Browsing by Author "Rempel, U."

Now showing items 1-7 of 7

    • Competition between electron transfer and energy migration in self-assembled porphyrin triads 

      Zenkevich, E. I.; Willert, A.; Bachilo, S. M.; Rempel, U.; Kilin, D. S.; Shulga, A. M.; Borczyskowski, C. von (2001)
      The photoinduced electron transfer (ET) and the energy migration (EM) processes have been studied in liquid solutions and polymeric (PMMA) films for the triads consisting of the Zn-octaethylporphyrin chemical dimer (the energy and electron donor, D) and dipyridyl substituted tetrapyrrole extra-ligands (porphyrins, chlorin, tetrahydroporphyrin) as the acceptors, A. On the basis ...
      2017-05-26

    • Complexation and interchromophoric interactions in self-organized porphyrin and chlorin triads 

      Chernook, A. V.; Shulga, A. M.; Zenkevich, E. I.; Rempel, U.; Borczyskowski, C. von (1996)
      Spectral properties and equilibrium constants of multimolecular complexes (triads) formed by 2-fold coordination of dipyridyl-substituted free bases of porphyrin, chlorin, or tetrahydroporphyrin with Zn-porphyrin and Zn-chlorin dimers bridged by either of two different spacers between the monomeric entities have been studied in methylcyclohexane at room temperature. The ability ...
      2017-05-18

    • Electron transfer in porphyrin multimolecular self-organized nanostructures 

      Zenkevich, E. I.; Bachilo, S. M.; Shulga, A. M.; Rempel, U.; Willert, A.; Borczyskowski, C. von (1998)
      On the base of of covalent and non-covalent bonds nanoscale self-assembling multiporphyrin arrays with well-defined geometry, the controllable number of interacting components and their spectral and photophysical properties were formed. The deactivation of excited singlet and triplet states was studied using steady-state, time-resolved picosecond fluorescence (∆½≈30 ps) and ...
      2017-05-25

    • Formation and optical properties of self-organized pentameric porphyrin arrays 

      Chernook, A. V.; Rempel, U.; Borczyskowski, C. von; Zenkevich, E. I.; Shulga, A. (1996)
      Principles of formation, electronic absorption and fluorescence spectra are reported for self-organized pentameric arrays of tetrapyrrolic macrocycles. In these arrays two molecules of Zn-porphyrin dimers, Zn(II)l,4-bis[5-(10,15,20-tri-p-hexylphenylporphyrinyl)]-benzene ((ZnHTPP)₂) are bound via one molecule of a tetrapyridyl-substituted free base of porphyrin or tetrahydroporphyrin. ...
      2017-05-25

    • Photoinduced electron transfer dynamics for self-assembled porphyrin arrays in solutions and films 

      Zenkevich, E. I.; Kilin, D. S.; Willert, A.; Bachilo, S. M.; Shulga, A. M.; Rempel, U.; Borczyskowski, C. von (2001)
      Electronic excitation energy deactivation in self-assembled porphyrin triads has been studied by the time correlated single photon counting technique as a function of the solvent polarity (toluene-acetone mixtures), temperature (77-350 K), and mutual spatial arrangement of the donor and acceptor subunits. The donor (Zn-octaethylporphyrin chemical dimer) fluorescence quenching ...
      2017-05-26

    • Self-assembled nanoscale photomimetic models: structure and related dynamics 

      Zenkevich, E. I.; Borczyskowski, C. von; Shulga, A. M.; Bachilo, S. M.; Rempel, U.; Willert, A. (2002)
      Using static and time-resolved measurements, dynamics of non-radiative relaxation processes have been studied in self-assembled porphyrin triads of various geometry, containing the main biomimetic components, Zn–porphyrin dimers, free-base extra-ligands (porphyrin, chlorin or tetrahydroporphyrin), and electron acceptors A (quinone or pyromellitimide). The strong quenching of the ...
      2017-05-26

    • Spectroscopy of interchromophoric interactions in self-organized porphyrin and chlorin complexes 

      Zenkevich, E. I.; Shulga, A. M.; Chernook, A. V.; Rempel, U.; Borczyskowski, C. von (1995)
      Spectral-luminescent properties of multimolecular complexes (triads and pentads, complexation constants range from 5∙10⁶ to 5∙10⁷ M⁻¹) formed by two-fold coordination of dipyridyl and tetra-pyridyl substituted porphyrin or related molecules with Zn-porphyrin and Zn-chlorin dimers having various spacers between macrocycles (-CH₂-CH₂- or phenyl ring) have been studied in methylcyclohexane ...
      2017-05-18