Author
Alexander A Karasyov
Bio: Alexander A Karasyov is an academic researcher. The author has contributed to research in topics: Electron transfer & Electron donor. The author has an hindex of 1, co-authored 1 publications receiving 16 citations.
Papers
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TL;DR: Bichromophoric 3-diethylamino-7-phenyl-7H-benzo-[4,5]-imidazo-[1,2-c]-chromeno-[3,2e]-pyrimidines were synthesized by the condensation of 7-diagramnino-3-(2-benzimidazolyl)-iminochromene with several aromatic aldehydes as discussed by the authors.
Abstract: Bichromophoric 3-diethylamino-7-phenyl-7H-benzo-[4,5]-imidazo-[1,2-c]-chromeno-[3,2-e]-pyrimidines were synthesized by the condensation of 7-diethylamino-3-(2-benzimidazolyl)-iminochromene with several aromatic aldehydes. Fluorescence properties of these compounds were studied in solvents of various polarity and acidity. The excited state intramolecular electron transfer was shown as the reason for the fluorescence quenching of the studied dyes with electron donor substituents in the minor chromophoric moiety. Prospects for the usage of these compounds as fluorescence probes sensitive to polarity and pH of their surrounding were elucidated.
16 citations
Cited by
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TL;DR: A new family of coumarin-based pH indicators was synthesized, sensitive to pH in either weakly acidic or weakly basic solution, which possess moderate to high brightness, excellent photostability and compatibility with light-emitting diodes.
Abstract: A new family of coumarin-based pH indicators was synthesized. They are sensitive to pH in either weakly acidic or weakly basic solution. The indicators possess moderate to high brightness, excellent photostability and compatibility with light-emitting diodes. The indicators were covalently immobilized on the surface of amino-modified polymer microbeads which in turn were incorporated into a hydrogel matrix to obtain novel pH-sensitive materials. When a mixture of two different microbeads is used, the membranes are capable of optical pH sensing over a very wide range comparable to the dynamic range of the glass electrode (pH 1-11).
97 citations
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TL;DR: In this paper, a dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) with carboxyl and hydroxyl anchoring groups was designed and synthesized for the application of DSSC.
48 citations
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TL;DR: Turki et al. as discussed by the authors showed that iminocoumarin derivatives can advantageously replace coumarins in this type of solvents, and confirms that substitution on the imino group is a convenient way to obtain good fluorescent probes designed for various purposes.
42 citations
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TL;DR: The results show that the absorption maxima and fluorescence emission maxima calculated using the Time-Dependent Density Functional Theory is in good agreement with the available experimental results.
Abstract: The electronic structures and photophysical properties of rigid coumarin dyes have been studied by using quantum chemical methods. The ground-state geometries of these dyes were optimized using the Density Functional Theory (DFT) methods. The lowest singlet excited state was optimized using Time -Dependent Density Functional Theory [TD-B3LYP/6-31G(d)]. On the basis of ground- and excited-state geometries, the absorption and emission spectra have been calculated using the DFT and TD-DFT method. All the calculations were carried out in gas phase and in acetonitrile medium. The results show that the absorption maxima and fluorescence emission maxima calculated using the Time-Dependent Density Functional Theory is in good agreement with the available experimental results. To understand the Non- Linear Optical properties of coumarin dyes we computed dipole moment (μ), electronic polarizability (α), mean first hyperpolarizability (βo) and second hyperpolarizability (γ) using B3LYP density functional theory method in conjunction with 6-31G(d) basis set.
32 citations
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TL;DR: A series of novel long-wavelength, fluorescent, novel iminocoumarin derived dyes were synthesized by extending the π-conjugation and spatial location of the benzimidazolic and iminochromene rings in a planar structure.
28 citations