Browsing by Author "Zenkevich, E."

Now showing items 1-8 of 8

    • Dynamics of photoinduced electron transfer in multiporphyrin nanoassemblies 

      Kilin, D.; Zenkevich, E.; Borczyskowski, C. von (World Scientific Publishing Co., 2015)
      In self-assembled nanoscale porphyrin triads based on Zn-octaethylporphyrin chemical dimer (donor, D) and dipyridyl substituted porphyrin free base (acceptor, A), fluorescence quenching of D (down to 1.7-10 ps) and A (by ~1.3-1.6 times) subunits is strongly dependent on the solvent polarity (toluene-acetone mixtures) and temperature (77-350 K). The obtained experimental findings ...
      2017-05-27

    • Formation Principles and Ligand Dynamics for Nanoassemblies of CdSe Quantum Dots and Functionalized Dye Molecules 

      Blaudeck, T.; Zenkevich, E.; Abdel-Mottaleb, M.; Szwaykowska, K.; Kowerko, D.; Cichos, F.; Borczyskowski, C. von (2012)
      Functional dye molecules, such as porphyrins, attached to CdSe quantum dots (QDs) through anchoring meso-pyridyl substituents, form quasi-stable nanoassemblies. This fact results in photoluminescence (PL) quenching of the QDs both due to Förster resonance energy transfer (FRET) and the formation of non-radiative surface states under conditions of quantum confinement (non-FRET). ...
      2017-05-27

    • Pathways for photoinduced electron transfer in meso-nitro-phenyl-octaethylporphyrins and their chemical dimers 

      Knyukshto, V.; Zenkevich, E.; Sagun, E.; Shulga, A.; Bachilo, S. (1999)
      The photophysical properties of meso-nitro-phenyl-octaethylporphyrins and their dimers with electron-accepting NO₂ groups in the para-, meta- and ortho-positions of the phenyl ring were studied. For the ortho-NO₂ case in deaerated toluene at 295 K, strong fluorescence quenching is caused by the intramolecular electron transfer from the porphyrin S₁ state in the absence of phenyl ...
      2017-05-25

    • Photonics and relaxation pathways for self-assembled nanostructures: multiporphyrin complexes and nanocomposites «semiconductor CdSe/ZnS quantum dot - organic dye» 

      Zenkevich, E.; Borczyskowski, C. von (BNTU, 2013)
      Zenkevich, E. Photonics and relaxation pathways for self-assembled nanostructures: multiporphyrin complexes and nanocomposites «semiconductor CdSe/ZnS quantum dot - organic dye» / E. Zenkevich, C. von Borczyskowski // Фотоника: наука в производство = Photonics: science into production : сборник материалов белорусско-китайского форума, 12-13 декабря 2013 г. – Minsk : BNTU, 2013. ...
      2018-05-28

    • Photophysical and photochemical properties of potential porphyrin and chlorin photosensitizers for PDT 

      Zenkevich, E.; Sagun, E.; Knyukshto, V.; Shulga, A.; Mironov, A.; Efremova, O.; Bonnett, R.; Pinda Songca, S.; Kassem, M. (1996)
      Structural and optical properties as well as photophysical and photochemical parameters (excited S₁ and T₁ state lifetimes at 77 K and in the presence of O₂ in solution at 293 K; efficiencies of singlet oxygen, ¹Δg, generation) are presented for porphyrins and chlorins with potential for the PDT of cancer: chlorin p₆ and its trimethyl ester, chlorin e₆ and its Na₃ and K₃ salts, ...
      2017-05-25

    • Temperature dependent steric hindrance effects in triplet state relaxation of meso-phenyl-substituted Pd-octaethylporphyrins 

      Gorski, A.; Knyukshto, V.; Zenkevich, E.; Starukhin, A.; Kijak, M.; Solarski, J.; Semeikin, A.; Lyubimova, T. (Elsevier, 2018)
      The analysis of spectral-kinetic results of transient absorption and phosphorescence experiments has been carried out in a wide temperature range (80-293K) for a series of Pd-octaethylporphyrin derivatives (PdOEP) with increasing number of bulky meso-phenyl substituents. In order to elucidate the influence of steric hindrance interactions, as well as porphyrin macrocycle non-planarity ...
      2018-09-14

    • Time resolved photoluminescence anisotropy of CdSe/ZnS nanoparticles in toluene at 300 K 

      Petrov, E. P.; Cichos, F.; Zenkevich, E.; Starukhin, D.; Borczyskowski, C. von (2005)
      For CdSe nanoparticles it has been theoretically and experimentally shown that at low temperatures the photoluminescence is circularly polarized in accordance with a wurtzite structure and the corresponding allowed optical transitions. In the present Letter, we report on related investigations on CdSe/ZnS colloids in toluene solution. From time resolved photoluminescence anisotropy ...
      2017-05-27

    • Unusual dynamic relaxation of triplet-excited meso-phenyl-substituted porphyrins and their chemical dimers at room temperatures 

      Knyukshto, V.; Zenkevich, E.; Sagun, E.; Shulga, A.; Bachilo, S. (1998)
      It has been found that for mono- and di-meso-phenyl-substituted octaethylporphyrin (OEPs), etioporphyrins, corresponding Zn complexes and OEP chemical dimers (with a meso-phenyl spacer) a drastic shortening of triplet lifetimes from a ms to μs timescale in deaerated toluene solutions at 295K takes place without any changes of the spectral-kinetic parameters of the S₀ and S₁ states. ...
      2017-05-25