A. I. Yanovskii

Bio: A. I. Yanovskii is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Ring (chemistry) & Hydrogen bond. The author has an hindex of 3, co-authored 39 publications receiving 135 citations. Previous affiliations of A. I. Yanovskii include Southern Federal University & A. N. Nesmeyanov Institute of Organoelement Compounds.

Synthesis, structures, and redox properties of some new dithiocarbamates that include a heteroaromatic ring

Abstract: New Cu, Ni, Pb, Zn, Co. Fe, Mn, Sb, and Bi dithiocarbamates that include 2-thenyl and 2-furfuryl radicals were synthesized. The potentials of polarographic oxidation on a rotating platinum electrode were determined for them and for the previously synthesized N-substituted unsymmetrical dithiocarbamates of the same metals. The results of x-ray diffraction analysis of bis-(di-2-thenyldithiocarbamato)nickel(2+) are presented and discussed.

Molecular structure of the 7-phenyl-12-(1′-phenyl-1′,2′-dicarba-closo-dodecaboran-2′-yl)-7, 8-dicarba-nido-dodecaborate anion-a representative of a new type of dicarba-nido-dodecaborate anion formed as a result of the opening of the closo structure of 1-phenyl-2-lithia-1,2-dicarba-closo-dodecaborane in the presence of HCONMe2 or Me2SO

Abstract: The reaction of DMFA or DMSO with 1-phenyl-2-lithia-1,2-dicarba-closo-dodecaborane results in unusual opening of the closo structure, which leads to the formation of the tetramethylammonium and methylpyridinium salts of the 7-phenyl-12-(1′-phenyl-1′,2′-dicarba-closo-dodecaboran-2′-yl)-7, 8-dicarba-nido-dodecaborate anion, whose structure was established by x-ray diffraction analysis.

Structural Studies of Novel Coordination Compounds Run in the Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences

Abstract: In this paper, selected results of the structural and theoretical studies of different types of coordination compounds synthesized in the Laboratory of X-ray Structural Studies of the Nesmeyanov Institute of Organoelement Compounds (NIOC), Russian Academy of Sciences (Center for X-ray Structural Studies in the General and Technical Chemistry Division, RAS) are presented.

The structures of MeP(C2B10H10)2CH2 and MeAs(C2B10H10)2, compounds containing o-carborane ring carbon atoms in the heterocycle

Abstract: Crystal and molecular structures have been determined for 1-methylphospha-2,3,5,6-bis-o-carboranocyclohexane and 1-methylarsa-2,3,4,5-bis-o-carboranocyclopentane.

Covalent versus Dative Bonds to Main Group Metals, a Useful Distinction

Abstract: Textbooks of inorganic chemistry describe the formation of adducts by coordination of an electron donor to an electron acceptor, often using the amine-boranes, X3N → BY3, as examples. In the Lewis (electron dot) formulas of the compounds, the dative bond in H3N → BH3 and the covalent bond in H3CCH3 are both represented by a shared electron pair. In the simple molecular orbital or valence bond models the wave functions of both electron pairs would be constructed in the same manner from the appropriate sp3 type atomic orbitals on the bonded atoms; the difference between the covalent and the dative bond becomes apparent only after the orbital coefficients have been analyzed. This may be the reason why many structural chemists seem reluctant to distinguish between the two types of bonds. The object of this article is to remind the reader that the physiocochemical properties of covalent and dative bonds may be – and often are – quite different, and to show that a distinction between the two provides a basis for understanding the structures of a wide range of main group metal compounds.

Chemical modification of titanium alkoxides for sol–gel processing

Abstract: The chemical modification of titanium alkoxides by alkoxy- and aminoalcohols, s-diketones, s-ketoesters, carboxylic and phosphonic acids, and related compounds, and the hydrolysis behavior of the organically modified precursors are reviewed Special focus is put on structural aspects and on the possibility to introduce functional organic groups Such precursors have a high potential for innovative materials syntheses because they permit control of the precursor reactivity in sol–gel processes and the preparation of titania-based inorganic–organic hybrid materials Coordination, solvation, aggregation and redistribution equilibria play an important role in the chemistry of the modified titanium alkoxides, and organic side reactions have to be taken into account

Direct Synthesis of Al−SBA-15 Mesoporous Materials via Hydrolysis-Controlled Approach

Abstract: Aluminum-substituted mesoporous SBA-15 (Al−SBA-15) materials were directly synthesized by a hydrolysis-controlled approach in which the hydrolysis of the silicon precursor (tetraethyl orthosilicate, TEOS) is accelerated by fluoride or by using tetramethyl orthosilicate (TMOS) as silicon precursor rather than TEOS. These materials were characterized by powder X-ray diffraction (XRD), N2 sorption isotherms, TEM, 27Al MAS NMR, IR spectra of pyridine adsorption, and NH3-TPD. It is found that the matched hydrolysis and condensation rates of silicon and aluminum precursors are important factors to achieve highly ordered mesoporous materials. 27Al MAS NMR spectra of Al−SBA-15 show that all aluminum species were incorporated into the silica framework for the samples prepared with the addition of fluoride. A two-step approach (sol−gel reaction at low pH followed by crystallization at high pH) was also employed for the synthesis of Al−SBA-15. Studies show that the two-step approach could efficiently avoid the leach...

Kovalente und dative Bindungen zu Hauptgruppenmetallen, eine nützliche Unterscheidung

Abstract: Lehrbucher der Anorganischen Chemie beschreiben die Bildung von Addukten als Koordination eines Elektronendonors an einen Elektronenacceptor, wobei als Beispiele oft die Amin-Borane X3N → BY3 herangezogen werden. In den Lewis(Elektronenstrich)-Formeln werden sowohl die dative Bindung (z. B. in H3N → BH3) als auch die kovalente Bindung (z. B. in H3CCH3) durch ein gemeinsames Elektronenpaar wiedergegeben. In den einfachen Molekulorbital- und Valence-Bond-Modellen wird in beiden Fallen die Wellenfunktion dieses Elektronenpaars auf die gleiche Weise aus geeigneten sp3-hybridisierten Atomorbitalen der beteiligten Atome konstruiert. Der Unterschied zwischen kovalenter und dativer Bindung tritt erst in Erscheinung, wenn die Orbitalkoeffizienten genau analysiert werden. Dies mag der Grund sein, weshalb so viele Strukturchemiker nur sehr widerwillig zwischen diesen beiden Bindungstypen unterscheiden wollen. Ziel dieses Aufsatzes ist es, dem Leser in Erinnerung zu rufen, das sich die physikochemischen Eigenschaften kovalenter und dativer Bindungen deutlich unterscheiden konnen – und sich oft auch tatsachlich unterscheiden-, und zu zeigen, das diese Betrachtungsweise eine gute Basis fur das Verstandnis der Strukturen einer Fulle von Hauptgruppenmetallverbindungen ist.