Publications by authors named "Anton Savchenkov"

A method for the visualization of noncovalent interactions using examples of the conformational polymorphs of four organic compounds: 2-(phenylamino)nicotinic, 2-(3-chloro-2-methylphenylamino)nicotinic, N-(3-chloro-2-methylphenyl)anthranilic and 2-(methylphenylamino)nicotinic acids is examined. The changes in noncovalent contacts are plotted against the angle between the planes of aromatic rings allowing a visual representation of conformational adjustment of molecules as well as packing features of crystal structures. According to the k-Φ criterion, the studied structures represent conformational polymorphs.

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Synthesis, FTIR spectral study, and X-ray diffraction analysis of single crystals of (CH)N[UO(mba)] (), (CH)N[NpO(mba)(NO)] (), (CH)N[PuO(mba)(NO)] (), and (CH)N[NpO(mba)(NO)] (), where mba is a monobromoacetate ion (CHBrCOO), were conducted. The main structural units of crystals - are mononuclear anionic complexes of the [AnO(mba)], [AnO(mba)(NO)], or [AnO(mba)(NO)] composition. All these complex units are characterized with the same crystal-chemical formula ( = AnO and = CHBrCOO or NO ).

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The structures of the single crystals of compounds KUO(tca)(tcaH) (I), KNpO(tca)(tcaH)(HO) (II), RbUO(tca)(tcaH)(HO) (III), and CsUO(tca)(tcaH)·HO (IV), where tca is the trichloroacetate ion, were established by X-ray diffraction analysis. The crystals of II-IV have a framework structure, whereas in the layered crystals of I, neighboring layers are connected to each other via halogen bonds. In this regard, the crystals of I possess perfect cleavage along the (001) plane: the crystals are easily cut into stacks of very thin layers.

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Two new gold(III) complexes with adenine or guanine nitrogenous bases as counter-cations were synthesized. These are 6-amino-7H-purine-1,9-diium tetrachloridogold(III) chloride monohydrate, (CHN)[AuCl]Cl·HO, 1, and 2-amino-6-oxo-6,7-dihydro-1H-purin-9-ium tetrachloridogold(III) hemihydrate, (CHNO)[AuCl]·0.5HO, 2.

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Synthesis and X-ray diffraction studies of {N(CH)}[AnO(CHBrCOO)] [An = U (), Np (), or Pu ()] and CHBrCOOH (), where CHBrCOO is an anion of the 3-bromopropionic acid, are reported. The isostructural coordination compounds - contain mononuclear anionic complexes [AnO(CHBrCOO)] belonging to the crystal chemical group AB (A = AnO; B = CHBrCOO). In the crystal structure of , the CHBrCOOH molecules are hydrogen bonded into centrosymmetric dimers R(8).

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Using the parameters of Voronoi-Dirichlet (VD) polyhedra the authors have verified the maximum space-filling principle in substructures constructed of actinide atoms (from thorium to einsteinium) in all crystal structures from the Inorganic Crystal Structure Database (ICSD) and Cambridge Structural Database (CSD). It is shown that most of the actinide atoms in such substructures are surrounded by 14 or 12 neighboring atoms. It was discovered that U substructures with greater than or equal to 20 crystallographically independent U atoms in the unit cell feature 15-faceted VD polyhedra as the most common type.

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A method for clear visualization of the variation of noncovalent interactions in crystal structures of conformational polymorphs is developed and introduced. The first stage of the method establishes the characteristics of all, without exception, noncovalent interactions in all crystal structures under discussion. This is possible using a strict and objective method of construction of Voronoi-Dirichlet polyhedra within the framework of the stereoatomic model of crystal structures.

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Single crystals of Na[(UO)(i-CHCOO)]·0.7HO (I), Cs[(UO)(i-CHCOO)] (II) and (NH)[(UO)(i-CHCOO)] (III) were obtained via isothermal evaporation and their structures were solved using X-ray diffraction techniques. Even though the ligands are branched, bulky and spatial, many carbon and hydrogen atoms are still disordered in these crystal structures at low temperature.

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The syntheses and crystal structures of six new heterometallic compounds containing the UO cation, o-, m-, and p-iodobenzoic acid ligands, and Tl, Rb, and Cs cations which adopt the role of both charge balancing cation and secondary metal center are described, as are the luminescent properties for Tl containing compounds 1, 4, and 6. The structures of compounds 1-3 are isomorphous and contain uranyl monomers bound by o-iodobenzoic acid ligands with Tl, Rb, and Cs cations acting as secondary metal centers. Compounds 4 and 5 are also isomorphous and feature m-iodobenzoic acid ligands bound to the uranyl cation along with Tl and Rb cations.

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X-ray diffraction was applied to the elucidation of crystal structures of single crystals of CsBa[AnO(CHCOO)], where An = U(I), Np(II), Pu(III), and KR(HO)[UO(CHCOO)], where R = Sr(IV), Ba (polymorphs V-a and V-b). FTIR spectra were analyzed for the uranium-containing crystals I, IV, and V-b. Isostructural cubic crystals I-III are constructed of typical mononuclear anionic complex units [AnO(CHCOO)] and charge-balancing Cs and Ba cations.

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Synthesis and X-ray crystallography of single crystals of [Mg(H2O)6][AnO2(C2H5COO)3]2, where An = U (I), Np (II), or Pu (III), are reported. Compounds I-III are isostructural and crystallize in the trigonal crystal system. The structures of I-III are built of hydrated magnesium cations [Mg(H2O)6](2+) and mononuclear [AnO2(C2H5COO)3](-) complexes, which belong to the AB(01)3 crystallochemical group of uranyl complexes (A = AnO2(2+), B(01) = C2H5COO(-)).

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Investigation of chemical bonding and electronic structure of coordination polymers that do not form high-quality single crystals requires special techniques. Here, we report the molecular and electronic structure of the first cesium butyratouranylate, Cs[UO(2)(n-C(3)H(7)COO)(3)][UO(2)(n-C(3)H(7)COO)(OH)(H2O)], as obtained from DFT-assisted powder X-ray diffraction data because of the low quality of crystalline sample. The topological analysis of the charge distribution within the quantum theory of atoms-in-molecules (QTAIM) space partitioning and the distribution of electron localization function (ELF) is reported.

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FT-IR spectroscopy and single-crystal X-ray structure analysis were used to characterize the discrete neutral compound diaquadioxidobis(n-valerato-κ(2)O,O')uranium(VI), [UO2(C4H9COO)2(H2O)2], (I), and the ionic compound potassium dioxidotris(n-valerato-κ(2)O,O')uranium(VI), K[UO2(C4H9COO)3], (II). The U(VI) cation in neutral (I) is at a site of 2/m symmetry. Potassium salt (II) has two U centres and two K(+) cations residing on twofold axes, while a third independent formula unit is on a general position.

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