Large Acceleration Effect of Photoinduced Electron Transfer in Porphyrin−Quinone Dyads with a Rigid Spacer Involving a Dihalosubstituted Three-Membered Ring

Tsue, Hirohito; Imahori, Hiroshi; Kaneda, Toshio; Tanaka, Yoshinori; Okada, Tadashi; Tamaki, Koichi; Sakata, Yoshiteru

doi:10.1021/ja9900454

Cited by 45 publications

(40 citation statements)

References 103 publications

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“…Similar analysis of the kinetic data revealed values of λ = 0.83 ± 0.07 eV and V = 65 ± 12 cm –1 for diPBI-TPA. The reorganization energy in diPBI-PdTPP is comparable to that in fullerene-linked dyads and those reported previously for porphyrin–quinone − and zincporphyrin–freebase porphyrin , linked dyads. The large electron coupling in the dyads agrees well with the aforementioned steady-state spectroscopic and theoretical results.…”

Section: Resultssupporting

confidence: 85%

Donor-Linked Di(perylene bisimide)s: Arrays Exhibiting Fast Electron Transfer for Photosynthesis Mimics

Zhen

Wang

et al. 2013

J. Phys. Chem. A

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The first example of donor-linked di(perylene bisimide)s is reported. UV-vis absorption spectra of these newly synthesized dyads showed intense absorption across the entire visible region, demonstrating their excellent light-harvesting activities. The severe fluorescence quenching event probed by steady-state fluorescence spectroscopy and the free-energy calculations suggested the possibility of electron transfer (ET) in these arrays upon photoexcitation. Further femtosecond transient absorption spectra clarified that the fluorescence quenching was due to fast intramolecular ET. The rate of the charge separation (CS) was found to be as high as 10(12) s(-1) in CH(2)Cl(2). It was suggested that the large ET driving forces, strong donor-acceptor electronic coupling, and relatively small reorganization energy of diPBI accounted for the rapid ET process in a synergic manner. The fate of the generated radical ion pair depended on the solvent used. Rapid charge recombination to ground state occurred for the dyads in polar CH(2)Cl(2) and for diPBI-TPA in nonpolar toluene. However, sufficient (3)diPBI* population was attained via efficient spin-orbit coupled intersystem crossing from the charge-separated state for diPBI-PdTPP in toluene. These photophysical properties are interpreted as the cooperation between thermodynamic feasibility and kinetic manipulation.

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Section: Resultssupporting

confidence: 85%

Donor-Linked Di(perylene bisimide)s: Arrays Exhibiting Fast Electron Transfer for Photosynthesis Mimics

Zhen

Wang

et al. 2013

J. Phys. Chem. A

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“…Namely, direct superexchange-mediated ET occurs from A •- to D •+ or sequential ET takes place from A •- to D •+ via D •+ −B •- −A. However, a switch between sequential and superexchange ET, especially for CR processes, has yet to be fully studied in a homologous series of D−B−A systems. − …”

Section: Introductionmentioning

confidence: 99%

Linkage Dependent Charge Separation and Charge Recombination in Porphyrin-Pyromellitimide-Fullerene Triads

et al. 2002

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A homologous series of zincporphyrin (ZnP)-pyromellitimide (Im)-C 60 linked triads where the pyromellitimide (Im) moiety is incorporated as an intermediate acceptor between the above two chromophores with a linkage of different spacers, ZnP-Im-CH 2 -C 60 , ZnP-Im-C 60 , and ZnP-CH 2 -Im-C 60 as well as the reference dyads (ZnP-Im-CH 2 -ref, ZnP-Im-ref, and ZnP-CH 2 -Im-ref) have been prepared to investigate linkage dependence of photoinduced electron transfer (ET) and back ET to the ground state in the triads. Time-resolved transient absorption spectra of the triads measured by picosecond laser photolysis as well as the fluorescence lifetimes in THF reveal the occurrence of photoinduced ET from the singlet excited state of the ZnP to the Im moiety to give the initial charge-separated state, i.e., the zincporphyrin radical cation (ZnP •+ )-imide radical anion (Im •-) pair, followed by a charge shift (CSH) to produce the final charge-separated state, the ZnP •+ -C 60 •-pair. The rate constants of photoinduced ETs in ZnP-Im-C 60 (1.8 × 10 10 s -1 ) and ZnP-Im-CH 2 -C 60 (1.3 × 10 10 s -1 ) in THF are much larger than those in ZnP-CH 2 -Im-C 60 (2.9 × 10 9 s -1 ) and ZnP-CH 2 -Im-ref (1.9 × 10 9 s -1 ). The larger charge separation (CS) rates in the former case are ascribed to the relatively strong electronic coupling because of the absence of a methylene linkage between the ZnP and the Im moieties in ZnP-Im-C 60 and ZnP-Im-CH 2 -C 60 as compared to the triad and dyad with the methylene linkage. The transient absorption spectra of the final charge-separated state, the ZnP •+ -C 60 •-pair, have been also measured by nanosecond laser photolysis. It has been found that the rate constants of charge recombination (CR) of ZnP •+ -Im-C 60 •-are temperature independent, but that the CR rate constants of ZnP •+ -Im-CH 2 -C 60 •-exhibit an Arrhenius-like temperature dependence with an activation energy of 0.13 eV which corresponds to the energy difference between ZnP •+ -Im •--CH 2 -C 60 and ZnP •+ -Im-CH 2 -C 60 •-. This indicates that the relatively strong electronic coupling without methylene linkage in ZnP-Im-C 60 results in the preference of the tunneling superexchange ET over the sequential ET in the CR process which requires the thermal activation to reach the higher energy state (i.e., ZnP •+ -Im •--C 60 ), whereas the sequential ET predominates in the triads with the methylene linkage.

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“…Compared to energy transfer, photoinduced electron transfer (PET) by transformation of excitation energy into chemical potentials in the form of long-lived carriers is at the heart of photoenergy conversion. On a molecular level, a large number of porphyrin-based dyads or triads (porphyrin-fullerene, porphyrin-quinone) have been intentionally designed to initiate the PET process [84,85]. For heterogenization, more consideration has been given to choice of π-conjugated carbon materials such as carbon nanotubes (CNTs), graphene, or C 3 N 4 as scaffolds.…”

Section: Carbon Materials As Supportsmentioning

confidence: 99%

Porphyrin‐Based Organophotocatalysts

Chen¹,

Huang²,

Wang³

2017

Phthalocyanines and Some Current Applications

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The planar geometric structure and the rich absorption feature endow porphyrins with interesting optoelectronic properties and also make it promising building blocks for supramolecular assembly. Recent advances in the photocatalytic applications of porphyrins, including homogeneous, heterogeneous photocatalysis, and photoelectrochemical solar cells are highlighted. Porphyrin photocatalysts are involved in the form of molecules, supported molecules, nanostructures, and thin film. Related rational design strategies are provided for each form with an aim to enhance the light conversion efficiency. Finally, the ongoing directions and challenges for the future development of porphyrin semiconductors in high-quality optoelectronic devices are also proposed.

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Large Acceleration Effect of Photoinduced Electron Transfer in Porphyrin−Quinone Dyads with a Rigid Spacer Involving a Dihalosubstituted Three-Membered Ring

Cited by 45 publications

References 103 publications

Donor-Linked Di(perylene bisimide)s: Arrays Exhibiting Fast Electron Transfer for Photosynthesis Mimics

Donor-Linked Di(perylene bisimide)s: Arrays Exhibiting Fast Electron Transfer for Photosynthesis Mimics

Linkage Dependent Charge Separation and Charge Recombination in Porphyrin-Pyromellitimide-Fullerene Triads

Porphyrin‐Based Organophotocatalysts

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