Institute of Problems of Chemical Physics

Providing a comprehensive review of reactions of oxidation for different classes of organic compounds and polymers, and biological processes mediated by free radicals, Oxidation and Antioxidants in Organic Chemistry and Biology puts the data and bibliographical information you need into one easy-to-use resource. You will find up-to-date information

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Abstract We have investigated a wide variety of surfactants for their efficiency in dissolving isolated single‐walled carbon nanotubes (SWNTs) in water. In doing so, we have completely avoided the harsh chemical or mechanical conditions, such as acid or ultrasonic treatments, that are known to damage SWNTs. Bile salts in particular are found to be exceptionally effective in dissolving individual tubes, as evidenced by highly resolved optical absorption spectra, bright bandgap fluorescence, and the unprecedented resolution (∼ 2.5 cm –1 ) of the radial breathing modes in Raman spectra. This is attributed to the formation of very regular and stable micelles around the nanotubes providing an unusually homogeneous environment. Quantitative information concerning the degree of solubilization is obtained from absorption spectroscopy.

Abstract Biocompatible‐ingestible electronic circuits and capsules for medical diagnosis and monitoring are currently based on traditional silicon technology. Organic electronics has huge potential for developing biodegradable, biocompatible, bioresorbable, or even metabolizable products. An ideal pathway for such electronic devices involves fabrication with materials from nature, or materials found in common commodity products. Transistors with an operational voltage as low as 4–5 V, a source drain current of up to 0.5 μA and an on‐off ratio of 3–5 orders of magnitude have been fabricated with such materials. This work comprises steps towards environmentally safe devices in low‐cost, large volume, disposable or throwaway electronic applications, such as in food packaging, plastic bags, and disposable dishware. In addition, there is significant potential to use such electronic items in biomedical implants.

Millenniums-old natural dye indigo - a “new” ambipolar organic semiconductor. Indigo shows balanced electron and hole mobilities of 1 × 10−2 cm2 V−1 s−1 and good stability against degradation in air. Inverters with gains of 105 in the first and 110 in the third quadrant are demonstrated. Fabricated entirely from natural and biodegradable compounds, these devices show the large potential of such materials for green organic electronics. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract The preparation of 27 different derivatives of C 60 and C 70 fullerenes possessing various aryl (heteroaryl) and/or alkyl groups that are appended to the fullerene cage via a cyclopropane moiety and their use in bulk heterojunction polymer solar cells is reported. It is shown that even slight variations in the molecular structure of a compound can cause a significant change in its physical properties, in particular its solubility in organic solvents. Furthermore, the solubility of a fullerene derivative strongly affects the morphology of its composite with poly(3‐hexylthiophene), which is commonly used as active material in bulk heterojunction organic solar cells. As a consequence, the solar cell parameters strongly depend on the structure and the properties of the fullerene‐based material. The power conversion efficiencies for solar cells comprising these fullerene derivatives range from negligibly low (0.02%) to considerably high (4.1%) values. The analysis of extensive sets of experimental data reveals a general dependence of all solar cell parameters on the solubility of the fullerene derivative used as acceptor component in the photoactive layer of an organic solar cell. It is concluded that the best material combinations are those where donor and acceptor components are of similar and sufficiently high solubility in the solvent used for the deposition of the active layer.

Abstract Our previously developed approaches for integrating quantum mechanical molecular orbital methods with microscopic solvent models are refined and examined. These approaches consider the nonlinear solute–solvent coupling in a self‐consistent way by incorporating the potential from the solvent dipoles in the solute Hamiltonian, while considering the polarization of the solvent by the potential from the solute charges. The solvent models used include the simplified Langevin Dipoles (LD) model and the much more expensive surface constrained All Atom Solvent (SCAAS) model, which is combined with a free energy pertubation (FEP) approach. Both methods are effectively integrated with the quantum mechanical AMPAC package and can be easily combined with other quantum mechanical programs. The advantages of the present approaches and their earlier versions over macroscopic reaction field models and supermolecular approaches are considered. A LD/MNDO study of solvated organic ions demonstrates that this model can yield reliable solvation energies, provided the quantum mechanical charges are scaled to have similar magnitudes to those obtained by high level ab initio methods. The incorporation of a field‐dependent hydrophobic term in the LD free energy makes the present approach capable of evaluating the free energy of transfer of polar molecules from non polar solvents to aqueous solutions. The reliability of the LD approach is examined not only by evaluating a rather standard set of solvation energies of organic ions and polar molecules, but also by considering the stringent test case of sterically hindered hydrophobic ions. In this case, we compare the LD/MNDO solvation energies to the more rigorous FEP/SCAAS/MNDO solvation energies. Both methods are found to give similar results even in this challenging test case. The FEP/SCAAS/AMPAC method is incorporated into the current version of the program ENZYMIX. This option allows one to study chemical reactions in enzymes and in solutions using the MNDO and AM1 approximations. A special procedure that uses the EVB method as a reference potential for SCF MO calculations should help in improving the reliability of such studies.

We report here all inorganic CsPbI3 planar junction perovskite solar cells fabricated by thermal coevaporation of CsI and PbI2 precursors. The best devices delivered power conversion efficiency (PCE) of 9.3 to 10.5%, thus coming close to the reference MAPbI3-based devices (PCE ≈ 12%). These results emphasize that all inorganic lead halide perovskites can successfully compete in terms of photovoltaic performance with the most widely used hybrid materials such as MAPbI3.

We report a careful and systematic study of thermal and photochemical degradation of a series of complex haloplumbates APbX3 (X = I, Br) with hybrid organic (A+ = CH3NH3) and inorganic (A+ = Cs+) cations under anoxic conditions (i.e., without exposure to oxygen and moisture by testing in an inert glovebox environment). We show that the most common hybrid materials (e.g., MAPbI3) are intrinsically unstable with respect to the heat- and light-induced stress and, therefore, can hardly sustain the real solar cell operation conditions. On the contrary, the cesium-based all-inorganic complex lead halides revealed far superior stability and, therefore, provide an impetus for creation of highly efficient and stable perovskite solar cells that can potentially achieve pragmatic operational benchmarks.

Abstract A short information is given on the results of work carried out at the Branch of the Institute of Chemical Physics, U.S.S.R. Academy of Sciences, since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion.fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds.

This article presents experimental results of the dynamic yield strength and dynamic tensile strength (“spall strength”) of aluminum single crystals at shock-wave loading as a function of temperature. The load duration was ∼40 and ∼200 ns. The temperature varied from 20 to 650 °C which is only by 10 °C below the melting temperature. A linear growth of the dynamic yield strength by more than a factor of 4 was observed within this temperature range. This is attributed to the phonon drag effect on the dislocation motion. High dynamic tensile strength was maintained over the whole temperature range, including the conditions at which melting should start in a material under tension. This could be an indication of the existence of superheated states in solid crystals.

High-explosive driven generators of cylindrical and plane shock waves in D2 and H2 were used for the generation of warm and dense strongly nonideal matter with an intense interparticle interaction and Fermi statistics. Highly resolved flash x-ray diagnostics were used to measure the adiabatic plasma compressibility. The thermodynamic measurements demonstrated the 20% increase of density at megabar pressure, just in the density range, where the electrical measurements indicated a sharp--5 orders of magnitude--increase of electrical conductivity due to pressure ionization in strongly coupled plasmas.

Various combinations of vanadium derivatives (n-Bu4NVO3 is the best catalyst) with pyrazine-2-carboxylic acid (PCA) catalyse the oxidation of saturated hydrocarbons, RH, with hydrogen peroxide and air in acetonitrile solution to produce, at temperatures <40 °C, alkyl hydroperoxides, ROOH, as the main primary products. These compounds are easily reduced with triphenylphosphine to the corresponding alcohols, which can then be quantitatively determined by GLC. Certain aminoacids similar to PCA can play the role of co-catalyst; however the oxidation rates and final product yields are lower for picolinic and imidazole-4,5-dicarboxylic acids, while imidazole-4-carboxylic and pyrazole-3,5-dicarboxylic acids are almost inactive. The oxidation is induced by the attack of a hydroxyl radical on the alkane, RH, to produce alkyl radicals, R˙. The latter further react rapidly with molecular atmospheric oxygen. The peroxyl radicals, ROO˙, thus formed can be converted to alkyl hydroperoxides. We conclude on the basis of our kinetic investigation of the oxidation of cyclohexane that the rate-limiting step of the reaction is the monomolecular decomposition of the complex containing one coordinated PCA molecule: VV(PCA)(H2O2) → VIV(PCA) + HOO˙ + H+. The VIV species thus formed reacts further with a second H2O2 molecule to generate the hydroxyl radical according to the equation VIV(PCA) + H2O2 → VV(PCA) + HO˙ + HO−. The concentration of the active species in the course of the catalytic process has been estimated to be as low as [V(PCA)H2O2] ≊ 3.3 × 10−6 mol dm−3. The effective rate constant for the cyclohexane oxidation (d[ROOH]/dt = keff[H2O2]0[V]0) is keff = 0.44 dm3 mol−1 s−1 at 40 °C, the effective activation energy is 17 ± 2 kcal mol−1. It is assumed that the accelerating role of PCA is due to its facilitating the proton transfer between the oxo and hydroxy ligands of the vanadium complex on the one hand and molecules of hydrogen peroxide and water on the other hand. For example: (pca)(O)V⋯H2O2 → (pca)(HO–)V–OOH. Such a “robot’s arm mechanism” has analogies in enzyme catalysis.

The review discusses the latest advances in the directed synthesis and application of macroheterocyclic compounds in science, engineering and technology, viz. as catalysts for various processes in photo-and electrocatalysis, optical chemosensors for metal cations, selective receptors of organic compounds, inductors and selectors, in nonlinear optics, organic electronics, as magnets, photosensitizers for PDT of a number of oncological diseases and for antimicrobial PDT, etc.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron Spin CatalysisAnatoly L. Buchachenko and Vitaly L. BerdinskyView Author Information Institute of Problems of Chemical Physics, Chernogolovka, Moscow Region, 142432 Russia Cite this: Chem. Rev. 2002, 102, 3, 603–612Publication Date (Web):February 2, 2002Publication History Received16 November 2001Published online2 February 2002Published inissue 1 March 2002https://pubs.acs.org/doi/10.1021/cr010370lhttps://doi.org/10.1021/cr010370lresearch-articleACS PublicationsCopyright © 2002 American Chemical SocietyRequest reuse permissionsArticle Views3929Altmetric-Citations126LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Catalysis,Catalysts,Ions,Magnetic properties,Quantum mechanics Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular Conductors and Superconductors Based on Trihalides of BEDT-TTF and Some of Its AnaloguesRimma P. Shibaeva and Eduard B. YagubskiiView Author Information Institute of Solid State Physics and Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow District, 142432 Russia Cite this: Chem. Rev. 2004, 104, 11, 5347–5378Publication Date (Web):October 9, 2004Publication History Received15 April 2004Published online9 October 2004Published inissue 1 November 2004https://pubs.acs.org/doi/10.1021/cr0306642https://doi.org/10.1021/cr0306642research-articleACS PublicationsCopyright © 2004 American Chemical SocietyRequest reuse permissionsArticle Views1868Altmetric-Citations156LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Anions,Crystal structure,Crystals,Phase transitions,Salts Get e-Alerts

The subject of high-energy-density (HED) states in matter is of considerable importance to numerous branches of basic as well as applied physics. Intense heavy-ion beams are an excellent tool to create large samples of HED matter in the laboratory with fairly uniform physical conditions. Gesellschaft für Schwerionenforschung, Darmstadt, is a unique worldwide laboratory that has a heavy-ion synchrotron, SIS18, that delivers intense beams of energetic heavy ions. Construction of a much more powerful synchrotron, SIS100, at the future international facility for antiprotons and ion research (FAIR) at Darmstadt will lead to an increase in beam intensity by 3 orders of magnitude compared to what is currently available. The purpose of this Letter is to investigate with the help of two-dimensional numerical simulations, the potential of the FAIR to carry out research in the field of HED states in matter.

[3]-Radialene-based dopant CN6-CP studied herein, with its reduction potential of +0.8 versus Fc/Fc+ and the lowest unoccupied molecular orbital level of −5.87 eV, is the strongest molecular p-dopant reported in the open literature, so far. The efficient p-doping of the donor–acceptor dithienyl-diketopyrrolopyrrole-based copolymer having the highest unoccupied molecular orbital level of −5.49 eV is achieved. The doped films exhibit electrical conductivities up to 70 S cm−1. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract The first ambient-pressure organic super-conductors based on sulfur compounds have been obtained and investigated in (BEDT-TTP)-I system.

The low-frequency electrical conductivity of strongly nonideal hydrogen, helium, and xenon plasmas was measured in the megabar range of pressures. The plasmas in question were generated by the method of multiple shock compression in planar and cylindrical geometries, whereby it was possible to reduce effects of irreversible heating and to implement a quasi-isentropic regime. As a result, plasma states at pressures in the megabar range were realized, where the electron concentration could be as high as n e ≈2×023 cm−3, which may correspond to either a degenerate or a Boltzmann plasma characterized by a strong Coulomb Γ D =1–10) and a strong interatomic Γ a =r a n a 1/3 ∼1) interaction. A sharp increase (by three to five orders of magnitude) in the electrical conductivity of a strongly nonideal plasma due to pressure-produced ionization was recorded, and theoretical models were invoked to describe this increase. Experimental data available in this region and theoretical models proposed by various authors are analyzed. The possibility of a first-order “phase transition” in a strongly nonideal plasma is indicated.