The single-crystal structures of the oxygen-ion-conducting fluorite-type compounds Nd5Mo2.90V0.10O15.3 and Nd5Mo2.76V0.24O15.5 were determined by X-ray diffraction. It was found that the displacements of atoms in the structure are retained after the doping of these compounds with vanadium. The dopant atoms occupy the molybdenum sites. The X-ray diffraction data were used to calculate the activation energies and analyze the possible pathways for the oxygen ion migration in the structures.

The reaction of pyridoxine with manganese sulfate in an aqueous solution gave the coordination compound MnSO4 · 2C8H11O3N · 2H2O (I). The structure of I was determined from single-crystal X-ray diffraction data. In the centrosymmetric complex (sp. gr. \(P\bar 1\), Z = 1), the Mn atom is coordinated by two pyridoxine molecules and two water molecules, thus adopting an octahedral coordination. The sulfate anion is also at a center of symmetry and, consequently, is disordered. The pyridoxine molecules are coordinated to the metal atom through the oxygen atoms of the deprotonated hydroxyl group and the CH2OH group that retains the hydrogen atom. The nitrogen atom is protonated in such a way that the heterocycle assumes a pyridinium character. The crystal structure also contains six water molecules of crystallization. A thermogravimetric study showed that the decomposition of I occurs in several successive steps, such as dehydration, the combustion of organic ligands, and the formation of an inorganic residue.

Mixed single crystals of [Co(OCN 2 H 4 ) 5 (H 2 O)][ZnCl 4 ] were grown by the isothermal evaporation of an aqueous solution. The crystal structure of this complex was established by X-ray diffraction ( R = 0.052 based on 7003 reflections). The crystals consist of [Co(OCN 2 H 4 ) 5 (H 2 O)] 2+ cations containing Co atoms in an octahedral coordination and [ZnCl 4 ] 2− ] anions containing Zn atoms in a tetrahedral coordination. The carbamide molecules are involved in both intramolecular and interionic hydrogen bonds. The H 2 O molecule forms hydrogen bonds with the anions.

Single crystals without Co and Ni have been crystallized by the substitution method in the K 2 Ni(SO 4 ) 2 -Ce(SO 4 ) 2 -H 2 SO 4 -H 2 O system using K 2 Co(SO 4 ) 2 · 6H 2 O, K 2 (Co,Ni)(SO 4 ) 2 · 6H 2 O, or K 2 Ni(SO 4 ) 2 · 6H 2 O as protocrystals. The structure of the single crystals obtained has been established by X-ray diffraction analysis. The crystal structure contains dimer complex anions [Ce 2 (μ-SO 4 ) 2 (SO 4 ) 6 ] 8− , K + cations, and crystallization water molecules.

The pyridoxine complexes with zinc and cadmium sulfates are synthesized. The IR absorption spectra and thermal behavior of the synthesized compounds are described. Crystals of the [ M (C 8 H 11 O 3 N) 2 (H 2 O) 2 ]SO 4 · 3H 2 O ( M = Zn, Cd) compounds are investigated using X-ray diffraction. In the structures of both compounds, the M atoms are coordinated by the oxygen atoms of the deprotonated OH group and the CH 2 OH group retaining its own hydrogen atom, as well as by two H 2 O molecules, and have an octahedral coordination. The nitrogen atom of the heterocycle is protonated, so that the heterocycle acquires a pyridinium character. The cationic complexes form layers separated by the anions and crystallization water molecules located in between. The structural units of the crystals are joined together by a complex system of hydrogen bonds.

A systematic X-ray diffraction study of the interaction products of Zr(IV), Hf(IV), Nb(V), and Ta(V) oxides (fluorides) with crown-ethers (CEs) in aqueous solutions of hydrofluoric acid is performed. It is shown that oxygen-containing CEs form oxonium complexes with [NbF6] s- and [TaF6] s- hexafluorometallate anions. In two systems, [ cis-syn-cis -DCH18C6-H 3 O][TaF 6 ] and [B18C6·H 3 O][TaF 6 ], the phenomenon of supramolecular isomerism is found, which is caused by a change in the conformation of the macrocycle or by a partial redistribution of intermolecular hydrogen bonds. The use of aza-crown ethers as extractants made it possible to extract unique hydrolytically unstable anions, the products of incomplete fluorine substitution for oxygen atoms in the starting oxides in the form of crystalline complexes with a composition of [(HA15C5) 2 ][Ta 2 F 10 O] and [(HA18C6·H 2 O)(A18C6·H 2 O)] [(H 2 O)Nb 2 F 9 O]. In [(18C6)(H 7 O 3 ) 2 ×(Hf 2 F 10 ·2H 2 O)], [(HA18C6)(M 2 F 10 ·2H 2 O)·(H 3 O)·H 2 O], and [(H 2 DA18C6) (M 2 F 10 ·2H 2 O)·2H 2 O] (M=Zr, Hf) complexes, the metals are extracted in the form of identical (M 2 F 10 ·2H 2 O) 2s- anions with a similar topology. The performed study demonstrates that macrocyclic complexones are undoubtedly promising to extract Zr(IV), Hf(IV), Nb(V), and Ta(V) from fluorine-containing aqueous solutions.

Проведено прецизионное рентгеноструктурное исследование кристаллических образцов KH2PO4 (KDP) из разных ростовых зон монокристалла, содержащего примесь атомов хрома. Показано, что структура образца из призматической зоны более совершенна, чем из зоны пирамиды. При захвате примесей на грани пирамиды возможно образование как минимум четырех разных типов структурных дефектов, в то время как на грани призмы только двух из них. Сравнение с соответствующими данными для “чистого” KDP свидетельствует о том, что количество дефектов и их характер приблизительно одинаков во всех образцах. ИК-спектры обнаруживают присутствие нитрат-ионов в образцах из обеих ростовых зон. Кроме того, в образце из призматической зоны фиксируются структурно связанные молекулы воды и ОН-группы.

The precision X-ray structural investigation of KH2PO4 (KDP) crystal samples from different growth sectors of a single crystal containing chromium impurities is performed. It is demonstrated that the structure of the sample from the prismatic growth sector is more perfect than the structure of the sample from the pyramidal growth sector. The impurity trapping can lead to the formation of at least four different types of structural defects on the face of the pyramid, whereas only two of them can be formed on the face of the prism. A comparison with the relevant data for the "pure" KDP crystal shows that the number of defects and their character are approximately identical for all samples. The analysis of the IR spectra indicates that nitrate ions are contained in the samples from both growth sectors. Moreover, structurally bound water molecules and OH groups are revealed in the sample from the prismatic sector.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The interaction of ZrO2/HfO2 or Nb2O5/Ta2O5 with an aqueous solution of hydrofluoric acid in the presence of aza-crown ether resulted in novel organically templated metal oxyfluorides of the compositions [(HA15C5)2][Ta2F10O] (1), [(HA18C6 · H2O)(A18C6 · H2O)][(H2O)Nb2F9O] · H2O (2), [(HA18C6 · H2O)(M2F10 · 2H2O) · (H3O) · H2O] (3, 4) and [(H2DA18C6)(M2F10 · 2H2O) · 2H2O] (5, 6) (M = Zr, Hf, A15C5 = aza-15-crown-5, A18C6 = aza-18-crown-6, DA18C6 = diaza-18-crown-6). Complexes 1–6 were identified by single crystal X-ray diffraction. In 1, the negative charge of the [(TaF5)2O]2− centrosymmetric dianion is balanced by two azonia-15C5 cations, while in 2 the charge of asymmetric [(H2O)NbF4ONbF5]− monoanion is compensated by azonia-18C6 cation. The crystal of 2 revealed an extensive hydrogen bonding between the anions, protonated and neutral macrocycles and water molecules that combine the components into 2D sheet. Complexes 3–4 and 5–6 are isostructural in pairs; in all of them the rigid 2D inorganic motif is formed through the association of the [(M2F10 · 2H2O)]2− anions by means of OH⋯F hydrogen bonds. The similar 3D supramolecular architecture in 3–6 represents an alternation of the negatively-charged inorganic sheets and the columns of (HA18C6)+ or (DA18C6)2+ organic cations glued by oxonium cations or water molecules.

Two isostructural complexes of dioxonium [H 5 O 2 ] + with tetrabenzo-30-crown-10 of the compositions [(tetrabenzo-30-crown-10 · H 5 O 2 )][TaF 6 ] ( I ) and [(tetrabenzo-30-crown-10 · H 5 O 2 )][NbF 6 ] ( II ) are studied using X-ray diffraction. The complexes crystallize in the monoclinic crystal system (space group C 2/ c , Z = 4). The unit cell parameters of these compounds are as follows: a = 15.6583(12) Å, b = 15.2259(13) Å, c = 16.4473(13) Å, and β = 99.398(6)° for complex I and a = 15.7117(12) Å, b = 15.2785(15) Å, c = 16.5247(15) Å, and β = 99.398(7)° for complex II . These complexes belong to the ionic type. The dioxonium cation [H 5 O 2 ] + in the form of the two-unit cluster [H 3 O · H 2 O] + is stabilized by the strong hydrogen bond OH⋯O [O⋯O, 2.353(4) Å] and encapsulated by the crown ether. Each oxygen atom of the dioxonium cation also forms two oxygen bonds O⋯O(crown). The crown ether adopts an unusual two-level (pocket-like) conformation, which provides a complete encapsulation of the oxonium associate. The interaction of the cationic complex with the anion in the crystal occurs through contacts of the C-H⋯F type.

Large single crystals of rubidium nickel hexahydrate Rb2Ni(SO4)2 · 6H2O (RNSH) of optical quality were grown for the first time. The atomic structure of RNSH crystals was refined. A comparative analysis of the crystal structures of (M 1+)2Ni(SO4)2 · 6H2O, where M 1+ is K, Rb, or Cs, was performed. The solubility curve of RNSH in water was measured. The optical and thermogravimetric properties of RNSH were investigated. The internal defect structure of RNSH crystals was studied by X-ray topography.

Two synthetic pathways, the interaction of Nb2O5 or Ta2O5 with an aqueous solution of hydrofluoric acid, HF, in the presence of 18-crown-6 (18C6), 15-crown-5 (15C5), benzo-15-crown-5 (B15C5) or benzo-12-crown-4 (B12C4), and the direct interaction of the corresponding pentafluorides, MF5 (M=Ta, Nb), in the presence of HF with the same crown ethers result in crystalline complexes of the same composition, [18C6·H3O][NbF6] (1), [18C6·H3O][TaF6] (2), [15C5·H5O2][TaF6] (3), [(B15C5)2·H5O2][(B15C5)2·H3O][TaF6]2 (4) and [(B12C4)2·H3O][TaF6] (5). Complexes 1–5 were identified by elemental and X-ray structural analysis. Compounds 1 and 2 are isostructural, with the [H3O]+ oxonium ion embedded in one crown molecule via OH⋯O hydrogen bonds. Complexes 3–5 represent sandwich-like adducts with the [H3O]+ or [H5O2]+ cations encapsulated. A plethora of weak C–H⋯F interactions with NbF6- and TaF6- anions is responsible for the extended supramolecular architectures.

The crystal structures of [(benzo-18-crown-6) · H3O]TaF6 and [(benzo-18-crown-6) · H3O]NbF6 complex compounds are determined by X-ray diffraction. It is revealed that the tantalum complex has two polymorphic modifications, namely, the monoclinic (I) and orthorhombic (II) modifications. The unit cell parameters of these compounds are as follows: a = 14.784(2) Å, b = 8.390(4) Å, c = 18.005(6) Å, β = 95.78(2)°, Z = 4, and space group P21/n for modification I; and a = 8.456(2) Å, b = 21.967(5) Å, c = 24.122(5) Å, Z = 8, and space group Pbca for modification II. The orthorhombic niobium complex [(benzo-18-crown-6) · H3O]NbF6 with the unit cell parameters a = 8.454(1) Å, b = 21.943(3) Å, c = 24.127(4) Å, Z = 8, and space group Pbca (III) is isostructural with tantalum complex II. The oxonium cation in complexes I–III is encapsulated by the crown ether and thus forms one ordinary and two bifurcate hydrogen bonds with the oxygen atoms of the crown ether. This macrocyclic cation is bound to the anions through the C-H ...F contacts (H...F, 2.48–2.58 Å).

The crystal structure of the new barium borate Ba5(BO3)2(B2O5) is established (R = 0.0436). Single crystals were grown by spontaneous crystallization in the BaO-B2O3-Na2O system using the flux method. This compound crystallizes in the orthorhombic system, sp. gr. P212121; the unit-cell parameters are a = 9.590(2) Å, b = 16.659(3) Å, c = 22.919(6) Å, and Z = 12. The structure consists of coordination polyhedra of barium cations and the anionic groups [BO3] (planar triangles) and [B2O5] (vertex-sharing double [BO3] triangles), which form a pseudohexagonal framework. Melting of barium borate occurs by a peritectic reaction at 1170 ± 10°C.

Differential thermal analysis and visual polythermal analysis are used to study phase equilibria in the BaO-BaB2O4 system. The following compounds are formed in the system: Ba5B4O11 (which melts peritectically at 1170 +/- 10 degrees C), Ba3B2O6 (which melts congruently at 1390 +/- 10 degrees C), and Ba4B2O7 (which decomposes in the solid state at 1190 +/- 10 degrees C).

The experimental results of the influence of bivalent (Ni2+, Co2+, Fe2+, Mn2+, Ba2+, Ca2+, Sr2+) and trivalent (Fe3+, Mn3+, Y3+, La3+) impurity ions on growth rates and surface morphology of potassium dihydrogen phosphate (KDP) crystal faces are presented and discussed. The analysis of the obtained results is performed in conjunction with the theoretical results presented in our previous paper (Rak et al., J. Crystal Growth) concerning modelling of structure of defect centres formed in KDP crystals by these impurities. It is found that the effect of Me3+ ions is caused mainly by their adsorption on crystal faces while, in case of Me2+impurities, the ions incorporated into surface crystal layer and the lattice stresses generated by them play a leading role in the effect of bivalent impurities on growth kinetics and surface morphology (the structural mechanism of the impurity influence–SMII).

Spontaneous NaBa4(BO3)(3) crystals were grown from BaO-B2O3-Na2O fluxed melts. The compound melts at 1260degreesC. It was structurally studied using X-ray diffraction (R = 0.035 for 606 reflections). The crystals are cubic with a = 15.783 Angstrom, Z = 16, space group 1a3d. The structure is a framework built of face- and edge-sharing barium octatopes and hexatopes. The Na and B atoms reside in framework voids. The borate anions exist as isolated triangles. The Na atoms are oxygen six-coordinated. Phase equilibria along the Ba3B2O6-NaBaBO3 stable join were studied.

The structures of two crystalline specimens cut out from the pyramidal and prismatic growth sectors of a K(H0.052D0.948)2PO4 single crystal have been studied by diffuse neutron scattering and precision diffuse X-ray scattering. Diffuse scattering is concentrated in the vicinity of the Bragg reflections and is practically the same in specimens cut out from different growth sectors of a single crystal. X-ray diffraction analysis using the extinction parameters provided the establishment of a higher perfection of the specimen cut out from the prismatic growth sector. The precision X-ray studies revealed different configurations of hydrogen bonds in the specimens.