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Natalia V Kuratieva

Publications and source records attributed to Natalia V Kuratieva.

9 recordsLinked to original sources
PubMed2006

Jørgensen complex within a molecular container: selective encapsulation of trans-[Co(en)2Cl2]+ into cucurbit[8]uril and influence of inclusion on guest's properties.

The unprecedented selective encapsulation of trans-[Co(en)2Cl2]+ from the mixture of trans and cis isomers into the cavity of macrocyclic cavitand cucurbit[8]uril (C48H48N32O16, CB[8]) leads to the inclusion compound {trans-[Co(en)2Cl2]@CB[8]}Cl.17H2O (1). Single-crystal X-ray analysis, 1H NMR, and ESI-MS spectra confirm the formation of host-guest complex 1 in both solid state and solution. The geometry of the complex cation alters significantly upon inclusion, which causes appreciable hypsochromic shifts of the absorption bands of the guest complex. According to TGA data, inclusion of trans-[Co(en)2Cl2]+ dramatically stabilizes the complex toward thermal decomposition. Encapsulation of trans-[Co(en)2Cl2]+ into the CB[8] cavity also increases the stability of the metal complex toward isomerization into the cis form. The supramolecular adduct {cis-[Co(en)2(H2O)2](CB[8])6}Cl3.ca109.5H2O (2) was isolated only after prolonged heating of an aqueous solution of 1 at 120 degrees C in an evacuated tube; it was characterized by X-ray crystallography, IR, and elemental analysis.

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PubMed2005

Iron(III) dihydrogenphosphate(I).

The structure of rhombohedral (R3) iron(III) tris[dihydrogenphosphate(I)] or iron(III) hypophosphite, Fe(H2PO2)3, has been determined by single-crystal X-ray diffraction. The structure consists of [001] chains of Fe3+ cations in octahedral sites with -3 symmetry bridged by bidentate hypophosphite anions.

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PubMed2005

Synthesis and crystal structure of unprecedented oxo/hydroxo-bridged polynuclear gallium(III) aqua complexes.

Two new polynuclear oxo/hydroxo-bridged polynuclear gallium(III) aqua complexes are obtained upon treatment of Ga(3+)(aq) with pyridine: the supramolecular compound of macrocyclic cavitand cucurbit[6]uril with gallium complex containing 32 metal atoms [Ga(32)(mu(4)-O)(12)(mu(3)-O)(8)(mu(2)-O)(7)(mu(2)-OH)(39)(H(2)O)(20)](PyH subsetC(36)H(36)N(24)O(12))(3)(NO(3))(6).53H(2)O (1) and the tridecanuclear complex [Ga(13)(mu(3)-OH)(6)(mu(2)-OH)(18)(H(2)O)(24)](NO(3))(15).12H(2)O (2). It follows that two modes of nucleation exist when Ga(3+)(aq) is hydrolyzed: one around the tetrahedral GaO(4) units (complex 1) and the other around the octahedral GaO(6) units (complex 2). This is the first time that polynuclear oxo/hydroxo-bridged aqua complexes of Ga(III) have been isolated without the use of other ligands to control or block olygomerization.

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PubMed2005

The bivalent metal hypophosphites Sr(H2PO2)2, Pb(H2PO2)2 and Ba(H2PO2)2.

The structures of isomorphous monoclinic strontium and lead bis(dihydrogenphosphate), Sr(H2PO2)2 and Pb(H2PO2)2, and orthorhombic barium bis(dihydrogenphosphate), Ba(H2PO2)2, consist of layers of hypophosphite anions and metal cations exhibiting square antiprismatic coordination by O atoms. The Sr and Pb atoms are located on sites with point symmetry 2, and the Ba atoms are on sites with point symmetry 222. Within the layers, each anion bridges four metal cations.

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PubMed2004

The alkali hypophosphites KH2PO2, RbH2PO2 and CsH2PO2.

The structures of the hypophosphites KH(2)PO(2) (potassium hypophosphite), RbH(2)PO(2) (rubidium hypophosphite) and CsH(2)PO(2) (caesium hypophosphite) have been determined by single-crystal X-ray diffraction. The structures consist of layers of alkali cations and hypophosphite anions, with the latter bridging four cations within the same layer. The Rb and Cs hypophosphites are isomorphous.

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PubMed2002

Hexaaquanickel(II) bis(hypophosphite).

The structure of hexaaquanickel(II) bis(hypophosphite), [Ni(H(2)O)(6)](H(2)PO(2))(2), has been determined. The crystals are prismatic. The packing of the Ni and P atoms (not the entire hypophosphite anions) is the same as in the structures of [Co(H(2)O)(6)](H(2)PO(2))(2) and [Co(0.5)Ni(0.5)(H(2)O)(6)](H(2)PO(2))(2). The Ni(II) cations have a pseudo-face-centered cubic cell, with cell parameter a approximately= 10.216 A and tetrahedral cavities occupied by P atoms. The Ni(II) cation has crystallographically imposed twofold symmetry and has an octahedral coordination sphere consisting of six water O atoms, two of which also lie on the twofold axis. The planes of oppositely coordinated water molecules are in a cross conformation. The geometry of the hypophosphite anion is close to point symmetry mm2. The hypophosphite anions are hydrogen bonded to the coordinated water molecules.

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PubMed2002

Hexaaquacobalt(II) bis(hypophosphite) and hexaaquacobalt(II)/nickel(II) bis(hypophosphite).

The title compounds, hexaaquacobalt(II) bis(hypophosphite), [Co(H(2)O)(6)](H(2)PO(2))(2), and hexaaquacobalt(II)/nickel(II) bis(hypophosphite), [Co(0.5)Ni(0.5)(H(2)O)(6)](H(2)PO(2))(2), are shown to adopt the same structure as hexaaquamagnesium(II) bis(hypophosphite). The packing of the Co(Ni) and P atoms is the same as in the structure of CaF(2). The Co(II)(Ni(II)) atoms have a pseudo-face-centred cubic cell, with a = b approximately 10.3 A, and the P atoms occupy the tetrahedral cavities. The central metal cation has a slightly distorted octahedral coordination sphere. The geometry of the hypophosphite anion in the structure is very close to ideal, with point symmetry mm2. Each O atom of the hypophosphite anion is hydrogen bonded to three water molecules from different cation complexes, and each H atom of the hypophosphite anion is surrounded by three water molecules from further different cation complexes.

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PubMed2002

Copper(II) hypophosphite: the alpha- and beta-forms at 270 and 100 K, and the gamma-form at 270 K.

Copper(II) hypophosphite has been shown to exist as several polymorphs. The crystal structures of monoclinic alpha-, orthorhombic beta- and orthorhombic gamma-Cu(H(2)PO(2))(2) have been determined at different temperatures. The geometry of the hypophosphite anion in all three polymorphs is very close to the idealized one, with point symmetry mm2. Despite having different space groups, the structures of the alpha- and beta-polymorphs are very similar. The polymeric layers formed by the Cu atoms and the hypophosphite ions, which are identical in the alpha- and beta-polymorphs, stack in the third dimension in different ways. Each hypophosphite anion is coordinated to three Cu atoms. On cooling, a minimum amount of contraction was observed in the direction normal to the layers. The structure of the polymeric layers in the gamma-polymorph is quite different. There are two symmetry-independent hypophosphite anions; the first is coordinated to two Cu atoms, while the second is coordinated to four Cu atoms. In all three polymorphs, the Cu atoms are coordinated by six O atoms of six hypophosphite anions, forming tetragonal bipyramids; in the alpha- and beta-polymorphs, there are four short and two long Cu-O distances, while in the gamma-polymorph, there are four long and two short Cu-O distances.

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