Cuprous oxide microcrystals via hydrothermal approach: morphology evolution and photocatalytic properties

Cuprous oxide (Cu₂O) microcrystals with various morphologies were prepared under mild hydrothermal condition. The samples were characterized by means of XRD, SEM, and UV/DRS. The morphology of the as‐prepared Cu₂O microcrystals typically had cubic symmetry and the morphology evolution from radial, six hollow branches to truncated octahedra (again cubic) were realized by adding acetic acid. The peak relative intensity of XRD pattern shows that the exposed planes of samples is consistent with their morphology. A possible growth mechanism of Cu₂O microcrystals is also proposed. The behavior of adsorption and photocatalysis of Cu₂O microcrystals was investigated by degrading methyl orange (MO) in aqueous solution. The results show that the as‐prepared Cu₂O radial six hollow branches microcrystals with exposed {110} planes have higher degradation efficiency to methyl orange (MO) than cubic ones with exposed {100} planes and truncated octahedral with exposed {111} planes microcrystals.     

Crystal and Molecular Structure of Bis{2,6‐bis(hydroxymethyl)pyridine‐O,O,N}{μ‐bis(2‐hydroxymethylpyridyl)methanolate‐O,N}dicopper(II)di(propionate). First example of non‐coordinate propionate anoins

Bis{2,6‐bis (hydroxymethyl) pyridine‐O,O,N} {μ‐bis(2‐hydroxymethylpyridyl) methanolate‐O,N} dicopper(II) di(propionate) (CCDC 143763) has been prepared and studied by single‐crystal X‐ray diffraction methods at 293(2) K. The crystal structure consists of dimeric complex cation, [Cu₂(μ‐bhmp)₂(bhmpH)₂]⁺² and propionate anions (bhmp ‐ 2,6‐bis(hydroxymethyl) pyridine; bhmpH ‐ 2‐(6‐hydroxymethylpyridyl) methanolate ) and propionate anions. The complex cation contains two neutral and two monodeprotonated bhmp molecules, each coordinate to one Cu(II) atom in a tridentate chelating manner, via two O atoms and N atom. The monodeprotonated bmph molecules are also tridentate coordinate via N atom and only one O atom, which serve as bridge between two CuO₄N₂ moieties. The propionate anions are “ fixed” to the complex by the hydrogen bonds.     

Abscheidung von Cu2O aus der Gasphase im strömenden Medium

CVD-experiments in the system Cu O H Cl N result in the growth of Cu₂O single crystals. The characteristic faces of the various forms are the {100} ones. A thermodynamic analysis permits to predict such conditions under which Cu₂O is deposited without deposition of any other phases.     

On the question of symmetry classification of ordered tetrahedrally coordinated structures

Substructures of tetrahedrally coordinated polytopes (4D polyhedra) are determined as “polytopes” {136} and {408}, which are divided into nonintersecting 17-vertex aggregations of four centered tetrahedra. It is shown that 17-vertex polyhedra of the diamond structure and polytopes 〈136〉, {240}, 〈408〉, and {5, 3, 3} differ only by the angle of synchronous rotation of external vertex triads, and the cell of each structure is determined by the two nearest nonintersecting 17-vertex polyhedra. The following sequence is proposed as a basis for symmetry classification of ordered tetrahedrally coordinated structures: diamond structure 〈136〉 {240} → 〈408〉 → {5, 3, 3}. The possibilities of the developed approach are demonstrated by the example of constructing a rod with the screw axis 8₂ from cells of the polytope 〈136〉; this rod can be transformed into a diamond substructure: a helicoid of diamond parallelohedra with the screw axis 4₁.     

Synthesis,characterization and crystal structure of a novel 3‐D copper(II) polymer with bent N‐containing ligand

An exploration of the mixed‐ligand system under hydrothermal condition, has led to the isolation of a 3‐D novel framework {[Cu₂(mp)L₂)(H₂O)₂]·6H₂O}_n ( 1 ) (mp = benzene‐1,2,4,5‐ tetracarboxylate tetraanion, L = 4‐(5‐(pyridin‐4‐yl)‐1,3,4‐thiadiazol‐2yl)pyridine). Single‐crystal X‐ray analyses reveal that it crystallizes in the triclinic space group P‐1, a = 8.807(4) Å, b =11.139(6) Å, c = 11.291(5) Å, α=75.337(7), β = 73.584(5), γ= 66.795(5)°. The Cu^II ions are linked into an extended 2‐D grid net via mp molecules. Further these layers are united together through the bridging L to form a 3‐D structure, which exhibits a new 4‐connected topological network. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structures of copper(II) and nickel(II) nitrate and chloride complexes with 4-bromo-2-[(2-hydroxyethylimino)-methyl]phenol

The crystal structures of {4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}aquacopper(II) nitrate hemihydrate (I), chloro-{4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}copper hemihydrate (II), and chloro-{4-bromo-2-[(2-hydroxyethylimino)-methyl]phenolo}aquanickel (III) are determined using X-ray diffraction. Crystals of compound I are formed by cationic complexes, nitrate ions, and solvate water molecules. In the cation, the copper atom coordinates the singly deprotonated molecule of tridentate azomethine and the water molecule. The copper complexes are joined into centrosymmetric dimers by the O _w -H···O hydrogen bonds. The crystal structure of compound II is composed of binuclear copper complexes and solvate water molecules. The copper atom coordinates the O,N,O ligand molecule and the chlorine ion, which fulfills a bridging function. The coordination polyhedron of the metal atom is a distorted tetragonal bipyramid in which the vertex is occupied by the chlorine atom of the neighboring complex in the dimer. Compound III is a centrosymmetric dimer complex. The coordination polyhedra of two nickel atoms related via the inversion center are distorted octahedra shared by the edge.     

Structural characteristics of gas hydrates within the framework of generalized crystallography

It is shown that the symmetry of the {5, 3, 3} polytope (four-dimensional dodecahedron) embedded into E⁴ enables one to derive all the polyhedra—cavities that make up gas hydrates from the {5, 3} dodecahedron. Consideration is given to the allomorphic embedding of the {5, 3} subgraph into the incidence graph of the Desargues configuration 10₃, which determines the mechanism of incorporation of guest molecules into the polyhedra—cavities of gas hydrates and their escape from these polyhedra at the symmetry level. The relationships obtained may be considered as a basis for an a priori derivation of the determined (periodic and aperiodic) structures of gas hydrates.     

Controls on Morphology of Analcime-Pollucite in Natural Minerals,Synthetic Phases,and Nuclear Waste Products

Crystals of the analcime-pollucite series (NaAlSi₂O₆ · H₂O CsAlSi₂O₆) exhibit tetragon-trioctahedral {211} and hexahedral {100} morphology, with rare modification by tetrahexahedral {210} or rhombic dodecahedral {110} forms. Under weakly acidic to weakly basic conditions {100} is dominant; with increasing alkalinity (cation concentration), basicity (pH), and temperature {211} is dominant over {100}, with minor development of {210}. The morphology does not appear to be influenced by broad ranges in Si/Al (from 2.0 to 2.6 in the natural minerals) and Na-Cs contents between analcime and pollucite, by substitutions of univalent cations Li, K, Rb, and Tl, or by small amounts of divalent cations Mg, Mn, Ni, Zn, Fe. Larger amounts of Ca, however, and possible substitutions for framework Al and Si seem to produce a more complex morphology.     

Hydrothermal Synthesis and Structure of Fe<Subscript>6.36</Subscript>Mn<Subscript>0.64</Subscript>(PO<Subscript>3</Subscript>(OH))<Subscript>4</Subscript>(PO<Subscript>4</Subscript>)<Subscript>2</Subscript>

Abstract  

Single crystals of iron and manganese phosphate Fe_6.36Mn_0.64(PO₃(OH))₄(PO₄)₂ was synthesized by hydrothermal method. The compound crystallizes in the Fe₇(PO₄)₆ structure type and is isotypic with the solid solution \textM_{7 - \textx} \textM_\textx^￠ ( \textHPO₄ )₄ ( \textPO₄ )₂ {\text{M}}_{{7 - {\text{x}}}} {\text{M}}_{\text{x}}^{\prime} \left( {{\text{HPO}}_{4} } \right)_{4} \left( {{\text{PO}}_{4} } \right)_{2} where M is Fe, Co, Mg, Mn. The compound is triclinic, P-1, a = 6.571(5), b = 7.993(3), c = 9.547(2) Ǻ, α = 103.97(1)°, β = 109.29(2)°, γ = 101.57(3)°. The structure is based on a three-dimensional framework of distorted edge-sharing MO₆ and MO₅ polyhedra, forming infinite chains, which are interlinked by corner-sharing with PO₄ tetrahedra. The formula unit is centrosymmetric, with all atoms in general positions except for one Fe atom, which has site symmetry −1.     

Crystal structure of aluminum sulfate hexadecahydrate and its morphology

A single‐crystal structure of aluminum sulfate hexadecahydrate (Al₂(SO₄)₃·16H₂O) was captured with a polarizing microscope. The structure was similar to a hexagonal plate and consistent with the predicted morphology derived from the modified AE model. An octagonal plate morphology was first obtained in a vacuum but was transformed into hexagonal plate‐like when the effect of the solvent with two disappearing {1 1 0} and {1 0 −1} faces was considered.     

Twins in CdMnTe single crystals grown by Bridgman method

Cd_1‐xMn_xTe (x =0.2, CdMnTe) crystal was grown by the vertical Bridgman method, which exhibits a pure zincblende structure in the whole ingot. The major defect, twins, which is fatal to CdMnTe crystal, was analyzed with scanning electron microscopy (SEM), X‐ray energy disperse spectroscopy (XEDS) and optic microscopy on the chemical etching surface. The twins observed in the as‐grown ingot are mainly lamellar ones, which lie on the {111} faces from the first‐to‐freeze region of the ingot and run parallel to the growth axis of the ingot. Coherent twins with {115}_t‐{111}_h orientations when indexed with respect to both the twin and host orientations, are often found to be terminated by {110}_t‐{114}_h lateral twins. Te inclusions with about 20 μm in width are observed to preferentially decorate the lamellar twin boundaries. The origin of the twins, relating to the growth twin and the phase transformation twin, is also discussed in this paper. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structure of 2-Aminopyridinium Dihydrogendiphosphate Monohydrate

Abstract  

Chemical preparation, X-ray single-crystal of the bis(2-aminopyridinium)-dihydrogendiphosphate monohydrate (C₅H₇N₂)₂H₂P₂O₇·H₂O are described. The title compound crystallizes in the triclinic system with P \mathop 1^- \mathop 1\limits^{-} space group. The unit cell dimensions are a = 8.4378(4) ?, b = 8.5567(4) ?, c = 12.3245(5) ?, α = 105.678(2)°, β = 94.503(3)°, γ = 104.885(3)° with V = 817.44(6) ?³ and Z = 2. The structure of this compound includes two types of hydrogen bonds: (i) O–H···O, links the H₂P₂O₇ groups to form infinite inorganic layers [\textH ₂ \textP ₂ \textO ₇ ( \textH ₂ \textO)]_n ^{2n -} . [{\text{H}}_{ 2} {\text{P}}_{ 2} {\text{O}}_{ 7} ( {\text{H}}_{ 2} {\text{O)}}]_{n}^{ 2n - } . in (101) plan, (ii) N–H···O assemble inorganic layers leading to a three-dimensional arrangement.     

Synthesis,transformation to octahedron‐like crystals,and gas‐sensing property of six‐horned nanospheres of Cu2O

Single‐crystal six‐horned nanospheres of Cu₂O with a diameter of 760 nm in average were prepared in aqueous solution of CuCl₂and NaOH by using ascorbic acid as the reductant in the presence of sodium dodecyl benzenesulfonate (SDBS) at room temperature. The horn grows along the <100> direction, which is consistent with the protuberant direction of an apex of octahedron. The formation process of six‐horned nanospheres included two steps: the formation of Cu₂O nanospheres via Ostwald ripening process, and the appearance of horns on the surface of nanospheres under low concentration of SDBS. As increasing the concentration of SDBS, the six‐horned nanospheres could be transformed into octahedron‐like Cu₂O. And at the same concentration of SDBS, keeping the volume ratio of water and ethanol in mixed solutions as 1:1, Cu₂O octahedra were obtained. Moreover, gas‐sensing property showed that six‐horned nanospheres of Cu₂O had higher sensitivity compared with Cu₂O nanospheres and Cu₂O octahedra to ethanol gas (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and structural characterization of a novel polymeric gadolinium(III)–copper(II) complex of iminodiacetic acid

A novel polymeric Gd₂Cu₃ complex of iminodiacetic acid (H₂L¹=NH{CH₂COOH}₂), namely, Gd₂Cu₃(L¹)₆, 1, has been synthesized and structurally characterized. In the title complex, the Gd³⁺ ion is nine-coordinated by six O atoms from three bidentate chelating carboxylate groups and three O atoms from three anti-anti bridging carboxylic groups of six L¹ ligands; the Cu²⁺ ion is six-coordinated by four O and two N atoms from two chelating L¹ ligands. Each pair of Gd(III) atoms is bridged by three L¹ ligands, each of which also chelates with one copper(II) ion, thus forming a Gd₂Cu₃ cluster unit. Such cluster units are cross-linked by flexible L¹ ligands into a three-dimensional coordination framework. The title complex crystallizes in the trigonal space group P-3c1 (No. 165) with a = b = 13.433(4), c = 14.770(6) Å; V = 2308(1) ų; D_calca = 1.859 g cm^–3; Z = 2.     

Growth and morphological study of copper oxide single crystals

Experiments on the growth of CuO single crystals by crystallization from flux in the CuO-Bi₂O₃-PbO-PbF₂, CuO-Bi₂O₃-Li₂O, CuO-Bi₂O₃-B₂O₃, CuO-BaO-Y₂O₃, and CuO-MO_x systems (M = P, V, or Mo) have been performed. The best results were obtained in crystallization in the CuO-Bi₂O₃-PbF₂ system: prismatic single crystals of platelet-and needlelike or isometric habit with dimensions up to 1 × 10 × 10, 1 × 1 × 20, or 6 × 6 × 8 mm, respectively, have been grown. The CuO crystals show polysynthetic twinning in the form of numerous alternating light and dark bands bound by systems of parallel straight lines on the {110} and {111} faces. A possible model of twinning associated with the Cu₂O → CuO transformation is considered.     

Synthesis,Crystal Structure and Spectroscopic Characterization of {6-[2-(2-chlorophenyl)-1,3-thiazol-4-yl]-2-oxo-1,3-benzothiazol-3(2<Emphasis Type="Italic">H</Emphasis>)-yl}acetic acid

Abstract  

The title compound {6-[2-(2-chlorophenyl)-1,3-thiazol-4-yl]-2-oxo-1,3-benzothiazol-3(2H)-yl}acetic acid was prepared and characterized by elemental analyses, FT-IR, ¹H NMR spectroscopy, X-ray diffraction. A quantum-chemical calculation was performed using the CNDO method. In the title compound, C₁₈H₁₁ClN₂O₃S₂, the crystal structure is stabilized by intermolecular hydrogen bonds (C–H···O=C) to form centrosymmetric R₂² R_{2}^{2} (16) dimers and the C–H···O, O–H···N, and C–H···N interactions generating the graph set motifs R₂² R_{2}^{2} (9) and R₂² R_{2}^{2} (22).     

Phase‐manipulable synthesis of Cu‐based nanomaterials using ionic liquid 1‐butyl‐3‐methyl‐imidazole tetrafluoroborate

Using the ionic liquid (IL), 1‐butyl‐3‐methyl‐imidazole tetrafluoroborate, and the precursor Cu₇Cl₄(OH)₁₀·H₂O, series of phase‐manipulable Cu‐based nanomaterials were synthesized by hydrothermal and microwave assisted routes, respectively. The structural characters of the as‐prepared CuO, CuO/Cu₂O composites and pure Cu nanoparticles were investigated by XRD, SEM, TEM and HRTEM, and their surface photovoltaic properties were studied by surface photovoltage spectra. Via hydrothermal route Cu²⁺ ions were found to be reduced gradually into Cu⁺ and subsequently Cu⁰ with increasing the IL, and various phase ratio of CuO, Cu₂O and Cu composite nanosheets and pure Cu nanoparticles were obtained. This implies that the IL could function as both a reductant in the oxygen‐starved condition and a template for the nanosheet products. The ¹H‐NMR result of the IL supports it being a reductant. In microwave assisted route, however, only monoclinic single crystalline CuO nanosheets were obtained, which indicates the IL being a template only in oxygen‐rich condition. Therefore, the crystal phase, composition and morphology of the Cu‐based products could be controlled by simply adjusting the quantity of the IL and oxygen in solution routes. The molecular structure of the IL after oxidation reactions was investigated by ¹H‐NMR and a possible reaction mechanism was proposed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Two Mononuclear Compounds with bis(Pyrimidin-2-yl)amine as a Ligand and as a Hydrogen-bonded Lattice Molecule. Synthesis, Structure and Spectroscopy of {[M(dipm)(H2O)(A)](dipm)(A)(H2O)} (M?=?Cd with A?=?ClO4; and Zn with A?=?BF4)

Abstract  Two isostructural mononuclear compounds with formula {[Cd(dipm)(H₂O)(ClO₄)](dipm)(ClO₄)(H₂O)} (1) {[Zn(dipm)(H₂O)(BF₄)](dipm)(BF₄)(H₂O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. The structure of compound 1 has been solved in the space group P2₁/n with a = 18.860(4), b = 8.579(2), c = 20.917(4) ?, β = 101.33(3)°, V = 3318.4(12) ?³, Z = 4 with final R = 0.0454. The structure of compound 2 has also been solved in the space group P2₁/n with a = 19.026(4), b = 8.389(1), c = 20.720(4) ?, β = 101.37(3)°, V = 3242.2(10) ?³, Z = 4 with final R = 0.0689. The geometry around the metal ions is octahedral, and is constituted by four nitrogen atoms from two dipm molecules, an oxygen atom from a water molecule and a semi-coordinating anion atom ( for compound 1 and for compound 2). In the lattice are also present: a non-coordinating water molecule, an anion molecule and a dipm molecule. For compound 1, the Cd–N distances are between 2.296 and 2.328 ?. The distance is 2.310 ? and the is 2.477 ?. The Zn–N distances in compound 2 are between 2.121 and 2.164 ?. The distance is 2.147 ? and the distance is 2.373 ?. A hydrogen bond interaction of the Watson–Crick type is observed between the amine N atom of a dipm ligand to a pyrimidyl N atom and a non-coordinating dipm ligand with N···N distances, which vary from 3.066(5) to 3.109(5) ?. Furthermore medium to strong hydrogen bond interactions are present between oxygen atoms of the water molecules and the anions of the compounds. Index Abstract  Two isostructural mononuclear compounds with formula {[Cd(dipm)(H₂O)(ClO₄)](dipm)(ClO₄)(H₂O)} (1) {[Zn(dipm)(H₂O)(BF₄)](dipm)(BF₄)(H₂O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. . Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Hydrothermal conversion of ZnO2 to ZnO flowers: A mechanistic investigation and characterization

In this article, we report a novel but simple method for the phase transformation of ZnO₂ to flower‐like ZnO microstructures hydrothermally at 90 °C with and without the assistance of hexadecylamine as surfactant. The generation of zincate ion ZnO$^{2-}_{2}$ as a growth unit from the reaction between ZnO₂ and peroxide ion O$^{2-}_{2}$ in situ plays a key role in the phase transformation of ZnO₂ to ZnO. The morphology, structure, and composition of the products have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Powder X‐ray diffraction (PXRD) and energy dispersive X‐ray analysis (EDX). It has been demonstrated that the as‐fabricated ZnO flowers are composed of self‐assembled brooms and rods in the presence and absence of hexadecylamine respectively. On the basis of experimental results, a possible reaction mechanism and the growth processes involved in the formation of flower‐like ZnO microstructures are discussed.