Isomerization kinetics of carbon clusters 1. Potential of interatomic interaction

Formation of fullerenes — spherical carbon clusters C₆₀ and clusters of other sizes — during condensation of carbon vapors has not yet received theoretical explanation. Recent experimental works concerned with cluster formation in carbon vapors have established that during condensation carbon atoms form rings and then polycyclic clusters, which are precursors of fullerenes. Theoretical investigation of the spontaneous formation of fullerenes from polycyclic rings calls for a simple model of the potential of interatomic interaction of carbon, which would allow fast calculations of bond energies and statistical sums of the clusters. We use the modified Brenner potential, which was developed for hydrocarbon molecules. The parameters of the potential are refitted according to the results of quantum chemical calculations. Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences. Institute of Computation Technologies, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 37, No.4, pp. 664–670, July–August, 1996. Translated by I. Izvekova     

Interactions between cyclic carbon clusters

This work reports on the results of MINDO/3 calculations of the structures and energies of monocyclic and bicyclic carbon clusters. Interactions between the rings and between the cyclic and linear clusters are considered. For the most typical reactions (cyclization of linear clusters and insertion of chains into rings and formation of bicyclic structures), the energy barriers are estimated. The bond energies of the bicyclic structures depend on the parities of the initial rings. The most stable configurations with bond energies of the order of 5 eV result from coupling of the odd-membered rings. It is shown that typical condensation conditions correspond to the absorption of the linear clusters by the cyclic structures. Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences. Institute of Computational Technologies, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 991–997, November–December, 1995. Translated from I. Izvekova     

Interactions of linear carbon clusters

Collisions of linear carbon clusters are investigated theoretically using the MINDO/3 method. It is shown that if a collision of two clusters transfers the system into a bound state, at the next step a four-or three-pronged star is formed. If the prongs are not closed in rings, the system evolves to a linear isomer due to “migration of atoms through the center”, which is a diffusion mechanism, by which the atoms overcome relatively small barriers to migrate through the center of the star from one prong to another. When a prong is reduced to two atoms, it is absorbed. If one or two pairs of prongs have time for cyclization, the final product is a monocyclic or bicyclic isomer. Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences. Institute of Computational Technologies, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 983–990, November–December, 1995. Translated by I. Izvekova     

Conformational combinatorial analysis of polyhedral water clusters

A topological model of polyhedral water clusters that takes into account the conformational type of hydrogen bond is suggested. The polyhedral structures are classified according to the number of transand cis-conformations. The structural features of clusters with the maximal number of more stable trans-conformations are studied. Institute of Earth Cryosphere, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 1, pp. 98–106, January–February, 1996 Translated by L. Smolina     

Coordinated diaminoguanidinium(1+) ion in the crystal structure of the [Cu(CH8N5)Cl3] complex

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Institute of Organoelement Compounds, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 936–941, September–October, 1995.     

Crystal and molecular structure of 1-(2′-methoxyphenyl)-3,7,10-trimethylstannatrane

A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 5, pp. 199–203, September–October, 1994.     

Inorganic crystal structure database. Design and operational experience

The Inorganic Crystal Structure Database is a section of the Databank on the Properties of Materials for Electronics that was created at the Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. The database, which is supplied with constantly updated software, includes quantitative structural data and is designed for solving materials-technology problems. The database contains information on crystal structures of complex and ordinary oxides (including compounds with HTSC properties), chalcogenides, intermetallic compounds, inorganic complexes, etc. More than 20 scientific works on different topics were performed using the database. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 3, pp. 559–563, May–June, 1995. Translated by L. Smolina     

Construction of crystal structure sections using the clat software package

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Institute of Physical Chemistry, Polish Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 5, pp. 956–959, September–October, 1995.     

Production of (+)-norsolanadione

Institute of Chemistry, Bashkir Scientific Center, Urals Branch, Russian Academy of Sciences, Ufa. Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 735–736, September–October, 1991.     

Matrix method of conformational optimization. Application to cyclic and polyhedral water clusters

A matrix method for conformational optimization of quasi-one-dimensional molecular structures is suggested. The method is used to determine cyclic and polyhedral configurations of water clusters with the maximal number of stable trans-conformations of molecular pairs forming hydrogen bonds. Institute of Earth Cryosphere, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 1, pp. 107–115, January–February, 1996 Translated by L. Smolina     

MNDO calculations of the electronic structure of lead β-diketonates

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturmoi Khimii, Vol. 35, No. 6, pp. 186–190, November–December, 1994.     

Problems of using dynamic NMR techniques in studies of photoinduced molecular dynamics

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 4, pp. 753–756, July–August, 1995.     

X-ray diffraction study of polycrystals and films of lead (II) hexafluoroacetyl acetonate and pivaloyltrifluoroacetyl acetonate

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturmoi Khimii, Vol. 35, No. 3, pp. 136–140, May–June, 1994.     

Paramagnetic nickel defect withC 3v symmetry in synthetic diamonds

Institute of Inorganic Chemistry, Siberian Branch Russian Academy of Sciences Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 4, pp. 138–141, July–August, 1994.     

IR spectral study of SO2 adsorption on polysiloxane layers containing tertiary amino groups

Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 1, pp. 164–167, January–February, 1996.     

Crystal structure of bis(5,5-dimethyl-1-hydroxo-4-oxo-2-phenyl-pyrrolin-2-YL-3), recyclization product of 3-imidazoline enaminoketone

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 3, pp. 145–151, May–June 1994.     

Crystal and molecular structure of lead(II) pivalyl trifluoroacetonate

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 6, pp. 197–201, November–December, 1994.     

Synthesis and x-ray diffraction study of rhodium and iridium hexanitrite plumbates

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 141–143, January–February, 1994.     

X α-SW calculation of the XANES spectra of molybdenum in NiMoO4 and MoO3 crystals

Disadvantages of the modeling of the nearest crystal environment by a traditionally charged cluster for an atom with essentially covalent bonds are demonstrated by a comparison between the numerical and experimental XANES absorption spectra of molybdenum in NiMoO₄ and MoO₃. A model of boundary conditions is proposed, which allows adequate calculation of the covalent character of bonds in terms of the SCF-X_α-SW method. The oxygen environment of molybdenum in NiMoO₄ is determined. Institute of Solid State Chemistry and Processing of Minerals, Siberian Branch, Russian Academy of Sciences. Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1004–1011, November–December, 1995. Translated by I. Izvekova     

On the symmetry-stability problem

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 6, pp. 1156–1157, November–December, 1995.