Yuriy Kovtun - Academia.edu (original) (raw)
Papers by Yuriy Kovtun
The Journal of Physical Chemistry Letters, 2019
All the chemicals and solvents were purchased from Sigma Aldrich or TCI or Carlo Erba and used as... more All the chemicals and solvents were purchased from Sigma Aldrich or TCI or Carlo Erba and used as received without further purification. Dioleoylphosphatidylcholine (DOPC), and cholesterol were purchased from Sigma-Aldrich. Bovine brain sphingomyelin (SM) was from Avanti Polar Lipids (Alabaster, AL). Lipid tracker green was from Sigma Aldrich. ER-tracker green, Hoeschst-33342 were obtained from molecular probes. Analytical Methods 1 H and 13 C NMR spectra were recorded on Bruker Avance III 400/500 MHz spectrometer. Mass spectra were obtained using Agilent Q-TOF 6520 mass spectrometer. Absorption spectra were recorded on a Cary 4000 spectrophotometer (Varian). Fluorescence spectra were recorded on an Edinburg FS5 spectrofluorometer. All the spectra were corrected from the fluorescence of the corresponding blank (solvents or suspension of lipid vesicles without the probe) and for the wavelength-dependent response function of the detector. Absorption and emission measurements were systematically done at 20°C, unless indicated otherwise. Photostability experiment was carried out using Fluoromax-4 (Jobin Yvon, Horiba) spectrofluorometer. Relative fluorescence quantum yields were measured using DiD in methanol 1 (QY = 0.33) and Nile Red in methanol 2 (0.38) as standards.
Chemistry of Heterocyclic Compounds, Aug 16, 2023
Handbook of Porphyrin Science (Volumes 36 – 40), 2016
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Chemical Communications, 2016
Diferrocene-containing meso-cyano-BODIPY (4) was prepared and characterized by spectroscopy, X-ra... more Diferrocene-containing meso-cyano-BODIPY (4) was prepared and characterized by spectroscopy, X-ray crystallography, and DFT calculations.
ChemistrySelect, 2016
A preparative synthetic procedure to the meso-CN substituted BODIPY has been developed. This meth... more A preparative synthetic procedure to the meso-CN substituted BODIPY has been developed. This method is based on the addition of KCN to the borondipyrromethene moiety of the mesounsubstituted molecules in the presence of a crown ether with further oxidation with Pb(OAc) 4. The CN group at this position causes an essential bathochromic shift in absorption/emission and influence on other physicochemical properties of borondipyrromethenes over a wide range.
The Journal of Physical Chemistry Letters, 2012
The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is... more The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is grown by self-nucleation of a subsaturated hot solution of acetonitrile, and is composed of an asymmetrical donor-π-acceptor cyanine-like dye molecule. To our knowledge, this is the first report of the 2PA spectrum of single crystals made from a cyanine-like dye. The linear and nonlinear properties of the single crystalline material are investigated and compared with the molecular properties of a toluene solution of its monomeric form. The maximum polarization-dependent 2PA coefficient of the single crystal is 52 ± 9 cm/GW, which is more than twice as large as that for the inorganic semiconductor CdTe with a similar absorption edge. The optical properties, linear and nonlinear, are strongly dependent upon incident polarization due to anisotropic molecular packing. X-ray diffraction analysis shows π-stacking dimers formation in the crystal, similar to H-aggregates. Quantum chemical calculations demonstrate that this dimerization leads to the splitting of the energy bands and the appearance of new red-shifted 2PA bands when compared to the solution of monomers. This trend is opposite to the blue shift in the linear absorption spectra upon Haggregation.
Journal of Molecular Structure, 2013
A series of the merocyanines containing the aminocoumarin as an acceptor terminal group and typic... more A series of the merocyanines containing the aminocoumarin as an acceptor terminal group and typical donor residues with different length of the polymethine chain were studied in detail. Joint spectral and quantum-chemical analysis of their molecular geometries and electronic structures as well as origin of their lowest electron transitions have been performed. It was shown that the electronic and spectral properties of the neutral merocyanines are similar to the well-known cationic cyanine dyes, being determined by the same structure of the lowest electron transitions in molecule. The elongation of the chromophore chain of the studied merocyanines leads to the significant bathochromic shift of the long wavelength band in their absorption spectra, approximately to that in the symmetrical cyanines. The calculated third hyperpolarizability increases for the higher merocyanine vinylog due to the dependence of the energy of the excited state on the elongation of the conjugated chain. It was confirmed by nonlinear optical (NLO) study performed within the picosecond range pulsed laser excitation at 532 nm.
Bioorganic & Medicinal Chemistry Letters, 1999
Results of investigations of fluorescent properties of a 13-substituted carbocyanine and its comp... more Results of investigations of fluorescent properties of a 13-substituted carbocyanine and its complexes with nucleic acids in comparison with those for the unsubstituted dye are presented. Carbocyanine substituted in polymethine chain has shown promising properties for use as a fluorescent probe in homogeneous systems of nucleic acids detection.
![Research paper thumbnail of Flexible BODIPY Platform That Offers an Unexpected Regioselective Heterocyclization Reaction toward Preparation of 2-Pyridone[a]-Fused BODIPYs](https://attachments.academia-assets.com/103578910/thumbnails/1.jpg)
](The Journal of Organic Chemistry, 2019
We have explored the synthetic routes for regioselective formation of 2-pyridone[a]-and 2pyridone... more We have explored the synthetic routes for regioselective formation of 2-pyridone[a]-and 2pyridone[b]-fused BODIPYs using 1,3,5,7-tetramethyl-2,6-dicarbethoxy-BODIPY as the universal starting platform. While heterocyclization of the 3-(dimethylaminovinyl)-BODIPY and 3,5bis(dimethylaminovinyl)-BODIPY results in the formation of mono-2-pyridone-and bis-2pyridone[b]-fused BODIPYs, respectively, similar heterocyclization of the 1,3bis(dimethylaminovinyl)-BODIPY leads to the regioselective formation of the 2-pyridone[a]-fused BODIPY core, which is the first example of heterocycle[a]-fused BODIPYs. The regioselective formation of the 2-pyridone[a]-fused BODIPY was further confirmed by X-ray crystallography and explained on a basis of the DFT and TDDFT calculations that are suggestive of the energy-favorable out-of-plane rotation of the dimethylaminovinyl group located at first position, which accelerates reaction with n-butylamine. Trends in the UV-vis and fluorescence spectra of the BODIPYs 1-17 were discussed on the basis of DFT and TDDFT calculations.
Chemical communications (Cambridge, England), Jan 4, 2017
Ferrocene-BODIPYmerocyanine dyads 5 and 6 were prepared and characterized by a variety of spectro... more Ferrocene-BODIPYmerocyanine dyads 5 and 6 were prepared and characterized by a variety of spectroscopic, electrochemical, and theoretical methods. Experimental and theoretical data on these NIR absorbing compounds are suggestive of unusual susceptibility (for BODIPY chromophores) of the delocalized π-system in 5 and 6 to protonation and low-potential oxidation of their π-systems.
Linear and nonlinear absorption of a series of new donor-pi-acceptor polymethines with different ... more Linear and nonlinear absorption of a series of new donor-pi-acceptor polymethines with different lengths of conjugation are investigated and include quantum chemical analysis. Two-photon absorption cross-sections as large as 11,000 GM and solvatochromism are observed.
Dyes and Pigments, 2007
A series of symmetrically and non-symmetrically substituted dyes were prepared from 9-methylxanth... more A series of symmetrically and non-symmetrically substituted dyes were prepared from 9-methylxanthylium salts. The absorbance spectra of these compounds contain two bands e intense longwave and less intense shortwave. The nature of electronic transitions in polymethine dyes and dependence of the position and intensity of absorbance bands on the structure of end nucleus are discussed. The electron-donating properties of the synthesized xanthylium cores were studied.
ChemInform, 2010
ABSTRACT A reaction of 3,5-dimethylborondipyrromethene 3 with the DMF dimethylacetal gives rise t... more ABSTRACT A reaction of 3,5-dimethylborondipyrromethene 3 with the DMF dimethylacetal gives rise to monoenamine 4. The latter is converted to the corresponding aldehyde 5. A considerable contribution of the enolic form of the aldehyde allows preparing numerous 3-vinyl substituted borondipyrromethenes and some heterocyclic derivatives. A reaction of the aldehyde 5 with tertiary aliphatic amines and the consecutive Hofmann-type decomposition of the intermediary quaternary salt give rise to the corresponding dialkylaminovinyl derivatives.
Inorganic Chemistry, 2015
Stepwise modification of the methyl groups at the α positions of BODIPY 1 was used for preparatio... more Stepwise modification of the methyl groups at the α positions of BODIPY 1 was used for preparation of a series of mono- (2, 4, and 6) and diferrocene (3) substituted donor-acceptor dyads in which the organometallic substituents are fully conjugated with the BODIPY π system. All donor-acceptor complexes have strong absorption in the NIR region and quenched steady-state fluorescence, which can be partially restored upon oxidation of organometallic group(s). X-ray crystallography of complexes 2-4 and 6 confirms the nearly coplanar arrangement of the ferrocene groups and the BODIPY π system. Redox properties of the target systems were studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the first oxidation process in all dyads is ferrocene centered, while the separation between the first and the second ferrocene-centered oxidation potentials in diferrocenyl-containing dyad 3 is ∼150 mV. The density functional theory-polarized continuum model (DFT-PCM) and time-dependent (TD) DFT-PCM methods were used to investigate the electronic structure as well as explain the UV-vis and redox properties of organometallic compounds 2-4 and 6. TDDFT calculations allow for assignment of the charge-transfer and π → π* transitions in the target compounds. The excited state dynamics of the parent BODIPY 1 and dyads 2-4 and 6 were investigated using time-resolved transient spectroscopy. In all organometallic dyads 2-4 and 6 the initially excited state is rapidly quenched by electron transfer from the ferrocene ligand. The lifetime of the charge-separated state was found to be between 136 and 260 ps and demonstrates a systematic dependence on the electronic structure and geometry of BODIPYs 2-4 and 6.
The Journal of Physical Chemistry Letters, 2019
All the chemicals and solvents were purchased from Sigma Aldrich or TCI or Carlo Erba and used as... more All the chemicals and solvents were purchased from Sigma Aldrich or TCI or Carlo Erba and used as received without further purification. Dioleoylphosphatidylcholine (DOPC), and cholesterol were purchased from Sigma-Aldrich. Bovine brain sphingomyelin (SM) was from Avanti Polar Lipids (Alabaster, AL). Lipid tracker green was from Sigma Aldrich. ER-tracker green, Hoeschst-33342 were obtained from molecular probes. Analytical Methods 1 H and 13 C NMR spectra were recorded on Bruker Avance III 400/500 MHz spectrometer. Mass spectra were obtained using Agilent Q-TOF 6520 mass spectrometer. Absorption spectra were recorded on a Cary 4000 spectrophotometer (Varian). Fluorescence spectra were recorded on an Edinburg FS5 spectrofluorometer. All the spectra were corrected from the fluorescence of the corresponding blank (solvents or suspension of lipid vesicles without the probe) and for the wavelength-dependent response function of the detector. Absorption and emission measurements were systematically done at 20°C, unless indicated otherwise. Photostability experiment was carried out using Fluoromax-4 (Jobin Yvon, Horiba) spectrofluorometer. Relative fluorescence quantum yields were measured using DiD in methanol 1 (QY = 0.33) and Nile Red in methanol 2 (0.38) as standards.
Chemistry of Heterocyclic Compounds, Aug 16, 2023
Handbook of Porphyrin Science (Volumes 36 – 40), 2016
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Chemical Communications, 2016
Diferrocene-containing meso-cyano-BODIPY (4) was prepared and characterized by spectroscopy, X-ra... more Diferrocene-containing meso-cyano-BODIPY (4) was prepared and characterized by spectroscopy, X-ray crystallography, and DFT calculations.
ChemistrySelect, 2016
A preparative synthetic procedure to the meso-CN substituted BODIPY has been developed. This meth... more A preparative synthetic procedure to the meso-CN substituted BODIPY has been developed. This method is based on the addition of KCN to the borondipyrromethene moiety of the mesounsubstituted molecules in the presence of a crown ether with further oxidation with Pb(OAc) 4. The CN group at this position causes an essential bathochromic shift in absorption/emission and influence on other physicochemical properties of borondipyrromethenes over a wide range.
The Journal of Physical Chemistry Letters, 2012
The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is... more The two-photon absorption (2PA) spectrum of an organic single crystal is reported. The crystal is grown by self-nucleation of a subsaturated hot solution of acetonitrile, and is composed of an asymmetrical donor-π-acceptor cyanine-like dye molecule. To our knowledge, this is the first report of the 2PA spectrum of single crystals made from a cyanine-like dye. The linear and nonlinear properties of the single crystalline material are investigated and compared with the molecular properties of a toluene solution of its monomeric form. The maximum polarization-dependent 2PA coefficient of the single crystal is 52 ± 9 cm/GW, which is more than twice as large as that for the inorganic semiconductor CdTe with a similar absorption edge. The optical properties, linear and nonlinear, are strongly dependent upon incident polarization due to anisotropic molecular packing. X-ray diffraction analysis shows π-stacking dimers formation in the crystal, similar to H-aggregates. Quantum chemical calculations demonstrate that this dimerization leads to the splitting of the energy bands and the appearance of new red-shifted 2PA bands when compared to the solution of monomers. This trend is opposite to the blue shift in the linear absorption spectra upon Haggregation.
Journal of Molecular Structure, 2013
A series of the merocyanines containing the aminocoumarin as an acceptor terminal group and typic... more A series of the merocyanines containing the aminocoumarin as an acceptor terminal group and typical donor residues with different length of the polymethine chain were studied in detail. Joint spectral and quantum-chemical analysis of their molecular geometries and electronic structures as well as origin of their lowest electron transitions have been performed. It was shown that the electronic and spectral properties of the neutral merocyanines are similar to the well-known cationic cyanine dyes, being determined by the same structure of the lowest electron transitions in molecule. The elongation of the chromophore chain of the studied merocyanines leads to the significant bathochromic shift of the long wavelength band in their absorption spectra, approximately to that in the symmetrical cyanines. The calculated third hyperpolarizability increases for the higher merocyanine vinylog due to the dependence of the energy of the excited state on the elongation of the conjugated chain. It was confirmed by nonlinear optical (NLO) study performed within the picosecond range pulsed laser excitation at 532 nm.
Bioorganic & Medicinal Chemistry Letters, 1999
Results of investigations of fluorescent properties of a 13-substituted carbocyanine and its comp... more Results of investigations of fluorescent properties of a 13-substituted carbocyanine and its complexes with nucleic acids in comparison with those for the unsubstituted dye are presented. Carbocyanine substituted in polymethine chain has shown promising properties for use as a fluorescent probe in homogeneous systems of nucleic acids detection.
The Journal of Organic Chemistry, 2019
We have explored the synthetic routes for regioselective formation of 2-pyridone[a]-and 2pyridone... more We have explored the synthetic routes for regioselective formation of 2-pyridone[a]-and 2pyridone[b]-fused BODIPYs using 1,3,5,7-tetramethyl-2,6-dicarbethoxy-BODIPY as the universal starting platform. While heterocyclization of the 3-(dimethylaminovinyl)-BODIPY and 3,5bis(dimethylaminovinyl)-BODIPY results in the formation of mono-2-pyridone-and bis-2pyridone[b]-fused BODIPYs, respectively, similar heterocyclization of the 1,3bis(dimethylaminovinyl)-BODIPY leads to the regioselective formation of the 2-pyridone[a]-fused BODIPY core, which is the first example of heterocycle[a]-fused BODIPYs. The regioselective formation of the 2-pyridone[a]-fused BODIPY was further confirmed by X-ray crystallography and explained on a basis of the DFT and TDDFT calculations that are suggestive of the energy-favorable out-of-plane rotation of the dimethylaminovinyl group located at first position, which accelerates reaction with n-butylamine. Trends in the UV-vis and fluorescence spectra of the BODIPYs 1-17 were discussed on the basis of DFT and TDDFT calculations.
Chemical communications (Cambridge, England), Jan 4, 2017
Ferrocene-BODIPYmerocyanine dyads 5 and 6 were prepared and characterized by a variety of spectro... more Ferrocene-BODIPYmerocyanine dyads 5 and 6 were prepared and characterized by a variety of spectroscopic, electrochemical, and theoretical methods. Experimental and theoretical data on these NIR absorbing compounds are suggestive of unusual susceptibility (for BODIPY chromophores) of the delocalized π-system in 5 and 6 to protonation and low-potential oxidation of their π-systems.
Linear and nonlinear absorption of a series of new donor-pi-acceptor polymethines with different ... more Linear and nonlinear absorption of a series of new donor-pi-acceptor polymethines with different lengths of conjugation are investigated and include quantum chemical analysis. Two-photon absorption cross-sections as large as 11,000 GM and solvatochromism are observed.
Dyes and Pigments, 2007
A series of symmetrically and non-symmetrically substituted dyes were prepared from 9-methylxanth... more A series of symmetrically and non-symmetrically substituted dyes were prepared from 9-methylxanthylium salts. The absorbance spectra of these compounds contain two bands e intense longwave and less intense shortwave. The nature of electronic transitions in polymethine dyes and dependence of the position and intensity of absorbance bands on the structure of end nucleus are discussed. The electron-donating properties of the synthesized xanthylium cores were studied.
ChemInform, 2010
ABSTRACT A reaction of 3,5-dimethylborondipyrromethene 3 with the DMF dimethylacetal gives rise t... more ABSTRACT A reaction of 3,5-dimethylborondipyrromethene 3 with the DMF dimethylacetal gives rise to monoenamine 4. The latter is converted to the corresponding aldehyde 5. A considerable contribution of the enolic form of the aldehyde allows preparing numerous 3-vinyl substituted borondipyrromethenes and some heterocyclic derivatives. A reaction of the aldehyde 5 with tertiary aliphatic amines and the consecutive Hofmann-type decomposition of the intermediary quaternary salt give rise to the corresponding dialkylaminovinyl derivatives.
Inorganic Chemistry, 2015
Stepwise modification of the methyl groups at the α positions of BODIPY 1 was used for preparatio... more Stepwise modification of the methyl groups at the α positions of BODIPY 1 was used for preparation of a series of mono- (2, 4, and 6) and diferrocene (3) substituted donor-acceptor dyads in which the organometallic substituents are fully conjugated with the BODIPY π system. All donor-acceptor complexes have strong absorption in the NIR region and quenched steady-state fluorescence, which can be partially restored upon oxidation of organometallic group(s). X-ray crystallography of complexes 2-4 and 6 confirms the nearly coplanar arrangement of the ferrocene groups and the BODIPY π system. Redox properties of the target systems were studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the first oxidation process in all dyads is ferrocene centered, while the separation between the first and the second ferrocene-centered oxidation potentials in diferrocenyl-containing dyad 3 is ∼150 mV. The density functional theory-polarized continuum model (DFT-PCM) and time-dependent (TD) DFT-PCM methods were used to investigate the electronic structure as well as explain the UV-vis and redox properties of organometallic compounds 2-4 and 6. TDDFT calculations allow for assignment of the charge-transfer and π → π* transitions in the target compounds. The excited state dynamics of the parent BODIPY 1 and dyads 2-4 and 6 were investigated using time-resolved transient spectroscopy. In all organometallic dyads 2-4 and 6 the initially excited state is rapidly quenched by electron transfer from the ferrocene ligand. The lifetime of the charge-separated state was found to be between 136 and 260 ps and demonstrates a systematic dependence on the electronic structure and geometry of BODIPYs 2-4 and 6.