Fullerene compounds with transition metals MnC60: Preparation, structure, and properties

This review summarizes the results of studies on complexation of fullerene C₆₀ with transition metals. The structural background for metal-fullerene interaction is discussed. Much attention is focused on the compounds M_nC₆₀. Methods of their preparation, structure, and properties are considered in detail. The nature of their catalytic activity is discussed. Translated from Zhumal Struktumoi Khimii, Vol. 41, No. I, pp. 164-181, January–February, 2000.     

Molecular Architecture and Function of Polymeric Oriented Systems: Models for the Study of Organization,Surface Recognition,and Dynamics of Biomembranes

The Part and the Whole. The principle of self-organization for the creation of functional units is not an invention of modern natural sciences. It was already a basic idea of the ancient philosophies in Asia and Europe: only the mutuality of the parts creates the whole and its ability to function. Translated into the language of chemistry this means: the self-organization of molecules leads to supramolecular systems and is responsible for their functions. Thermotropic and lyotropic liquid crystals are such functional units, formed by self-organization. As highly oriented systems, they exhibit new properties. The importance of lyotropic liquid crystals for the life sciences has been known for a long time. They are a prerequisite for the development of life and the ability of cells to function. In materials sciences this concept of function through organization led to the development of new liquid-crystalline materials. From the point of view of macromolecular chemistry, this review tries to combine these two different fields and especially hopes to stimulate their interaction and joint treatment. To exemplify this, the molecular architecture of polymeric organized systems will be discussed. Polymeric liquid crystals combine the ability to undergo spontaneous self-organization–typical of liquid-crystalline phases–with the polymer-specific property of stabilizing these ordered states. As new materials, polymeric liquid crystals have already been investigated intensively. As model systems for biomembranes as well as for the simulation of biomembrane processes, they so far have been little discussed. The intention of this review article is to show that polymer science is able to contribute to the simulation of cellular processes such as the stabilization of biomembranes, specific surface recognition, or even the “uncorking” of cells. Polymer science, having an old tradition as an inter-disciplinary field, can no longer restrict itself to common plastics. Attempts to reach new horizons have already begun. The borderland between liquid crystals and cells will certainly play an important role. Basic requirements to work in this frontier area between organic chemistry, membrane biology, life science, and materials science will be the delight in scientific adventures as well as the courage to go ahead. The most important prerequisite will be the willingness to cooperate with disciplines which so far have not really accepted each other. From this point of view, this review does not aim at giving defined answers. It wants instead to encourage the scientific venture: too often we cling to painfully acquired knowledge, fearing adventures.     

Self-propagating high-temperature synthesis in the solid-phase triphenylphosphine-chloramine system

The macrokinetics and products of self-propagating high-temperture synthesis (SHS) in the solid-phase triphenylphosphine—chloramine system were studied by TGA-DTA, XRD, and³¹P NMR techniques. The temperature of SHS ignition (59°C), the velocity of reaction waves (1.6–5.0 mm s⁻¹), and the maximum temperature (155–239°C) in the SHS wave were measured. The chemical composition of the product obtained was established: phosphine oxide, triphenyl-N-(phenylsulfoyl)-phosphinimine, benzenesulfonamide, NaCl, and water. The scheme of chemical reactions occurring during SHS was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 301–305, February, 1999.     

Phase-transfer catalysis in reactions of electrophilic aromatic substitution

Electrophilic substitution in aromatic compounds under conditions of phase-transfer catalysis is considered. Catalysts of phase transfer of electrophilic reagents are used; their efficiency and the mechanism of their action in organic solvent-water systems are discussed.This review is based on materials of the report delivered at the Conference Phase-Transfer Catalysis. New Ideas and Methods (March 1994).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1895–1900, October, 1995.     

Membranology: an interdisciplinary science

The author's studies on membrane materials and the membrane technology of mixture separation are briefly reviewed. New, promising membrane materials as well as some mechanistic features of membrane-mediated separation of gases are discussed. With a view to desalting solutions by means of the reversed-osmosis technique, the role of the mass transfer process in the membrane apparatus is considered. The prospects of the membrane methodology in solving various biotechnological and environmental problems are apprised.On the occasion of the award of a D. Sc. (honoris causa) degree to Prof. E. Drioli (Università degli Studi della Calabria, Dipartimento di Chimica) for his works on chemical membranology by the Russian Academy of Sciences in 1991.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 826–839, May, 1993.     

Chemistry of fullerenes, novel allotropic modifications of carbon

The currently available data on the structure and reactivity of fullerenes, including the formation of metal complexes (including optically active ones) with fullerenes as ligands, are briefly surveyed. The properties and reactions of fullerenyl radicals and endohedral complexes are considered. The review is based on the report of the same name delivered at the XVI Mendeleev Congress (May 28, 1988, St. Petersburg). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1211–1218, July, 1999.     

Novel superelectrophilic complexes for low-temperature alkane and cycloalkane transformations

The results of studies on the elaboration of new superelectrophilic complexes and their use for efficient low-temperature transformations of alkanes and cycloalkanes, such as cracking, isomerization, alkylation, and single-step functionalization (acylation, carbonylation, ionic monobromination, sulfurization, thioacylation,etc.), are summarized. The activity of new aprotic organic and inorganic superacids is compared to that of known electrophilic systems, including protic superacids. The reasons for the superelectrophilic properties of new active systems are considered. This review, which was initiated by Mark Efimovich Vol'pin, is a tribute of our memory and gratitude to him. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 771–795, May, 1998.     

Advances in the Chemistry of 2,4,6-Tri(thiophen-2-yl)-1,3,5-triazine

Heterocyclic systems are now considered to be an integral part of material chemistry. Thiophene, selenophene, furan, pyrrole, carbazole, triazine and others are some such examples worth mentioning. 2,4,6-Tri(thiophen-2-yl)-1,3,5-triazine is a C_3h-symmetric system with thiophene as the donor unit and s-triazine as the acceptor unit. This review gives an insight into the advances made in the thienyl-triazine chemistry over the past two to three decades. The synthetic pathways for arriving at this system and all its important derivatives are provided. The major focus is on the materials synthesized using the thienyl-triazine system, including star molecules, linear and hyperbranched polymers, porous materials and their diverse applications. This review will play a catalytic role for new dimensions to be explored in thienyl-triazine chemistry.     

Regularities of self-propagating high-temperature synthesis in the solid 8-hydroxyquinoline—chloramine B system

The regularities of chemical reactions in solid 8-hydroxyquinoline—chloramine B mixtures were studied under conditions of organic self-propagating high-temperature synthesis (SHS), isothermal reaction, and thermal explosion in the 20–220 °C temperature range. Comprehensive physicochemical analysis and microstructural study of the reaction products were carried out. The temperature of SHS initiation (58 °C), the heat of the reaction (129±9 kJ mol⁻¹), the stoichiometric coefficient (1), the maximum temperature (T _max=98–140 °C), and the velocity of SHS wave propagation (u=0.15–0.55 mm s⁻¹) were determined. Depending on the ratio of the reactants (n), a low-temperature non-degeerate stable gasless mode (n≤1,T _max=115 °C,E _a=42 kcal mol⁻¹) and a high-temperature mode (n>1,T _max=140 °C,E _a=0.4 kcal mol⁻¹) are possible for SHS. The SHS affords monohydroxy and monochloro derivatives of 8-hydroxyquinoline, benzenesulfonamide, NaCl, NaOH, and H₂O. The mechanism of the solid-phase reaction at temperatures below 58 °C includes surface, solid-phase, and gas-phase diffusion; that for SHS is capillary spreading of the hydroxyquinoline melt. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2271–2284, December, 1999.     

SHS metallurgy of high-entropy transition metal alloys

The first positive experience in synthesis of cast high-entropy alloys in the combustion mode, referred to as SHS metallurgy (SHS is self-propagating high-temperature synthesis) has been reported. Analysis of the data obtained enables the conclusion that the one-stage SHS method is promising for the production of cast metal materials using a new principle of formation of high-entropy polymetallic alloys.     

Progresses in organic field-effect transistors and molecular electronics

In the past years, organic semiconductors have been extensively investigated as electronic materials for organic field-effect transistors (OFETs). In this review, we briefly summarize the current status of organic field-effect transistors including materials design, device physics, molecular electronics and the applications of carbon nanotubes in molecular electronics. Future prospects and investigations required to improve the OFET performance are also involved. __________ Translated from Huaxue Tongbao (Chemistry), 2006, 69(6) (in Chinese)     

SHS of NbSi2: A Comparison Between Experiments and Simulations

Computer simulation results for the Self-propagating High-temperature Synthesis (SHS) of the intermetallic compound NbSi₂ are discussed in comparison with experiments for SHS of mechanically activated powders. The variation of wave speed of the propagation front is considered while varying Nb grain size and thermal conductivity of the starting mixture. A co-operating effect of these two parameters (due to the change in morphology of reactants after milling) is outlined.     

SHS of NbSi<Subscript>2</Subscript>: A Comparison Between Experiments and Simulations

Summary. Computer simulation results for the Self-propagating High-temperature Synthesis (SHS) of the intermetallic compound NbSi₂ are discussed in comparison with experiments for SHS of mechanically activated powders. The variation of wave speed of the propagation front is considered while varying Nb grain size and thermal conductivity of the starting mixture. A co-operating effect of these two parameters (due to the change in morphology of reactants after milling) is outlined.     

New inorganic materials for medicine

New inorganic materials (metals and their alloys, carbon materials, ceramics, glass, and glass-ceramics) that are used in one of the branches of medicine,viz., bone endoprosthetics and implantology, are considered. Attention is concentrated on calcium- and phosphoruscontaining glassy and glass-ceramic materials that exhibit bioactivity with respect to a living bone. The main statements of the modern theory of bioactivity of these materials are outlined; physicochemical aspects of this theory are considered in detail. Extensive possibilities for controlling the structures, medico-biological, physicochemical, and mechanical properties of bioactive glasses, glass-ceramics, ceramics, and composites based on them are demonstrated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 246–253, February, 1997.     

New marine prostanoids, clavulones, halogenovulones, and punaglandins

In this review, questions of the isolation, biosynthesis, and total chemical synthesis of new marine prostanoids — clavulones, halogenovulones, and punaglandins — are considered.Institute of Bioorganic Chemistry, Belarus Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 315–334, May–June, 1993.     

Alkaloids ofVeratrum,Petilium, andKorolkowia

The review is devoted to a study of the steroid alkaloids of plants of the generaVeratrum, Petilium, andKorolkowia. Characteristic reactions, spectra, and some chemical transformations of the alkaloids subdivided into groups according to structure are discussed. Some methods for determining their structures are considered.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–22, January–February, 1980.     

Thermodynamc properties of energy-saturated materials

The results of thermodynamic calculation of the interaction between energy-saturated self-propagating high-temperature synthesis (SHS) and highly active chemical reagents (HCRs) are given. The results of calculation can be used to develop new technologies of joint application of HCRs and SHS in designs of the items the operation of which is based on energy-saturated materials.     

DNA as a nanomateria

This review discusses information about the use of DNA as a basis for preparing materials with new properties. The unique molecular recognition property of nucleic acids that underlies the synthesis of targeted controllable structures, where DNA functions as an engineering material rather than a genetic-information carrier, is considered. Causes of significant advances in this field are discussed. The new functional potential of novel materials is examined.     

Poly(styrene-acrylic acid) magnetic polymer microspheres

Magnetic polymer microspheres have been considered as a kind of new biopolymer materials with great advantages in bioseparation engineering and biomedicine engineering because they have not only polymer functional groups but also magnetic characteristics. Styrene-acrylic acid copolymer (p(S-AA)) magnetic microspheres were synthesized by dispersion polymerization with Fe₃O₄ as core and p(S-AA) as shell. The microspheres were characterized by SEM, size analysis, molecular weight and solid content measurement. All of them indicate that the microspheres are small in size, narrow in distribution, stable in chemistry and rich in functional groups on their surface. __________ Translated from Journal of Beijing Union University (Natural Science) 2008, 21(3): 82–84     

Processing of mineral and technogeneous raw materials by carbothermal reduction

Current studies dealing with the preparation of promising materials (most of all, ceramics) by carbothermal reduction (CR) of mineral and technogeneous raw materials is surveyed. Attention is concentrated on the mechanisms and kinetics of chemical reactions occurring during the CR process and on the effects of varying some factors during the reduction (temperature, duration of annealing, composition of the gas phase, ratio of the components, density of the blend,etc.) on the compositions and properties of the final products. Ways of optimizing particular technological schemes for the production of new materials by the CR method are discussed. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 233–245, February, 1997.