C–H⋅<Emphasis Type="Italic">s</Emphasis>O hydrogen bond networks in <Emphasis Type="Italic">E</Emphasis>- and Z-unsaturated esters of C-glycosides

Methyl E(Z)-4,7 anhydro-5-benzamido-6,8-di-O-benzoyl-2,3,5-trideoxy-d-allo-oct-2-enoate have been synthesized like intermediates and isolated as single crystals during the synthesis of pyrazole-related C nucleosides as synthetic product with cytotoxic activity.¹ Crystal structures of E(Z) isomers were determined by X-ray analysis. E isomer crystallizes in the triclinic crystal system, space group P1, a = 5.319(1) Å, b = 10.758(2) Å, c = 12.229(2) Å, α = 72.38(2)^∘, β = 89.97(2)^∘, γ = 87.07(2)^∘, D_x = 1.320 Mgm⁻³ and Z isomer in the orthorhombic crystal system, space group P2₁2₁2₁, a = 5.1297(13) Å, b = 19.667(5) Å, c = 25.871(6) Å, D_x = 1.348 Mgm⁻³. The molecular structure was solved by direct method on the basis of 2609 and 2727 unique reflections recorded at the temperature 293 K (E-isomer) and 173 K (Z-isomer) up to the final R-factor 0.0378 and 0.0435, respectively. C–H⋅sO contact networks were analyzed and the correlation established between the existence of the weak C–H⋅sO hydrogen bonds and the melting point of the single crystals.     

Solid-state Spectroscopic and Structural Investigation of <Emphasis Type="Italic">cis</Emphasis>-(CH<Subscript>3</Subscript>)<Subscript>2</Subscript>Au(<Emphasis Type="Italic">O</Emphasis>,<Emphasis Type="Italic">O</Emphasis>′-acac)

Abstract  The structure of cis-(CH₃)₂Au(O,O′-acac) was investigated by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Cmca with unit cell dimensions a = 6.7831(13) ?, b = 15.080(3) ?, c = 18.073(3) ? and α = β = γ = 90°. The molecule is planar but lacks a C₂ axis in the solid-state, with two Au–C bond lengths that differ by 0.078(21) ? due to crystal packing effects. The inequivalence of the crystallographic carbon positions is evident in the solid-state ¹³C CP-MAS NMR spectrum, which was recorded at low temperature due to the thermal sensitivity of the compound during magic-angle spinning. Head-to-tail stacking, which creates short intermolecular paths, was reproduced computationally in a dimer model. Graphical Abstract   Solid-state Spectroscopic and Structural Investigation of cis -(CH ₃ ) _Au 2 ( O , O ′-acac) Miyako Hisamoto • Swarup Chattopadhyay • Juergen Eckert • Guang Wu • Susannah L. Scott In the solid state, cis-(CH₃)₂Au(O,O′-acac) has no C₂ axis, two different Au–C bond lengths (1.960, 2.038 ?; Δd = 0.078(21) ?) and a close Au–C…C–Au contact; these features give rise to additional features in the ¹³C CP-MAS NMR spectrum.     

Simulation of ion transport in layered cuprates La<Subscript>2 − <Emphasis Type="Italic">x</Emphasis></Subscript>Sr<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>CuO<Subscript>4 − <Emphasis Type="Italic">δ</Emphasis></Subscript>

The processes of oxygen diffusion in La_{2 ? x} Sr _x CuO_{4 ? δ} phases have been simulated for the first time by the molecular-dynamics method. Calculations were performed for the temperature range 300–2500 K. The behavior of the radial pair correlation functions, which characterize the degree of order of O1 ions in CuO₂ layers, indicates that O^2? anions form a weakly correlated subsystem within a CuO₂ layer. To quantitatively confirm the conclusions about the predominantly two-dimensional character of ion transport and different mobilities of O1 and O2 particles in the cuprates under study, the pair oxygen diffusion coefficients in the La_{2 ? x} Sr _x CuO_{4 ? δ} lattice were calculated. It is shown that oxygen diffusion occurs through the conventional hopping mechanism mainly in CuO₂ layers; correspondingly, the diffusion coefficient for equatorial ions (O1) exceeds that for apical oxygen anions (O2) by an order of magnitude. The motion of oxygen anions was traced at the microscopic level through analysis of the particle transport trajectories. It has been proven for the first time that diffusion of O1 ions in the ab plane in a nonstoichiometric LaSrCuO_3.61 sample occurs through jumps to the nearest position or along CuO₂ layers; in a more complicated way, it may occur through unoccupied O2 lattice sites.     

C(4) helices,Br⋅<Emphasis Type="Italic">s</Emphasis>Br interaction and <Emphasis Type="Italic">R</Emphasis><Stack><Subscript>4</Subscript><Superscript>2</Superscript></Stack> (10) ring in bromoipriflavone

The title compound, 8-bromo-7-isopropoxyisoflavone (bromoipriflavone), C₁₈H₁₅O₃Br, crystallizes in tetragonal crystal system, space group I4₁/a with cell constants a = 21.396(2) Å, c = 13.588(2) Å, V = 6220.2(14) ų and Z = 16. Bromoipriflavone is composed of a benzopyranone moiety, a phenyl moiety, an isopropoxy group and a bromine atom. The benzopyranone ring is not coplanar with the phenyl ring with a dihedral angle of 55.1. The molecules are stacked into a C(4) helices down [001] via – stacking and hydrogen bonds, the C(4) helices are assembled into three-dimensional network via strong BrsBr interactions and synthons R₄²(10) formed by two tri-centered C–HsO hydrogen bonds, resulting in a distinctive high-symmetry supramolecule. The title compound was also characterized by IR and ¹H NMR.     

Synthesis and Crystal Structure of Bis (<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylethylendiammonium) Octaiodo Pentachloroantimonate (III)

Abstract  

The synthesis and Crystal structure are given for the bis (N,N,N′,N′-tetramethylethylendiammonium) octaiodo pentachloroantimonate (III) salt. An X-ray investigation has shown that the title compound crystallizes in a monoclinic system, space group P2₁/m with the following lattice parameters a = 9.786(2) Ǻ, b = 14.024(5) Ǻ, c = 14.336(3) Ǻ, β = 91.35(2)° and Z = 2. The structure was solved from 3085 independent reflections with R ₁ = 0.0402 and wR ₂ = 0.0952 and refined with 152 parameters. The structure shows a layer arrangement perpendicular to the [(b)\vec] \vec{b} -axis: planes of [SbCl₅]²⁻, I₃ ⁻ and I₅ ⁻ anions alternate with planes of [(CH₂)₂(NH(CH₃)₂)₂]²⁺ cations. The [SbCl₅]²⁻ square pyramids present an active lone electron pair (LEP) on the Sb atoms and they are interconnected by means of N–H···Cl hydrogen bond originating from [(CH₂)₂(NH(CH₃)₂)₂]²⁺ entities. The polyiodides (I₃ ⁻ and I₅ ⁻) anions form a planer zigzag polymeric chains via I···I linking interactions. These chains are linked to the [SbCl₅]²⁻ anions by a long range contact.     

Crystal and molecular structures of [Co(<Emphasis Type="Italic">D</Emphasis>H)(<Emphasis Type="Italic">o-phen</Emphasis>)<Subscript>2</Subscript>][BF<Subscript>4</Subscript>]<Subscript>2</Subscript> · 2H<Subscript>2</Subscript>O

The crystal structure of a new mixed-ligand complex [Co(DH)(o-phen)₂][BF₄]₂ · 2H₂O is determined by X-ray diffraction. The crystal is monoclinic, a = 12.2081(11) Å, b = 14.3474(9) Å, c = 17.7393(16) Å, β = 104.95(1)°, and space group P2₁/c. The coordination octahedron of Co³⁺ is formed by two nitrogen atoms of the dimethylglyoxime molecule and four nitrogen atoms of o-phenanthroline molecules. The dimethylglyoxime molecule is singly deprotonated and acts as DH^?. The mean Co-N distances for dioxime and o-phenanthroline are 1.911 and 1.964 Å, respectively. The key role in the formation of the crystal structure is played by [BF₄]^? outer-sphere anions and crystallization water molecules, which form an extended hydrogen-bond system.     

Unclassical hydrogen bonds of C—H⋅<Emphasis Type="Italic">s</Emphasis>O and C—H⋅<Emphasis Type="Italic">s</Emphasis>N in the crystals of 2-amino-3-cyano-4-(3,4-dichlorophenyl)-5-oxo-1,4,5,6-tetrahydro-4H-pyrano[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

The 2-amino-3-cyano-4-(3,4-dichlorophenyl)-5-oxo-1,4,5,6-tetrahydro-4H-pyrano[2,3-d] pyrimidine (1, C₁₇H₁₅Cl₂N₅O₃) was synthesized and characterized by IR,¹H NMR and elemental analysis. The molecular structure of1 was further studied by using X-ray crystallography. The crystals of compound1 are triclinic, space groupP-1,a = 6.0090(4) Å,b = 10.4056(7) Å,c = 15.6021(11) Å, α = 70.983(4), β = 84.056(6), γ = 84.611(6),Z = 2,V = 915.47(11) ų. Two types of unclassical hydrogen bonds C–H?sO and C–H?sN were presented in the crystals. In addition, there were classical hydrogen bonds in the crystal structure.     

Crystal structure of Сu<Subscript>2–<Emphasis Type="Italic">m</Emphasis></Subscript>Te (<Emphasis Type="Italic">m</Emphasis> = 0.25)

The Сu₂Te compound has been synthesized by alloying Сu and Te taken in stoichiometric ratios. A Сu₂Te sample has been homogenized by annealing at 773 K for 100 h. A pure copper phase in the form of thin filaments is found to segregate from the synthesized product (4 g) by the end of annealing. It is established by X-ray diffraction analysis that the copper-deficient sample is crystallized into the trigonal system with lattice parameters а = 8.328(1) Å, с = 7.196(1) Å, V = 432.2(1) ų, sp. gr. \(P\overline 3 m1\), Z = 8. The crystal structure is determined and the sample composition Сu_2–m Te (m = 0.25) is refined by the Rietveld method. The three independent copper atoms in the lattice are found to have different coordination numbers: 3, 4, and 5.     

Structure and magnetism of low-doped monoclinic crystals of (Ga<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Mn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>)<Subscript>2</Subscript>Se<Subscript>3</Subscript>

The influence that doping with Mn³⁺ ions has on the fine crystal structure of the monoclinic compound Ga₂Se₃ was studied by single-crystal neutron diffraction and the measurements of magnetic properties. It was found that the structural state of the crystals changes even at relatively low doping levels (x = 0.04). Local Jahn-Teller distortions were shown to be responsible for the formation of the fine structure and magnetism in this type of compounds.     

Cationic transport mechanism in α-Ag<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Cu<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>I(0 < <Emphasis Type="Italic">x</Emphasis> < 0.25): Molecular-dynamics simulation

The structural and transport characteristics of an Ag_{1 ? x} Cu _x I(0 < x < 0.25) solid solution have been simulated by the molecular-dynamics method. It is found that the cation diffusion coefficient decreases with increasing copper concentration; this correlation is in agreement with the experimentally observed decrease in ionic conductivity. It is shown that the cationic transport in disordered Ag_{1 ? x} Cu _x I phases is mainly due to the migration of silver cations, whereas the mobility of copper cations is much lower. Cu⁺ cations are found to reside in the 8c positions in a bcc cell; this finding suggests the existence of nanoscale α-CuI regions.     

Synthesis and crystal structure of <Emphasis Type="Italic">N</Emphasis>-(6methoxylbenzothiazol-2-yl)-1-(4-fluorophenyl)<Emphasis Type="Italic">O</Emphasis>,<Emphasis Type="Italic">O</Emphasis>-dipropyl-<Emphasis Type="Italic">α</Emphasis>-aminophosphonate

Molecular and crystal structure of N-(6-methoxybenzothiazol-2-yl)-1-(4-fluorophenyl)-O,O-dipropyl-α-aminophosphonate, C₂₁H₂₆FN₂O₄PS, have been determined by single-crystal X-ray diffraction study. The title compound is tetragonal, with a = 21.35(3) Å, c = 20.16(5) Å, Z = 16, D _x = 1.308 Mg/m³, μ(MoKα) = 0.247 mm^?1, and space group is I4₁/a. The structure was solved by direct method and refined to a final R = 0.0687 for 2370 reflections with I > 2σ(I). The compound shows a fully delocalized benzothiazole system with a sp² hybridization of the N(2). There is a strong intermolecular hydrogen bond between P=O and NH. The crystal structure is stabilized by a strong intermolecular N–H?sO hydrogen bond.     

Synthesis and Crystal Structure of <Emphasis Type="Italic">Tris</Emphasis>-(<Emphasis Type="Italic">N</Emphasis>–<Emphasis Type="Italic">N</Emphasis> dimethyl benzylammonium)-hexachlorobismuthate(III)

Abstract  The salt tris-(N–N dimethyl benzylammonium)-hexachlorobismuthate(III) crystallizes in the triclinic system P1 with unit cell parameters: a = 9.0300(12), b = 9.9220(3), c = 19.575(2) ?, α = 79.955(5), β = 89.952(2), γ = 88.108(6)°, V = 1726.0(3) ?³, Z = 2. The examination of the structure shows an alternate stacking of inorganic layers of hexachlorobismuthate(III) anions and organic layers of [C₆H₅CH₂NH(CH₃)₂]⁺ cations parallel to the a-axis. The cohesion forces of the packing of N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Index Abstract  The examination of the structure shows a layer arrangement parallel to the a-axis: planes of octahedral anions [BiCl₆]³⁻ alternate with planes of [C₆H₅CH₂NH(CH₃)₂]⁺ cations (Fig. 3). The cohesion forces of the packing of the N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal nucleation of high-temperature Fe<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Ga<Subscript>2 − <Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>3</Subscript> multiferroics in bismuth trimolybdate-borate fluxes

Crystallization of the orthorhombic phase of variable Fe _x Ga_{2 − x} O₃ composition in fluxes based on the Bi₂Mo₃O₁₂-B₂O₃ system with monitoring of the Néel temperature of this phase has been investigated. The data obtained are used to choose the flux composition for growing single crystals with Néel temperatures T _N > 0°C in order to investigate their properties as multiferroics. The method of group growth of single crystals on seeds and the regime of their subsequent heat treatment (which increases T _N) are described.     

Growth of ultrathin twin-free <Emphasis Type="Italic">b</Emphasis>-oriented YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7 – <Emphasis Type="Italic">x</Emphasis></Subscript> films

Twin-free b-oriented YBa₂Cu₃O_{7 – x} films with a thickness less than 40 nm have been epitaxially grown on (100)SrLaGaO₄ crystals. Based on the temperature dependence of resistance, the onset temperature of the transition to the superconducting state is found to be 90 K; the transition width is 4 K. The film growth has been performed in two stages. A (100)PrBa₂Cu₃O_{7 – x} buffer layer was previously grown on a (100)SrLaGaO₄ substrate by rf magnetron sputtering in an Ar–O₂ gas mixture at a continuous and monotonic increase in temperature from 660 to 830°C. The main YBa₂Cu₃O_{7 – x} film was grown on the buffer layer surface by pulsed laser deposition in an oxygen medium at a fixed temperature (800°C). The above processes were implemented in different chambers, which were connected by a vacuum channel for transporting samples. Both films were grown in situ, without contacting atmosphere in all growth stages. An X-ray diffraction study has shown that the YBa₂Cu₃O_{7 – x} films are single-crystal and free of precipitates of other phases and domains of other orientations.     

Growth and dielectric properties of KTiOPO<Subscript>4</Subscript> and K<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Rb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>TiOPO<Subscript>4</Subscript> crystals

Methods of growth of KTiOPO₄ and K_{1 ? x} Rb _x TiOPO₄ crystals of high optical quality have been optimized. The dielectric properties (permittivity and conductivity) of the crystals grown have been investigated at frequencies from 10² to 10⁶ Hz in the temperature range from 100 to 350 K, along the [001] crystallographic direction. It is established that partial substitution of K⁺ ions with Rb⁺ ions leads to a decrease in the permittivity and conductivity.     

Refinement of the composition and structure of YBaCo<Subscript>4−<Emphasis Type="Italic">x</Emphasis></Subscript>Al<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>7+δ</Subscript> crystals

YBa(Co_{4 ? x} Al _x )O_{7 + δ} (114Y) crystals have been grown in the Y-Ba-Co-O system by spontaneous crystallization from a slowly cooled nonstoichiometric melt. To change the oxygen content, the crystals were isothermally annealed in air in the range of 280–490°C. The crystals grown were characterized by scanning electron microscopy and powder X-ray diffraction. According to the data of an X-ray spectroscopic quantitative microprobe analysis, the average compositions of “as-grown” and oxygen-saturated crystals were Y_1.04Ba₁Co_3.54Al_0.50O_7.8 and Y_1.02Ba₁Co_3.55Al_0.51O_8.4, respectively. The refinement of the crystal structure after saturation on an automatic Bruker X8APEX diffractometer with a CCD detector (MoKα radiation, graphite monochromator, θ_max = 32.54°, sp. gr. P6₃ mc, a = 6.2746(9), c = 10.257(3) Å, V = 349.71(13) ų, Z = 2, d _calcd = 5.220 g/cm³) reveals the location of Al in two independent positions of Co atoms and yields the general formula of the compound as YBaCo_3.26Al_0.74O₇. Problems related to the difference in the compositions obtained by different methods are discussed.     

Synthesis and Characterization of the Osmium Compound <Emphasis Type="Italic">cis</Emphasis>(CO)<Emphasis Type="Italic">–</Emphasis>ClOs(CO)<Subscript>2</Subscript>(bpcd)[C(O)Et]

Photochemical activation of the triosmium cluster Os₃(CO)₁₂ in CH₂Cl₂ solvent and ethylene, followed by treatment with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd), furnishes the new octahedral compound cis(CO)–ClOs(CO)₂(bpcd)[C(O)Et] in low yield. The title compound has been isolated and characterized in solution by IR and ¹H NMR spectroscopies, with the solid-state structure of cis(CO)–ClOs(CO)₂(bpcd)[C(O)Et] determined by X-ray diffraction analysis. cis(CO)–ClOs(CO)₂(bpcd)[C(O)Et] crystallizes in the triclinic space group P-1, a = 10.043(2), b = 11.455(2), c = 16.221(3) Å, α = 74.900(3)°, β = 76.150(3)°, γ = 76.221(2)°, V = 1718.2(5) ų, Z = 2, D _cacl = 1.717 Mg/m³; R = 0.0453, R _w = 0.0778 for 6703 observed reflections with I > 2σ(I). The presence of the chlorine and propanioyl groups in cis(CO)–ClOs(CO)₂(bpcd)[C(O)Et] is structurally confirmed, and the origin of the these groups from the reaction solvent and ethylene is discussed.     

Intermolecular Hydrogen Bonds and the Supramolecular Structure of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis(<Emphasis Type="Italic">p</Emphasis>-tolylsulfonyl)diethylenetriamine

Abstract  The title compound N,N′-bis(p-tolylsulfonyl)diethylenetriamine (1) was synthesized and its crystal structure determined by X-ray diffraction. Adjacent molecules of 1, symmetrically related through a c-glide, are linked by alternating hydrogen bonds that form molecular chains along [0 0 1]. Two molecular chains occur in each unit cell and pack to form alternating layers in a three-dimensional supramolecular structure. The compound crystallizes in the Pca2₁ space group stabilized by the inclusion of solvent dichloromethane molecules in structural voids between molecules of 1. The dichloromethane molecules are related through a twofold screw rotation axis and are not disordered. Index Abstract  Intermolecular hydrogen bonds involving sulfonamide moieties of title compound afford a supramoleular structure that accommodates the inclusion of dichloromethane in alternating layers.      

Synthesis and Structure Determination of <Emphasis Type="Italic">S</Emphasis>,<Emphasis Type="Italic">S</Emphasis>′-(Naphthalen-2-ylmethyl sulfanyl (1-<Emphasis Type="Italic">p</Emphasis>-tolyl-ethylidene) Hydrazine

Abstract  

S,S′-(Naphthalen-2-ylmethyl sulfanyl (1-p-tolyl-ethylidene) hydrazine (SNM4MA) was prepared by the condensation of S-napthalen-2-ylmethyldithiocarbazate (SNMDTC) and 4-methylacetophenone. Yellow needles of SNM4MA were obtained upon slow evaporation of a 50:50 mixture of acetonitrile and DMSO over a period of weeks. The compound crystallizes in the monoclinic system with the space group C 2/c and Z = 4. The unit cell parameters are a = 7.0221(2) ?, b = 22.8428(6) ?, c = 23.5127(6) ? with β = 94.0222(13)°. Single crystal X-ray analysis shows that the molecule has crystallographic two-fold rotational symmetry coincident with the S–S bond. The title compound exists as a trans–cis conformer in which the naphthalene group is trans with respect to the thione sulfur while the benzyl group adopts a cis geometry. ¹³C and ¹H spectra confirm that the dimeric nature is retained in DMSO solution.     

Growth of ZnSe<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>S<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solution crystals from vapor phase

Partially faceted ZnSe_{1 − x} S _x solid solution crystals have been grown from a vapor phase in a closed stationary horizontal system. The growth has been performed in cylindrical quartz ampoules—∼10 mm in diameter and evacuated to a residual pressure of less than ∼10⁻³ Pa-at a temperature of 1050°C and a temperature drop between the source and growth zones of 10–16°C. The crystal structure, optical absorption, and composition inhomogeneity along the ingot length have been investigated by X-ray diffractometry and optical spectroscopy in the wavelength range of 300–3000 nm. The solid-solution composition range corresponding to cubic polymorphs is determined. The concentration dependences of the lattice parameter and band gap are presented.