The paper shows a wave-like change in the Russian territorial structure occurred under the influence of governance factors; presents a number of detailed definitions; and formulates the basic methodical requirements to be met in decision-making processes.
The paper analyzes economic inequalities in the development of municipal units, and compares them with those concerning the subjects of the Russian Federation. We can state that the economic inequalities within the RF subject may be higher by some indicators than those between the RF subjects; and also can state that there are some municipal units observed in different RF subj ects and characterized by equal indicators. This proves the existence of trans-border regions that are economically similar. We also identify the scales of backwardness existing in most regions in comparison with regional capitals and industrial centers, and show their steady character.
The author offers a set of tools of how the applied multi-sectoral forecasts for regional development, which provide better opportunities to analyze the forecasts of the regional structure of natural and financial indicators, could be substituted for continuous time models. As our calculations show, this allows the application of such tools to most tasks of regional strategic development planning.
The paper provides an overview of methodologies applied to analyzing inter-regional income inequalities such as a cross-section approach, a time-series approach, and a distribution dynamics approach. In the paper we present some of them and describe the domains of their applicability.
The paper proposes a new scheme of spatial planning applicable to an administrative area, i.e. by selecting a set of investment projects, each of them affecting the use of land. At present the spatial planning at the level of an administrative area is «bottom-up» since there is no a national system of spatial planning yet. The paper offers new rales for demographic forecasting under a project approach suggested, and discusses some criteria which local communities or local authorities may apply if they want to reject undesirable projects.
The paper analyzes the socio-economic development in the agrarian regions of the Russian Federation. To initiate the raralization processes is considered advisable to overcome the negative social and demographic impacts. The paper identifies the basic social groups, which could be involved in such processes, and the starting conditions under which the said process could be initiated; and suggests a production agglomeration to be used as a form of agricultural production. The author shows the conditions which limit the development of agglomerations at present.
V. M. Bouznik1, Y. E. Vopilov2, S. A. Dedov3, L. N. Ignatieva4, A. S. Murin3, A. B. Slobodyuk4 1 Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences 2 Lomonosov Moscow State University, Leninskiye Gory 3 Polimer Plant of Kirovo-Chepetsk Chemical Combine 4 Institute of Chemistry, Far East Branch of the Russian Academy of Sciences bouznik@ngs.ru, vopilov@polly.phys.msu.ru
Keywords: polytetrafluoroethylene, steam thermal processing, structural features
Pages: 33-39
The structure of ultrafine polytetrafluoroethylene (PTFE) powder obtained via waste PTFE thermal treatment by superheated steam was studied. The condensation of the resulting gaseous pyrolysis products has been performed with the use of water. The features of molecular and morphological structure of the powder have been established, the potentialities of its practical application have been revealed. The technology allows processing the wastes on the industrial scale to obtain commercial product, thus solving one of the problems of fluoropolymer production.
I. P. Kremenetskaya, A. T. Belyavskiy, T. N. Vasilieva, O. P. Korytnaya, T. I. Makarova
Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre of the Russian Academy of Sciences kremen@chemy.kolasc.net.ru
Keywords: serpentine minerals, thermal activation, metaserpentine, amorphous phase, micromorphology, activity
Pages: 41-48
The processes were studied concerning the amorphization of three structural types of serpentine minerals (antigorite, lizardite, and chrysotile) and the formation of an active metastable phase resulting from thermal impact. It has been established that the level of antigorite activation is lower than the activation level for lizardite and chrysotile.
K. P. Koutsenogii1, T. I. Savchenko1, O. V. Chankina1, E. Y. Zhuravskaya2, L. A. Gyrgolkau2 1 Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences 2 Scientific Research Institute of Therapy, Siberian Branch of the Russian Academy of Medical Sciences savchenko@kinetics.nsc.ru
Keywords: elemental composition, SR XPA, blood, hair, populations
Pages: 49-59
Elemental composition has been studied for the blood of Chukchi people living in the continental part of Chukotka, and Eskimo people living at the coast of the Bering Bay, as well as for a group of Novosibirsk townspeople. Elemental composition has been determined for the hair of the Chukchi and Yakut people living in the continent. Using the Synchrotron Radiation X-ray Fluorescence Analysis (SR XFA) technique, a simultaneous determination of chemical elements in the blood of the mentioned populations has been performed, as it follows: K, Ca, Fe, Cu, Zn, Ge, Se, Br, Rb, Sr, Zr, Pb. The technique potentialities of determining the concentration of chemical elements in the hair of some groups of Yakut and Chukchi men and women using XPA SR have allowed detecting simultaneously K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Y, Zr, Mo, Hg, Pb, Bi. Individual, sexual and regional differences in the concentration of elements in blood and hair of the populations under investigation have been established. The data obtained have allowed us to estimate the level of elemental exchange for some groups of Chukchi, Yakut, Eskimo people, to reveal the features of elemental distribution, as well as to perform a certain biogeochemical characterization of the environment.
V. F. Raputa1, V. V. Kokovkin2, S. V. Morozov3 1 Institute of Computational Mathematics and Mathematical Geophysics, Siberian Branch of the Russian Academy of Sciences 2 Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences 3 Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences raputa@sscc.ru
Keywords: motor transport, snow cover, aerosol pollution, chemical composition, polyaromatic hydrocarbons, lead, numerical modelling
Pages: 61-68
Snow samples have been taken from ten points according to a special route at a distance of 150 m from the Sovetskoye highway of the Novosibirsk City, in February 2008. The studies on this object are being carried out by the authors for more than 10 years running. With the use of two sample preparation schemes, the major inorganic and organic components of automobile emission chemical composition were determined. The analysis of data concerning almost all the parameters under investigation indicates monotonously decreasing pollutant concentrations with an increase in the distance from the road. A model with a small number of parameters has been developed to estimate the precipitation of a polydisperse contaminant resulting from a linear source. Approbation of the model constructed has been performed using route observations data for snow cover aerosol pollution with polyaromatic hydrocarbons, macro components and heavy metals. Considerable composition heterogeneity of the precipitating aerosol contaminants has been demonstrated. A high level of PAH concentration in the snow was revealed both in the vicinity of and at a long distance from the road, which indicates considerable atmospheric pollution with fine-dispersed components.
A. P. Solonenko, L. V. Belskaya, O. A. Golovanova
Dostoevsky Omsk State University anna.petrovna@bk.ru
Keywords: hydroxyapatite, amino acids, inhibition, crystallization
Pages: 69-76
Thermodynamic and experimental studies were performed concerning phase formation process in the solution compositionally close to the oral fluid of humans with respect to the mineral and amino acid content. It has been established that amino acids to a considerable extent contribute into the ionic strength of the system promoting an increase in the electrostatic repulsion between the ions of the like charge and inhibiting the deposition of low-soluble calcium phosphates. In this process, the complexation of amino acids with Са2+ does not result in a decrease of the solution supersaturation level and in changing the sequence of salt precipitation. The experimental simulation results for hydroxyapatite crystallization process have demonstrated that the inhibiting effect of amino acids is caused by the adsorption interaction between ionized species and the surface of the solid phase.
E. V. Timakova, T. A. Udalova, Y. M. Yukhin
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences Yukhin@solid.nsc.ru
Keywords: bismuth (III) oxide benzoate, bismuth (III) tribenzoate, synthesis, IR and Raman spectra, thermal analysis
Pages: 77-84
Precipitation of bismuth (III) benzoates from hydrochloric and nitric solutions depending on the concentration of benzoate ions, process temperature and the concentration of hydrogen ions in solution was studied by means of X-ray phase analysis, IR and Raman spectroscopy, thermogravimetry and chemical analysis. It was established that, depending on synthesis conditions, precipitating compounds can be bismuth oxide benzoate BiOC7H5O2 or bismuth tribenzoate Bi(C7H5O2)3. The reasonability to obtain medical bismuth tribenzoate from metal bismuth after its preliminary oxidation with atmospheric oxygen was demonstrated. The formed bismuth oxide is dissolved in nitric acid (1 : 1), and bismuth (III) tribenzoate is precipitated by adding the bismuth-containing solution to the solution of sodium benzoate at the molar ratio of benzoate ions to bismuth equal to 3.0-3.2, and process temperature (70±10) °C.
K. V. Tsyplenkov
High Voltage Research Institute Kostich2004@yandex.ru
Keywords: silt sulphide therapeutic mud, lipids, antioxidants, ?-carotene, extraction, recovery
Pages: 85-92
An effect of the major technological parameters of lipid recovery from therapeutic mud was studied. The optimal conditions of lipid recovery from the silt sulphide mud of the Tukhloye Lake (Novosibirsk Region) have been determined.
N. V. Yudina, I. V. Prozorova, A. A. Ivanov, V. N. Burkova
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences nata@ipc.tsc.ru
Keywords: therapeutic muds, mechanochemical activation, lipids, carotenoids, antioxidants
Pages: 93-96
Effect of the mechanochemical activation of therapeutic mud in the planetary mill AGO-2 on the degree of dispersing, the yield of free and bound lipids and the content of β-carotene and antioxidants in them was studied. It was shown that the amount of extractable free lipids increases substantially after mechanochemical activation of the organomineral raw material in the planetary mill in the presence of orthophosphoric acid due to the release of a part of bound lipids. An increase in the content of β-carotene and antioxidants in lipids was established.
Data are presented concerning the technology employed for anionite АV-17-8 industrial production as compared to the technology developed at the Kemerovo Azot JSC, as well as an experience is described concerning the operation of AV-17-8 anionite manufactured according to a novel technology, with improved kinetic properties at the stage of finishing water purification in a water treatment plant.
L. A. Leonova1, T. I. Guzeeva1, V. V. Guzeev2 1 Tomsk Polytechnical University 2 Seversk Technological Institute, Branch State Budget Educational Institution of Higher Professional Education "National Research Nuclear University MEPhl" liliya@phtd.tpu.ru
Keywords: hydroxyapatite, sodium ethylenediaminetetraacetate, conductometric, potentiometric and photocolorimetric analysis methods, X-ray fluorescence analysis
Pages: 105-108
Transformations taking place in the system Ca(NO3)2-Na2H2Y-(NH4)2HPO4-NH4OH-H2O during the homogeneous precipitation of hydroxyapatite were studied by means of conductometric, potentiometric and photometric analysis. It was established that the synthesis of hydroxyapatite from the aqueous solutions of calcium and phosphorus salts proceeds as a sequence of several stages, and the use of disodium ethylenediaminetetraacetate promotes the formation of microcrystalline powder with Ca/P ratio close to the biological value (1.67).
We propose new algorithms to generate (predict) the structures of molecular crystals, which are based on the method of discrete modeling of molecular packings. We consider the specific features of generation algorithms for homomolecular and some heteromolecular compounds. We also study the possibility to use these algorithms for interpreting X-ray diffraction experiment.
V. G. Rau, A. A. Pugaev, T. F. Rau, A. V. Maleev
Keywords: models of crystal growth, nanosized growth nuclei, cell clusterization, coordination spheres and sequences
Pages: 12-17
Different growth models of crystal structures are briefly considered. A metric model of layer-by-layer sectoral growth proposed in [1] is described along with its application for computer modeling of the assembly of nanosized crystal growth nuclei by clusterizing the unit cell content.
V. N. Serezhkin, D. V. Pushkin, L. B. Serezhkina
Keywords: principle of maximum space filling, crystal structures, atomic sublattices, Voronoi-Dirichlet polyhedra
Pages: 18-25
Using Voronoi-Dirichlet polyhedra, the principle of maximum space filling in sublattices containing atoms of a particular element (from H to Cf) is tested in the structures of all crystalline compounds studied so far. It is found that atoms of the overwhelming majority of elements are most often surrounded by 14 neighboring atoms in these sublattices. Anomalous features of H- and C-sublattices, in which hydrogen and carbon atoms most commonly have 15 and 16 neighboring atoms respectively, and sublattices consisting of Ar, Ac, Pa, Am, Cm, Bk, or Cf atoms, in which the number of nearest neighboring atoms is usually 12, are discovered. The main reasons for the revealed differences are discussed.
V. S. Urusov, T. N. Nadezhdina
Keywords: statistics of space groups, abundant and rare (empty) groups, role of the center of symmetry and twofold axes, rules for filling positions with atoms, relationship between occurrence and symmetry of lattice complexes
Pages: 26-43
Statistical analysis of modern structural databases on inorganic crystals and minerals is carried out to elucidate the classification of crystal structure distributions over space groups. The known fact about extremely uneven occupation of space groups is confirmed; the relative abundance of all and, in particular, 24 most frequent groups (>1%) is derived, and the latter are noted to belong to holohedral and centrosymmetric classes. The data on occupation of extremely rare and empty space groups are analyzed and refined separately, which allows the reduction of a number of unreliable structural data. The theoretical analysis of empirical regularities is performed from the standpoint of filling rules for special structural positions (Wyckoff positions) and the symmetry of lattice complexes. It is shown that only combined consideration of different symmetry rules and restrictions provides an explanation for most regularities observed in occupation of symmetry point groups.
B. M. Shchedrin, E. M. Burova
Keywords: mineral classification, decimal symbols of minerals, computer analysis, statistical analysis, software
Pages: 44-47
The paper describes G. B. Bokii's idea of separating the primary classification levels of the mineral world and the results of developing the database containing G. B. Bokii's decimal symbols.
N. L. Smirnova
Keywords: local coordination, formulas, polygonal nets, simple and dual forms, Kepler-Shubnikov and Laves nets, solids of Plato, Archimedes, Hessel, and Fedorov, potential map, zeolite net, models of crystal nucleus forms, abcdefg alphabet
Pages: 48-54
Formulas of the local coordination of vertices and faces of simple and dual forms, solids of Plato, Archimedes, Hessel, and Fedorov, Kepler-Shubnikov and Laves nets, maps of potentials and zeolite nets, models of crystal nuclei are presented. All the obtained formulas enter the arrays determined previously. Alphabet formulas of ligand sequences contain no more than 1-7 different letters. The revealed formula sets predetermine the stability of a small number of qualitative and quantitative relations in multi-scale systems and the similarity of local coordination in the ordering and disordering.
The role of crystal chemical factors in the development of conditions for the formation of the magnetic structure of inorganic compounds is shown. A crystal chemical method is proposed to quantitatively estimate the strength of magnetic interactions and to determine magnetic moment orientation based on the structural data. By the example of determining the magnetic structures of two known antiferromagnetics Cs2CuCl4 and Sr2CuO3 the correspondence between the results obtained by this method and the experiment is shown. It is found that the search for new materials with the sought magnetic structure can be made using the data on the crystal structure of compounds. New Tl2Cu(CO3)2, BaCu2(AsO4)2, BaV2P2O10, VOSe2O5, KCu(CO3)F, and A(VO)(XO4) (A = Li, Na, NH4, K; X = P and As) magnets containing low-dimensional fragments are found. Magnetic interactions are analyzed; based on the structural data, the sign and strength of magnetic interactions is calculated both inside the low-dimensional fragments and between them; geometrical frustrations are studied in all compounds found.
The work considers the structural features of condensed phases under negative pressures that can be implemented under all-round stretching. It results in a decrease in the phase density due to an increase in interatomic distances, the appearance of structural defects, and the formation of new low density structures. It is noted that the stretched states are also characteristic of metastable phases such as liquids, glasses, and loose crystal structures in the region of positive pressures.
Based on structural studies of SrxBa1-xNb2O6 crystals with different concentrations of strontium and barium, the structural causality of optical nonlinearity of these crystalline materials is established. YAG:Nd laser radiation of the crystals results in a monotonic decrease in the second harmonic intensity with increasing strontium concentration in a sample. Fine details of the structure responsible for this effect are determined.
Different approaches to the individualization of mineral species formulated by G. B. Bokii and his opponents are considered. It is shown that with the development of techniques of X-ray experiments the "dominance principle" used in structural chemistry became the main tool in discovering new minerals. On the example of the eudialyte group, the individualization of mineral species distinguished by chemical and structural features, physical properties, and formation conditions is demonstrated.
S. F. Solodovnikov, E. G. Khaikina, Z. A. Solodovnikova
Keywords: lithium, complex oxides, triple molybdates, structural stabilization, crystal chemical design
Pages: 85-92
Crystal chemical features of some complex oxide lithium-containing compounds, in particular, triple molybdates, are considered to reveal the structure-forming significance of lithium. Its role is actually reduced to the realization of structures with a simpler composition through the introduction and heterovalent substitution. Specific stabilization ways can be very diverse owing to the high adaptability of lithium atoms in the structure. They can reside in the same crystallographic positions together with alkali metals (including potassium), medium-size, and even larger two- and three-charged cations and also to occupy the cavities. Such an adaptability and a low charge of the Li+ ion with its appropriate distribution in the structure allow the elimination of imbalance in cation charges and sizes of their coordination polyhedra. They also provide the filling of available vacancies, which produces a significant stabilizing effect. The stabilization of the structures with other cations or their combinations is exemplified. Attention is drawn to the relation between the structural and thermal stabilization. It is concluded that the crystal chemical stabilizing features of lithium and other cations can be used as an instrument for the design of novel compounds and materials.
N. A. Bulienkov, E. A. Zheligovskaya, V. V. Klechkovskaya
Keywords: surface layer of a liquid, mercury, water, Langmuir monolayer, modular design
Pages: 93-99
A model crystalline approximant of the surface layer (SL) structure of liquid mercury is formed using the algorithm, previously applied to form a crystalline approximant of the SL structure of water, the experimental data on the SL structure of mercury, and the stereochemical data for Hg atoms in the α-Hg crystalline phase and bulk liquid mercury. The correspondence of the metrics of the crystalline approximant proposed for the SL structure of mercury and Langmuir monolayers composed of organic molecules with hydrocarbon tails and different hydrophilic groups on liquid mercury to the position of molecules along mercury SL is shown.
K. B. Aleynikova, E. N. Zinchenko
Keywords: diffraction amorphous nanodispersed materials, glasses, structural analysis, identification, fragment model
Pages: 100-106
The main theoretical principles of the fragment model are presented. It is shown that in constructing the model radial distribution functions of atoms the parameters of the experimental radial distribution function are not used, and the model can be used to identify diffraction amorphous nanodispersed materials, to analyze the atomic structure of classic glasses, and also in the phase analysis of amorphous materials. The procedure is easy to use and does not require cumbersome calculations; the necessity to perform relaxation is absent.
The application of high pressure techniques that stimulated the development of inorganic crystal chemistry, provided the discovery of new types of polymorphic transformations, showed the insufficiency of the ionic model to describe the crystal structures of even binary compounds, poses some unexpected theoretical questions.
S. V. Borisov, S. A. Magarill, N. V. Pervukhina
Keywords: structure forming factors, cation and anion matrices, building blocks, crystal structures of sulfides and sulfosalts
Pages: 111-116
The geometry of cation and anion matrices is analyzed in the crystal structures of complex sulfides with the symmetry mirror planes perpendicular to the short translation of ~4 Å. In support of the developed crystalline state concept, the structures exhibit the spatial atomic ordering by the systems of crystallographic planes. This includes the absolute ordering by the symmetry mirror planes that tend to form hexagonal sublattices with trigon 36 nets.
N. A. Palchik, T. N. Grigoreva, T. N. Moroz
Keywords: crystal chemistry, X-ray diffraction, infrared spectroscopy, clay material, smectite-nontronite
Pages: 117-122
Crystal chemical analysis of natural clay material that formed under different physicochemical parameters shows that the analyzed samples are represented in series I by almost pure smectite (K,Na,Mg,Ca)x·nH2O·(Fe,Mg)2(Si,Al,Fe)4О10(OH)2, in series II by smectite with a small impurity (~15%) of quartz (SiO2) and plagioclase (NaAlSi3O8/CaAl2Si2O8). The studies are performed by X-ray diffraction, IR spectroscopy, electron microscopy, and microprobe analysis. It is shown that the values of d001 basal reflections of the smectites in question within 11-13 Å are due to the degree of cation occupation and hydration of the interlayer space, and differences in the frequencies of IR spectra are caused by isomorphic substitutions in the structure. Microprobe analysis results, calculated crystal chemical formulas, and values of b parameters are held only for the extreme terms in a series of dioctahedral ferric smectites: nontronites. The results reveal differences both in the composition, structure, properties, morphology and IR spectroscopic characteristics of nontronites of different origin.
Formulas of natural zeolites are generally cumbersome and not easily comparable because of differences in their written form. A summary of the formulas normalized at n = 1 is given for aluminosilicate zeolites with the [(Si,Al)nO2n] frameworks. Novel volume parameters are proposed for the framework instead of the framework density (FD) and a zeolite as a whole, which are calculated as the effective volumes of a mean (Si, Al, O) atom and a mean atom of the compound. We show the efficiency of the comparative crystal chemical analysis of zeolites in a common scale with the use of unified characteristics.
A systematic X-ray diffraction study of the interaction products of Zr(IV), Hf(IV), Nb(V), and Ta(V) oxides (fluorides) with crown-ethers (CEs) in aqueous solutions of hydrofluoric acid is performed. It is shown that oxygen-containing CEs form oxonium complexes with [NbF6]- and [TaF6]- hexafluorometallate anions. In two systems, [cis-syn-cis-DCH18C6·H3O][TaF6] and [B18C6·H3O][TaF6], the phenomenon of supramolecular isomerism is found, which is caused by a change in the conformation of the macrocycle or by a partial redistribution of intermolecular hydrogen bonds. The use of aza-crown ethers as extractants made it possible to extract unique hydrolytically unstable anions, the products of incomplete fluorine substitution for oxygen atoms in the starting oxides in the form of crystalline complexes with a composition of [(HA15C5)2][Ta2F10O] and [(HA18C6·H2O)(A18C6·H2O)] [(H2O)Nb2F9O]. In [(18C6)(H7O3)2∙(Hf2F10·2H2O)], [(HA18C6)(M2F10·2H2O)·(H3O)·H2O], and [(H2DA18C6) (M2F10·2H2O)·2H2O] (M = Zr, Hf) complexes, the metals are extracted in the form of identical (M2F10·2H2O)2- anions with a similar topology. The performed study demonstrates that macrocyclic complexones are undoubtedly promising to extract Zr(IV), Hf(IV), Nb(V), and Ta(V) from fluorine-containing aqueous solutions.
Y. A. Simonov, M. S. Fonari, J. Lipkowski, È. V. Ganin, A. A. Yavolovskii, G. L. Kamalov
Keywords: 1,3-dihydropyrimidine-2,4-diones, macrocyclic polyethers, hydrogen bonds
Pages: 143-149
The results of studies on the structure of organic complexes of the derivatives of 1,3-dihydropyrimidine-2,4-diones and their structural analogues with macrocyclic poly- and azapolyethers are generalized.
The article summarizes the results of the study of conformational states of triosmium clusters with organic ligands. Special attention is paid to the structural features of molecular carbonyl cluster complexes with Mn(CO)mL organic ligands. The effect of the structure surface charge, solvent, cluster crystalline state, and intermolecular and intramolecular interactions on the cluster conformational state is also determined.
L. V. Zorina, S. V. Simonov, S. S. Khasanov, R. P. Shibaeva
Keywords: low-dimensional conductors, radical cation salts, crystal structure, bis(ethylenedithio)tetrathia-fulvalene, octahedral anion, osmium, ruthenium
Pages: 159-165
We analyze the specific features of the structure and properties of crystals that belong to the family of low-dimensional molecular conductors based on BEDT-TTF (ET) radical cation salts with [MNOX5]2- (M = Os, Ru; X = Cl, Br) mononitrosyl metal complexes as anions. It is shown that when the synthesis components are changed single crystals with α′, β, δ, and κ-types of the conducting layers form. All radical cation salts of this family can be considered as pseudopolymorphous phases with a general formula of (ET)4[MNOX5]2-xGx (G is a guest solvent molecule, BN or NB). The studied crystals display a range of remarkable structural features such as conformational and charge ordering in the conducting ЕТ layers as well as commensurate and incommensurate structural modulations mainly related to the positional ordering of the components of complex anion layers.
The current development level of new crystal chemical methods connected with the topological analysis of atomic nets is briefly reviewed. The terminology used to describe atomic nets is considered along with the main methods for their classification and some special issues such as the study of interpenetrating nets and tilings. It is noted that the crucial problem of the modern crystal chemistry is the search for regularities underlying the global properties of a structure (both geometric and topological) such as the atomic net topology, types of atomic and molecular packing, size and architecture of voids and channels.
Results of studies performed under the guidance of A. E. Shvelashvili and continued after his decease are analyzed. We consider the coordination compounds containing both mono- and dihydrazides of carbonic acids; in particular, monohydrazides of monobasic benzoic and m-hydroxy benzoic acids (BH=C6H5C(O)NHNH2, m-HBH=HOC6H5C(O)NHNH2) and dihydrazides (DHs) of dibasic acids: malonic, succinic, and glutaric (DM=H2NHN(O)C(CH2)C(O)NHNH2, DS=H2NHN(O)C(CH2)2C(O)NHNH2, and DG=H2NHNOC(CH2)3CONHNH2). Complex compounds of metals with carbonic acid hydrazides are grouped by the ratio between main components (M:Lig = 1:1 and M:Lig = 1:2) and by the gross formulas: M(Lig)XYnH2O and M(Lig)2XYnH2O, where M(II) = Ca, Mn, Fe, Co, Ni, Cu, Zn, and Sr; Lig = ВН, m-HBH, DM, DS, DG, Х, Y (X, Y = Cl-, NCS-, I-, Br-, and are identical or different acido ligands, n = 0-4. The compounds with carbonic acid dihydrazides are classified by the redistribution criterion of ligands in the -M-DH-M- bonds depending on the M:DH ratio and the nature of the acido ligand. A division into two groups is performed by the criteria: 1) pairs of metal atoms with single bis-bidentate bridges; 2) pairs of metal atoms with double bis-bidentate bridges. Packing features of structural units are revealed in compounds containing residuals of carbonic acid hydrazides.
Intermolecular interactions in crystals of various azachalcagenenes with aromatic substituents, including polyfluorinated derivatives, are first analyzed and systematized. A topological analysis of crystal packing is carried out, and main supramolecular motifs are identified.