Supramolecular ultrafast energy and electron transfer in a directly linked BODIPY–oxoporphyrinogen dyad upon fluoride ion binding

2020 ◽  
Vol 56 (27) ◽  
pp. 3855-3858 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Anuradha Liyanage ◽  
Habtom B. Gobeze ◽  
Daniel T. Payne ◽  
Katsuhiko Ariga ◽  
...  

Photosynthetic mimicry of sequential ultrafast energy transfer followed by electron transfer upon fluoride binding to the oxoporphyrinogen cavity in a BODIPY–oxoporphyrinogen dyad is demonstrated.

2001 ◽  
Vol 665 ◽  
Author(s):  
P.A. van Hal ◽  
R.A.J. Janssen ◽  
G. Lanzani ◽  
G. Cerullo ◽  
M. Zavelani-Rossi ◽  
...  

ABSTRACTThe intramolecular photoinduced energy and electron transfer within a fullereneoligothiophene-fullerene triad with nine thiophene units (C60-9T-C60) and an oligo(p-phenylene vinylene)-fullerene dyad with four phenyl groups (OPV4-C60) is investigated with femtosecond pump-probe spectroscopy with sub-10 fs and 200 fs time resolution in solvents of different polarity. Photoexcitation of the π-conjugated oligomer moiety in the triad and dyad results in an ultrafast singlet-energy transfer reaction to create the fullerene singlet-excited state with a time constant of 150-190 fs, irrespective of the polarity of the medium. In a polar solvent, intramolecular electron transfer occurs from the oligomer moiety to the C60 moiety with a time constant of 10-13 ps as a secondary reaction, subsequent to the ultrafast singlet-energy transfer. The charge-separated state has a lifetime of 50-80 ps and recombines to the ground state.


2020 ◽  
Vol 19 (7) ◽  
pp. 976-986
Author(s):  
Ramkumar Varadharajan ◽  
A. Mohan Raj ◽  
V. Ramamurthy

Energy and electron transfer sensitizers present outside trigger the photoisomerization of encapsulated stilbenes; thus establishing communication between a donor and an acceptor is not arrested by a molecular wall.


2015 ◽  
Vol 17 (17) ◽  
pp. 11848-11867 ◽  
Author(s):  
Markus Steeger ◽  
Stefanie Griesbeck ◽  
Alexander Schmiedel ◽  
Marco Holzapfel ◽  
Ivo Krummenacher ◽  
...  

Chromophores with many donors and acceptors show electron transfer which is identical to energy transfer.


2020 ◽  
Vol 22 (25) ◽  
pp. 14356-14363 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Habtom B. Gobeze ◽  
Whitney A. Webre ◽  
Paul A. Karr ◽  
Daniel T. Payne ◽  
...  

Competitive energy and electron transfer in a newly synthesized supramolecular triad composed of zinc porphyrin, oxoporphyrinogen and C60 has been demonstrated using ultrafast pump–probe spectroscopy.


2015 ◽  
Vol 6 (2) ◽  
pp. 1049-1054 ◽  
Author(s):  
Kaifeng Wu ◽  
Qiuyang Li ◽  
Yongling Du ◽  
Zheyuan Chen ◽  
Tianquan Lian

Large in-plane exciton mobility in CdSe nanosheets leads to ultrafast exciton quenching by energy transfer to Pt.


2020 ◽  
Vol 24 (05n07) ◽  
pp. 693-704
Author(s):  
B. Shivaprasadachary ◽  
A. R. Ramya ◽  
Govind Reddy ◽  
L. Giribabu

We report two corrole based donor–acceptor (D–A) dyads, Cbz-Cor and Ptz-Cor to understand the energy/electron transfer reactions. In these D–A systems, the donor, either carbazole (Cbz) or phenothiazine (Ptz), is covalently connected at the meso-phenyl position of 10-(phenyl)-5,15-bis-(pentafluorophenyl)corrole (Ph-Cor) by C–N linkage. Both the dyads were characterized by 1H NMR, MALDI-TOF MS, UV-vis, electrochemical, computational methods, study state fluorescence and TCSPC techniques. A comparison of absorption spectra with their reference monomeric compounds (Cbz-Ph, Ptz-Ph and Ph-Cor) revealed minimal ground-state interactions between chromophores in both dyads. Fluorescence studies suggested that singlet–singlet energy transfer from 1Cbz* to corrole is the major photochemical pathway in the Cbz-Cor dyad with a quenching efficiency of [Formula: see text]99%. Detailed analysis of the data suggests that Forster’s dipole–dipole mechanism does not adequately explain this energy transfer. However, at a 410 nm excitation, florescence quenching is detected in Ptz-Cor (49%) supporting a photo induced electron transfer (PET) process from the ground state of PTZ to the excited state of corrole macrocycle. The electron-transfer rates ([Formula: see text] of Ptz-Cor are found in the range [Formula: see text] to [Formula: see text] and are concluded to be solvent dependent.


1988 ◽  
Vol 53 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Viktor Řehák ◽  
Yvona Rybová

In the micellar medium of sodium dodecyl sulphate the monomer-dimer equilibrium of methylene blue is shifted markedly in favour of the monomer. Methylene blue quenches the fluorescence of pyrene solvated in micelles, which is explained in terms of resonance energy transfer. Based on the theoretical model, the pyrene fluorescence quenching constant in the micelles was determined (kqm = 1.8 106 s-1) and the average pyrene-methylene blue interaction distance for the singlet-singlet energy transfer estimated. The T1 → Tn absorption of methylene blue is quenched by pyrene and tetrasodium salt of ethylenediaminetetraacetic acid (EDTA); the quenching rate constants corresponding to the electron transfer are 5 106 and 2.05 108 1 mol-1 s-1, respectively.


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