Showing papers in "Russian Chemical Reviews in 2000"
TL;DR: In this article, the main problems in the development of this new line of research in materials technology, which has arisen on the border of the science of polymers, colloid chemistry and physical chemistry of the ultradisperse state, are discussed.
Abstract: Approaches to the preparation of organic–inorganic nanocomposites are considered from a unified viewpoint for the first time. The major problems in the development of this new line of research in materials technology, which has arisen on the border of the science of polymers, colloid chemistry and physical chemistry of the ultradisperse state, are discussed. The main methods for the formation of composite materials and polymer–inorganic cross-linked hybrids with interpenetrating networks are analysed. Primary attention is given to sol-gel procedures for their preparation, including template processes, which occur under conditions of strict stereochemical orientation of reactants, intercalation of monomers and polymers into porous and layered matrices and their intracrystalline and post-intercalation transformations. Methods for the synthesis and properties of metallopolymeric polymolecular Langmuir–Blodgett films, which are peculiar supramolecular ensembles incorporating nanosized metal-containing particles, are discussed. The generality of the processes of formation of organic–inorganic nanocomposites in living and nonliving natural objects is demonstrated and the major fields of application of nanocomposites are considered. The bibliography includes 566 references.
156 citations
TL;DR: In this article, data on the use of sulfones and sulfoxides in total stereo-, regio-and enantioselective syntheses of natural compounds is discussed and classified into the most important types of reactions.
Abstract: Data on the use of sulfones and sulfoxides in total stereo-, regio- and enantioselective syntheses of natural compounds published over the last 15–20 years are discussed and classified into the most important types of reactions. The bibliography includes 420 references.
155 citations
TL;DR: In this paper, the structure of filamentous carbon formed upon catalytic decomposition of hydrocarbons on iron subgroup metals and their alloys is considered and the regularities of the deposition of carbon on these metals are generalised.
Abstract: The structure of filamentous carbon formed upon catalytic decomposition of hydrocarbons on iron subgroup metals and their alloys is considered. The regularities of the deposition of carbon on these metals are generalised. The carbide cycle mechanism of carbon formation is considered in detail. The growth models of some morphological modifications of filamentous carbon are discussed. The bibliography includes 151 references.
130 citations
TL;DR: The most important methods of synthesis and purification of carbon nanotubes, a new form of material, are described in this paper, and the prospects for increasing the scale of preparation processes and for more extensive application of nanotsubes are evaluated.
Abstract: The most important methods of synthesis and purification of carbon nanotubes, a new form of material, are described. The prospects for increasing the scale of preparation processes and for more extensive application of nanotubes are evaluated. The bibliography includes 282 references.
87 citations
TL;DR: In this article, the use of organoaluminium reagents in organic synthesis and novel reactions involving these compounds are discussed, including carbo-and cyclo-alumination reactions of alkenes, conjugated dienes and alkynes catalysed by Ti and Zr complexes.
Abstract: The published data on the synthesis of organoaluminium compounds involving metal complex catalysts are generalised and systematised. Hydro-, carbo- and cycloalumination reactions of alkenes, conjugated dienes and alkynes catalysed by Ti and Zr complexes are considered in detail. The use of organoaluminium reagents in organic synthesis and novel reactions involving these compounds are discussed. The bibliography includes 240 references.
84 citations
TL;DR: Theoretical approaches to the analysis of electron behavior in systems with quantum-size effects are outlined in this article, where the results of experimental investigations of the thermodynamic and optical characteristics of small metal particles and thin films are presented.
Abstract: Methods for the preparation of nano-sized metal particles are considered. Theoretical approaches to the analysis of electron behaviour in systems with quantum-size effects are outlined. The results of experimental investigations of the thermodynamic and optical characteristics of small metal particles and thin films are presented. The data of experiments on the electron dynamics in single nanoparticles and nanoparticle ensembles are described. The self-assembly of nanoparticles to form supported ordered structures is considered. The bibliography includes 343 references.
81 citations
TL;DR: In this paper, the results of studies of inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands are discussed.
Abstract: The results of studies of inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands are discussed. Syntheses and structures of model compounds are surveyed and the classification of dynamic processes in these compounds is proposed. The major regularities, mechanisms and kinetics of inter-ring haptotropic rearrangements in these systems are analysed. The bibliography includes 143 references.
75 citations
TL;DR: In this paper, the synthesis, chemical properties and applications of naphthyridines are described systematically and analyzed over the last 15 years and a bibliography includes 238 references.
Abstract: Data on the synthesis, chemical properties and applications of naphthyridines published mainly over the last 15 years are described systematically and analysed. The bibliography includes 238 references.
74 citations
TL;DR: In this article, the synthesis of rhodium and palladium complexes with optically active P,N-bidentate ligands and their applications in homogeneous asymmetric catalysis are summarised and discussed.
Abstract: Published data on the synthesis of rhodium and palladium complexes with optically active P,N-bidentate ligands and their applications in homogeneous asymmetric catalysis are summarised and discussed. The effect of the nature of the P,N-bidentate compounds on the structure of the metal complexes and on enantioselectivity in catalysis is examined. Allylic substitution, cross-coupling, hydroboration and hydrosilylation catalysed by Rh or Pd complexes with optically active P,N-bidentate ligands are considered. The prospects for the development of this field of chemistry are demonstrated. The bibliography includes 186 references.
73 citations
TL;DR: The structure and properties of tetrahydroborate complexes from X-ray diffraction analysis, neutron and electron diffraction, and IR and NMR spectroscopy are considered in this article.
Abstract: Data on the structures of tetrahydroborate complexes from X-ray diffraction analysis, neutron and electron diffraction, and IR and NMR spectroscopy are considered. It is shown that, in addition to the diversity of stabilising ligands, complexes of Group III and IV transition metals are characterised by diverse types of coordination of terminal (η1, η2 and η3) and bridging (between neutral molecular units) tetrahydroborate groups. Compounds with BH4 groups with different denticities can be found among these complexes. Most tetrahydroborates of these metals in the oxidation states +3, +4 comply with the principle of maximum occupancy of the coordination sphere. Tetrahydroborates of Group III and IV metals exhibit clear-cut stereochemical non-rigidity (fluxionality): the protons of the BH4 ligand are equivalent on the NMR time scale. Group I and V–VIII transition metals mainly form η2-complexes, which are stereochemically much more rigid than complexes of Group III and IV metals. It is suggested that electronic configuration of the central atom is the crucial factor determining different structures and stereochemical behaviours of the tetrahydroborate complexes. Data on the structures and properties of post-transition and s-element tetrahydroborates are also consistent with this assumption. The bibliography includes 248 references.
73 citations
TL;DR: In this article, the role of polynuclear complexes in various reactions of alkynes is discussed based on studies of the compositions and structures of copper(I) chloride (bromide) complexes, alkyne π-complexes, and ethynyl organometallic poynuclear compounds formed in this system in solutions and in the crystalline state.
Abstract: Characteristic features of the coordination chemistry of Cu(I) and mechanisms of catalytic conversions of alkynes in the CuCl–MCl–H2O–HC≡CR system (MCl is alkali metal or ammonium chloride or amine hydrochloride; R=H, CH2OH, CH=CH2, etc.) are analysed based on studies of the compositions and structures of copper(I) chloride (bromide) complexes, alkyne π-complexes and ethynyl organometallic polynuclear compounds formed in this system in solutions and in the crystalline state. The role of polynuclear complexes in various reactions of alkynes is discussed. The bibliography includes 149 references.
TL;DR: In this paper, the problem of search for heat-accumulating materials with the required properties based on multi-component systems of anhydrous inorganic compounds is discussed, and a bibliography includes 57 references.
Abstract: Data on the heat-accumulating properties of melts are generalised. The principles and methods of thermal energy accumulation with the use of melts are considered. The problem of search for heat-accumulating materials with the required properties based on multi-component systems of anhydrous inorganic compounds is discussed. The bibliography includes 57 references.
TL;DR: In this article, the effect of mechanochemical activation on the catalytic properties of various systems is discussed, and hypotheses concerning the nature of the effect on the reactivity (including catalytic property) are considered.
Abstract: Data on the use of mechanochemical activation for the preparation of catalysts and supports are generalised. The effect of mechanochemical activation on the catalytic properties of various systems is noted. Catalytic reactions occurring under conditions of mechanochemical activation are discussed. The hypotheses concerning the nature of the effect of mechanochemical activation on the reactivity (including catalytic properties) are considered. The bibliography includes 197 references.
TL;DR: In this article, the effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed, and special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers.
Abstract: The effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed. Special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers. These mixtures can be used in the development of novel environmentally safe materials (films, coatings, packaging materials) and various articles for short-term use. The bibliography includes 105 references.
TL;DR: In this paper, data on sorption-spectroscopic and test methods for the determination of metal ions on the solid phase of ion exchange materials published over the past decade are reviewed.
Abstract: Data on sorption-spectroscopic and test methods for the determination of metal ions on the solid-phase of ion-exchange materials published over the past decade are reviewed. The advantages and disadvantages of ion-exchange materials are discussed. The detection limits and selectivity of these techniques are described. The bibliography includes 151 references.
TL;DR: In this paper, a review is devoted to various types of compounds used as agents for 'living' radical polymerization, such as alkoxyamines formed upon addition of the chain carrier radicals, R•, to stable nitroxyl radicals, as well as products of the addition of radicals to transition metal complexes with different ligands, etc.
Abstract: The review is devoted to various types of compounds used as agents for 'living' radical polymerisation, such as alkoxyamines formed upon addition of the chain carrier radicals, R•, to stable nitroxyl radicals, as well as products of the addition of the radicals to transition metal complexes with different ligands, etc In all cases, the mechanism of the action of these agents consists in their reversible dissociation A⇄R• + X•, where X• is a stable free radical or a metal-containing complex which can accept radicals R• (R• + X•→A) and thus compete with the quadratic chain termination Particular attention is paid to the studies which allowed a quantitative formulation of the mechanism of 'living' radical polymerisation in the form of a mathematical model suitable for predicting both the parameters of the polymerisation and the properties of the resulting polymer (molecular mass and polydispersity) The bibliography includes 359 references
TL;DR: In this article, the physicochemical and thermodynamic properties for pure C60F48, which is the only compound formed selectively in direct fluorination of C60, and for fluorofullerene mixtures are surveyed.
Abstract: Data on the synthesis of a new class of fluorocarbon compound, fluorofullerenes, by reactions of C60, C70, their mixtures and higher fullerenes with molecular fluorine are surveyed. The physicochemical and thermodynamic properties are presented for pure C60F48, which is the only compound formed selectively in direct fluorination of C60, and for fluorofullerene mixtures. The bibliography includes 70 references.
TL;DR: In this paper, a review deals with chemical aspects of the problem of preparation of a novel class of advanced materials, viz., high-temperature superconducting cuprates of complex chemical composition and structure.
Abstract: The review deals with chemical aspects of the problem of preparation of a novel class of advanced materials, viz., high-temperature superconducting cuprates of complex chemical composition and structure. Investigations into these types of superconductors not only made it possible to reveal the 'composition–treatment–structure–property' correlations, but also contributed significantly to the development of concepts of chemical interactions in complex oxide systems, high-temperature phase transformations, the nature of peritectic reactions, properties of cuprate melts and structural phase transitions. Particular attention is paid to the analysis of different experimental results obtained in the studies of features of physicochemical processes occurring in complex metal–oxide systems. The bibliography includes 292 references.
TL;DR: In this paper, the most reliable values of the basic thermodynamic parameters of the C60 and C70 fullerenes are recommended based on the analysis of the published data and original calculations.
Abstract: The most reliable values of the basic thermodynamic parameters of the C60 and C70 fullerenes are recommended based on the analysis of the published data and original calculations, viz., enthalpies of formation in the solid and gaseous states, saturated vapour pressures, enthalpies of sublimation, enthalpies of phase transitions, heat capacities, entropies in the condensed state and heat capacities and entropies in the ideal gas state. The factors influencing the results of thermodynamic studies of fullerenes are discussed. Various aspects of crystal structure determination, PVT-relationships and frequencies of normal modes of the C60 and C70 fullerenes are considered in order to interpret and correlate the thermodynamic data and extend them to a wide temperature range. The bibliography includes 135 references.
TL;DR: The use of crown ethers in different fields of radiochemistry is discussed systematically in this paper, where a bibliography of crown-containing extraction systems can be found in Section 2.1.
Abstract: Methods for the immobilisation of dicyclohexano- and non-substituted crown ethers are reviewed. Data on the radiation chemistry of these compounds and on the influence of irradiation on the properties of crown-containing extraction systems published over the last decade are discussed systematically. Examples of the use of crown ethers in different fields of radiochemistry are presented. The bibliography includes 199 references.
TL;DR: In this article, the authors considered the activation of perfluoroalkyl halides used as intermediates in the synthesis of partially fluorinated compounds, and the conditions for reactions of organic compounds with perfluoralkyl iodides in the presence of reductants (Na2S2O4, HOCH2SO2Na), metals and metal salts, redox systems (Na 2S2 O8, ButOOH, Pb(OAc)4, H2O2-FeSO4, Ce(SO4)2) and transition metal
Abstract: The approaches to the activation of perfluoroalkyl halides used as intermediates in the synthesis of partially fluorinated compounds are considered. The conditions for reactions of organic compounds with perfluoroalkyl iodides in the presence of reductants (Na2S2O4, HOCH2SO2Na), metals and metal salts, redox systems (Na2S2O8, ButOOH, Pb(OAc)4, H2O2–FeSO4, Ce(SO4)2) and transition metal complexes are described. The generation of perfluoroalkyl radicals by a single-electron transfer mechanism are discussed. The introduction of perfluoroalkyl groups into aromatic and unsaturated organic compounds and functionalisation of perfluoroalkyl iodides, particularly, their transformation into perfluoroalkanesulfinic and perfluoroalkanecarboxylic acids and aldehydes, are considered. The bibliography includes 442 references.
TL;DR: In this paper, the activation energy of radical addition was analyzed in terms of the parabolic model, and the following characteristics and factors were shown to affect the activation power: the reaction enthalpy, the strength of the arising bond, the radius of the atom having a free valence, the presence of a π bond adjacent to the reaction center, the interaction of two polar groups, the multidipole interaction, the steric factor, the non-linearity of the reaction centre, and force constants of the reacting bonds.
Abstract: Empirical relations describing the reactivity of reagents in radical addition reactions and the results of quantum-chemical calculations of the activation energy of these processes are considered. The experimental data obtained for the addition of atoms and radicals to molecules with multiple bonds are analysed in terms of the parabolic model. The following characteristics and factors are shown to affect the activation energy of radical addition: the reaction enthalpy, the strength of the arising bond, the radius of the atom having a free valence, the presence of a π bond adjacent to the reaction centre, the interaction of two polar groups, the multidipole interaction, the steric factor, the non-linearity of the reaction centre, and the force constants of the reacting bonds. The bibliography includes 85 references.
TL;DR: The main chemical aspects of the preparation of thin copper films from the vapour of monovalent and divalent copper derivatives as precursors in the CVD technique are considered.
Abstract: The main chemical aspects of the preparation of thin copper films from the vapour of monovalent and divalent copper derivatives as precursors in the CVD technique are considered. Data on the methods of synthesis and the properties of various types of these compounds are generalised and described systematically. The possible decomposition mechanisms of copper compounds under CVD conditions are discussed. The prospects of using the CVD technology for the preparation of thin copper films in integrated circuits of microelectronic devices are outlined. The bibliography includes 432 references.
TL;DR: Data on tandem transformations initiated by the Michael reaction published over the last five years are analysed, systematised and generalised.
Abstract: Data on tandem transformations initiated by the Michael reaction published over the last five years are analysed, systematised and generalised. The bibliography includes 86 references.
TL;DR: In this article, conditions for extrapolation of phenomenological laws of colloid chemistry to nanosize objects are considered and examples of self-organised colloidal structures are given.
Abstract: Experimental methods and theoretical concepts of colloid chemistry regarding their possible use in nanochemistry and nanotechnology are considered. The main types of disperse systems which can be regarded as nanosystems are distinguished. Some methods for the preparation of colloidal nanosystems are described. Conditions for extrapolation of phenomenological laws of colloid chemistry to nanosize objects are considered. Examples of self-organised colloidal structures are given. The bibliography includes 205 references.
TL;DR: The published data on the synthesis, structure, properties and applications of dendrimers containing conjugated π-systems, transition metal complexes and organometallic compounds are surveyed and systematised in this article.
Abstract: The published data on the synthesis, structure, properties and applications of dendrimers containing conjugated π-systems, transition metal complexes and organometallic compounds are surveyed and systematised. The bibliography includes 83 references.
TL;DR: In this paper, the authors surveyed data on procedures for protection of the carbonyl group by its conversion into the 1,3-dithiolane moiety and on cleavage of the latter under the action of different reagents.
Abstract: Data on procedures for protection of the carbonyl group by its conversion into the 1,3-dithiolane moiety and on cleavage of the latter under the action of different reagents are surveyed. The preparation of 1,3-dithiolanes from carbonyl compounds followed by deprotection can be used in syntheses of various organic compounds. The bibliography includes 54 references.
TL;DR: In this paper, the influence of the number and positions of chlorine atoms in dioxin molecules on the optical spectra (IR and UV absorption, fluorescence and phosphorescence spectra), in particular, on the low-temperature fine-structure phosphorescence spectrum of solid solutions and on the photophysical deactivation of triplet electronic states are discussed.
Abstract: Published data on the optical spectra and theoretical investigations of dioxins, polychlorinated derivatives of dibenzo-p-dioxin, which are well-known environmental toxins, are generalised. The geometrical and electronic structures of the molecules and their vibrational and electronically excited states are considered. The influence of the number and positions of chlorine atoms in dioxin molecules on the optical spectra (IR and UV absorption, fluorescence and phosphorescence spectra), in particular, on the low-temperature fine-structure phosphorescence spectra of solid solutions and on the photophysical deactivation of triplet electronic states are discussed. The results of the use of optical spectroscopy for identification and quantification of dioxins are presented. The bibliography includes 108 references.
TL;DR: In this article, published data on thermolysis of organic compounds of divalent sulfur and on thermal synthesis involving these compounds are summarised and a bibliography including 201 references is provided.
Abstract: Published data on thermolysis of organic compounds of divalent sulfur and on thermal synthesis involving these compounds are summarised The bibliography includes 201 references
TL;DR: In this article, the formation of stable nitroxyl radicals has been studied in the context of spin-labelled polymers and the use of the ESR imaging technique (ESR tomography) for the investigation of the structure of the reaction front during nitration of solid polymers.
Abstract: The mechanisms of the reactions of nitrogen oxides and different classes of solid polymers are considered. Particular emphasis is given to the analysis of the mechanisms of the formation of stable nitroxyl radicals. Double bonds and amide groups of macromolecules, as well as hydroperoxides and peroxide macroradicals are shown to be involved in the reactions with nitrogen oxides. The application of nitrogen oxides for the preparation of spin-labelled polymers and the use of the ESR imaging technique (ESR tomography) for the investigation of the structure of the reaction front during nitration of solid polymers are considered. The bibliography includes 111 references.