K. K. Palkina

Synthesis and crystal structure of phosphate Ba1.5Fe2(PO4)3

Double phosphate Ba1.5Fe2(PO4)3 was synthesized and structurally studied. Single crystals were synthesized by the fusion method. Cubic crystals, Z = 4, space group P213, a = 9.866(1) Å. This structure is built of polyhedrons of four types: PO4 tetrahedrons, two virtually regular FeO6 octahedrons, BaO12 twelve-vertex polyhedrons, and BaO9 nine-vertex polyhedrons. These polyhedrons share common oxygen vertices to form three-dimensional [Fe2(PO4)3]3∞ framework containing barium atoms in cavities.

Synthesis, structure, geometrical, and spectral characteristics of the (HLn)2[CuCl4] complexes. Crystal and molecular structure of bis(2-methylimidazolium) tetrachlorocuprate(II)

The (HLn)2[CuCl4] complexes (where Ln are organic nitrogen-containing bases with n = 1–6) were synthesized. The crystal and molecular structures of bis(2-methylimidazolium) tetrachlorocuprate(II), (HL1)2[CuCl4], were determined. The spectral characteristics of the complexes were measured. The correlations between the degree of distortion of the crystal structure of the tetrachlorocuprate anion and the hydrogen bond parameters and the spectral characteristics of compounds were obtained.

Nanostructuring in the Process of the Formation of Mixed-Anion Compounds: Rare-Earth Borogermanates, Germanophosphates, and Borotungstates

Specific features of the textures (the preferred orientation of the nanometer building blocks) in the structures of mixed-anion compounds—rare-earth borogermanates, germanophosphates, and borotungstates that arise from the acid-base interaction in the Ln2O3-B2O3-GeO2, Ln2O3-GeO2-P2O5, and Ln2O3-B2O3-WO3 systems (Ln = La-Gd)—have been studied. Based on characteristic texture traits, the mixed-anion compounds of early rare-earth elements can be divided into three groups: (i) Ln2O3: ExOy > 1, (ii) Ln2O3: ExOy = 1, and (iii) Ln2O3: ExOy < 1. Because of the dominant structural effect of the basic oxide Ln2O3 in the compounds of the first group, the structures of Nd14O8(BO3)6(GeO4)2 and Pr11O10(GeO4)(PO4)3 are composed of infinite [LnOn] bands and layers and discrete groups [EOm] located in the interband and interlayer spaces. The dominant structural effect of the acid oxides [ExOy] in the compounds of the third group leads to the appearance of ring textures composed of [LnOn], as well as to the appearance of chains and networks composed of [EOm], in the structures of Ln(BGeO5) and Ln(BO2)(WO4).

Interaction of copper(II) halides with 4-azafluorene derivatives in neutral and acid media. Crystal and molecular structure of 4-aza-9-oxofluorenium tetrabromocuprate hydrate (HL4)2CuB4 · H2O

Complexes of copper(II) halides (chlorides and bromides) with some 4-azafluorene derivatives have been synthesized and studied by X-ray crystallography and IR and UV spectroscopy. In neutral media, Cu(L)2X2 (X = Cl, Br) complexes are formed in which the ligands are coordinated to the metal atoms though the lone pair of the endocyclic nitrogen atom and through the oxygen atoms of substituents. In acid media at pH 2, (HL2)2CuX4 complexes are formed in which the 4-azafluorene molecules protonated at the endocyclic nitrogen atom act as an outer-sphere cation. The molecule and crystal structure of 4-aza-9-oxofluorenium tetrabromocuprate hydrate (HL4)2CuBr4·H2O has been determined.

Growth and structure of ZnSnAs2 crystals

High-quality ZnSnAs2 (I) single crystals have been grown. The unit cell parameters of compound I have been refined (a = b = 5.8360(1), c = 11.686(2) Å), and its crystal structure has been determined.

Complexes of Some Pyrido[1,2-a]pyrimidinium Perchlorates with Scandium, Yttrium, and Lanthanum. Crystal and Molecular Structure of 3-Chloro-9-Hydroxy-2,4-Dimethylpyrido[1,2-a]pyrimidinium Perchlorate

Complexes of scandium, yttrium, and lanthanum nitrates with 3-chloro-9-hydroxy-2,4-dimethylpyrido[1,2-a]pyrimidinium perchlorate (HL1ClO4) and 9-hydroxy-2,4-dimethylpyrido[1,2-a]pyrimidinium perchlorate (HL2ClO4) were obtained. Their composition was formulated as Sc(LClO4)2(NO3) and M(LClO4)2(NO3)2 (L = L1 or L2; M = Y or La); structures for the complexes obtained were proposed. The crystal and molecular structure of HL1ClO4 was determined. Dissociation and complexation of HL1ClO4 and HL2ClO4 in aqueous ethanol were studied using the spectroscopic method. Ligand dissociation and complexation constants were calculated. It was shown that a chlorine-containing organic ligand only slightly changes the composition and stability of the metal complexes.

Crystal structure of magnesium(II) diaquatetracarbamidenitrate

Magnesium(II) diaquatetracarbamidenitrate nitrate was structurally studied. Crystals of composition [Mg(H2O)2(ur)4](NO3)2 (I) are monoclinic, Z = 2, P21/n, a = 6.449(1) Å, b = 17.670(2) Å, c = 7.578(1) Å; β = 91.637(2)°. In the structure of complex I, the central magnesium atom has octahedral geometry: the four carbamide molecules are in equatorial positions, and water molecules occupy axial positions.

Synthesis and crystal structure of the sodium complex with 2-(diphenylacetyl)indandione-1,3

The sodium complex with 2-(diphenylacetyl)indandione-1,3 (HL) have been synthesized and studied by X-ray diffraction analysis. Crystals of [Na4(H2O)4L4] (I) precipitated from aqueous acetone are monoclinic, Z = 2, space group P21/c, a = 12.171(1) Å, b = 10.527(1) Å, c = 29.777(2) Å, β = 97.455(1)°. The structure of compound I is based on a centrosymmetric tetranuclear [Na4O12] cage. Two central Na(2) atoms are coordinated to four O atoms of two L ligands. The central and peripheral atom polyhedrons [Na(2)O6] and [Na(1)O5] are joined by a common edge formed by two O atoms of two L ligands. Tetranuclear moieties are joined into the framework by hydrogen bonds, numerous C-H-π contacts, and π-π stacking-contacts between the conjugated and aromatic ligand systems of neighboring tetramers.

Bis(1-amino-4-azafluoren-9-olium) and bis(2-amino-3-hydroxypyridinium) tetrachlorocobaltates(II): Crystal and molecular structure

Crystal and molecular structure and spectral characteristics are determined for bis(1-amino-4-azafluoren-9-olium) and bis(2-amino-3-hydroxypyridinium) tetrachlorocobaltates(II): CoCl4(C12H11N2O)2 and CoCl4(C5H7N2O)2, respectively. The structural units of the complexes are CoCl42− anions and organic cations protonated at the pyridine nitrogen atom.

Synthesis and structure of lithium and rubidium compounds with 2-(diphenylacetyl)-1,3-indanedione

Complexes RbL (I) and [Li2(C2H5OH)L2] (II) (L = C23H15O3) have been synthesized and their crystal structures have been studied. Both compounds have monoclinic crystals with space group P21/c and Z = 4; I: a = 11.632(2) Å, b = 15.154(3) Å, c = 11.457(2) Å, β = 104.34(3)°; II: a = 12.982(3)Å, b = 12.083(2) Å, c = 25.317(5) Å β = 100.11(3)°. In the structure of I, dimeric groups [Rb2O6] with a shared edge are linked by the ligands to give infinite layers perpendicular to the x axis and cavities that form oblong channels. In the structure of II, Li2O7 dimers are formed by vertex sharing. The coordination of one of the lithium atoms (Li(1)) is completed to tetrahedral by the oxygen atom of the ethanol molecule. The structure of II, like that of I, is layered.