Journal ArticleDOI
Triplet−Triplet Intramolecular Energy Transfer in a Covalently Linked Copper(II) Porphyrin−Free Base Porphyrin Hybrid Dimer: A Time-Resolved ESR Study
TLDR
In this paper, the TRESR spectra of the free base moiety in the hybrid dimer in toluene glass at 77 K exhibit a spin polarization pattern different from that for the free-base porphyrin monomer.Abstract:
Triplet−triplet intramolecular energy transfer in a covalently linked copper(II) porphyrin−free base porphyrin hybrid dimer was examined by time-resolved (TR) ESR measurements of the lowest excited triplet (T1) state of the free base porphyrin component after laser pulse excitation at 532 nm. The TRESR spectra of the free base moiety in the hybrid dimer in toluene glass at 77 K exhibit a spin polarization pattern different from that for the free base porphyrin monomer. The observed pattern for the dimer cannot be explained by any intersystem crossing (ISC) process, and it is ascribed to intramolecular energy transfer that takes place from the copper porphyrin part to the free base counterpart between the triplet manifolds. On the other hand, the TRESR spectrum in 2-methyltetrahydrofuran (2-MTHF) glass, where the energy transfer is prohibited by the fast deactivation of the excited copper porphyrin, shows the same spin polarization pattern as that of the free base porphyrin monomer. Therefore, the copper p...read more
Citations
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Journal ArticleDOI
Elucidating excited state electronic structure and intercomponent interactions in multicomponent and supramolecular systems
TL;DR: This work reviews several approaches taken towards gaining a clear understanding of both the mechanism of energy and electron transfer processes and how these processes can be manipulated, with particular focus on the physical techniques employed.
Journal ArticleDOI
Delocalisation of photoexcited triplet states probed by transient EPR and hyperfine spectroscopy.
TL;DR: The theoretical and practical aspects of the investigation of triplet states and triplet state delocalisation by transient continuous wave and pulse EPR are discussed and the advantages and limitations of the presently available techniques and the current trends in the field are highlighted.
Book ChapterDOI
113 – Recent Advances in Free and Metalated Multiporphyrin Assemblies and Arrays; A Photophysical Behavior and Energy Transfer Perspective
Journal ArticleDOI
Photoprocesses in dimers of thiacarbocyanines
TL;DR: In this article, the properties of monomeric and dimeric thiacarbocyanine and three derivatives with methyl (2) and ethyl (3 and 4) meso-substituents were studied in aqueous solution by time-resolved and steady-state spectroscopic methods.
Journal ArticleDOI
Triplet-triplet energy transfer controlled by the donor-acceptor distance in rigidly held palladium-containing cofacial bisporphyrins.
Sébastien Faure,Sébastien Faure,Christine Stern,Enrique Espinosa,Jasmin Douville,Roger Guilard,Pierre D. Harvey +6 more
TL;DR: Measurements allowed the range of distance over which the Dexter mechanism for T(1)-T(1) energy transfer ceases to operate to be determined, and found it to be somewhere between 4.3 and 6.3 A, in agreement with recent findings on singlet-singlet energy transfer.
References
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Journal ArticleDOI
Photoinduced energy transfer in associated, but noncovalently-linked photosynthetic model systems.
TL;DR: In this paper, the Watson-Crick nucleobase-pairing interactions between guanosine- and cytidine-bearing porphyrins are used to assemble the hydrogen-bonded ensembles.
Journal ArticleDOI
The photoexcited triplet state and photosynthesis
Haim Levanon,James R. Norris +1 more
Journal ArticleDOI
The Triplet State in Bacterial Photosynthesis: Possible Mechanisms of the Primary Photo-Act
TL;DR: The unusual esp and ZFS properties of the observed in vivo triplet state are best interpreted as arising from a short-lived radical pair precursor formed in or with the special pair of bacteriochlorophyll molecules involved in the primary photo-act.
Journal ArticleDOI
Luminescence of porphyrins and metalloporphyrins. Part 1.—Zinc(II), nickel(II) and manganese(II) porphyrins
TL;DR: In this article, the absorption spectra show that there is little interaction between the metal and the porphyrin π-system so that the excited states can be regarded as (ππ*) in nature.
Journal ArticleDOI
Porphyrins XIV. Theory for the luminescent state in VO, Co, Cu complexes
TL;DR: In this paper, the trip doublet and quartet energy gap for closed shell metal porphyrins was evaluated and it was shown that luminescence comes from both the triplet and the quartet states, their relative importance varying with metal, porphrin skeleton, and temperature.
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