical.

scholarly journals How can infra-red excitation both accelerate and slow charge transfer in the same molecule?

2018 ◽  
Vol 9 (30) ◽  
pp. 6395-6405 ◽  
Author(s):  
Zheng Ma ◽  
Zhiwei Lin ◽  
Candace M. Lawrence ◽  
Igor V. Rubtsov ◽  
Panayiotis Antoniou ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Charge Separation ◽  
Charge Recombination ◽  
Recombination Rates ◽  
Infra Red ◽  
Induced Changes

A UV-IR-Vis 3-pulse study of infra-red induced changes to electron transfer (ET) rates in a donor–bridge–acceptor species finds that charge-separation rates are slowed, while charge-recombination rates are accelerated as a result of IR excitation during the reaction.

Photoinduced electron transfer in 5-bromouracil labeled DNA. A contrathermodynamic mechanism revisited by electron transfer theories

2019 ◽  
Vol 21 (8) ◽  
pp. 4387-4393 ◽  
Author(s):  
Lorenzo Cupellini ◽  
Paweł Wityk ◽  
Benedetta Mennucci ◽  
Janusz Rak
Keyword(s):  
Electron Transfer ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Charge Recombination ◽  
Photoinduced Charge Separation ◽  
Photoinduced Charge

Neither the rates of photoinduced charge separation nor charge recombination account for the substantial damage observed in the 5′-ABrU sequence.

Molecular-structure control of electron transfer dynamics of push–pull porphyrins as sensitizers for NiO based dye sensitized solar cells

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77184-77194 ◽  
Author(s):  
Lei Zhang ◽  
Ludovic Favereau ◽  
Yoann Farre ◽  
Antoine Maufroy ◽  
Yann Pellegrin ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Electron Transfer ◽  
Solar Cells ◽  
Charge Separation ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Charge Recombination ◽  
Structure Control ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Zn(ii)-porphyrin dyes for NiO dye-sensitized solar cells showed surprisingly rapid charge recombination, in spite of their push–pull character. Appending a secondary acceptor prolonged charge separation and led to improved photovoltaic performance.

Donor-acceptor conjugates derived from cobalt porphyrin and fullerene via metal-ligand axial coordination: Formation and excited state charge separation

2021 ◽  
pp. A-N
Author(s):  
Dili R. Subedi ◽  
Youngwoo Jang ◽  
Ashwin Ganesan ◽  
Sydney Schoellhorn ◽  
Ryan Reid ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Separation ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Cobalt Porphyrin ◽  
Axial Coordination ◽  
Cobalt Porphyrins ◽  
Donor Acceptor ◽  
Metal Ligand

Two types of cobalt porphyrins, viz., meso-tetrakis(tolylporphyrinato)cobalt(II), (TTP)Co (1), and meso-tetrakis(triphenylamino porphyrinato)cobalt(II), [(TPA)4P]Co, (2) were self-assembled via metal-ligand axial coordination of phenyl imidazole functionalized fulleropyrrolidine, ImC[Formula: see text] to form a new series of donor–acceptor constructs. A 1:2 complex formation with ImC[Formula: see text] was established in the case of (TTP)Co while for [(TPA)4P]Co only a 1:1 complex was possible to positively identify. The binding constants [Formula: see text] and [Formula: see text] for step-wise addition of ImC[Formula: see text] to (TTP)Co were found to be 1.07 × 105 and 3.20 × 104 M[Formula: see text], respectively. For [(TPA)4P]Co:ImC[Formula: see text], the measured [Formula: see text] values was found to be 6.48 × 104 M[Formula: see text], slightly smaller than that observed for (TTP)Co. Although both cobalt porphyrins were non-fluorescent, they were able to quench the fluorescence of ImC[Formula: see text] indicating occurrence of excited state events in the supramolecular donor-acceptor complexes. Electrochemistry coupled with spectroelectrochemistry, revealed the formation of cobalt(III) porphyrin cation instead of a cobalt(II) porphyrin radical cation, as the main product, during oxidation of phenyl imidazole coordinated cobalt porphyrin. With the help of computational and electrochemical results, an energy level diagram was constructed to witness excited state photo-events. Competitive energy and electron transfer from excited CoP to coordinated ImC[Formula: see text], and electron transfer from Im1C[Formula: see text]* to cobalt(II) porphyrin resulting into the formation of PCo[Formula: see text]:ImC[Formula: see text] charge separated state was possible to envision from the energy diagram. Finally, using femtosecond transient absorption spectroscopy and data analysis by Glotaran, it was possible to establish sequential occurrence of energy transfer and charge separation processes. The lifetime of the final charge separated state was [Formula: see text] 2 ns. A slightly better charge stabilization was observed in the case of [(TPA)4P]Co:ImC[Formula: see text] due to the presence of electron rich, peripheral triphenylamine substituents on the cobalt porphyrin.

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