Nikolai V Tkachenko

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A long-lived charge-separated (CS) state, which can be observed even at 900 mus after laser excitation, has been attained in the formanilide-anthraquinone dyad (FA-AQ) in dimethyl sulfoxide, whereas the CS lifetime is shortened significantly to 20 ps in the ferrocene-formanilide-anthraquinone triad (Fc-FA-AQ). Such a drastic decrease in the CS lifetime by(More)
Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red(More)
Exciton model for description of experimentally determined excitation energy transfer from carotenoids to chlorophylls in the LHC-II trimer of spinach is presented. Such an approach allows connecting the excitonic states to the spatial structure of the complex and hence descriptions of advancements of the initially created excitations in space and time.(More)
Eight previously inaccessible derivatives of 10-hydroxybenzo[h]quinoline were prepared via a straightforward strategy comprising formation of the benzo[h]quinoline skeleton followed by C-H acetoxylation at position 10. The occurrence of excited state intramolecular proton transfer (ESIPT) was detected in all cases since emission was observed only from the(More)
Fluorescent proteins are versatile tools for molecular imaging. In this study, we report a detailed analysis of the absorption and fluorescence properties of the chromophore-binding domain from Deinococcus radiodurans and its D207H mutant. Using single photon counting and transient absorption techniques, the average excited state lifetime of both studied(More)
Novel gold nanoparticles modified with a mixed self-assembled monolayer of porphyrin alkanethiol and short-chain alkanethiol were prepared (first step) to examine the size and shape effects of surface holes (host) on porphyrin-modified gold nanoparticles. The porphyrin-modified gold nanoparticles with a size of about 10 nm incorporated C60 molecules (guest)(More)
In this study we have explored the influence of mutual position of chlorin electron donor and fullerene C60 electron acceptor on photoinduced electron transfer. Two zinc-chlorin-aza-[18]crown-6 compounds and three pyrrolidino[60]fullerenes with alkyl aminium and varying coordinative moieties were synthesized and used for self-assembling of a set of(More)
N. V. Tkachenko,*,† A. Y. Tauber,†,‡ D. Grandell,§ P. H. Hynninen,‡ and H. Lemmetyinen† Institute of Materials Chemistry, Tampere UniVersity of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, Department of Chemistry, UniVersity of Helsinki, P.O. Box 55, FIN-00014 UniVersity of Helsinki, Finland, and Laboratory of Physical Chemistry, Helsinki(More)
J. Phys. Or es (SADs) in aqueous solutions was investigated in a wide range of pH by time-correlated single photon counting (lex1⁄4 350nm, tresp1⁄4 300ps) and fluorescence up-conversion (lex1⁄4 266nm, tresp1⁄4 300 fs) techniques. The acid–base equilibrium constants in the ground (pKa) and the excited states (pK a ), the fluorescence quantum yields as well(More)
We have systematically examined the substituent effects of meso-tetraphenylporphyrins on film structures and the photoelectrochemical properties of the composite clusters of free-base porphyrin and C(60) electrophoretically deposited on nanostructured SnO(2) electrodes. The photocurrent generation efficiency was found to correlate with the complexation(More)