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 Hypsochromic solvent shift of the charge separation band in ionic donor–acceptor Li+@C60⊂[10]CPP

2019 ◽  
Vol 55 (75) ◽  
pp. 11195-11198 ◽  
Author(s):  
Anton J. Stasyuk ◽  
Olga A. Stasyuk ◽  
Miquel Solà ◽  
Alexander A. Voityuk
Keyword(s):  
Electron Transfer ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Blue Shift ◽  
Polar Medium ◽  
Solvent Shift ◽  
Donor Acceptor

Photoinduced electron transfer in CPP-based donor–acceptor complexes C60⊂[10]CPP and Li+@C60⊂[10]CPP was studied using DFT/TDDFT. Unusual blue shift of charge separated states for Li+@C60⊂[10]CPP complexes in the polar medium is predicted.

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.

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.

Flavin Core as Electron Acceptor Component in a Zinc(II)-Phthalocyanine-Based Dyad

2008 ◽  
Vol 61 (4) ◽  
pp. 256 ◽  
Author(s):  
Andreas Gouloumis ◽  
G. M. Aminur Rahman ◽  
Julia Abel ◽  
Gema de la Torre ◽  
Purificación Vázquez ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Ground State ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Significant Interaction ◽  
Transient Absorption ◽  
Cross Coupling ◽  
Ion Pair ◽  
Donor Acceptor ◽  
Recombination Dynamics

A zinc(ii)-phthalocyanine-flavin dyad has been synthesized by Heck-type cross-coupling between a flavin that bears a p-iodophenyl group and a phthalocyanine functionalized with a vinyl moiety. Electrochemical experiments reveal that no significant interaction occurs at the ground state between the two electroactive subunits. However, the occurrence of a photoinduced electron transfer in this donor–acceptor conjugate is observed in transient absorption experiments. Charge-separation (i.e., 4.0 × 1011 s–1) and charge-recombination dynamics in benzonitrile (2.2 × 1010 s–1) reveal a remarkable stabilization of the radical ion pair in this solvent.

Long-lived charge-separated states of simple electron donor-acceptor dyads using porphyrins and phthalocyanines

2008 ◽  
Vol 12 (09) ◽  
pp. 993-1004 ◽  
Author(s):  
Kei Ohkubo ◽  
Shunichi Fukuzumi
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Electron Donor ◽  
Driving Force ◽  
Reorganization Energy ◽  
Charge Recombination ◽  
Zinc Phthalocyanine ◽  
Intramolecular Electron Transfer ◽  
Triplet Excited State ◽  
Donor Acceptor

Control of electron-transfer processes is described for a number of electron donor-acceptor dyads containing porphyrins or phthalocyanines as models for the photosynthetic reaction center. The rates for intramolecular electron transfer in the dyads are controlled by the driving force and reorganization energy of electron transfer. The small reorganization energy of electron transfer reactions and large driving force of charge recombination are required to form long-lived charge-separated states. A directly linked zinc chlorin-fullerene dyad, especially, has the longest lifetime of charge-separated state at 120 s at -150 °C, which is a much longer lifetime and higher energy than those of natural photosynthetic reaction centers. On the other hand, the charge-separated states of the phthalocyanine-based donor-acceptor dyads (silicon phthalocyanine-fullerene, and zinc phthalocyanine-perylenebisimide) are short-lived since charge recombination forms the low-lying triplet excited state of the chromophore. The energy of the charge-separated state of a zinc phthalocyanine-perylenebisimide dyad is decreased by binding of metal ions to the radical anion moiety in order to be lower than the triplet excited state. This results in formation of a long-lived charge-separated state. The mechanistic viability of formation of long-lived charge-separated states is demonstrated by a variety of examples based on the Marcus theory of electron transfer.

scholarly journals Sc3N@Ih-C80 based donor–acceptor conjugate: role of thiophene spacer in promoting ultrafast excited state charge separation

RSC Advances ◽  
2020 ◽  
Vol 10 (34) ◽  
pp. 19861-19866
Author(s):  
Rubén Caballero ◽  
Luis David Servián ◽  
Habtom B. Gobeze ◽  
Olivia Fernandez-Delgado ◽  
Luis Echegoyen ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Separation ◽  
Charge Recombination ◽  
Photoinduced Charge Separation ◽  
Donor Acceptor ◽  
Photoinduced Charge ◽  
State Charge

Photoinduced charge separation and dark charge recombination occurring within picoseconds is observed in newly synthesized triphenylamine–thiophene-Sc3N@Ih-C80 and triphenylamine–thiophene-C60 conjugates.

scholarly journals Remarkable Dependence of the Final Charge Separation Efficiency on the Donor-Acceptor Interaction in Photoinduced Electron Transfer

2015 ◽  
Vol 55 (2) ◽  
pp. 629-633 ◽  
Author(s):  
Tomohiro Higashino ◽  
Tomoki Yamada ◽  
Masanori Yamamoto ◽  
Akihiro Furube ◽  
Nikolai V. Tkachenko ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Separation Efficiency ◽  
Acceptor Interaction ◽  
Donor Acceptor ◽  
Charge Separation Efficiency
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