Electronic excitation energy migration in chemical dimers of cyclopentaneporphyrin molecule

Zenkevich, É. I.; Шульга, А. М.; Chernook, A. V.; Gurinovich, G. P.

doi:10.1007/bf00659748

Cited by 7 publications

(10 citation statements)

References 6 publications

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“…This dimer includes one Zn-3 0 ,5 0 -cyclo-3 0 -methyl-2,7,8,12,13, 17,18-heptaethyl-22H,24H-porphyrin molecule and one Zn-3 0 ,5 0 -cyclo-3 0 -exomethylene-2,7,8,12, 13,17,18-heptaethyl-22H,24H-porphyrin molecule. Absorption and fluorescence spectra as well as NMR an mass-spectroscopy data obtained for these five dimers have been described elsewhere [6,34,35]. Figs.…”

Section: Synthesis and Objectsmentioning

confidence: 99%

“…In addition, as far as strong electronic transitions form both B-and Q-bands in Zn-chlorins, the excitonic splittings are observed in both Soret and visible absorption bands of this dimer. For the rigid dimer Zn-3 0 ,3 0 -cyclodimer with almost orthogonal porphyrin macrocycles [33,34], the PYR action is individual for every half and does not differ from the monomeric case.…”

Section: Compoundmentioning

confidence: 99%

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Interaction of multiporphyrin systems with molecular oxygen in liquid solutions: extra-ligation and screening effects

et al. 2002

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Steady-state and time-resolved studies indicate that for a sequence of porphyrin or chlorin chemical dimers Zncyclodimer ! ðZnOEPÞ 2 Ph ! ðZnOEPÞ 2 ! ðZnHTPPÞ 2 ! ðZnOEChlÞ 2 with relative lowering of excited S 1-and T 1states, the extra-ligation by pyridine (PYR) does not influence essentially on fluorescence parameters but leads to an increase of T 1-states non-radiative decay (the most pronounced for dimers with higher lying T 1-levels). For pyridinated dimers at 293 K T 1-states quenching by molecular oxygen depends on the spacer flexibility and donor-acceptor interactions with PYR. In self-assembled triads and pentads energy and electron transfer (within a few ps) takes place from Zn-dimers to pyridyl substituted porphyrin extra-ligand, H 2 P, followed by the effective population of H 2 P T 1state. For these systems, bimolecular constants of H 2 P T 1-states quenching by O 2 decrease by 1.4-1.8 times with respect to those found for individual monomeric porphyrins. This effect is explained by the screening action of a strongly quenched Zn-porphyrin dimer subunit limiting the access of oxygen molecule to the excited extra-ligand.

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Section: Synthesis and Objectsmentioning

confidence: 99%

Section: Compoundmentioning

confidence: 99%

Interaction of multiporphyrin systems with molecular oxygen in liquid solutions: extra-ligation and screening effects

et al. 2002

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“…The effectiveness of resonance energy transfer from the nanocrystals to the porphyrin for the investigated composites with increase of the molar ratio x, calculated from sensitization of emission from the acceptor on the basis of the methods set out in [15,18,38,39], is presented in Fig. 3b.…”

Section: Resultsmentioning

confidence: 99%

“…b) Dependence of the effectiveness of resonance energy transfer NC ® P on the molar ratio x = C P /C NC in nanocomposites based on nanocrystals of various diameters and a ligand of the same type and structure (5,10,15,20-tetra-meta-pyridylporphyrin). The effectiveness of resonance energy transfer was calculated on the basis of the methods in [15,18,38,39]. Parameters of the nanocrystals: The same as in Fig.…”

Section: Resultsmentioning

confidence: 99%

Effects of electron tunneling and nonresonance quenching of photoluminescence in semiconducting CdSe/ZnS AND CdSe nanocrystals by porphyrin molecules in joint complexes

et al. 2009

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The quenching of photoluminescence (PL) in semiconducting CdSe/ZnS and CdSe nanocrystals (NC) of various sizes during surface passivation by molecules of tetrapyridylporphyrins (P) in toluene at 295 K was investigated. It was shown that resonance transfer of energy NC ® P plays a minor role in PL quenching (<10%), while photoinduced electron transfer NC ® P is absent. On the basis of experimental data and quantum-mechanical calculations it was established that with identical molar ratio x = C P /C NC the probability of quenching k q decreases with increase in the size of the NC while the PL quenching process itself under conditions of quantum confinement is due to electron tunneling of the excited electron-hole pair on the surface of the NC followed by localization of the organic ligand (P) on anchor groups. The obtained results are of interest for investigating the mechanisms of the blinking of PL in single semiconductor nanocrystals.Despite the recently obtained results of scientific and applied interest [1-3], a series of problems concerning the luminescent characteristics and relaxation processes in nanocrystals (NC) during their interaction with various types of organic ligands still remain unsolved in the creation of novel effective composite materials based on a semiconducting nanocrystals and an organic molecule. Of special interest in this respect is the study of photoinduced charge transfer [4] and electronic excitation energy [5] in NC-organic ligand nanocomposites in so far as they form the basis of the various applications of these materials as optical markers in biological systems [6][7][8] or in the optimization of photovoltaic devices [9,10].At the present time various methods have been proposed and implemented for the creation of NC-organic ligand nanocomposites: Simple mixing [11]; substitution of the surface stabilizer molecules by the molecules of dyes [12]; the 0040-5760/09/4501-0023

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“…In this series of papers, some topics were studied that later became central to the myriad of reports on photo-induced energy transfer (ET) relating to the photosynthetic reaction center. For example, the systematics of excited-state deactivation in dimers such as Ni 2 18a, Cu 2 18c, and Zn/Cu 18u were defined, [147][148][149] whereby quenching of the ZnPor fluorescence by the transition metal ion in the neighboring ring was noted for the heterometallic complexes. Major conclusions of this work were that the first singlet or triplet excited states of the dimer subunits are involved in weak dipole-dipole exchange interactions that allow pico-or nanosecond ET.…”

Section: Emission Spectroscopy and Electronically-excited Statesmentioning

confidence: 99%

Oligoporphyrins with One-and Two-Atom Covalent Bridges: Synthesis and Reactivity, Solid-State, Solution and Electronic Structures, Spectroscopy and Applications

Arnold¹,

Goh²,

Harper³

et al. 2014

Handbook of Porphyrin Science

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Electronic excitation energy migration in chemical dimers of cyclopentaneporphyrin molecule

Cited by 7 publications

References 6 publications

Interaction of multiporphyrin systems with molecular oxygen in liquid solutions: extra-ligation and screening effects

Interaction of multiporphyrin systems with molecular oxygen in liquid solutions: extra-ligation and screening effects

Effects of electron tunneling and nonresonance quenching of photoluminescence in semiconducting CdSe/ZnS AND CdSe nanocrystals by porphyrin molecules in joint complexes

Oligoporphyrins with One-and Two-Atom Covalent Bridges: Synthesis and Reactivity, Solid-State, Solution and Electronic Structures, Spectroscopy and Applications

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