Search

Hexafluoroacetylacetonate hafnium(IV) complex has been synthesized and studied by X-ray structural analysis. Crystal data for C30H8F36Hf2O14 are: a = 12.957(3) A, b = 16.687(3) A, c = 12.398(3) A, β = 108.97°, space group P21/c, Z = 2, dcalc = 2.137 g/cm3, R = 0.047. The molecular structure is built from discrete binuclear molecules of Hf2(OH)2(hfac)6 composition; the Hf...Hf distance in dimer is 3.533 A. The structural units are connected by van der Waals interactions in the crystal.

An integrated X‐ray diffraction study was performed on polycrystals and single crystals of three new isostructural phases with general formula Ag4A2[M(NO2)4]3 (M = Pd, Pt; A = K, Rb). Data on the crystal structure solution (CAD‐4 diffractometer, MoKα radiation, graphite monochromator θ = 2–30° are presented. In one crystallographically independent [M(NO2)4]2- complex anion, the planar square coordination of the central atom is completed to 4 + 2 by two oxygen atoms at a distance of 3.02–3.12A in the other anion, it is completed to 4 + 1 + 1 by an oxygen atom at a distance of 3.12–3.30 A and an Ag+ cation at a distance of 3.04–3.11 A. Part of the Ag+ cations form Ag - Ag dimers with a distance of 3.03–3.07A. Crystal‐chemical analysis of known structures containing [Pd(NO2)4]2- complex anions was performed. It has been established that in none of the cases do any of the possible limiting configurations occur.

The volatile complex of lead(II) with 2,2,6,6-tetramethylheptane-3,5-dione is investigated by X-ray diffractometry. Crystal data: a = 10.901(2), b = 21489(4), c = 10.203(2) a, space group Pccn (N 56), V = 2503.4(8) a3, M = 573.74, Z = 4, dcalc = 2.522 g/cm3. The crystal structure is of molecular type; the molecule of the complex has a nonplanar structure. The lead atom is coordinated by four oxygen atoms of the two bidentate ligands. Films of the complex on substrates of Si and SiO2 single crystals, melted quartz, and glass were obtained by thermal evaporation in vacuum. X-Ray diffraction analysis of the polycrystals and films of the complex showed that the films are distinctly textured along the b axis.

Single crystals of Li8Bi2(MoO4)7 were synthesized; the composition and crystal structure of this compound were determined from X-ray diffraction data (CAD-4 automatic diffractometer, MoKa radiation, 1767 reflections, R = 0.031). The parameters of the tetragonal unit cell are as follows: a = 21.130, c = 5.287 A, Z = 4, space group -14. The structure of the binary molybdate is a three-dimensional mixed framework of MoO4 tetrahedra of four varieties, Bi eight-vertex potyhedra, and Li(l)O6 and Li(2)O6 octahedra. The large channels of the framework along the c axis contain MoO4 tetrahedra of the fifth variety with Li(3)O4 and Li(4)O4 tetrahedra attached to them via common vertices and forming four symmetrically related chains of pyroxene type. The structure of Li8Bi2(MoO4)7 involves structural fragments of Li3Fe(MoO4)3 and a-RbPr(MoO4)2 and is a new structural type in the class of binary molybdates and tungstates of uniand trivalent metals.

Mixed salts of noble metals with the general formula [Pd(NH3)4][MA6], where M = Re, Os, Ir, Pt;A = Cl,Br, and Ag2[Pd(NO2)4]-Ag1-xNaxNO2 (x> 0.3) have been synthesized and studied by X-ray diffractometry. It was found that the former are isostructural to each other and the latter are isostructural to Na2[Pd(NO2)4j-NaNO2. The structural motif of these compounds was established and metal-metal distances were estimated by the cation sublattice method In all cases, metal atoms form common cation sublattices with lattice parameters between 4.5 and 6.3 A. An original approach to revealing common sublattices in crystal structures where the fragments differ considerably in weight is described.

The symmetry, composition, and crystal structure of Cs6.3W11O36 (a=7.2742, c=110.79 A, Z=6,\(R\bar 3c\), R=0.057), previously considered monoclinic and stoichiometric, are refined. The tungsten-oxygen octahedral units of the structure, which have an AB2O6 defective pyrochlore motif, lie in layers perpendicular to the c axis, with Cs+ ions located in the voids of layer units and between them. An additional interlayer position of cesium, occupied by 31(8)%, has been found. The structures of Cs8.5W11O48 and defective pyrochlore, related to Cs6+xW11O36, form a homologous series with the general formula A2nA′ 1−yM4n−1X12n (for the above members, n=3,4 and ∞, respectively); the members in the series differ in the number of storeys in pyrochlore-like layers.

The crystal structure of Cs2W3O10 (a=16.103, c=10.169 A, $$I\bar 4$$ , Z=120/11) was determined from three-dimensional X-ray diffraction data (CAD-4 automatic diffractometer, 1612 reflections, R=0.044). The structure has an AB2O6 defective pyrochlore motif in which some of the groups consisting of four WO6 octahedra have been subtracted from the tungsten-oxygen framework and substituted by Cs+. The crystal has no vacancies in the substitution site (as confirmed by the occupancy refinement), and the composition of the crystal is strictly stoichiometric with a fractional number of atoms in the unit cell. A similar composition is suggested for the isostructural rubidium compound, which was earlier considered nonstoichiometric.

The crystal structure of the dichlorobis(1-allyltetrazole-N4)copper(II) complex was determined by X-ray diffraction analysis. The crystals are monoclinic, a=14.233(3), b=6.755(1), c=7.273(1) A, β=104.63(3)°, Vcell=676.6(2), A3, space group P21/c, Z=4, dcalc=1.741g/cm3, dmsd=1.69 g/cm3, CAD-4, λMoKα radiation, RF=0.0377 for 520 Fhkl>4σ(Fhkl) and 0.0560 for all 872 independent reflections. The structure is layered; the coordination polyhedron of copper is a square bipyramid, in which the equatorial positions are occupied by two chlorine atoms (Cu−Cl 2.27(2)–2.31(2) A) and two N4 atoms of planar tetrazole ligands, whereas the axial positions are occupied by two chlorine atoms of the neighboring molecules of the complex (Cu−Cl 2.97(2)–3.01(2) A). The sublattice of chlorine atoms is disordered in such a way that the [CuCl4/2]∞∞ layer is a superposition of two variants with weights 61(3) and 39(3)% and with similar geometrical characteristics: the equatorial chlorine atoms in variant A are replaced by the axial atoms in variant B and vice versa. The tetrazole ligand has the same position in both variants. In general, the crystal is a polytype with random alternation of A and B type blocks. It is shown that the compound is isostructural to the complex with 1-ethyltetrazole [Cu(ettz)2Cl2], in which only variant B is realized.

Crystals of K(Mg0.5Zr0.5).(MoO4)2 were grown, and the composition and crystal structure of the compound were refined in an X-ray diffraction study (CAD-4 automatic diffractometer, MoKα radiation, 475 F(hkl), R=0.022). The parameters of the trigonal unit cell are: a=5.763(1); c=7.187(1) A,Z=1, space group P3m1. A typical feature of a glaserite-like structure is atomic arrangement in two layers: at z=0 the Mg and Zr atoms are statistically distributed in the oxygen octahedra, and at z=0.5 the K atoms are distributed inside the icosahedra. In the second layer, Mo atoms with tetrahedral environment are also distributed.

A procedure for preparing Li4[Ru(NO2)6]…12H2O and K4[Ru(NO2)6] is described. We have carried out an X-ray diffraction study of polycrystals (DRON-UM1 diffractometer, R=192mm, CuKα radiation, Ni filter) and single crystals (CAD-4 automatic diffractometer, MoKα radiation, graphite monochromator, ω/2ϕ scan mode). Crystal data for Li4[Ru(NO2)6]…12H2O are a=11.749(9), c=16.807(12) A, space group\(I\bar 4\), V=2320.0 A3, Z=4, dcalc=1.778 g/cm3; for K4 [Ru(NO2)6]: a=8.595(1) A, α=53.23 (2)o, space group\(R\bar 3\), V=367.0 A3, Z=1, dcalc=2.414 g/cm3. The structures are composed of [Ru(NO2)6]4− comple anions, alkaline metal cations, and crystallization water molecules. In both compounds, the coordination polyhedra of Ru are nearly regular octahedra formed by nitrite nitrogen atoms. The Ru-N bond lengths are 2.054–2.102 A. The NO2 groups have virtually the same geometric characteristics: the N−O distances are within 1.196–1.316 A and the O−N−O angles are 112.9–117.4o. The coordination environment of alkaline metals by oxygen atoms is discussed.

Synthesis and structure of a novel thermochromic complex (CH8N4)2[CuCl6] are reported. X-ray analysis of the compound was carried out for a single crystal 0.4×0.2×0.05 mm in size (a bright-yellow plate). The monoclinic unit cell parameters are a=7.167(1), b=15.561(3), c=7.328(1) A, β=118.73(3)°, V=716.7(2) A3, space group P21, Z=2 (CH8N4)2[CuCl6] dcalc=1.99 g/cm3, μ(MoKα)=2.65 mm−1, R=0.0264, and Rw=0.0290 for 1411 Ihkl>2σI.

The title compound has been studied by an X-ray structure analysis (a CAD-4 diffractometer, λMoKα, graphite monochromator, ω/2θ scan, 2θmax, direct methods, 884 reflections R=0.0416). The crystals are orthorhombic with a=20.326, b=8.828, c=7.3872 A, V=1325.6 A3, and Z=4. C8H18B9N, space group Pnam, dcalc=1.130 g/cm3, dexp=1.130 g/cm3. The compound is a molecular complex. The main feature of its crystal structure is the coexistence of two asymmetric mirror isomers which have the same pyridine cycle and the same atoms of the carborane skeleton (excluding C7, H7C, and H34). The methyl group has a disordered orientation in two positions. The complexes are linked by van der Waals interactions.

Single crystals of the title compound have been synthesized and its crystal structure has been determined. The compound crystallizes in the monoclinic system, space group C2/c, Z = 2 (a = 5.3056, b = 12.976, c = 19.578 A, β = 92.583°, R = 0.029). A distinctive feature of the structure is lacy layers of eight-vertex Bi polyhedra and Mo tetrahedra connected to them via common vertices. me adjacent layen are linked together by ten-vertex Rb polyhedra and Li octahedra.

The authors investigate the crystal structure of the heteropolyacid H5(SiMo11V1O40) x (30-36)H2O, the tetragonal unit cell of which has a = 12.79(5), c = 18.131(5) A, V = 2967(3) AT and contains two molecules. The structure is refined from three-dimensional diffraction data (Syntex P21 automatic diffractometer, Mo K radiation, -70C) in the anisotropic approximation to R = 0.081 for 1311 independent reflections. The heteropolyanions of the Keggin type in the crystal are statistically turned relative to one another through 90 about the tetrad axis. It is shown that in this case in the Raman spectra, both for the crystals and for their acid aqueous solutions in the intensity of the band sigma/sup rot/0(term) is higher than nu/sup S/M=O(term), and this sign is proposed as a criterion of formation of HPA of given structural type. The authors discuss the regularities in the construction of the proton-water framework in high-water HPAc.