Synthesis and structure of zirconium and 3d-transition metal phosphates M 0.5Zr2(PO4)3(M = Mn, Co, Ni, Cu, Zn)

Double zirconium and 3d-transition metal phosphates of the compositions M 0.5Zr2(PO4)3[M = Mn (I), Co (II), Ni (III), Cu (IV), Zn (V)] have been synthesized and the types of their structures have been refined. Compounds I, II, III, IV, and V are all monoclinic (sp. gr. P2₁/n, Z = 4) and have the unit cell parameters a = 12.390(3), 12.389(3), 12.385(3), 12.389(3), 12.389(2) Å; b = 8.931(4), 8.928(3), 8.924(4), 8.925(4), 8.929(3) Å; c = 8.843(3), 8.840(2), 8.840(3), 8.841(3), 8.842(2) Å, β = 90.55(1), 90.54(1), 90.53(1), 90.53(1), 90.54(1)°; V = 978.5, 977.7, 977.0, 977.4, 978.1 ų, respectively. All the structures have the {[Zr₂(PO₄)₃]^?}3_∞-type frameworks. The crystallographic data for 3d-transition and alkali earth metal phosphates described by the general formula M _0.5Zr₂(PO₄)₃ are compared.     

Synthesis and crystal structures of lithium polyphosphates, LiPO3, Li4H(PO3)5, and LiMn(PO3)3

Polyphosphates of the compositions LiPO₃, Li₄H(PO₃)₅, and LiMn(PO₃)₃ were prepared by the reactions of Li₂CO₃ and MnO₂ with melts of polyphosphoric acids at 240–350°C, and their crystal structures were established. The unit-cell parameters are a = 13.074 Å, b = 5.4068 Å, c = 16.452 Å, β = 99.00°, sp. gr. P2/n; a = 6.6434 Å, b = 7.253 Å, c = 11.399 Å, α = 72.60°, β = 83.36°, γ = 85.32°, sp. gr.; $P\bar 1$ ; a = 8.364 Å, b = 8.561 Å, c = 8.6600 Å, sp. gr. P2₁2₁2₁, respectively. The influence of cations on the structures of the compounds is discussed.     

Synthesis and crystal structure of new double indium phosphates M 3 I In(PO4)2 (M I = K and Rb)

Double potassium indium and rubidium indium phosphates K₃In(PO₄)₂ (I) and Rb₃In(PO₄)₂ (II) are synthesized by solid-phase sintering at T = 900°C. The compounds prepared are characterized by X-ray powder diffraction (I and II), X-ray single-crystal diffraction (II), and laser-radiation second harmonic generation. Structure I is solved using the Patterson function and refined by the Rietveld method. Both compounds crystallize in the monoclinic crystal system. For crystals I, the unit cell parameters are as follows: a = 15.6411(1) Å, b = 11.1909(1) Å, c = 9.6981(1) Å, β = 90.119(1)°, space group C2/c, R _p = 4.02%, and R _wp = 5.25%. For crystals II, the unit cell parameters are as follows: a = 9.965(2) Å, b = 11.612(2) Å, c = 15.902(3) Å, β = 90.30(3)°, space group P2₁/n, R ₁ = 4.43%, and wR ₂ = 10.76%. Structures I and II exhibit a similar topology of the networks which are built up of { In[PO₄]₂} (I) and { In₂[PO₄]₄} (II) structural units.     

Crystal structures of two modifications of sodium pentahydrogendiphosphate NaH5(PO4)2

Two crystalline modifications of NaH₅(PO₄)₂ are obtained by the reaction of Na₂CO₃ with an excess of orthophosphoric acid. The crystal structures of α-and β-NaH₅(PO₄)₂ are determined by X-ray diffraction analysis. The crystal data are a = 8.484(4) Å, b = 7.842(3) Å, c = 10.353(4) Å, β = 90.50(3)°, V = 689.3(3) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0250 for the α modification and a = 7.127(2) Å, b = 13.346(4) Å, c = 7.177(2) Å, β = 95.5(2)°, V = 679.5(3) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0232 for the β modification. Based of the hydrogen-bond system, the formulas of the α and β modifications can be represented as Na(H₂PO₄)(H₃PO₄) and Na[H(H₂PO₄)₂], respectively. They correspond to the stable and metastable forms of the compound.     

Crystal structure of Li2MgSiO4

The crystal structure of Li₂MgSiO₄ was established by single-crystal X-ray diffraction analysis. The crystals are monoclinic, a = 4.9924(7) Å, b = 10.681(2) Å, c = 6.2889(5) Å, β = 90.46(1)°, Z = 4, sp. gr. P2₁/n, V = 335.54 ų, R = 0.062. In a Li₂MgSiO₄ crystal, four types of independent T(1–4) tetrahedra share vertices to form a three-dimensional framework. Three of these tetrahedra are occupied simultaneously by Li and Mg cations, which corresponds to the crystallochemical formula (Li_0.98Mg_0.02)(Li_0.80Mg_0.20) · (Li_0.22Mg_0.78)SiO₄. In slightly distorted SiO₄ tetrahedra denoted as T(1), the average Si-O distance is 1.635(2) Å. The distortions of other tetrahedra and the average (Li _x Mg_{1 ? x} )-O distances increase with an increase in lithium content. These distances in the T(2), T(3), and T(4) tetrahedra are 1.955(2), 1.971(4), and 2.019(6) Å, respectively. The structure of the new compound is compared with the crystal structures of other Li₂ M ²⁺SiO₄ compounds and the luminescence spectra of Cr⁴⁺: Li₂MgSiO₄.     

The structure of solvate [Cu2(DfH)4(4,4′-Bipy)] · 2DMF

The crystal structure of [Cu₂(DfH)₄(4,4′-Bipy)] · 2DMF prepared by the reaction of copper(II) acetate with diphenylglyoxime (DfH₂) and 4,4′-bipyridine (4,4′-Bipy) was established by X-ray diffraction. The crystals are monoclinic; a = 15.5192(9) Å, b = 16.2427(11) Å, c = 14.0753(7) Å, β = 101.36(3)°, V = 3478.5(5) ų, Z = 2, and sp. gr. P2₁/c. The crystal structure is composed of discrete dinuclear molecules [Cu₂(DfH)₄(4,4′-Bipy)] and dimethylformamide (DMF) molecules. The coordination polyhedron of the Cu atom (the coordination number is 5) is a tetragonal bipyramid formed by the nitrogen atoms of two monodeprotonated bidentate oxime groups and the bidentate bridging 4,4′-Bipy ligand. The DMF molecules occupy the cavities formed by the dinuclear molecules [Cu₂(DfH)₄(4,4′-Bipy)]. The compound was characterized by IR and NMR spectroscopy.     

Crystal structure of [Rb0.24(H2O)0.76]VO(H2O)(PO4), a new monoclinic variety in the series of layered vanadyl phosphates

The crystal structure of a new monoclinic variety of hydrous rubidium vanadyl phosphate [Rb_0.24(H₂O)_0.76]VO(H₂O)(PO₄) doped with Al³⁺ ions is studied by X-ray (R = 0.054) diffraction: a = 6.2655(4) Å, b = 6.2712(3) Å, c = 6.8569(5) Å, β = 107.805(7)°, space group P2₁/m, Z = 2, and D _x = 2.792 g/cm³. The new phase obtained by the hydrothermal synthesis in the V₂O₅-Rb₂CO₃-AlPO₄-H₂O system has a layer-type structure in which Rb atoms and water molecules are located between layers of vertexsharing [VO₅(H₂O)] octahedra and [PO₄] tetrahedra. Rb intercalates based on VOPO₄ · 2H₂O are described by general formula [Rb _x (H₂O)_{1 ? x} ]V _1?x ^V V _x ^IV O(H₂O)(PO₄), where x ≤ 0.5, and the amount of reduced vanadium and interlayer water molecules is determined by the amount of introduced rubidium atoms.     

Synthesis and structure of new framework phosphates Li<Subscript>1/4</Subscript><Subscript>M</Subscript><Subscript>7/4</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>(<Emphasis Type="Italic">M</Emphasis> = Nb,Ta)

New lithium-niobium and lithium-tantalum phosphates Li_1/4 M _7/4(PO₄)₃(M = Nb, Ta) are synthesized by the solid-phase method. The compounds prepared are characterized using electron microprobe analysis, X-ray powder diffraction, and IR spectroscopy. The crystal structure of the Li_1/4Ta_7/4(PO₄)₃ phosphate is determined from the X-ray powder diffraction data (the Rietveld method) and belongs to the framework type. The framework of the structure consists of TaO₆ and LiO₆ vertex-shared octahedra and PO₄ tetrahedra. The isostructural phosphates Li_1/4 M _7/4(PO₄)₃ crystallize in the trigonal crystal system (space group R \(\bar 3\) c, Z = 6) and belong to the NaZr₂(PO₄)₃ structure type.     

Alkali-metal hydrogen selenate-phosphates M 2 H 3(SeO4)(PO4) (M = Rb or K) and M 4H5(SeO4)3(PO4)(M = K or Na)

Crystalline hydrogen selenate-phosphates M ₂H₃(SeO₄)(PO₄) [M = Rb (I) or K (II)] and M ₄H₅(SeO₄)₃(PO₄) [M = K (III) or Na (IV)] were obtained by reactions of Rb, K, and Na carbonates with mixtures of selenic and phosphoric acid solutions. The X-ray structure study of single crystals revealed that I and II are isostructural (sp. gr. Pn). In these structures, SeO₄ and H₃PO₄ tetrahedra are linked by hydrogen bonds to form corrugated layers. Structures III and IV (sp. gr. $P\bar 1$ ) have similar arrangements of non-hydrogen atoms but different hydrogen-bond systems. In III = K₄(HSeO₄)₂{H[H(Se,P)O₄]₂}, the HSeO₄ groups branch from the infinite anionic {H[H(Se,P)O₄]₂} chains. In IV = Na₄[H(SeO₄)₂]{H[H_1.5(Se, P)O₄]₂}, the anionic {H[H_1.5(Se,P)O₄]₂} chains are crosslinked by hydrogen bonds formed by the [H(SeO₄)₂] dimers.     

Crystal structure of the double magnesium zirconium orthophosphate at temperatures of 298 and 1023 K

Double magnesium zirconium orthophosphate Mg_0.5Zr₂(PO₄)₃ is synthesized by the sol-gel method. The compound prepared is characterized using electron probe microanalysis and X-ray diffraction. The crystal structure of the orthophosphate is refined by the Rietveld method in space group P2₁/n (Z = 4) at temperatures of 298 K [a = 12.4218(2) Å, b = 8.9025(2) Å, c = 8.8218(2) Å, β = 90.466(1)°] and 1023 K [a = 12.4273(5) Å, b = 8.9453(4) Å, c = 8.8405(4) Å, β = 90.320(3)°]. It is demonstrated that an increase in the temperature leads to an anisotropic expansion of the unit cell of the phosphate structure, but the structural type remains unchanged.     

Synthesis and crystal structure of Li3.17(P0.69Ge0.24Mo0.07)O4

The crystal structure of Li_3.17(P_0.69Ge_0.24Mo_0.07)O₄, which was synthesized by the flux method under the action of an electric field with a potential difference of 0.8 V, was studied by X-ray diffraction on a Nonius Kappa CCD diffractometer (MoK _α radiation, λ = 0.71073 Å, R = 0.0137). The crystal structure is based on a tetrahedral framework typical of γ-Li₃PO₄. The framework of the new compound is formed by (P,Ge,Mo)O₄ and LiO₄ tetrahedra. The positions of additional Li atoms in the structure of Li_3.17(P_0.69Ge_0.24Mo_0.07)O₄ are found to be different from those in the structure of Li_3.31(P_0.69Ge_0.31)O₄, which is synthesized in the absence of an electric field and also belongs to the γ-Li₃PO₄ structure type.     

Crystal structures of double vanadates, Ca9 R(VO4)7 ⋅ III. R = Nd, Sm, Gd, or Ce

The crystal structures of Ca₉ R(VO₄)₇ (R = Nd (I), Sm (II), or Gd (III)) were studied by the Rietveld method. The compounds are isostructural to Ca₃(VO₄)₂ and are crystallized in the trigonal system (sp. gr. R3c, Z = 6). The unit-cell parameters are as follows: for I, a = 10.8720(5) Å, c = 38.121(1) Å; for II, a = 10.8652(5) Å, c = 38.098(1) Å; and for III, a = 10.8631(5) Å, c = 38.072(1) Å. In the structures of I and II, the M(1), M(2), and M(3) positions are statistically occupied by the rare-earth cations and calcium anions. In the structure of III, the Gd³⁺ cations occupy the _M(1) and _M(2) positions. The distributions of the R ³⁺ cations over the positions are characteristic of each structure. The composition of the cerium-ontaining compound Ca_9.81Ce_0.42(VO₄)₇ (a = 10.8552(5) Å, c = 38.037(1) Å) was refined and its crystal structure was solved from the X-ray powder data. In this compound, cerium atoms are in the oxidation states +3 and +4.     

Crystal structure of double vanadates Ca9 R(VO4)7. II. R = Tb, Dy, Ho, and Y

Crystal structures of the compounds Ca₉ R(VO₄)₇ (R = Tb (I), Dy (II), Ho (III), and Y (IV) have been studied by the method of the full-profile analysis. All the compounds are crystallized in the trigonal system (sp. gr. R 3 c, Z = 6) with the unit-cell parameters (I) a = 10.8592(1), c = 38.035(1), V = 3884.2(2) ų; (II) a = 10.8564(1), c = 38.009(1) Å, V = 3879.6(2) ų, (III) a = 10.8565(1) and c = 37.995(1) Å, V = 3878.3(2) ų, and (IV) a = 10.8588(1), c = 37.995(1) Å, V = 3879.9(2) ų. In structures I–IV, rare earth and calcium cations occupy three positions—M(1), M(2), and M(5). Rare earth cations occupy the R ³⁺ positions almost in the same way: 2.7–2.6(2) cations in the M(1) position; 2.7–2.3(2) cations in the M(2) position, and 0.6–1.0(1) cation in the M(5) position. At the same time, the occupancy of the M(5) position regularly increases with a decrease of the R ³⁺ radius.     

X-ray mapping in heterocyclic design: XIII. Structure of substituted tetrahydroquinolines

The structures of 4-methyl-2-chloro-5,6,7,8-tetrahydroquinoline [a = 8.138(2) Å, b = 11.127(4) Å, c = 11.234(2) Å, β = 111.30(2)°, Z = 4, space group P2₁/c, 4-methyl-2-methoxy-5,6,7,8-tetrahydroquinoline [a = 5.7651(16) Å, b = 8.530(2) Å, c = 10.455(3) Å, α = 73.76(2)°, β = 86.95(2)°, γ = 83.97(2)°, Z = 2, space group P $\bar 1$ , 4-methyl-2-(4-chlorophenacyl)-5,6,7,8-tetrahydro-1H-quinolin-2-one [a = 8.873(2) Å, b = 17.137(2) Å, c = 24.515(4) Å, Z = 8, space group Pbn2₁], and 2-(4-chlorophenyl)-5-methyl-6,7,8,9-tetrahy-drooxazolo[3.2-a]quinolin-10-ylium perchlorate [a = 8.110(6) Å, b = 17.818(7) Å, c = 17.721(5) Å, β = 100.46(4)°, Z = 4, space group P2₁/c] are studied by single-crystal X-ray diffraction. The structures are solved by direct methods and refined by the full-matrix least-squares procedures in the anisotropic approximation to R = 0.0581, 0.0667, 0.0830, and 0.0607, respectively.     

Ligand substitution in the halo-bridged diruthenium compound [Ru(CO)3Cl2]2 by 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd). Synthesis, spectral properties, and X-ray diffraction structures of cis(CO), trans(Cl)-RuCl2(CO)2 (bpcd) and cis(CO)-RuCl[C(O)Et](CO)2(bpcd)

The reaction between 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) and the chlorobridged diruthenium complex [Ru(CO)₃Cl₂]₂ (1) proceeds readily at room temperature in CH₂Cl₂ to give the new ruthenium compounds cis(CO),trans(Cl)-RuCl₂(CO)₂(bpcd) (2) and cis(CO)-RuCl[C(O)Et](CO)₂(bpcd) (3) as the major and minor products, respectively. Compound 2 was isolated and fully characterized in solution, and the molecular structure was established by X-ray diffraction analysis. cis(CO),trans(Cl)-RuCl₂(CO)₂(bpcd) crystallizes in the triclinic space P-1, a = 9.931(5) Å, b = 12.093(7) Å, c = 13.529(7) Å, α = 72.886(9)°, β = 74.739(9)°, γ = 76.851(9)°, V = 1478.2(1) ų, Z = 2, and d _calc = 1.556 mg/m³; R = 0.0841, R _w = 0.1880 for 4137 reflections with I > 2σ(I). The chlorine atoms in 2 adopt a trans geometry at the octahedral ruthenium center, with the two CO groups exhibiting a cis orientation and trans to the bpcd ligand. cis(CO)–RuCl[C(O)Et](CO)₂(bpcd) crystallizes as two independent molecules in the unit cell in the triclinic space P-1, a = 9.941(2) Å, b = 14.867(2) Å, c = 22.414(3) Å, α = 80.257(3)°, β = 84.796(2)°, γ = 75.207(3)°, V = 3152.6(8) ų, Z = 4, and d _calc = 1.504 mg/m³; R = 0.0428, R _w = 0.0962 for 8242 reflections with I > 2σ(I). The two CO groups are situated cis to each and are opposite to chlorine and phosphine moieties. The production of the minor propionyl compound 3 is discussed with respect to the trace amount of EtOH that is present in the CHCl₃ solvent that is used in the preparation of [Ru(CO)₃Cl₂]₂.     

Mixed tetrahedral anionic framework in the K3Ga2(PO4)3 crystal structure

The crystal structure of a new synthetic potassium gallophosphate K₃Ga₂(PO₄)₃ grown from a solution in the melt of a mixture of GaPO₄ and K₂MoO₄ is determined using X-ray diffraction (Bruker Smart diffractometer, 2θ_max= 56.6°, R = 0.044 for 2931 reflections, T = 100 K). The main crystal data are as follows: a = 8.661(2) Å, b = 17.002(4) Å, c = 8.386(2) Å, space group Pna2₁, Z= 4, and ρ_calcd = 2.91 g/cm³. The synthesized crystals represent the third phase in the structure type previously established for the K₃Al₂[(As,P)O₄]₃ compound. It is shown that the structure consists of a three-dimensional anionic microporous tetrahedral framework of the mixed type, which is formed by PO₄ and GaO₄ tetrahedra shared by vertices. Large-sized cations K⁺ occupy channels of the zeolite-like framework. The crystal chemical features of the formation of structure types of compounds with mixed frameworks described by the general formula A ₃ ⁺ M ₂ ³⁺ (TO₄)₃ (where A = K, Rb, (NH₄), Tl; M = Al, Ga, Fe, Sc, Yb; T = P, As) are analyzed.     

Synthesis and crystal structure of (CN3H6)2[UO2(OH)2(NCS)]NO3 and β-Cs3[UO2(NCS)5]

Compounds (CN₃H₆)₂[UO₂(OH)₂(NCS)]NO₃ (I) and β-Cs₃[UO₂(NCS)₅] (II) are synthesized and studied by IR spectroscopy and single-crystal X-ray diffraction. I and II crystallize in the orthorhombic system. For I, a = 12.2015(13) Å, b = 7.3295(8) Å, c = 16.310(2) Å, space group Pnma, Z = 4, and R = 0.0327; for II, a = 21.7891(6) Å, b = 13.5120(3) Å, c = 6.8522(2) Å, space group Pnma, Z = 4, and R = 0.0268. In structure I, complex groups form infinite chains [UO₂(OH)₂(NCS)] _n ^n? belonging to the AM ₂ ² M ¹ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , M ² = OH^?, and M ¹ = NCS^?). The main structural elements of crystals II are mononuclear [UO₂(NCS)₅]^3? groups belonging to the AM ₅ ¹ group of uranyl complexes (A = UO ₂ ²⁺ and M ¹ = NCS^?). In I and II, uranium-containing complexes are connected with outer-sphere cations by electrostatic interactions, and in I a system of hydrogen bonds also contributes to their binding. Specific features of the packing of complex [UO₂(NCS)₅]^3? groups in the structures of two modifications of Cs₃[UO₂(NCS)₅] are discussed.     

X-ray mapping in heterocyclic design: IX. X-ray structure investigation of conjugated aminodienes

The single-crystal structures of two aminodienes containing an oxazole fragment, namely, 1-pip-eridyl-4-[5-(4-nitrophenyl)-oxazol-2-yl]-buta-1,3-diene C 18 H 19 N 3 O 3 (IIa) and 1-hexamethyleneimine-4-[5-(4-nitrophenyl)-oxazol-2-yl]-buta-1,3-diene C₁₉H₂₁N₃O₃ (IIb), are studied by X-ray diffraction. Structures IIa [a = 16.181(6) Å, b = 5.939(3) Å, c = 17.337(9) Å, β = 96.13(2)°, Z = 4, and space group P2₁] and IIb [a = 7.4704(11) Å, b = 10.9904(19) Å, c = 43.434(6) Å, β = 91.24(1)°, Z = 8, and space group P2₁/_c] are solved by the direct method and refined to R = 0.060 and 0.238, respectively. Although the ring sizes of the cyclic amines in compounds IIa and IIb are different, the designs of two structures are identical. Each structure contains two topologically identical but crystallographically independent molecules. In structure IIa, the intramolecular hydrogen bonds between the N atoms of the oxazole fragments and the H atoms of the diene fragments are formed. In structure IIb, similar bonds are absent.     

New rubidium pentaborate Rb[B5O7(OH)2] · 0.5H2O with a 5: [4Δ + 1T] anionic block and its relation to larderellite (NH4)[B5O7(OH)2] · H2O on the basis of the OD theory

A new rubidium pentaborate is synthesized under hydrothermal conditions. Its crystal structure is studied by the heavy-atom method without any a priori knowledge of chemical formula. The chemical formula is Rb[B₅O₆(OH)₄] · 0.5H₂O, sp. gr. $\bar P1$ , lattice parameters a = 7.679(4) Å, b = 9.253(6) Å, c = 12.053(9) Å, α = 98.55(5)°, β = 106.80(5)°, γ = 91.71°, R = 0.0573, R _w = 0.0638, S = 1.07. The anionic part of the structure consists of a chain of fundamental building blocks 5:[4Δ + 1T] built by four B triangles bound to one B tetrahedron, which are common to Na, K, Rb, and Cs pentaborates. This new pentaborate is closely related to the mineral larderellite (NH₄)[B₅O₆(OH)₄] · H₂O but possesses an original structure, which manifests itself in the different morphology of the new pentaborate and the absence of perfect cleavage. The Dornberger-Schiff OD theory allows one to describe in detail the structural relationships, predict possible hypothetical structures, and write the OD groupoid.     

Crystal structures of mixed compounds Cu(2)Gly(D-Ser)(L-Ser)2 and Cu(2)Gly 3(L-Ser)

-The crystal structures of mixed coordination compounds, Cu(2)Gly(D-Ser)(L-Ser)₂(I) and Cu(2)Gly ₃(L-Ser)(II), which contain the amino acid residues of glycine (Gly) and serine (Ser) in the 1: 3 and 3: 1 ratio, respectively, are studied by electron diffraction. Crystals I and II are triclinic, Z = 1, and space group P1. For I, a = 8.96(2) Å, b = 9.66(2) Å, c = 5.07(2) Å, α = β = 90°, and γ = 92.8(3)°. For II, a = 8.37(2) Å, b = 9.65(2) Å, c = 5.06(2) Å, α = β = 90°, and γ = 92.8(3)°. Compounds I and II have layered structures that are based on the CuGly(L-Ser) fragment. Structures I and II differ mainly in their interlayer spacing and configuration of the interlayer space.