Home – Home – Jornals – Russian Geology and Geophysics 2011 number 10

Chronostratigraphic space is defined as information about the geologic history and paleobiosphere that elucidates the Earth's evolution in the interaction of different layers of the geosphere. Stratigraphic subdivisions act as an information-carrying medium. Elementary units in the Phanerozoic chronostratigraphic space are biostratigraphic zones, whereas in the Proterozoic space, sequenthemes. The Vendian sequentheme has a unique paleontological characterstic, which continuously expands and is refined. Its lower boundary determines the top of cryogenic suberatheme and is marked by deposition of the last diamictite (Varangerian, Marinoan) and the largest postglacial transgression. In the chronostratigraphic space, the Vendian is surely Neoproterozoic but constitutes a single acrochrone of the biosphere evolution with the Phanerozoic. The Vendian stage divides and connects two different-sized intervals in the evolution of Geomerida: a long interval of time (from the origin of life to the beginning of the Vendian) marked by a predominance of prokaryotic ecosystems and a relatively short interval with the incredible biodiversity of modern-type ecosystems dominated by eukaryotes.

The hierarchical structure and conceptual bases of the International Stratigraphic Сhart (ISS) were created during the first eight sessions of the International Geological Congress (IGC) (1878-1900) by the systematization and unification of mainly the West European regional stratigraphic references, except for the Permian and, partly, Carboniferous systems with stratotypes in the Russian territory. In the next age, the structure was refined and supplemented on the basis of the same principles. Since the middle 1980s, a radical ISS reforming has been performed in the framework of the International Commission on Stratigraphy (ICS), which revealed the contradictory tendencies in the development of modern stratigraphy. They are expressed first of all in the principal difference between the new methodology of the "rational" substantiation of global stratigraphic references adopted by the ICS and the real practice of the development of their regional equivalents based not on the choice of chronometric markers for global correlations but on the revealing of natural geohistorical stages in the evolution of ecosystems, using the total set of paleontological, sedimentological, and isotope-chronometric data. The new approach is based mainly on the concept of the self-sufficiency of limiting types, i.e., monotaxon markers for graduating the ICS, which replace the stratotypes of subunits, their integral complex characteristics reflecting the trends and periodicity of the Earth's evolution. The negative consequences of this "rational" substantiation and revision of the stratigraphic references of the ICS are particularly obvious by the example of innovations in the subdivision of the Cambrian and Ordovician systems on the comparison of the new series and stages adopted by the ISC with the global ecosystem rebuildings in the Early Paleozoic.

The present-day notions of the Paleogene history, paleogeography, and paleobiogeography of Central Asia middle latitudes are based on studies carried by A.L. Yanshin in the second quarter of the 20th century. Here, main phases in the geologic history of the West Siberian and Turan Plates and Turgai depression are considered. In the Paleocene and Eocene, these regions were key links of a continuous meridional marine communication system connecting the Tethys and Arctic Oceans. Before the emergence of the latitudinal Alpine-Himalayan orogenic belt, the Tethys and its marginal seas formed a united shelf area. The closest linkage of the water bodies and biota exchange between them existed in the Thanetian and in the first half of the Ypresian. There was intense heat transfer from tropical to higher latitudes through the entire system of epeiric seas and straits. From the end of the Paleocene, this system was supplemented and complicated by latitudinal straits that ensured the connection of the seas of the Northern Peri-Tethys with the Northern Sea basin and the Atlantic. The combination of two sea systems determined the climatic history of this region from the Paleocene till the Late Eocene. The Arctic Basin influenced mainly the structure of cold-water benthos, and the Tethys, the composition of planktonic biota in the photic zone. During the Bartonian and Priabonian, in the last phase of marine sedimentation, the West Siberian epeiric sea was completely isolated from the Arctic Basin and connected only with the Turan sea through the Turgai strait. The Azolla beds accumulated during the low stand of the World Ocean in desalted surface waters and in disoxic bottom waters inhabited by depauperated benthos. At the Eocene/Oligocene boundary, the drainage of the Tavda-Chegan sea was followed by the formation of an N-S-directed river network in the vast areas of West Siberia, Turgai, and the northern cis-Aral region. The climate was unstable, moderately warm to subtropical, with variable humidity. The formation of the Turgai ecotype of mesophytic conifer-broadleaved flora was completed by the end of the Early Oligocene.

Seismostratigraphic analysis of Paleogene deposits in northeastern Ustyurt was carried out. Four seismostratigraphic complexes have been recognized: Paleocene-Ypresian, Lutetian-Bartonian (Tasaran unit), Bartonian-Priabonian (Saksaul'skaya-Chegan), and Oligocene. We have established for the first time the clinoform structure of the Tasaran and Saksaul'skaya-Chegan complexes, which explains various concepts of their age. Seismostratigraphic analysis must be an integral part of stratigraphic research, which will significantly increase the reliability of correlation between geologic sequences.

Recent studies of the continental sources of aerosol production, transport, and deposition to the ocean (natural sink) allowed us to recognize the possibility of long-range high-altitude (transoceanic) transport of aerosol dust of specific composition and properties. The dust consists of fine (micro- and nanosized) particles (94%, less than 2 ?m) originated in the arid (undrained) tropical and subtropical regions extending into the oceans and are similar in composition to deep-sea (pelagic) red clays. Satellite and aircraft observation data were used to track trajectories of long-range (and transoceanic) transport of dust clouds. These data were coupled with direct shipboard measurements on ice core records and data on nuclear explosions and volcanic eruptions.
Several zones of arid sedimentation were identified based on climatic conditions (shortage of water), conditions of dust production, wind-blown transport at different altitudes, and deposition onto the ocean surface. The main transport occurs at two altitude scales (fr om land to the cloud top and above) (5-7 km) wh ere wind speed of 300 km/h will be critical for a long-range transport.
Three types of transport are identified based on the particle dynamics, composition and properties: 1 - local (0-10 km from the source); 2 - regional (100-1000 km); and 3 - global (over 1000 km). The finer particles are the product of local-scale transport with a total flux of 1.6 billion t/yr, which is almost equal to the net influx of the riverine terrigenous material to the pelagic zones of the oceans (outside the marginal filters). There are four main sources of aerosol dust, which is transported and deposited over arid oceanic regions. The arid oceanic regions account for about 1/3 of the modern ocean surface. During glacial periods, the sea-level drop of 100-120 m caused a significant increase in the size of arid regions as a result of the exposure of the shelf areas, which is equal to the area of the African continent. This caused 3-5 times higher dust emission and a decrease in the heat flux and in the transparency of the atmosphere. Comparison of ice core records and deep drilling data provide a basis for studies of the ancient arid sedimentation.

The first bacterial (bacillus-like) form in phosophorites was described by B. Renault and C.E. Bertrand fr om coprolites of vertebrates in the bituminous shales from the Autun region, France, in 1895. In 1990, B. Renault revealed coccoid bacteria from the same deposits. In 1983, D. Soudry and Y. Champetier described for the first time the capsules of cyanobacterial threads from Campanian phosphorites of the Negev desert, Israel. Glycocalics was first found in the Upper Jurassic-Lower Cretaceous phosphorites of the Egor'evskoe deposit on the Russian Platform, wh ere it coexists with coccoid bacteria.

Diverse stromatolitic buildings are recognized in the Meso-Neoproterozoic basins in southern East Siberia: simple (bioherms and biostromes), individual, barrier, shore reefs and reef-like structures, and large reef-like banks. These data and results of macro- and microscopic studies of stromatolites point to the leading role of microbial communities in the production of primary carbonate material. Most of the carbonate mud was supplied to the deep-water shelf zones, slopes, and plains of the Meso-Neoproterozoic East Siberian basins from shallow-water shelves. Analysis of the materials from almost all Precambrian carbonate complexes shows that the microbial communities have played the leading role in the generation of carbonate material since the Late Mesoarchean. Both the shallow- and deep-water Precambrian carbonate sedimentary systems have much in common with the Phanerozoic ones. Their diversity and development are controlled by a number of factors, which exert different effects in geodynamically different basins, and the carbonate systems of different ranks are fine indicators of various events in the basin evolution, from the low-amplitude eustatic fluctuations of the sea level to the global epochs of flooding and highstand of supercontinents.
The absence of lime-producing organisms in the Precambrian determined the similar composition of carbonate rocks and sometimes the indistinct structure-morphologic differentiation of the Precambrian organogenic buildings.
The evolution of reef systems in the Precambrian was determined first of all by the evolution of the lithosphere, which periodically led to the formation and cessation of development of basins favorable for the mass evolution of microbial communities, and by the structural complication of microbial communities producing stromatolites. The epochs of stromatolite formation reduction and destruction of sea basins correlate well with the global epochs of the formation and highstand of supercontinents.

Results of isotope (Sr, C, and O) and geochemical studies of the carbonate deposits of the Yenisei Group of the Azyr-Tal Ridge (Kuznetsk Alatau) are presented. Using the Sr and C isotope chemostratigraphy, the age restrictions for these deposits have been made. It is shown that the sediments of the Charyshtag, Bidzha, and Martyukhina Formations and the lower part of the Sorna Formation accumulated in the Late Vendian and Early Cambrian, at 580-530 Ma, and those of the upper part of the Sorna Formation, at 525-517 Ma. Their successive accumulation in the same sedimentary basin is not confirmed by the performed geochemical studies. The deposits of the upper part (members 2 and 3) of the Sorna Formation accumulated in a sedimentary basin of other type as compared with the rest underlying deposits of the Yenisei Group. For example, at least two types of shallow-water sea basins are recognized within Kuznetsk Alatau in the Late Vendian: shelf, localized within a block with a passive tectonic regime (Charyshtag, Bidzha, and Martyukhina Formations and lower part of the Sorna Formation), and oceanic, where accumulation proceeded within oceanic islands with underwater hydrothermal activity (upper part of the Sorna Formation).

Estimating the paleobasin depth is one of the most difficult problems in studying the evolution of sedimentation. Considerable depth variations in ocean and shelf paleobasins are due not only to their origin but also to the evolution of their large constituents owing to the differentiation of the dissected bottom. The Early Paleozoic volcano sedimentary and sedimentary rocks of Gorny Altai have been studied from this standpoint. They formed in the paleoceanic mounts of the Early Cambrian Kuznetsk-Altai island arc, in the Late Cambrian-Early Ordovician Altai segment of the Paleoasian Ocean, and in the outer zone of the Late Ordovician Altai shelf basin. Geological, geochemical, and lithofacies data permitted expert estimates of the absolute vertical depths of individual paleobasin fragments with siliceous sedimentation, calibrated at the final stage by bioindicator methods. The upper parts of the paleoceanic mounts in the Early Cambrian Kuznetsk-Altai island arc are presumed to occur at depths of 300-400 m; those of the paleoceanic mounts in the Late Cambrian-Early Ordovician Altai segment of the Paleoasian ocean, at depths of 500-1200 m; and the outer edge of the outer zone of the Late Ordovician Altai shelf basin, at depths of 150-500 m.

We summarize the results of the integrated lithological and ichnofacies studies of the Callovian-Oxfordian sediments in the West Siberian sedimentary basin on the basis of core samples from more than 200 wells. In the sections of various structure-facies zones, ten ichnofossils of the ichnofacies Skolithos, Cruziana, and Zoophycos have been identified and spatial variations in the species composition of ichnofacies assemblages have been traced. It has been found that lateral and vertical variations in the ichnofossil distribution agree with the regional structural patterns of the Vasyugan Horizon and are related to the Callovian-Oxfordian cyclic turnovers of the basin depositional systems.

An integrated sedimentological study of the Vasyugan Horizon in the Aleksandrovskoe arch area was performed, during which its depositional environments were reconstructed and a series of paleogeographic maps was plotted. It has been established that shallow-marine, marginal-marine, transitional, and continental depositional environments existed here at various stages. Most of the arch area is characterized by sections of the transitional Naunak-Vasyugan and Vasyugan-Naunak types; the westernmost part, by sections of the Vasyugan type; and the easternmost part, by sections of the Naunak type. The sand beds of the J₁ horizon are low-quality reservoirs, whereas those on the western slope and the northern pericline of the Aleksandrovskoe arch are of better quality.

Seismic gravity modeling along the Eurobridge-96-Eurobridge-97 DSS geotransects has shown that the Central Belarus suture zone formed in the Paleoproterozoic as a result of the subduction and collision processes at the convergent junction of the Fennoscandian and Sarmatian segments of the East European Platform. The influence of pre-Riphean processes on the subsequent tectonic events occurring on the territory of Belarus during the Phanerozoic has been established.

Spatial distribution of terrestrial Invertebrata assemblages is analyzed for West-Siberian Plain. Several functional groups, namely soil nematodes, annelids, microarthropods, mesoarthropods, snails, grass layer arthropods, are discriminated. Their air-dry biomass and roles in the local ecosystems are estimated. Two classifications of invertebrate assemblages are made: the first classification is for data averaged relative to primary contours of the vegetation map of West-Siberian Plain and the latter one is for the contour groups on this map. The digital thematic map of invertebrate assemblages' distribution is made. Some peculiarities of their spatial heterogeneity are revealed in comparison with the vegetation and humus distribution patterns. The biomass distribution pattern of invertebrate groups is less heterogeneous, but it corresponds to the distribution of life zones.

Differentiation of vertebrate population and ecosystems over vegetation at the level of type, judging from formalized classifications of different blocks of ecosystems of East Siberia over the allocations of the geobotanical map, coincide almost completely and substantially differs from that in the underground component due to the strong effect of waterlogging on the latter. In the communities of invertebrates, the differences in the boreal-subboreal parts are essential, where waterlogging is more significant and more similarity is observed for middle- and south-taiga communities than for subtaiga-steppe ones.  Over the groups of map allocations, heterogeneity of vertebrates population differs from that in all the considered blocks of ecosystems by larger differentiation in the tundra zone. In the pre-tundra - northern taiga subzones and from middle taiga to the steppe zone, the heterogeneity of vertebrate communities is somewhat smaller than that of vegetation and especially of the underground block of ecosystems. However, these differences relate only to the hierarchy of division and are often exhibited at the level of taxons at the range of sub-type or class. These are the evidences of relative independence of changes of the distinguished blocks of ecosystems, which gives rise to non-coincidence of the boundaries and amounts of taxons in them, as well as continuality of ecosystems in general. Essential non-coincidence of traditional geobotanical and typological-chorologic population bands of terrestrial vertebrates is observed.

Investigation revealed 21 kinds of pathologies in the embryonal development of amphibia and more than 30 kinds in small mammals at the territories with radiation-chemical environmental pollution. Differences in embryonal mortality and pathologies of embryogenesis were demonstrated both for the representatives of amphibia and mammals and within one class at the regions with different technogenic load. Embryonаl death and pathologies of embryonal development are considered as important reasons of reproductive losses for different species.

Investigation of the sensitivity of seven zooplankton species Daphnia magna, D. longispina, D. pulex, Simocephalus vetulus, Scapholeberis mucronаta, Eudiaptomus graciloides, Cyclops strenuus to sumicidin-alpha insecticide was carried out. The values of LC₅₀ for 24 h exposure were determined. The most sensitive species turned out to be Daphnia pulex and D. longispina, the least sensitive ones - representatives of natural population of Daphnia magna. The data on the distribution of zooplankton species sensitivity are presented. The concentrations potentially dangerous for 5 and 50 % of species in the community were calculated.

In the first communication, the main features of the spatial nonuniformity of Mesostigmata mites populations at the territory of North-Eastern Altay are revealed on the basis of the results of investigations carried out in June 2006 and 2007.

Carabid community in the forest-steppe in the south of West Siberia at the 180 m continuous transect from the centre of a small birch forest through steppe and mesophytic meadows to a single tree was studied. It was shown that the carabid сommunities can be divided into versions characteristic of open and forest habitats. The community of open habitats is more differentiated than the forest one, and it is subdivided into the versions of steppe and meadow habitats. Generalist species exhibiting no preferences for definite grass habitats were also revealed.

Distribution of black grouse and hazel grouse was evaluated on the basis of the results of bird records from July 16 to August 31, 1959-2005, over the territories of all the natural geographic zones and subzones of West Siberia (with fractioning down to the type of landscape tract). Data averaging over the groups of vegetation map allocations (dynamic series), and other specific averaging procedures, revealed that black grouse is common in north-, middle-, and south-taiga bogs; in sub-taiga pineries; in grassy bogs in combination with halophytic meadows within the boundaries of sub-taiga forests and northern forest-steppe; and at the agricultural land of the northern forest-steppe. Hazel grouse is numerous in southern taiga and dark coniferous middle-taiga forests and their derivatives. The number of hazel grouse individuals in these habitats is larger than in other lands. In general, over the sub-zones, both black grouse and hazel grouse are most numerous in middle and southern taiga and sub-taiga forests. To the north and to the south of these sub-zones the abundance of these species decreases. They were not encountered in tundras and some open forest-steppe and steppe habitats.

Results of comparative analysis of selectivity patterns of food items for two ecologically close hollow-nesting birds - red-breasted flycatcher Ficedula parva (Muscicapidae) and Siberian tit Parus cinctus (Paridae) according to the way of catching, the place of foraging and the daily activity in nestling feeding are considered. The main diet of nestlings studied consists of spiders and insects; the proportion of these taxons is almost identical for both species. So, the share of spiders in the diet of red-breasted flycatcher is 37 %, insects 59 % (totally 424 food items), and for Siberian tit it is 36.9 and 61.6 % (totally 130), respectively. However, the first species catches predominantly flying imago forms of insects (32.6 %), and the second one - non-flying, larval forms (37.7 %). The observed selectivity of these two bird species reflects the difference in the ways and places of foraging. The identified selectivity of victims testifies about the difference in their way and place of food catching. Daily duration of nestling feeding is 17-18 h for red-breasted flycatcher and 16-17 h for Siberian tit. Daily frequency of nestling feedings depends on weather and varies in different ways. In red-breasted flycatcher, it varies from 209 to 656 times in warm and cold weather, while in Siberian tit from 182 to 151, respectively. Apparently relatively low daily activity of nestling feeding and absence of strong fluctuations depending on weather conditions in Siberian tit relate to low need of its nestlings in food resources and condition larger adaptation of this species to acute fluctuations of environmental temperature.

Many indices of bird moult are not only species- but also population-related characteristics. Investigation of post-juvenile moult of black-faced buntings revealed substantial differences in its completeness for young birds in the south of Primorsky Territory in comparison with the birds from more northern populations (Khingan-Bureya upland). In Primorye, partial replacement of primaries was observed in the young birds of the first broods. Measurements of feathers before and after moulting revealed the difference in the length of juvenile primaries and analogous feathers of the next generation. On the basis of this difference, a procedure was developed that allows us to differentiate the major part of black-faced buntings in Primorye during autumn.

New foci of hantavirus circulation were revealed at the territories of Altay and Krasnoyarsk Territories, in Novosibirsk, Kemerovo, Tomsk Regions and in the Republic of Altay. It was shown that hantaviruses are distributed over all the landscape zones and subzones. The carriers of hantaviruses at the studied territory are bank vole, large-toothed redback vole, northern red-backed vole, narrow-skulled vole, dark vole, root vole, sagebruch vole, east-asian and field mouse.

Species composition of helminthes and population genetic variability indices of small mammals were studied in 17 localities of Western Siberia. There is a positive correlation between species diversity indices of small mammals and their helminthes (r = + 0.57, P < 0.001) and a negative correlation between species diversity indices of helminthes and population genetic variability of their hosts.

Long-term monitoring of helminth communities in rodents of small-leaved woods in Northern Baraba ( Novosibirsk area) was carried out. It was established that the fractions of vole populations infected with nematoda Hepaticola hepatica (Bancroft, 1893) Hall, 1916 are: 32,1 % - Arvicola terrestris, L., 1758; 9,1 % - Microtus agrestis, L., 1761; 3,1 % - M oeconomus, Pall., 1776 ; 2,6 % - Clethrionomys glareolus, Schreb, 1780; 2,2 % - C. rutilus, Pall., 1779 and 0,9 % of Apodemus agrarius, Pall., 1771. It is shown that during the mass reproduction of water vole it occupies the dominant position in the structure of rodent community and has major importance in the realization of the life cycle of the parasite. During its low number, the centers of H. hepatica infection in the biosenosis are supported by M. agrestis and C. glareolus voles.

New data on shrew faunа and inhabitants in steppe and forest zones of the Eastern Transbaikalia are presented in the paper. The data were sampled by the author or are based on the review of previous collections.

Composition, structure and functioning of the communities of small rodents in the Kuznetsky Alatau mountains are studied and their comparative characterization is made. It is demonstrated that the complicated differentiation of the mountain range into altitudinal belts leads to the formation of several types of small rodent communities: forest-steppe, dark coniferous forest, chern forest, high mountain tundra. The communities differ from each other in species composition, structure, and total domination number. Communities are formed under the influence of environmental parameters such as the level of wetting, the composition of vegetation and the degree of anthropogenic transformation of the territory.

The interannual variation of the water vole (Arvicola terrestris L.) has been analyzed with respect to two linear combinations of craniometric characters with the highest additive heritability. The greatest phenotypic differences have been revealed between samples from the low phase of population density and others.

The dynamics of habitat and number of elk in West Siberia is described on the basis of analysis of perennial data. For the south-eastern region of the West Siberian part of the habitat, on the basis of investigation of the structure of hypervariable domain of the D-loop of mtDNA, the joint habitation of alk with haplotypes of both European (A. a. alces L.) and East-Siberian (A. a. pfizenmayeri Zukowski) subspecies was demonstrated. The high nucleotide () and haplotypic (H) diversity substantially exceeding similar indices for elk in the European part of Russia and the Urals was demonstrated.

Interdecadal variations in the migration of Alopex lagopus Linnaeus in East-European tundras are studied. The most intense and long-distance migrations are detected during the periods of the highest number of these animals. The directions of migration are determined to a substantial extent by the features of behavioral responses of different sex and age groups of the animals to the environment.

Skull dimensions of nine sable populations in Yakutia (n = 1230 ind.) were studied. Differentiation in the dimensional structure between autochthon left-bank (large dimensions) and introduced right-bank (small dimensions) population groups was revealed. Allochthonous groups occupy an intermediate position between the founders (Vitim, Bureya, Kamchatka) and left-bank aboriginals exhibiting morphological trends that lead to the appearance of new forms of the species.

The (NH₄)₃[Yb^III(ttha)]·5H₂O (I) (H₆ttha = triethylenetetramine-N,N,N′,N″,N′′′,N′′′-hexaacetic acid) and (NH₄)[Yb^III(pdta)(H₂O)₂]·5H₂O (II) (H₄pdta = propylenediamine-N,N,N′,N′-tetraacetic acid) complexes are synthesized by heat-refluxing and acidity-adjusting methods, and their structures are determined by single crystal X-ray diffraction techniques. These two complexes are all mononuclear structures. The complex I crystallizes in the monoclinic crystal system with the P2₁/c space group. The central Yb^III ion is nine-coordinated only by one ttha ligand, and one non-coordinate carboxyl group is left. The crystal data are as follows: a = 10.321(4), b = 12.744(5), c = 23.203(9) Å, β = 91.082(6)°, V = 3051(2) ų, Z = 4, D_c =
= 1.754 g/cm³, μ = 3.150 mm^-1, F(000) = 1636, R = 0.0357, and wR = 0.0672 for 6203 observed reflections with I ≥ 2σ(I). The YbN₄O₅ part in the [Yb^III(ttha)]³⁻ complex anion forms
a pseudo-monocapped square antiprismatic polyhedron. The complex II is coordinated with one pdta ligand and two water molecules, which form an eight-coordinate structure, and crystallizes in the triclinic crystal system with the space group. The YbN₂O₆ part in the [Yb^III(pdta)(H₂O)₂]⁻ complex anion makes a pseudo-square antiprismatic polyhedron. The crystal data are as follows: a = 9.8923(9), b = 10.9627(10), c = 12.2618(11) Å, α = 67.284(5)°, β = 70.956(6)°, γ = 68.741(5)°, V = 1115.97(18) ų, Z = 2, D_c = 1.843 g/cm³, μ = 4.264 mm^-1, F(000) = 618, R = 0.0177, and wR = 0.0409 for 4036 observed reflections with I ≥ 2σ(I).

3,5-Dimethyl-1Н-pyrazolide of 3-O-acetyl ursolic acid (II) is obtained in the course of the interaction of 3-O-acetyl ursolic acid acyl chloride (I) and 3,5-dimethyl-1Н-pyrazole. The crystal structure of compound II is determined from the single crystal XRD data (150 K, Вruker X8 Apex CCD autodiffractometer, МоK_α radiation). The crystals are rhombic, the unit cell parameters are as follows: a = 10.6034(2) Å, b = 12.4096(2) Å, c = 24.5972(5) Å, Р2₁2₁2₁ space group. The structure consists of discrete acentric molecules. When pyrazolide II is boiled in the alcohol alkali solution, secondary hydroxyl is deacetylated and 3,5-dimethyl-1H-pyrazolide of ursolic acid IV is formed. Compounds II and IV are studied by NMR spectroscopy.

The title compound is analyzed by X-ray diffraction. ONIOM(B3LYP/6-31G(d,p):PM3) is used to investigate the optimized calculation and the frequency analysis of the molecule, in which the PM3 method was used for carbon and hydrogen atoms of the benzene ring and the B3LYP/6-31G(d,p) method was used for the other parts. Energy changes in the molecule are numerically investigated by the flexible scan at PM3 level. The nature of intramolecular interactions that stabilize the structure in vacuo and solid is studied. The results reveal that the molecule is flexible and molecular conformations can easily be mutually transformed through very small potential barriers.

The title compound 2-{[3-Methyl-3-phenyl-cyclobutyl)-thiazol-2-yl]-hydrazonomethyl}-phenol (C₂₁H₂₁N₃S₁O₁) crystallizes in the P-1 triclinic space group with a = 5.8880(4), b = 9.5618(5), c = 17.0484(10) Å, α = 80.214(5)°, β = 80.532(5)°, γ = 80.116(5)°. In addition to molecular geometry and packing from X-ray experiment, we have also calculated the molecular geometry and vibrational frequencies of the title compound in the ground state using density functional theory DFT (B3LYP) with the 6-31G(d,p) basis set. Apart from this, the structure of the title compound is characterized by ¹H NMR, ¹³C NMR, IR and UV-vis. Spectra, and the experimental emission energies are compared with the HOMO-LUMO energy gaps calculated by the DFT method.

Crystal structure parameters (coordination numbers, interatomic distances, unit cell volumes), characteristics of phase transformations, and physical properties of macrosamples can depend on the size of crystal grains. The size effect is especially significant in the electrophysical properties of crystals, including the effect of dispersed powders on the properties of polar liquids contacting with them.

The crystal structure of a newly synthesized molecular adduct of antimony(III) fluoride with L-phenylalanine of the composition SbF₃(C₉H₁₁NO₂) is determined for the first time (monoclinic crystal system: a = 5.8742(1) Å, b = 6.2079(1) Å, c = 15.5401(3) Å, β = 90.741(1)°, Z = 2, P2₁ space group). The structure consists of SbF₃ molecules and L-phenylalanine bound into polymer chains by bidentate bridging carboxyl groups of amino acid molecules. Weak Sb…F(3)^b bonds organize the adjacent chains into polymer ribbons that are bound into layers by N-H…F and N-H…O hydrogen bonds

A cadmium(II) complex, tetrakis(N,N′-diethylthiourea)sulfatocadmium(II), [Cd(Detu)₄SO₄] (1) was prepared and its crystal structure was determined by x-ray crystallography. The crystal structure of the complex consists of an independent molecule with the central cadmium atom coordinated to four thione sulfur atoms of Detu and two oxygen atoms of the sulfate ligand. The Cd atom has a pseudo-octahedral coordination environment with the cis angles varying from 57.68 to 126.57°, while the trans angles fall in the range of 142 to 169°. The new complex was also characterized by IR and NMR spectroscopy and the spectroscopic data are discussed in terms of the nature of bonding.

A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex [Tb_0.5(C₆NO₂H₅)₃(H₂O)₂]_2n·(H₃O)_4n(ZnCl₅)_n(ZnCl₄)_2n (1) is synthesized. It has a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that it displays interesting emissions in the violet, blue, green, and yellow regions.

The title compound (C₂₀H₁₈FN₃O₂, Mr = 351.37) is prepared and its crystal structure is determined by single crystal X-ray diffraction. The crystal is tetragonal, the P-42(1)c space group with a = 11.0922(6), b = 11.0922(6), c = 28.6271(15) Å, V = 3522.2(3) ų, Z = 8, d_x =
= 1.325 g/cm³, F(000) = 1472, μ = 0.095 mm^-1, MoK_α radiation (λ = 0.71073), R = 0.0505, wR = 0.1090 for 2433 observed reflections with I > 2σ(I). The X-ray diffraction analysis reveals that all ring atoms in the benzo[4,5]furo[3,2-d]pyrimidinone moieties are almost coplanar.

3-chloro-N-(8′-quinolyl)benzo[b]thiophene-2-carboxamide was synthesized from 3-chlorobenzo[b] thiophene -2-carboxyl chloride and 8-aminoquinoline in the presence of triethylamine. The single crystal X-ray structure determination confirmed the earlier proposed structure and also characterized by ¹HNMR, and Mass spectroscopy. Crystallographic study reveals that the structure crystallizes in monoclinic system, a = 14.878(4), b = 8.4292(15), c = 25.461(7) Å, β = 112.022(18)°, Z = 8, V = 2960.20(12) ų with space group C2/c (No. 15). In the structure packing, three kinds of interactions are responsible for the stability of the structure. Infinite two-dimensional stair-like layered chains are formed by relatively strong intermolecular hydrogen bonds [C14-H14…O1]. These parallel chains are connected by several
π-π and CH-π interactions, alternatively. There are two such parallel chains with 70.53°, which are in contact by van der Waals interactions.