42 results on '"Elena E. Zvereva"'
Search Results
2. Fast Quantum Chemical Simulations of Infrared Spectra of Organic Compounds with the B97-3c Composite Method
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Sergey A. Katsyuba, Stefan Grimme, and Elena E. Zvereva
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Quantum chemical ,010304 chemical physics ,Infrared ,Chemistry ,Quantum chemical computations ,Composite number ,Infrared spectroscopy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,010402 general chemistry ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Organic molecules ,0103 physical sciences ,Astrophysics::Earth and Planetary Astrophysics ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Astrophysics::Galaxy Astrophysics ,Vibrational spectra - Abstract
The ability of the quantum chemical computations to reproduce spectral positions and relative intensities of infrared (IR) bands for experimental vibrational spectra of organic molecules is assessed. The efficient B97-3c density functional approximation, routinely applicable to hundreds of atoms on a single processor, has been applied for the simulation of IR spectra for species containing up to 216 atoms. The results demonstrate that B97-3c, being much faster than the well-recognized hybrid functional B3LYP, offers similarly good quantitative performance in comparison to experimental data for relative IR intensities and fundamental frequencies (ν ≤ 2200 cm
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- 2019
3. Leaching from Palladium Nanoparticles in an Ionic Liquid Leads to the Formation of Ionic Monometallic Species
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Alexey Aleksandrov, Sergey A. Katsyuba, Elena E. Zvereva, and Paul J. Dyson
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010405 organic chemistry ,Inorganic chemistry ,Ionic bonding ,chemistry.chemical_element ,Palladium nanoparticles ,010402 general chemistry ,01 natural sciences ,Oxidative addition ,0104 chemical sciences ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,Pd nanoparticles ,Ionic liquid ,General Materials Science ,Leaching (metallurgy) ,Physical and Theoretical Chemistry ,Palladium - Abstract
Molecular dynamics simulations and DFT calculations suggest that leaching of palladium species from Pd nanoparticles in ionic liquids does not involve "naked" Pd(0) atoms or neutral ArPdX species formed by oxidative addition of arylhalides. Instead, the ionic liquid contributes largely to leaching of ionic PdX- or PdAr+ species.
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- 2017
4. The role of London dispersion interactions in strong and moderate intermolecular hydrogen bonds in the crystal and in the gas phase
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Elena E. Zvereva, Sergey A. Katsyuba, J. Gerit Brandenburg, and Mikhail V. Vener
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Electron density ,010304 chemical physics ,Chemistry ,Hydrogen bond ,Infrared ,Intermolecular force ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,London dispersion force ,0104 chemical sciences ,Crystal ,Crystallography ,Computational chemistry ,0103 physical sciences ,Density functional theory ,Physical and Theoretical Chemistry ,Dispersion (chemistry) - Abstract
Two variants of density functional theory computations have been applied to characterization of hydrogen bonds of the 1-(2-hydroxylethyl)-3-methylimidazolium acetate ([C2OHmim][OAc]), i.e. with and without inclusion of dispersion interactions. A comparison of the results demonstrates that London dispersion interactions have very little impact on the energetical, geometrical, infrared spectroscopic and electron density parameters of charge-assisted intermolecular hydrogen bonds functioning both in the crystal of the [C2OHmim][OAc] and in the isolated [C2OHmim]+ [OAc]− ion pairs.
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- 2017
5. Resolving the Singlet Excited State Manifold of Benzophenone by First-Principles Simulations and Ultrafast Spectroscopy
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Javier Segarra-Martí, Antonio Monari, Xavier Assfeld, Jérémie Léonard, Marco Garavelli, Ivan Rivalta, Johanna Brazard, Marco Marazzi, Elise Dumont, Stefan Haacke, Elena E. Zvereva, Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), A.E. Arbuzov Institute of Organic and Physical Chemistry (IOPC), Kazan Scientific Centre of the Russian Academy of Sciences, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Chimica 'G. Ciamician', Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and Segarra-Marti Javier, Zvereva Elena, Marazzi Marco, Brazard Johanna, Dumont Elise, Assfeld Xavier, Haacke Stefan, Garavelli Marco, Monari Antonio, Leonard Jeremie, Rivalta Ivan
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0307 Theoretical And Computational Chemistry ,DNA-PHOTOSENSITIZATION ,2-DIMENSIONAL ELECTRONIC SPECTROSCOPY ,Physics, Atomic, Molecular & Chemical ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Molecular physics ,ABSORPTION-SPECTRA ,DENSITY-FUNCTIONAL THEORY ,PHOTOEXCITED BENZOPHENONE ,chemistry.chemical_compound ,0103 physical sciences ,Ultrafast laser spectroscopy ,medicine ,Benzophenone ,PRIMARY PHOTOISOMERIZATION EVENT ,WAVE-FUNCTIONS ,Singlet state ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Spectroscopy ,ComputingMilieux_MISCELLANEOUS ,Physics ,Science & Technology ,Chemical Physics ,010304 chemical physics ,Chemistry, Physical ,Computer Science Applications1707 Computer Vision and Pattern Recognition ,0104 chemical sciences ,Computer Science Applications ,MOLECULAR-ORBITAL METHODS ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Chemistry ,chemistry ,Excited state ,Physical Sciences ,ANO BASIS-SETS ,Density functional theory ,Ground state ,Ultraviolet ,OPTICAL SPECTROSCOPY - Abstract
Accurate characterization of the high-lying excited state manifolds of organic molecules is of fundamental importance for the interpretation of the rich response detected in time-resolved nonlinear electronic spectroscopies. Here, we have characterized the singlet excited state manifold of benzophenone (BP), a versatile organic photoinitiator and a well-known DNA photosensitizer. Benchmarks of various multiconfigurational/multireference (RASSCF/PT2) and time-dependent density functional theory (TD-DFT) approaches allowed assignments of experimental linear absorption signals of BP in the ultraviolet (UV) region, with unprecedented characterization of ground state absorptions in the far UV. Experimental transient absorption spectra obtained by UV-vis pump-probe spectroscopy at very short time delays are shown to be directly comparable to theoretical estimates of excited state absorptions (from the low-lying nOπ∗ and π π∗ singlet states) in the Franck-Condon region. Multireference computations provided reliable interpretation of the PP spectra, with TD-DFT results yielding a fair agreement as long as electronic transitions featuring double excitations contributions are not involved. These results lay the groundwork for further computational studies and interpretation of experimental nonlinear electronic spectra of benzophenone in more complex systems, such as BP/DNA adducts.
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- 2018
6. Conjugation effects and optical spectra of 1,2-diphosphole cycloadducts
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Sergey A. Katsyuba, Oleg G. Sinyashin, Elena E. Zvereva, Almaz Zagidullin, Vasily A. Miluykov, and Timur I. Burganov
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chemistry.chemical_classification ,Double bond ,010405 organic chemistry ,General Chemistry ,Conjugated system ,Chromophore ,010402 general chemistry ,Ring (chemistry) ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry ,Absorption band ,Steric factor ,Molecule ,Hypsochromic shift - Abstract
Quantum chemical calculations and a comparative analysis of Raman spectra of 3,4,5-triphenyl-1-propyl-1,2-diphosphole (1), anti-endo-4,7,8,9-tetraphenyl-10-propyl-4-aza-1,10-diphosphatricyclo[5.2.1.02,6]deca-8-ene-3,5-dione (2) and 1,2,6,7-tetraphospha-3,4,5,8,9,10-hexaphenyltricyclo[5.3.0.02,6]deca-3,9-diene (3) made it possible to explain considerable differences in the UV absorption spectra of these compounds. The phenyl groups in the compounds under study, despite the steric factor, are conjugated with the π-system of the heterocycle, which in the case of diphosphole 1 comprises π-electrons of the C=C and P=C bonds. The disturbance of this diene system in molecules 2 and 3 decreases the effective length of conjugation of phenyl groups with the attached double bonds of the phosphorus-containing ring, that results in the hypsochromic shift of the π—π* electron transition bands in the UV absorption spectrum from 411 to 312 nm. The formation in molecule 3 of the four-membered ring P4, which is a new chromophore group, leads to the appearance of an additional absorption band with the maximum at ∼342 nm.
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- 2015
7. Conjugation in and Optical Properties of 1-R-1,2-Diphospholes and 1-R-Phospholes
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Sergey A. Katsyuba, Elena E. Zvereva, Peter Lönnecke, Almaz Zagidullin, Oleg G. Sinyashin, Vasily A. Miluykov, Timur I. Burganov, and Evamarie Hey-Hawkins
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Cyclopentadiene ,Diene ,Absorption spectroscopy ,Chemistry ,Aromaticity ,Ring (chemistry) ,Photochemistry ,Medicinal chemistry ,symbols.namesake ,chemistry.chemical_compound ,Bathochromic shift ,symbols ,Hypsochromic shift ,Physical and Theoretical Chemistry ,Raman spectroscopy - Abstract
The strength of conjugation between the diene moieties of 1-R-1,2-diphospholes and 1-R-phospholes and exocyclic phenyl groups of these P-heteroles has been quantitatively characterized by the use of Raman activities of the bands of the phenyl substituents. It is shown that conjugation in both types of phospholes is very similar to the conjugation of phenyl groups with the diene system of cyclopentadiene. Introduction of substituents (-OMe, -C(═O)H, -NO2, -NMe2, and -CH═CH2) in the para-position of the phenyl groups of 1-R-1,2-diphospholes extends π-delocalization of exocyclic groups into the electronic system of the 1,2-diphosphole ring, producing bathochromic shifts of the absorption bands up to 63 nm. In contrast, hypsochromic shifts up to 40 nm can be achieved by introduction of SnMe3 or SiMe3 groups at the phosphorus(III) atom of the 1,2-diphosphole and concomitant increase of aromaticity of the P-heterole. Conjugation shifts the "centre of gravity" of the whole electronic absorption spectrum, whereas positions of separate absorption bands are not simply dependent on conjugation lengths.
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- 2014
8. Synthesis and Some Properties of Transition Metal Complexes Based on the Octathiophophetane Ammonium Salts
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Liliya V. Frolova, Nadezhda V. Yanberdina, Robert W. Lebrun, Elvira S. Batyeva, Oleg G. Sinyashin, Elena E. Zvereva, Snezna Rogelj, Jolene D. Lujan, L. I. Kursheva, Mary R. Reisenauer, Aleksandеr E. Vandyukov, and Leslie Edwards
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chemistry.chemical_classification ,chemistry.chemical_compound ,Metal halides ,chemistry ,Transition metal ,Polymer chemistry ,Organic chemistry ,Salt (chemistry) ,Ammonium ,General Chemistry ,Piperidine ,Triethylamine - Abstract
Cyclic octathiotetraphosphetanes, and speciafically their ammonium salt, represent novel polyfunctional heterocyclic ligands that are valuable in the development of organometallic and coordinated chemistry. Coordination features of octathiotetraphosphetane ammonium salts with structures differing only by piperidine and triethylamine substituents in the reaction with transition d-metals of I and VIII groups [Cu(I), Ag(I), Fe(II), Co(II)] are described. Some similarities and differences in the behavior of piperidinium and triethylammonium salts of the octathiotetraphosphetane upon complexation with metal halides are discussed.
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- 2014
9. Solvation and stabilization of palladium nanoparticles in phosphonium-based ionic liquids: a combined infrared spectroscopic and density functional theory study
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Daria Arkhipova, Sergey A. Katsyuba, Oleg G. Sinyashin, Stefan Grimme, V. V. Ermolaev, Alexey Aleksandrov, Vasili Miluykov, Ning Yan, Elena E. Zvereva, A.E. Arbuzov Institute of Organic and Physical Chemistry (IOPC), Kazan Scientific Centre of the Russian Academy of Sciences, Westfälische Wilhelms-Universität Münster (WWU), Laboratoire de Biochimie de l'Ecole polytechnique (BIOC), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
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Models, Molecular ,Spectrophotometry, Infrared ,Phosphines ,Binding energy ,Inorganic chemistry ,Ionic Liquids ,Metal Nanoparticles ,General Physics and Astronomy ,chemistry.chemical_element ,Infrared spectroscopy ,chemistry.chemical_compound ,Cluster (physics) ,Computer Simulation ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,Phosphonium ,Physical and Theoretical Chemistry ,Ions ,Solvation ,Models, Chemical ,chemistry ,Ionic liquid ,Solvents ,Quantum Theory ,Physical chemistry ,Density functional theory ,Palladium - Abstract
Analysis of infrared spectra of palladium nanoparticles (NPs) immersed in the tri-tert-butyl-R-phosphonium-based ionic liquids (ILs) demonstrates that both cations and anions of the ILs interact with the NPs. According to quantum-chemical simulations of these interactions, the binding energy of anions to the Pd-6 cluster, taken as a minimal-size model of the NPs, increases from similar to 6 to similar to 27 kcal mol(-1) in the order [PF6](-) approximate to [BF4](-) < [Tf2N](-) < [OTf](-) < [Br](-) << [TFA](-). In contrast, the binding energy for all types of the [(Bu3PR)-P-t](+) cations slightly varies at about similar to 22 kcal mol(-1) only moderately depending on the choice of the R moiety (n-pentyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxy-2-oxoethyl). As a result, the energies of interaction between a Pd-6 cluster and various ion pairs, formed by the abovementioned counter-ions, follow the order found for the anions and vary from similar to 24 to similar to 47 kcal mol(-1). These values are smaller than the energy of addition of a Pd atom to a Pd-n cluster (similar to 58 kcal mol(-1)), which suggests kinetic stabilization of the NPs in phosphonium-based ILs rather than thermodynamic stabilization. The results are qualitatively similar to the trends found earlier for interactions between palladium clusters and components of imidazolium-based ILs, in spite of much larger contributions of the London dispersion forces to the binding of the [(Bu3PR)-P-t](+) cations to the cluster (up to 80%) relative to the case of 1-R-3-methylimidazolium cations (up to 40%).
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- 2014
10. Is There a Simple Way to Reliable Simulations of Infrared Spectra of Organic Compounds?
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Sergey A. Katsyuba, Timur I. Burganov, and Elena E. Zvereva
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Vibration ,Basis (linear algebra) ,Infrared ,Chemistry ,Computation ,Analytical chemistry ,Molecule ,Infrared spectroscopy ,Physical and Theoretical Chemistry ,Molecular physics ,Basis set ,Spectral line - Abstract
To assess the ability of the quantum-chemical computations to reproduce the experimental relative intensities in the infrared (IR) spectra of both the gas- and condensed-phase systems, the hybrid DFT functional B3LYP has been applied to simulation of IR spectra for species containing from three to twelve first- or second-row atoms, both in the gas phase and in CCl4 solutions. The results demonstrate that B3LYP, combined with the highly compact double-ζ basis set 6-31+G* and "scaled quantum mechanics" techniques, offers excellent quantitative performance in the calculations of relative IR intensities and frequencies (ν ≤ 2200 cm(-1)) for the bands of vibrations of medium-size isolated molecules, whereas it produces unsatisfactory results for the solutions of the same species. Neither larger basis sets nor implicit treatment of the media effects improve the agreement of the simulated spectra with the condensed-phase experiment. At the same time, some preliminary results suggest that explicit modeling of media effects could offer better quality of the IR spectral simulations for the condensed-phase systems.
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- 2013
11. A cobalt(ii) acetate complex with 1-(3,5-di-tert-butyl-4-hydroxybenzyl)-1H-indole-2,3-dione 3-thiosemicarbazone: synthesis and structure
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N. A. Mukmeneva, Aidar T. Gubaidullin, Sergey A. Katsyuba, G. N. Nugumanova, R. G. Tagasheva, S. V. Bukharov, Elena E. Zvereva, and A.E. Vandyukov
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Indole test ,Tert butyl ,Hydrogen bond ,Stereochemistry ,Infrared spectroscopy ,General Chemistry ,Medicinal chemistry ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,X-ray crystallography ,symbols ,Cobalt(II) acetate ,Raman spectroscopy ,Semicarbazone - Abstract
A complex of CoII with 1-(3,5-di-tert-butyl-4-hydroxybenzyl)-1H-indole-2,3-dione 3-thiosemicarbazone was obtained and identified by X-ray diffraction, IR and Raman spectroscopy, and quantum chemical calculations. The characteristic C=S frequencies in the IR spectra of the thiosemicarbazones were refined. The data obtained from different methods were compared, which allows more accurate spectroscopic studies of related structures.
- Published
- 2012
12. IR and Raman spectra, hydrogen bonds, and conformations of N-(2-hydroxyethyl)-4,6-dimethyl-2-oxo-1,2-dihydropyrimidine (drug Xymedone)
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Sergey A. Katsyuba, I. I. Vandyukova, Ayrat R. Khamatgalimov, Elena E. Zvereva, A.E. Vandyukov, and Valeri I. Kovalenko
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Chemistry ,Hydrogen bond ,Intermolecular force ,Infrared spectroscopy ,General Chemistry ,Photochemistry ,Solvent ,Crystallography ,symbols.namesake ,Intramolecular force ,symbols ,Raman spectroscopy ,Dissolution ,Conformational isomerism - Abstract
Hydrogen bonds and structure of drug Xymedone in different phase and aggregate states were studied using IR and Raman spectroscopy, IR microscopy, quantum chemical calculations (B3LYP/6-31G*), X-ray powder diffractometry, and DSC and TGA methods. It was found that the synthesized specimen of Xymedone powder is a mixture of two gauche-conformers. First one is bound by intermolecular hydrogen bonds and second one is stabilized by an intramolecular hydrogen bond. Upon the dissolution of Xymedone the conformational equilibrium shifted in favor of conformers of the first or second type depending on the solvent nature.
- Published
- 2012
13. Synthesis, IR/Raman, and quantum-chemical structural analysis of new octathiotetraphosphetane ammonium salts
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Elena E. Zvereva, Valeryi I. Kovalenko, Elena V. Platova, Aleksander. E. Vandyukov, Sergey A. Katsyuba, L. I. Kursheva, E. K. Badeeva, Oleg G. Sinyashin, and Elvira S. Batyeva
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chemistry.chemical_classification ,Heteroatom ,Inorganic chemistry ,Salt (chemistry) ,chemistry.chemical_element ,General Chemistry ,Chloride ,Sulfur ,Pyrrolidine ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Morpholine ,medicine ,symbols ,Ammonium ,Raman spectroscopy ,medicine.drug - Abstract
New octathiotetraphosphetane ammonium salts are obtained based on the reaction of white phosphorus (P4) and elemental sulfur with aliphatic mercaptans in the presence of amines (morpholine, methylmorpholine, pyrrolidine, and N,N-dimethylbenzylamine). Both the salts and novel Cu(I) chloride complex with the pyperidinium salt of octathiotetraphosphetane are characterized by IR/Raman spectroscopy in combination with DFT methods. The comparative spectral analysis reveals clear spectral features, characteristic for a P4S84− anion, which are present in IR and Raman spectra of all the compounds obtained. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:24–30, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20651
- Published
- 2010
14. IR and NMR spectra, intramolecular hydrogen bonding and conformations of para-tert-butyl-aminothiacalix[4]arene in solid state and chloroform solution
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Alexander I. Konovalov, Igor S. Antipin, Svetlana E. Solovieva, Valery I. Kovalenko, Sergey A. Katsyuba, Elena E. Zvereva, Alla V. Chernova, and A.E. Vandyukov
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Models, Molecular ,Magnetic Resonance Spectroscopy ,Spectrophotometry, Infrared ,Band gap ,Molecular Conformation ,Analytical Chemistry ,chemistry.chemical_compound ,Computational chemistry ,Spectroscopy, Fourier Transform Infrared ,Instrumentation ,Dissolution ,Conformational isomerism ,Spectroscopy ,Chloroform ,Molecular Structure ,Hydrogen bond ,Intermolecular force ,Hydrogen Bonding ,Atomic and Molecular Physics, and Optics ,Solutions ,NMR spectra database ,Crystallography ,Models, Chemical ,chemistry ,Intramolecular force ,Quantum Theory ,Calixarenes - Abstract
It is demonstrated that dissolution of aminothiacalix[4]arene in chloroform results in transformation of 1,3-alternate conformation, adopted in single-crystal and bulk polycrystalline solids, to the pinched-cone form. This conformer is stabilised by the intramolecular hydrogen bonds of two distal amino-groups acting as H-donors with another two amino moieties that appear as H-acceptors. The H-bonds cause quite small (ca. 10-20 cm(-1)) red shift of the IR bands of the NH(2) stretching vibrations, which suggests rather weak NHcdots, three dots, centeredN hydrogen bonding. This latter is sufficient to stabilize the pinched-cone conformation in the chloroform solution, but the energy gap between the pinched-cone and other conformations is small, and solid-state intermolecular forces easily overcome it, leading to realisation of the 1,3-alternate conformer. The comparison of the DFT computed and experimental vibrational and NMR spectra demonstrates good quality of present quantum-chemical computations, allows complete interpretation of the spectra and reveals simple IR and NMR spectroscopic markers of the conformers of aminothiacalix[4]arenes.
- Published
- 2010
15. Quantum chemical investigation of the structures of ionic liquids based on 1-ethyl-3-methylimidazolium halides: IR spectra and hydrogen bonds
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Sergey A. Katsyuba and Elena E. Zvereva
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Quantum chemical ,chemistry.chemical_compound ,Chemistry ,Computational chemistry ,Hydrogen bond ,Ionic liquid ,Infrared spectroscopy ,Physical chemistry ,Molecule ,Halide ,Density functional theory ,General Chemistry ,Vibrational spectra - Abstract
Hydrogen bonds, structures, and vibrational spectra of 1-ethyl-3-methylimidazolium halides ([emim][Hal]) were analyzed in the framework of the Hartree—Fock method (HF/6-31G*, 6-31+G*) and the density functional theory (B3LYP/6-31G*, 6-31+G*, 6-31G**, 6-31+G**). It is shown that the use of the approximation of an isolated ion pair cation—anion is incorrect for the ionic liquids studied. It is more reasonable to consider “clusters” including at least two-three cations and being more appropriate models for the study of hydrogen bonds and vibrational spectra of ionic liquids of this type.
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- 2009
16. Molecular structure and properties of oxime phosphonates: an FTIR and quantum chemical study
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R. S. Garaev, A. O. Vizel, Elena E. Zvereva, L. I. Shchukina, I. I. Vandyukova, and R. R. Shagidullin
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Quantum chemical ,chemistry.chemical_compound ,chemistry ,Hydrogen bond ,Quantum chemical computations ,Molecule ,Organic chemistry ,General Chemistry ,Fourier transform infrared spectroscopy ,Oxime - Abstract
Peculiar features of the molecular structure, isomeric composition, and hydrogen bonding in new, potentially physiologically active γ-oxime alkylphosphonates were established.
- Published
- 2007
17. Coordination Features of P,S-Ligands Based on the Phosphorus Derivatives with I and Viii Group Metals
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Elena E. Zvereva, L. I. Kursheva, Elvira S. Batyeva, Elena V. Platova, E. K. Badeeva, and Oleg G. Sinyashin
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Stereochemistry ,Phosphorus ,Organic Chemistry ,chemistry.chemical_element ,Halide ,Biochemistry ,Medicinal chemistry ,Single Crystal Diffraction ,Inorganic Chemistry ,symbols.namesake ,chemistry ,Group (periodic table) ,symbols ,X ray analysis ,Raman spectroscopy - Abstract
Continuing the study of the coordination ability of P,S-ligands, we have investigated the behavior of some P(IV)-S-phosphorus derivatives, in particular, trialkyltetrathiophosphates (R = i-Pr, Bu) and piperidinium and triethylammonium salts of octathiotetraphosphetane in reaction with Cu(I), Ag(I), Co(II), and Fe(II) halides. The series of complexes were obtained and characterized by the X-ray single crystal diffraction and IR/Raman spectroscopy.
- Published
- 2013
18. Application of time-dependent density functional theory and optical spectroscopy toward the rational design of novel 3,4,5-triaryl-1-R-1,2-diphospholes
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Sergey A. Katsyuba, V. A. Milyukov, Stefan Grimme, Elena E. Zvereva, Almaz Zagidullin, Timur I. Burganov, and Oleg G. Sinyashin
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Crystallography ,Absorption spectroscopy ,Computational chemistry ,Chemistry ,Molecular orbital ,Density functional theory ,Time-dependent density functional theory ,Physical and Theoretical Chemistry ,Absorption (electromagnetic radiation) ,Spectroscopy ,HOMO/LUMO ,Basis set - Abstract
Twenty 3,4,5-triaryl-1-R-1,2-diphospholes were studied within the framework of density functional theory (DFT) and experimentally by UV/vis spectroscopy to check their suitability for opto-electronic applications. Time-dependent DFT (TD-DFT) calculations employing the PBE0 hybrid density functional combined with moderately sized def-TZVP basis set were shown to excellently reproduce the experimental absorption spectra of various 1,2-diphospholes. Frontier molecular orbital analysis reveals that HOMO and LUMO are mainly localized on the diphosphole ring and, to some extent, on the aryl moieties. The HOMO-LUMO energy gap can be easily tuned by variation of substituents introduced in para-positions of the aryl moieties and, to a lesser extent, by modification of the R group at phosphorus atom. As a result, both position and intensity of the absorption bands with highest wavelength are strongly influenced by the above structural changes. The UV-spectra simulations reveal that the introduction of donor groups like para-OMe, para-NMe2, and para-N(H)Ph, which are in n-π conjugation with the aryl moieties, should result in absorption of visible light by the corresponding 1,2-diphospholes, thus making them promising candidates for new functional materials.
- Published
- 2013
19. Rationalization of solvation and stabilization of palladium nanoparticles in imidazolium-based ionic liquids by DFT and vibrational spectroscopy
- Author
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Sergey A. Katsyuba, Elena E. Zvereva, Xiao Yuan, Paul J. Dyson, Ning Yan, and Yuan Kou
- Subjects
Chemistry ,Hydrogen bond ,Solvation ,Infrared spectroscopy ,chemistry.chemical_element ,Interaction energy ,Atomic and Molecular Physics, and Optics ,symbols.namesake ,Crystallography ,chemistry.chemical_compound ,Computational chemistry ,Ionic liquid ,symbols ,Cluster (physics) ,Physical and Theoretical Chemistry ,Raman spectroscopy ,Palladium - Abstract
A combined DFT/vibrational spectroscopy approach is used to determine the interactions of the 1,3-dimethylimidazolium ([Mmim](+)) and 1-ethyl-3-methylimidazolium ([Emim](+)) cations and [BF(4)](-) anions with each other in the liquid state and with Pd nanoparticles (NPs) immersed in ionic liquids (ILs) composed of these ions. Formation of aggregates of the counter-ions in the liquid does not have a strong influence on the interaction energy of the IL components with the palladium clusters used to model NPs, which is smaller than the energy of addition of a Pd atom to the cluster. Stronger Pd-Pd interactions in comparison to the interactions of the palladium cluster with the IL suggest kinetic stabilisation of Pd-NPs in 1,3-dialkylimidazolium tetrafluoroborates rather than thermodynamic stabilisation. Moreover, the palladium clusters interact more strongly with the anions than with the cations, and this suggests an important role of the anions in formation and stabilisation of Pd-NP in ILs. At the same time, binding between an isolated Pd atom and [Mmim](+) cation is stronger than Pd-[BF(4)](-) binding. IR and Raman spectral simulations reveal that surface-enhanced Raman spectroscopy is much less sensitive to interactions of Pd-NPs with the [BF(4)](-) anion compared to interactions with [Mmim](+) cations. In contrast, IR spectroscopy is better suited to study the anion-metal interactions, whereas IR spectral manifestations of the cation-metal interactions are rather modest. The splitting of the strong ν(as)(BF(4)(-)) IR band into three components appears to be a convenient spectroscopic marker for Pd-[BF(4)](-) interactions, which is confirmed by actual spectra of Pd-NPs stabilised by [Emim][BF(4)]. The IR spectra and their assignment with quantum chemical computations suggest that both the anions and cations of [Emim][BF(4)] interact with the Pd-NP surface in the IL. The cation ring orientation close to the surface normal appears to be the dominant interaction. The anion is bound to the surface through either two or three fluorine atoms.
- Published
- 2012
20. Ab initio and DFT predictions of infrared intensities and Raman activities
- Author
-
A. R. Shagidullin, Elena E. Zvereva, and Sergey A. Katsyuba
- Subjects
Infrared ,Chemistry ,Ab initio ,Analytical chemistry ,Molecular physics ,Hybrid functional ,symbols.namesake ,Quality (physics) ,symbols ,Molecule ,Physical and Theoretical Chemistry ,Perturbation theory ,Raman spectroscopy ,Basis set - Abstract
Relative infrared (IR) intensities and relative Raman activities have been computed for vibrations of test molecules, including from two to nine heavy atoms, using second-order Moller-Plesset perturbation theory (MP2), and three hybrid density functionals (B3LYP, M05, and M05-2X). The basis set convergence of vibrational properties is discussed. Our results demonstrate that B3LYP offers the most cost-effective choice for the prediction of molecular vibrational properties, but the predictions of another two tested hybrid functionals are very similar and in very good agreement with experimental data. MP2 shows good performance for the IR intensities, whereas the quality of prediction of the relative Raman activities should be characterized as only moderate. B3LYP calculations of the relative IR intensities using highly compact Sadlej's Z3PolX basis set retain the high accuracy of the more CPU expensive Sadlej's pVTZ and much more expensive aug-cc-pVTZ calculations. Relative Raman activities are more sensitive to basis set effects and require at least Sadlej's pVTZ to obtain quantitative results.
- Published
- 2010
21. A simple physical model for the simultaneous rationalisation of melting points and heat capacities of ionic liquids
- Author
-
Sergey A. Katsyuba, Paul J. Dyson, and Elena E. Zvereva
- Subjects
chemistry.chemical_classification ,Tetrafluoroborate ,General Physics and Astronomy ,Heat capacity ,chemistry.chemical_compound ,chemistry ,Ab initio quantum chemistry methods ,Hexafluorophosphate ,Ionic liquid ,Melting point ,Physical chemistry ,Physical and Theoretical Chemistry ,Counterion ,Conformational isomerism - Abstract
The analysis of potential energy surfaces of ion pairs within the framework of an anharmonic oscillator model allows rationalization and prediction of melting points (T(mp)) and heat capacities (C(p)) of ionic liquids (ILs) comprising di- and trialkylimidazolium or tetraalkylphosphonium cations and weakly coordinating BF(4), PF(6), or Tf(2)N anions. Multiple short contacts between the counterions are demonstrated to be typical for the imidazolium based ILs. Differences in the types of contacts result in moderate changes of melting points of the ILs, comparable with differences in T(mp) experimentally determined for the same crystal. The theoretical evaluation of IL heat capacities additionally requires a consideration of conformational behaviour of the corresponding cations. A similar conformational composition of 1-butyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate at ambient temperature is demonstrated by the combined DFT-vibrational spectroscopy approach. A rough proportionality of C(p) to 1/T(mp) of ionic liquids is suggested, provided that the conformational composition of the ILs does not change on crystal-to-liquid transition.
- Published
- 2010
22. Revisiting ether-derivatized imidazolium-based ionic liquids
- Author
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Sergey A. Katsyuba, Dongbin Zhao, Elena E. Zvereva, Paul J. Dyson, Zhaofu Fei, Rosario Scopelliti, and Wee Han Ang
- Subjects
Inorganic chemistry ,Supramolecular chemistry ,Infrared spectroscopy ,Halide ,Ether ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Ionic liquid ,Materials Chemistry ,Side chain ,Melting point ,Density functional theory ,Physical and Theoretical Chemistry - Abstract
A series of ether-derivatized imidazolium halides have been prepared and characterized. Contrary to literature reports, they are all crystalline solids and have melting points well above room temperature (50-100 degrees C). Single crystals of the imidazolium salts, obtained in situ by slow cooling from their molten state to room temperature, were analyzed by X-ray crystallography, revealing various anion-cation interactions in the solid state. Exchange of the halides with [Tf(2)N]- yielded room temperature ionic liquids with viscosities that are comparable to related 1-alkyl-3-methylimidazolium ionic liquids. Density functional theory combined with IR spectroscopy has been used to analyze the role of functionalization of the imidazolium side chain on the formation of the molecular and supramolecular structure of the compounds and its possible impact on their physical properties.
- Published
- 2007
23. New Method for the Preparation of Octathiotetraphosphetanes on the Basis of Elemental Phosphorus and Sulfur: Structure and Properties
- Author
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Elena E. Zvereva, A.E. Vandyukov, Valery I. Kovalenko, E. K. Badeeva, Oleg G. Sinyashin, Elena V. Platova, L. I. Kursheva, and Elvira S. Batyeva
- Subjects
White Phosphorus ,Phosphorus ,Organic Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Biochemistry ,Sulfur ,Pyrrolidine ,Ion ,Inorganic Chemistry ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Morpholine ,symbols ,Ammonium ,Raman spectroscopy - Abstract
New octathiotetraphosphetane ammonium salts are obtained based on the reaction of white phosphorus (Р4) and elemental sulfur with aliphatic mercaptans in the presence of amines (morpholine, methylmorpholine, pyrrolidine, and N,N-dimethylbenzylamine). The salts of octathiotetraphosphetane are characterized by IR/Raman spectroscopy. Several common IR and Raman bands can be used as structural markers for establishing the structures of [P4S8]4− anion in new compounds.
- Published
- 2011
24. A remarkable anion effect on palladium nanoparticle formation and stabilization in hydroxyl-functionalized ionic liquids
- Author
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Elena E. Zvereva, Yuan Kou, Sergey A. Katsyuba, Ning Yan, Xiao Yuan, and Paul J. Dyson
- Subjects
Inorganic chemistry ,General Physics and Astronomy ,Nanoparticle ,chemistry.chemical_element ,C4mim ,Medicinal chemistry ,Decomposition ,Coupling reaction ,Catalysis ,Ion ,chemistry.chemical_compound ,chemistry ,Ionic liquid ,Physical and Theoretical Chemistry ,Palladium - Abstract
Pd nanoparticles (NPs) with a small size and narrow size distribution were prepared from the decomposition of Pd(OAc)(2) in a series of hydroxyl-functionalized ionic liquids (ILs) comprising the 1-(2'-hydroxylethyl)-3-methylimidazolium cation and various anions, viz. [C(2)OHmim][OTf] (2.4 ± 0.5 nm), [C(2)OHmim][TFA] (2.3 ± 0.4 nm), [C(2)OHmim][BF(4)] (3.3 ± 0.6 nm), [C(2)OHmim][PF(6)] (3.1 ± 0.7 nm) and [C(2)OHmim][Tf(2)N] (4.0 ± 0.6 nm). Compared with Pd NPs isolated from the non-functionalized IL, [C(4)mim][Tf(2)N] (6.2 ± 1.1 nm), it would appear that the hydroxyl group accelerates the formation of the NPs, and also helps to protect the NPs from oxidation once formed. Based on the amount of Pd(OAc)(2) that remains after NP synthesis (under the given conditions) the ease of formation of the Pd NPs in the [C(2)OHmim](+)-based ILs follows the trend [Tf(2)N](-), [PF(6)](-)[BF(4)](-)[OTf](-)[TFA](-). Also, the ability of the [C(2)OHmim](+)-based ILs to prevent the Pd NPs from undergoing oxidation follows the trend [Tf(2)N](-)[PF(6)](-)[TFA](-)[OTf](-)[BF(4)](-). DFT calculations were employed to rationalize the interactions between Pd NPs and the [C(2)OHmim](+) cation and the various anions.
- Published
- 2012
25. Ab Initio and DFT Predictions of Infrared Intensities and Raman Activities.
- Author
-
Elena E. Zvereva, Artur R. Shagidullin, and Sergey A. Katsyuba
- Subjects
- *
INFRARED radiation , *DENSITY functionals , *RAMAN effect , *VIBRATION (Mechanics) , *QUANTUM chemistry , *BASIS sets (Quantum mechanics) , *STOCHASTIC convergence , *QUANTUM perturbations - Abstract
Relative infrared (IR) intensities and relative Raman activities have been computed for vibrations of test molecules, including from two to nine heavy atoms, using second-order MollerâPlesset perturbation theory (MP2), and three hybrid density functionals (B3LYP, M05, and M05-2X). The basis set convergence of vibrational properties is discussed. Our results demonstrate that B3LYP offers the most cost-effective choice for the prediction of molecular vibrational properties, but the predictions of another two tested hybrid functionals are very similar and in very good agreement with experimental data. MP2 shows good performance for the IR intensities, whereas the quality of prediction of the relative Raman activities should be characterized as only moderate. B3LYP calculations of the relative IR intensities using highly compact Sadlejâs Z3PolX basis set retain the high accuracy of the more CPU expensive Sadlejâs pVTZ and much more expensive aug-cc-pVTZ calculations. Relative Raman activities are more sensitive to basis set effects and require at least Sadlejâs pVTZ to obtain quantitative results. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
26. Revisiting Ether-Derivatized Imidazolium-Based Ionic Liquids.
- Author
-
Zhaofu Fei, Wee Han Ang, Dongbin Zhao, Rosario Scopelliti, Elena E. Zvereva, Sergey A. Katsyuba, and Paul J. Dyson
- Published
- 2007
- Full Text
- View/download PDF
27. Application of Density Functional Theory and Vibrational Spectroscopy Toward the Rational Design of Ionic Liquids.
- Author
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Sergey A. Katsyuba, Elena E. Zvereva, Ana Vidiš, and Paul J. Dyson
- Subjects
- *
IONS , *PHYSICAL & theoretical chemistry , *DENSITY functionals , *POLYWATER - Abstract
Density functional theory methods in combination with vibrational spectroscopy are used to investigate possible variants of molecular structure of the ion pairs of several imidazolium-based ionic liquids (ILs). Multiple stable structures are determined with the anion positioned (a) near to the C2 atom of the imidazolium ring, (b) between N1 and C5, (c) between N3 and C4, and (d) between C4 and C5. Chloride and bromide anions in vacuum also occupy positions above or below the imidazolium ring, but in the condensed state these positions are destabilised. In comparison with the halides that almost equally occupy the positions (a−d), tetrafluoroborate and hexafluorophosphate anions strongly prefer position (a). The position and the type of the anion influence the conformation of the side chains bound to the imidazolium N1 atom, which are able to adopt in vacuum all usual staggered or eclipsed conformations, although in the liquid state some of the conformations are present only as minor forms if at all. Vibrations of the cations depend both on the conformational changes and on the association with the anion. The formation of the ion pairs influences mainly stretching and out-of-plane vibrations of the imidazolium C−H groups and stretching vibrations of the perfluoroanions. Other modes of the ions retain their individuality and practically do not mix. This allows “interionic” vibrations to be separated and to regard the couple of the ions as an anharmonic oscillator. Such a model correlates the molecular structure of various ILs and their melting points without involving the energy of the interaction between the cations and anions but explains structure-melting point correlations on the grounds of quasy-elastic properties. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
28. Quantification of Conventional and Nonconventional Charge-Assisted Hydrogen Bonds in the Condensed and Gas Phases
- Author
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Sviatlana Siankevich, Mikhail V. Vener, Zhaofu Fei, Jan Gerit Brandenburg, Sergey A. Katsyuba, Rosario Scopelliti, Elena E. Zvereva, Paul J. Dyson, A.E. Arbuzov Institute of Organic and Physical Chemistry (IOPC), Kazan Scientific Centre of the Russian Academy of Sciences, Mendeleev University of Chemical Technology of Russia, Laboratory of Atomistic Simulation (LSIM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute of Chemical Sciences and Engineering, SB, GGEC Station 6 (EPFL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Rheinische Friedrich-Wilhelms-Universität Bonn, Institut des Sciences et Ingénierie Chimiques, Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn
- Subjects
Electron-Density Properties ,Ionic Liquids ,Cooperativity ,Nanotechnology ,010402 general chemistry ,01 natural sciences ,Vibration ,Ion ,chemistry.chemical_compound ,Complexes ,Phase (matter) ,Interaction Energy ,Non-covalent interactions ,General Materials Science ,Physical and Theoretical Chemistry ,Spectroscopy ,chemistry.chemical_classification ,[PHYS]Physics [physics] ,010405 organic chemistry ,Hydrogen bond ,Water ,Magnitude ,Interaction energy ,0104 chemical sciences ,Crystallography ,chemistry ,Ionic liquid ,Noncovalent Interactions ,X-Ray - Abstract
International audience; Charge-assisted hydrogen bonds (CAHBs) play critical roles in many systems from biology through to materials. In none of these areas has the role and function of CAHBs been explored satisfactorily because of the lack of data on the energy of CAHBs in the condensed phases. We have, for the first time, quantified three types of CAHBs in both the condensed and gas phases for 1-(2'-hydroxylethyl)-3-methylimidazolium acetate ([C(2)OHmim][OAc]). The energy of conventional OH center dot center dot center dot[OAc](-) CAHBs is similar to 10 kcal. mol(-1), whereas nonconventional C(sp2)H center dot[OAc](-) and C(sp3)H center dot center dot center dot[OAc](-) CAHBs are weaker by similar to 5-7 kcal.mol(-1). In the gas phase, the strength of the nonconventional CAHBs is doubled, whereas the conventional CAHBs are strengthened by
29. Application of Density Functional Theory and Vibrational Spectroscopy Toward the Rational Design of Ionic Liquids
- Author
-
and Ana Vidiš, Elena E. Zvereva, Sergey A. Katsyuba, and Paul J. Dyson
- Subjects
Tetrafluoroborate ,Infrared spectroscopy ,Ionic bonding ,Ion ,chemistry.chemical_compound ,Crystallography ,chemistry ,Bromide ,Computational chemistry ,Hexafluorophosphate ,Ionic liquid ,Physics::Atomic and Molecular Clusters ,Density functional theory ,Physical and Theoretical Chemistry ,Physics::Chemical Physics - Abstract
Density functional theory methods in combination with vibrational spectroscopy are used to investigate possible variants of molecular structure of the ion pairs of several imidazolium-based ionic liquids (ILs). Multiple stable structures are determined with the anion positioned (a) near to the C2 atom of the imidazolium ring, (b) between N1 and C5, (c) between N3 and C4, and (d) between C4 and C5. Chloride and bromide anions in vacuum also occupy positions above or below the imidazolium ring, but in the condensed state these positions are destabilized. In comparison with the halides that almost equally occupy the positions (a-d), tetrafluoroborate and hexafluorophosphate anions strongly prefer position (a). The position and the type of the anion influence the conformation of the side chains bound to the imidazolium N1 atom, which are able to adopt in vacuum all usual staggered or eclipsed conformations, although in the liquid state some of the conformations are present only as minor forms if at all. Vibrations of the cations depend both on the conformational changes and on the association with the anion. The formation of the ion pairs influences mainly stretching and out-of-plane vibrations of the imidazolium C-H groups and stretching vibrations of the perfluoroanions. Other modes of the ions retain their individuality and practically do not mix. This allows "interionic" vibrations to be separated and to regard the couple of the ions as an anharmonic oscillator. Such a model correlates the molecular structure of various ILs and their melting points without involving the energy of the interaction between the cations and anions but explains structure-melting point correlations on the grounds of quasy-elastic properties.
30. How Strong Is Hydrogen Bonding in Ionic Liquids? Combined X-ray Crystallographic, Infrared/Raman Spectroscopic, and Density Functional Theory Study
- Author
-
Paul J. Dyson, Gábor Laurenczy, Rosario Scopelliti, Sergey A. Katsyuba, Mikhail V. Vener, Emilia Păunescu, Elena E. Zvereva, Zhaofu Fei, and Ning Yan
- Subjects
Tetrafluoroborate ,Hydrogen bond ,Enthalpy ,Infrared spectroscopy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Acceptor ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Crystallography ,chemistry ,Hexafluorophosphate ,Ionic liquid ,Materials Chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,Single crystal - Abstract
Hydrogen bonding in ionic liquids based on the 1-(2'-hydroxylethyl)-3-methylimidazolium cation ([C(2)OHmim](+)) and various anions ([A](-)) of differing H-bond acceptor strength, viz. hexafluorophosphate [PF6](-), tetrafluoroborate [BF4](-), bis-(trifluoromethanesulfonimide) [Tf2N](-), trifluoromethylsulfonate [OTf](-), and trifluoroacetate [TFA](-), was studied by a range of spectroscopic and computational techniques and, in the case of [C(2)OHmim][PF6], by single crystal X-ray diffraction. The first quantitative estimates of the energy (E-HB) and the enthalpy (-Delta H-HB) of H-bonds in bulk ILs were obtained from a theoretical analysis of the solid-state electron-density map of crystalline [C(2)OHmim][PF6] and an analysis of the IR spectra in crystal and liquid samples. E-HB for OH center dot center dot center dot[PF6](-) H-bonds amounts to similar to 3.4-3.8 kcal.mol(-1), whereas weaker H-bonds (2.8-3.1 kcal-mol(-1)) are formed between aromatic C2H group of imidazolium ring and the [PF6](-) anion. The enthalpy of the OH center dot center dot center dot[A](-) H-bonds follows the order: [PF6] (2.4 kcal.mol(-1)) < [BF4] (3.3 kcal.mol(-1)) < [Tf2N] (3.4 kcal-mol(-1))
31. Effects of Non-Stoichiometry on the Ground State of the Frustrated System Li 0.8 Ni 0.6 Sb 0.4 O 2 .
- Author
-
Vavilova E, Salikhov T, Iakovleva M, Vasilchikova T, Zvereva E, Shukaev I, Nalbandyan V, and Vasiliev A
- Abstract
The non-stoichiometric system Li
0.8 Ni0.6 Sb0.4 O2 is a Li-deficient derivative of the zigzag honeycomb antiferromagnet Li3 Ni2 SbO6 . Structural and magnetic properties of Li0.8 Ni0.6 Sb0.4 O2 were studied by means of X-ray diffraction, magnetic susceptibility, specific heat, and nuclear magnetic resonance measurements. Powder X-ray diffraction data shows the formation of a new phase, which is Sb-enriched and Li-deficient with respect to the structurally honeycomb-ordered Li3 Ni2 SbO6 . This structural modification manifests in a drastic change of the magnetic properties in comparison to the stoichiometric partner. Bulk static (dc) magnetic susceptibility measurements show an overall antiferromagnetic interaction ( Θ = -4 K) between Ni2+ spins ( S = 1), while dynamic (ac) susceptibility reveals a transition into a spin glass state at a freezing temperature TSG ~ 8 K. These results were supported by the absence of the λ-anomaly in the specific heat Cp (T) down to 2 K. Moreover, combination of the bulk static susceptibility, heat capacity and7 Li NMR studies indicates a complicated temperature transformation of the magnetic system. We observe a development of a cluster spin glass, where the Ising-like Ni2+ magnetic moments demonstrate a 2D correlated slow short-range dynamics already at 12 K, whereas the formation of 3D short range static ordered clusters occurs far below the spin-glass freezing temperature at T ~ 4 K as it can be seen from the7 Li NMR spectrum.- Published
- 2021
- Full Text
- View/download PDF
32. Chirality and Magnetocaloricity in GdFeTeO 6 as Compared to GdGaTeO 6 .
- Author
-
Zvereva E, Vasilchikova T, Evstigneeva M, Tyureva A, Nalbandyan V, Gonçalves J, Barone P, Stroppa A, and Vasiliev A
- Abstract
GdFeTeO
6 and GdGaTeO6 have been prepared and their structures refined by the Rietveld method. Both are superstructures of the rosiaite type (space group P3¯1c). Their thermodynamic properties have been investigated by means of magnetization M and specific heat Cp measurements, evidencing the formation of the long-range antiferromagnetic order at TN = 2.4 K in the former compound and paramagnetic behavior down to 2 K in the latter compound. Large magnetocaloric effect allows considering GdFeTeO6 for the magnetic refrigeration at liquid hydrogen stage. Density functional theory calculations produce estimations of leading Gd-Gd, Gd-Fe and Fe-Fe interactions suggesting unique chiral 120° magnetic structure of Fe3+ ( S = 5/2) moments and Gd3+ ( J = 7/2) moments rotating in opposite directions (clockwise/anticlockwise) within weakly coupled layers of the rosiaite type crystal structure.- Published
- 2021
- Full Text
- View/download PDF
33. First-principles characterization of the singlet excited state manifold in DNA/RNA nucleobases.
- Author
-
Jaiswal VK, Segarra-Martí J, Marazzi M, Zvereva E, Assfeld X, Monari A, Garavelli M, and Rivalta I
- Subjects
- DNA chemistry, RNA chemistry, Adenine chemistry, Cytosine chemistry, Density Functional Theory, Guanine chemistry, Thymine chemistry, Uracil chemistry
- Abstract
An extensive theoretical characterization of the singlet excited state manifold of the five canonical DNA/RNA nucleobases (thymine, cytosine, uracil, adenine and guanine) in gas-phase is carried out with time-dependent density functional theory (TD-DFT) and restricted active space second-order perturbation theory (RASPT2) approaches. Both ground state and excited state absorptions are analyzed and compared between these different theoretical approaches, assessing the performance of the hybrid B3LYP and CAM-B3LYP (long-range corrected) functionals with respect to the RASPT2 reference. By comparing the TD-DFT estimates with our reference for high-lying excited states, we are able to narrow down specific energetic windows where TD-DFT may be safely employed to qualitatively reproduce the excited state absorption (ESA) signals registered in non-linear and time-resolved spectroscopy for monitoring photoinduced phenomena. Our results show a qualitative agreement between the RASPT2 reference and the B3LYP computed ESAs of pyrimidines in the near-IR/Visible spectral probing window while for purines the agreement is limited to the near-IR ESAs, with generally larger discrepancies obtained with the CAM-B3LYP functional. This outcome paves the way for appropriate application of cost-effective TD-DFT approaches to simulate linear and non-linear spectroscopies of realistic multichromophoric DNA/RNA systems with biological and nanotechnological relevance.
- Published
- 2020
- Full Text
- View/download PDF
34. MnSnTeO 6 : A Chiral Antiferromagnet Prepared by a Two-Step Topotactic Transformation.
- Author
-
Zvereva E, Bukhteev K, Evstigneeva M, Komleva E, Raganyan G, Zakharov K, Ovchenkov Y, Kurbakov A, Kuchugura M, Senyshyn A, Streltsov S, Vasiliev A, and Nalbandyan V
- Abstract
MnSnTeO
6 , a new chiral antiferromagnet, was prepared both by topotactic transformation of the metastable rosiaite-type polymorph and by direct synthesis from coprecipitated hydroxides. Its structure and its static and dynamic magnetic properties were studied comprehensively both experimentally (through X-ray and neutron powder diffraction, magnetization, specific heat, dielectric permittivity, and ESR techniques) and theoretically (by means of ab initio density functional theory (DFT) calculations within the spin-polarized generalized gradient approximation). MnSnTeO6 is isostructural with MnSb2 O6 (space group P 321) and does not show any structural transition between 3 and 300 K. The magnetic susceptibility and specific heat exhibit an antiferromagnetic ordering at TN ≈ 9.8 K, which is confirmed by low-temperature neutron data. At the same time, the thermodynamic parameters demonstrate an additional anomaly on the temperature dependences of magnetic susceptibility χ( T ), specific heat Cp ( T ) and dielectric permittivity ε( T ) at T * ≈ 4.9 K, which is characterized by significant temperature hysteresis. Clear enhancement of the dielectric permittivity at T * is most likely to reflect the coupling of dielectric and magnetic subsystems leading to development of electric polarization. It was established that the ground state of MnSnTeO6 is stabilized by seven exchange parameters, and neutron diffraction revealed incommensurate magnetic structure with propagation vector k = (0, 0, 0.183) analogous to that of MnSb2 O6 . Ab initio DFT calculations demonstrate that the strongest exchange coupling occurs between planes along diagonals. All exchange parameters are antiferromagnetic and reveal moderate frustration.- Published
- 2020
- Full Text
- View/download PDF
35. Synthesis and Characterization of Sodium-Iron Antimonate Na 2 FeSbO 5 : One-Dimensional Antiferromagnetic Chain Compound with a Spin-Glass Ground State.
- Author
-
Uma S, Vasilchikova T, Sobolev A, Raganyan G, Sethi A, Koo HJ, Whangbo MH, Presniakov I, Glazkova I, Vasiliev A, Streltsov S, and Zvereva E
- Abstract
A new oxide, sodium-iron antimonate, Na
2 FeSbO5 , was synthesized and structurally characterized, and its static and dynamic magnetic properties were comprehensively studied both experimentally by dc and ac magnetic susceptibility, magnetization, specific heat, electron spin resonance (ESR) and Mössbauer measurements, and theoretically by density functional calculations. The resulting single-crystal structure ( a = 15.6991(9) Å; b = 5.3323 (4) Å; c = 10.8875(6) Å; S.G. Pbna ) consists of edge-shared SbO6 octahedral chains, which alternate with vertex-linked, magnetically active FeO4 tetrahedral chains. The57 Fe Mössbauer spectra confirmed the presence of high-spin Fe3+ (3d5 ) ions in a distorted tetrahedral oxygen coordination. The magnetic susceptibility and specific heat data show the absence of a long-range magnetic ordering in Na2 FeSbO5 down to 2 K, but ac magnetic susceptibility unambigously demonstrates spin-glass-type behavior with a unique two-step freezing at Tf1 ≈ 80 K and Tf2 ≈ 35 K. Magnetic hyperfine splitting of57 Fe Mössbauer spectra was observed below T * ≈ 104 K ( Tf1 < T *). The spectra just below T * ( Tf1 < T < T *) exhibit a relaxation behavior caused by critical spin fluctuations, indicating the existence of short-range correlations. The stochastic model of ionic spin relaxation was used to account for the shape of the Mössbauer spectra below the freezing temperature. A complex slow dynamics is further supported by ESR data revealing two different absorption modes presumably related to ordered and disordered segments of spin chains. The data imply a spin-cluster ground state for Na2 FeSbO5 .- Published
- 2019
- Full Text
- View/download PDF
36. Resolving the Singlet Excited State Manifold of Benzophenone by First-Principles Simulations and Ultrafast Spectroscopy.
- Author
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Segarra-Martí J, Zvereva E, Marazzi M, Brazard J, Dumont E, Assfeld X, Haacke S, Garavelli M, Monari A, Léonard J, and Rivalta I
- Abstract
Accurate characterization of the high-lying excited state manifolds of organic molecules is of fundamental importance for the interpretation of the rich response detected in time-resolved nonlinear electronic spectroscopies. Here, we have characterized the singlet excited state manifold of benzophenone (BP), a versatile organic photoinitiator and a well-known DNA photosensitizer. Benchmarks of various multiconfigurational/multireference (RASSCF/PT2) and time-dependent density functional theory (TD-DFT) approaches allowed assignments of experimental linear absorption signals of BP in the ultraviolet (UV) region, with unprecedented characterization of ground state absorptions in the far UV. Experimental transient absorption spectra obtained by UV-vis pump-probe spectroscopy at very short time delays are shown to be directly comparable to theoretical estimates of excited state absorptions (from the low-lying n
O π* and ππ* singlet states) in the Franck-Condon region. Multireference computations provided reliable interpretation of the PP spectra, with TD-DFT results yielding a fair agreement as long as electronic transitions featuring double excitations contributions are not involved. These results lay the groundwork for further computational studies and interpretation of experimental nonlinear electronic spectra of benzophenone in more complex systems, such as BP/DNA adducts.- Published
- 2018
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37. The effect of solvent relaxation in the ultrafast time-resolved spectroscopy of solvated benzophenone.
- Author
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Zvereva E, Segarra-Martí J, Marazzi M, Brazard J, Nenov A, Weingart O, Léonard J, Garavelli M, Rivalta I, Dumont E, Assfeld X, Haacke S, and Monari A
- Abstract
Benzophenone (BP) despite its relatively simple molecular structure is a paradigmatic sensitizer, featuring both photocatalytic and photobiological effects due to its rather complex photophysical properties. In this contribution we report an original theoretical approach to model realistic, ultra-fast spectroscopy data, which requires describing intra- and intermolecular energy and structural relaxation. In particular we explicitly simulate time-resolved pump-probe spectra using a combination of state-of-the art hybrid quantum mechanics/molecular mechanics dynamics to treat relaxation and vibrational effects. The comparison with experimental transient absorption data demonstrates the efficiency and accuracy of our approach. Furthermore the explicit inclusion of the solvent, water for simulation and methanol for experiment, allows us, despite the inherent different behavior of the two, to underline the role played by the H-bonding relaxation in the first hundreds of femtoseconds after optical excitation. Finally we predict for the first time the two-dimensional electronic spectrum (2DES) of BP taking into account the vibrational effects and hence modelling partially symmetric and asymmetric ultrafast broadening.
- Published
- 2018
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38. The mechanism of citryl-coenzyme A formation catalyzed by citrate synthase.
- Author
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Aleksandrov A, Zvereva E, and Field M
- Subjects
- Protein Conformation, Protons, Quantum Theory, Thermodynamics, Water chemistry, Water metabolism, Acyl Coenzyme A metabolism, Biocatalysis, Citrate (si)-Synthase chemistry, Citrate (si)-Synthase metabolism, Molecular Dynamics Simulation
- Abstract
The enzyme citrate synthase is used by all living cells to catalyze the first step of the citric acid cycle. In this work, we have investigated the enolization and condensation steps catalyzed by citrate synthase, using ab initio (B3LYP/def2-TZVP and MP2/aug-cc-pVDZ) quantum chemical/molecular mechanical hybrid potentials in conjunction with reaction-path-location algorithms and molecular dynamics free energy simulations. The results of the latter indicate that the catalytic His238 residue is in its neutral form, and also argue strongly for the presence of a water molecule in the enzyme's catalytic center. Such a water is observed in some, but not all, of the experimentally resolved structures of the protein. The mechanism itself starts with an enolization that proceeds via an enolate intermediate rather than the enol form, which is much more unstable. This is in agreement with the results of other workers. For the condensation step, we investigated two mechanisms in which there is a direct nucleophilic attack of the enolate intermediate on the oxaloacetate carbonyl carbon, and found the one in which there is no proton transfer from the neighboring arginine to be preferred. Although this residue, Arg329, is not implicated directly in the reaction, it helps to stabilize the negative citryl-CoA formed during the condensation step.
- Published
- 2014
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39. Crystal structure and magnetic properties of a new layered sodium nickel hydroxide phosphate, Na2Ni3(OH)2(PO4)2.
- Author
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Yakubovich O, Kiriukhina G, Dimitrova O, Volkov A, Golovanov A, Volkova O, Zvereva E, Baidya S, Saha-Dasgupta T, and Vasiliev A
- Abstract
Mixed sodium nickel hydroxide phosphate, Na2Ni3(OH)2(PO4)2, has been synthesized hydrothermally from the system NiCO3-Na4P2O7-NaCl-H2O. Its monoclinic crystal structure has been determined by single crystal X-ray diffraction: a = 14.259(5), b = 5.695(2), c = 4.933(1) Å, β = 104.28(3)°, space group C2/m, Z = 2, ρc = 3.816 g cm(-3), R = 0.026. The underlying spin model has been characterized in terms of first-principles electronic structure calculations. The compound is formed by alternating layers of [NiO6] octahedra and [NaO7] polyhedra, combined in the [100] direction with tetrahedral [PO4] oxocomplexes and hydrogen bonds. The novel phase is treated as an isostructural variant of the two-dimensional potassium manganese hydroxide vanadate, K2Mn3(OH)2(VO4)2, which can be formally obtained by morphotropic substitutions of all positions in the cationic sublattice. The stripe arrangement of Ni(2+) ions (S = 1) within [NiO4(OH)2] layers of Na2Ni3(OH)2(PO4)2 is unique in the sense that its magnetic topology places it in between widely discussed honeycomb and kagomé lattices. The Na2Ni3(OH)2(PO4)2 is a low-dimensional magnet, which reaches the short-range correlation regime at Tmax = 38.4 K and orders antiferromagnetically at TN = 33.4 K.
- Published
- 2013
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40. Complex formation of d-metal ions at the interface of Tb(III)-doped silica nanoparticles as a basis of substrate-responsive Tb(III)-centered luminescence.
- Author
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Davydov N, Mustafina A, Burilov V, Zvereva E, Katsyuba S, Vagapova L, Konovalov A, and Antipin I
- Subjects
- Colloids chemistry, Hydrogen-Ion Concentration, Surface Properties, Water chemistry, Luminescence, Nanoparticles chemistry, Silicon Dioxide chemistry, Terbium chemistry
- Abstract
The complex formation of d-metal ions at the interface of Tb(III)-doped silica nanoparticles modified by amino groups is introduced as a route to sensing d-metal ions and some organic molecules. Diverse modes of surface modification (covalent and noncovalent) are used to fix amino groups onto the silica surface. The interfacial binding of d-metal ions and complexes is the reason for the Tb(III)-centered luminescence quenching. The regularities and mechanisms of quenching are estimated for the series of d-metal ions and their complexes with chelating ligands. The obtained results reveal the interfacial binding of Cu(II) ions as the basis of their quantitative determination in the concentration range 0.1-2.5 μM by means of steady-state and time-resolved fluorescence measurements. The variation of chelating ligands results in a significant effect on the quenching regularities due to diverse binding modes (inner or outer sphere) between amino groups at the interface of nanoparticles and Fe(III) ions. The applicability of the steady-state and time-resolved fluorescence measurements to sense both Fe(III) ions and catechols in aqueous solution by means of Tb(III)-doped silica nanoparticles is also introduced., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
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41. Phosphonium ionic liquids based on bulky phosphines: synthesis, structure and properties.
- Author
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Ermolaev V, Miluykov V, Rizvanov I, Krivolapov D, Zvereva E, Katsyuba S, Sinyashin O, and Schmutzler R
- Abstract
A series of new ionic liquids based on sterically hindered decyl(tri-tert-butyl)phosphonium (DTBP) or decyl(tricyclohexyl)phosphonium (DCHP) cations were prepared using quaternisation of tri-tert-butyl- or tricyclohexylphosphine with decylbromide and subsequent bromide exchange with the weakly-coordinating anions BF(4)(-), PF(6)(-), SO(3)CF(3)(-), N(SO(2)CF(3))(2)(-). The salts obtained melt below 100 degrees C and possess a broad electrochemical window. Density functional theory combined with X-ray crystallography, IR and Raman spectroscopy has been used to analyze the molecular and supramolecular structures of the compounds obtained and their possible influence on their physical properties.
- Published
- 2010
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42. Activity and heavy metal resistance of non-specific esterases in leaf beetle Chrysomela lapponica from polluted and unpolluted habitats.
- Author
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Zvereva E, Serebrov V, Glupov V, and Dubovskiy I
- Subjects
- Analysis of Variance, Animals, Copper analysis, Environment, Environmental Pollutants analysis, Enzyme Inhibitors analysis, Enzyme Inhibitors poisoning, Esterases antagonists & inhibitors, Larva enzymology, Nickel analysis, Coleoptera enzymology, Copper poisoning, Environmental Pollutants poisoning, Esterases metabolism, Nickel poisoning
- Abstract
We compared the general activity and heavy metal resistance of non-specific esterases in two populations of the leaf beetle Chrysomela lapponica from habitats severely contaminated by heavy metals (mostly Ni and Cu) and two populations from unpolluted habitats. Concentrations of Ni and Cu in adult beetles from the most polluted site were 7.7 and 3.6 times higher that in beetles from unpolluted habitats. Larval esterases showed higher activity and lower susceptibility to heavy metals than esterases of adults. Larval esterase activity did not differ between populations from polluted and unpolluted sites, but adult beetles from polluted localities had lower esterase activity than beetles from unpolluted habitats. Both Cu and Ni sulfates in millimolar concentrations in vitro suppressed esterase activity of larvae from unpolluted habitats, but caused no negative effect on esterases of larvae from polluted sites. Similarly, inhibition of adult esterase activity by Ni was stronger in beetles from unpolluted localities than in beetles from polluted localities. This indicates that resistance of non-specific esterases to heavy metals is higher in leaf beetle populations from contaminated environment.
- Published
- 2003
- Full Text
- View/download PDF
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