Ultrafast Energy And Electron Transfer In Conjugated Oligomer-Fullerene Molecules

2001 ◽  
Vol 665 ◽  
Author(s):  
P.A. van Hal ◽  
R.A.J. Janssen ◽  
G. Lanzani ◽  
G. Cerullo ◽  
M. Zavelani-Rossi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Time Constant ◽  
Transfer Reaction ◽  
Polar Solvent ◽  
Phenylene Vinylene ◽  
Intramolecular Electron Transfer ◽  
Pump Probe ◽  
Energy And Electron Transfer ◽  
Probe Spectroscopy

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.

Electron and energy transfer in a porphyrin–oxoporphyrinogen–fullerene triad, ZnP–OxP–C60

2020 ◽  
Vol 22 (25) ◽  
pp. 14356-14363 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Habtom B. Gobeze ◽  
Whitney A. Webre ◽  
Paul A. Karr ◽  
Daniel T. Payne ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Pump Probe ◽  
Zinc Porphyrin ◽  
Energy And Electron Transfer ◽  
Probe Spectroscopy

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.

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

Sequential Energy and Electron Transfer in Aggregates of Tetrakis[oligo(p-phenylene vinylene)] Porphyrins and C60in Water

2005 ◽  
Vol 127 (39) ◽  
pp. 13484-13485 ◽  
Author(s):  
Martin Wolffs ◽  
Freek J. M. Hoeben ◽  
Edwin H. A. Beckers ◽  
Albertus P. H. J. Schenning ◽  
E. W. Meijer
Keyword(s):  
Electron Transfer ◽  
Phenylene Vinylene ◽  
Energy And Electron Transfer

scholarly journals Excited-state dynamics of overlapped optically-allowed 1B(u)+ and optically-forbidden 1B(u)- or 3A(g)- vibronic levels of carotenoids: possible roles in the light-harvesting function.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Yasushi Koyama ◽  
Yoshinori Kakitani ◽  
Hiroyoshi Nagae
Keyword(s):  
Internal Conversion ◽  
Selection Rule ◽  
Polar Solvent ◽  
Selective Excitation ◽  
Stimulated Emission ◽  
Quantum Beat ◽  
Pump Probe ◽  
Cross Term ◽  
Hand Pump ◽  
Probe Spectroscopy

Pump-probe spectroscopy after selective excitation of all-trans Cars (n = 9-13) in nonpolar solvent identified a symmetry selection rule of diabatic electronic mixing and diabatic internal conversion, i.e., '1B(u)(+)-to-1B(u)(-) is allowed but 1B(u)(+)-to-3A(g)(-) is forbidden'. Kerr-gate fluorescence spectroscopy showed that this selection rule breaks down, due to the symmetry degradation when the Car molecules are being excited, and, as a result, the 1B(u)(+)-to-3A(g)(-) diabatic electronic mixing and internal conversion become allowed. On the other hand, pump-probe spectroscopy after coherent excitation of the same set of Cars in polar solvent identified three stimulated-emission components (generated by the quantum-beat mechanism), consisting of the long-lived coherent cross term from the 1B(u)(+) + 1B(u)(-) or 1B(u)(+) + 3A(g)(-) diabatic pair and incoherent short-lived 1B(u)(+) and 1B(u)(-) or 3A(g)(-) split incoherent terms. The same type of stimulated-emission components were identified in Cars bound to LH2 complexes, their lifetimes being substantially shortened by the Car-to-BChl singlet-energy transfer. Each diabatic pair and its split components appeared with high intensities in the first component. The low-energy shifts of the 1B(u)(+)(0), 1B(u)(-)(0) and 3A(g)(-)(0) levels and efficient triplet generation were also found.

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