Crystal Structure and Computational Analysis of a Two-Dimensional Coordination Polymer,BiI<Subscript>3</Subscript>(DppeO<Subscript>2</Subscript>)<Subscript>3/2</Subscript>

Catena-poly[fac-triiodobismuth(III)-tris-(µ-ethane-1,2-diylbis(diphenylphosphane oxide-κ²O,O′))], a 2-D sheet network of BiI₃ was synthesized from BiI₃ and ethane-1,2-diylbis(diphenylphosphane oxide) (DppeO₂) in tetrahydrofuran. The crystal structure revealed a trigonal structure with three-fold symmetry at Bi. Bismuth centers show fac-BiI₃O₃ coordination, with Bi–I?=?2.9416(2) Å and Bi–O?=?2.4583(17) Å. The I–Bi–I and O–Bi–O angles (95.520(7)° and 79.04(6)°, respectively) indicate trigonal distortion in the Bi octahedron. Bridging DppeO₂ ligands centered on inversion centers give rise to a 2-D sheet polymer. The 8.3 Å thick sheets consist of three layers in a sandwich structure. The outer layers are composed of phenyl rings and BiI₃ groups with the iodide atoms pointing outward. The central layer consists of the O=PCH₂CH₂P=O bridging groups. Computational results suggest that semi-conducting behavior arises from Bi(III) centers. A halide to DppeO₂ π* transition is suggested by theoretical results.     

New Organotin/CuCN/Quinazoline 3D-Supramolecular Coordination Polymers Having Catalytic and Luminescence Activities

The new bimetallic supramolecular coordination polymers (SCP); ³ _∞[Cu(CN)₂·Me₃Sn·qaz], 1 and ³ _∞[Cu₂(CN)₄·(Ph₃Sn)₂·qaz], 2 (qaz?=?quinazoline), are prepared in water/acetonitrile solvent at room temperature. The structure of 1 consists of the anionic Cu(CN)₂ building blocks connected by the Me₃Sn cations to form zigzag chains which are bridged by qaz creating 2D-sheets. The interwoven infinite sheets are arranged in parallel A···A···A fashion developing 3D-network structure via H-bonds, π–π stacking, and Cu–C contacts. The network structure of 2 exhibits two different copper sites forming two Cu(CN)₂ building blocks which are connected by the Ph₃Sn groups constructing elongated corrugated chains. The qaz ligand connects these chains forming 3D-network structure containing the rhombic [Cu₂(μ₃-CN)₂] motif. 1 and 2 are luminescent materials which can be used in applications as molecular sensing systems. Also, the catalytic activity of 1 and 2 was investigated towards the degradation of Metanil Yellow (MY) dye by dilute solution of hydrogen peroxide as oxidant.     

A Novel Coordination Polymer with Helical Chain: Synthesis and Crystal Structure of [Cu<Subscript>4</Subscript>(PMEP-Sal)<Subscript>4</Subscript>·H<Subscript>2</Subscript>O]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>

Summary A novel coordination polymer, [Cu₄(PMEP-sal)₄·H₂O] _n (PMEP-sal = 4-(2′-hydroxyl benxoylhydrazinyl) ethylidene-5-methyl-2-phenyl-pyrazole-3-one), is synthesized. Single crystal X-ray analysis reveals the polymer contains tetranuclear building blocks in helical arrangement.     

Ultrasound and Microwave-Assisted Co-precipitation Synthesis of La<Subscript>0.75</Subscript>Sr<Subscript>0.25</Subscript>MnO<Subscript>3</Subscript> Perovskite Nanoparticles from a New Lanthanum(III) Coordination Polymer Precursor

In the present study nano-sized strontium-doped lanthanum manganite, La_0.75Sr_0.25MnO₃ (LSM), were synthesized by three simple different methods (a) co-precipitation, (b) ultrasonic and (c) microwave-assisted co-precipitation. A lanthanum(III) coordination polymer, [pyda.H]₂[La₂(pydc)₄(H₂O)₄]·2H₂O, where [pyda.H]⁺?=?2,6-diaminopyridinium, and (pydc)^2??=?2,6-pyridinedicarboxylate, was used as a new precursor. The products were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), thermal gravimetric (TG) and differential thermal analyses (DTA), as well as by Energy-dispersive X-ray spectroscopy (EDX). The XRD results showed that the crystal lattice of the product obtained was orthorhombic perovskite structure. The porosity, particle size and homogeneity of calcinated LSM were strongly dependent on the preparation method. In addition, the results proved that the product formation time was decreased considerably when ultrasonic or microwave irradiation methods were used.     

A Novel 3D Photoactive Coordination Polymer with Alternate Cd(H<Subscript>2</Subscript>O)<Superscript>2+</Superscript> and Mg(Hen)<Superscript>3+</Superscript> Units and Sandwich-Shaped Cluster Linkages

A novel organic–inorganic hybrid, cadmium(II)-magnesium(II)-molybdenum(V) phosphate, {Cd[(PO₄)₂(HPO₄)₂Mo₆O₁₁(OH)₄]₂}[Cd(H₂O)]₂[Mg(Hen)]₂{Cd[(PO₄)₃(HPO₄)Mo₆O₁₀(OH)₃Cl₂]₂}·(H₂en)₄·(Hen)₂·(en)₂·9H₂O (en = ethylenediamine), was prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, elemental analysis, inductively coupled plasma (ICP) analysis, thermogravimetric analysis, fluorescence, FT-IR and bond valence sum calculations. As revealed by single-crystal X-ray diffraction studies, the sandwich-shaped clusters of [Cd(Mo₆P₄)₂] are interconnected by additional [Mg(Hen)] units and [Cd(H₂O)] fragments to form an extended three-dimensional supramolecular framework with channels occupied by ethylenediamine molecules, protonated ethylenediamine cations and water molecules. Luminescent measurement of the title compound exhibits intensive blue and greenish-blue radiation emission upon excitation with ultraviolet light.     

Electroconducting ceramics based on In<Subscript>2</Subscript>O<Subscript>3</Subscript>, CdO,and LaCrO<Subscript>3</Subscript>

The possibility of fabricating electroconducting (10¹–10⁴ S cm^–1) ceramics based on In₂O₃, CdO, and LaCrO₃ by liquid-phase synthesis methods has been demonstrated. The results of studies of the effect of temperature, dopants, and partial oxygen pressure on the specific electroconductivity of ceramic composites are presented.     

Novel SO<Subscript>3</Subscript>H-Functionalized Ionic Liquids Based on Benzimidazolium Cation: Efficient and Recyclable Catalysts for One-Pot Synthesis of Biscoumarin Derivatives

Abstract  

In this article, a new group of SO₃H-functionalized ionic liquids based on benzimidazolium cation was synthesized and used as environmentally benign catalysts for the one-pot synthesis of biscoumarin derivatives. The ionic liquids showed high catalytic activities and reusabilities with good to excellent yields of the desired products. H ₀ (Hammett function) values and the minimum-energy geometries of SO₃H-functionalized ionic liquids were determined and the results revealed that the acidities and catalytic activities of ionic liquids in the synthesis of biscoumarin derivatives were related to their structures.     

Synthetic spinels of the system MgO-Cr<Subscript>2</Subscript>O<Subscript>3</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>

Synthetic spinels of the system MgO-Cr₂O₃-Al₂O₃-Fe₂O₃ are considered and the desirability of organizing their production for the refractory industry is demonstrated. Translated from Novye Ogneupory, No. 6, pp. 32–35, June 2008.     

Electrical conductivity of CuI-AsI<Subscript>3</Subscript>-As<Subscript>2</Subscript>Se<Subscript>3</Subscript> and CuI-SbI<Subscript>3</Subscript>-As<Subscript>2</Subscript>Se<Subscript>3</Subscript> chalcogenide films prepared by chemical deposition

The electrical conductivity of chalcogenide semiconductor films in the CuI-AsI₃-As₂Se₃ and CuI-SbI₃-As₂Se₃ systems, which have been prepared by chemical deposition from mono-n-butylamine, has been studied as a function of the temperature and film composition. It has been established that the electrical conductivity of the CuI-AsI₃-As₂Se₃ and CuI-SbI₃-As₂Se₃ films is predominantly determined by the copper iodide content. It has been demonstrated that the electrical properties of the chalcogenide glasses and the related films are characterized by the same values to within the experimental error, which is explained by the same model of dissolution of vitreous semiconductors in amines with the retention of the electrical properties of chalcogenide glasses after the deposition of films from their solutions.     

Simple One-Pot Preparation of In<Subscript>2</Subscript>O<Subscript>3</Subscript> Nano-particles Using a Supramolecular 3D Framework Polymer

An indium(III) three-dimensional coordination framework, [In₂(OH)₃(O₄C₈H₄)_1.5] _n (1), was synthesized by hydrothermal method and characterized by elemental analyses, X-ray powder diffraction (XRD) and IR spectroscopy. Indium(III) oxide nanoparticles was prepared by direct thermal decomposition of 1 at 450 °C in air. The indium(III) oxide nanoparticles were characterized by scanning electron microscopy, X-ray powder diffraction (XRD) and energy-dispersive X-ray analysis (EDAX). This study demonstrates the coordination polymer frameworks may be suitable precursors for a simple one-pot preparation of nanoscale metal oxide materials with different and interesting morphologies.     

Unexpected Formation of a Doubly Bridged Cyclo-1,2-dithian 1D Coordination Cu<Subscript>2</Subscript>I<Subscript>2</Subscript>-Containing Luminescent Polymer

Abstract  

CuI reacts instantaneously with butanedithiol in MeCN solution to form a sparingly soluble and thermally stable colorless polymeric material 1 of composition [(Cu₂I₂){HS(CH₂)₄SH}] _n . Raman and IR spectroscopy confirm the presence of Cu(I) bound S–H functions. Furthermore, small amounts of the yellow compound [{Cu(μ₂-I)₂Cu}(C₄H₈S₂)₂] _n 2 co-crystallize after several days. If the reaction mixture is exposed to air, polymeric 2 is isolated as the main product. An X-ray diffraction study reveals that 1D polymer 2 is assembled by rhomboid Cu(μ₂-I)₂Cu clusters (d Cu···Cu 2.6843(18) ?), which are linked through the S-atoms of six-membered 1,2-dithian heterocycles, thus generating an infinite ribbon. The low-frequency region in the Raman spectra show a striking similarity suggesting that polymers 1 and 2 bear the same cluster rhomboid Cu(μ₂-I)₂Cu clusters. The photophysics and luminescence properties of 2 have been studied experimentally and by means of DFT/TDDFT calculations.     

A Novel Method For Fabricating Cr-Doped Alpha-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Nanoparticles: Green Approach To Nanotechnology

The aim of this work was to produce Cr-doped alpha-alumina nanoparticles using a modified sol–gel method that employs the complexation capacity of natural organic matter (NOM). For this synthesis, the initial pH of the sol was adjusted to 4.0, and final calcination of the xerogel was performed at 1100?°C for 4 h. XRD and FTIR analyses confirmed that the hexagonal α-Al₂O₃ phase was produced under these conditions. Chromaticity analyses revealed that more intense pink colors were obtained for the samples with higher Cr concentrations. XANES measurements showed that the oxidation state of chromium in the alumina matrix was strongly dependent on the dopant concentration and that it was possible to produce samples free from Cr(VI). The photo- and radioluminescence spectra of the nanoparticles were found to be sensitive to the dopant concentration. All these findings demonstrated that the synthesis procedure using NOM could provide considerable environmental, technological, and economic benefits.     

Low-temperature anti-icing reagents in the Ca(NO<Subscript>3</Subscript>)<Subscript>2</Subscript>-Mg(NO<Subscript>3</Subscript>)<Subscript>2</Subscript>-CO(NH<Subscript>2</Subscript>)<Subscript>2</Subscript>-H<Subscript>2</Subscript>O system and their properties

The polytherms of ice melting in sections of the Ca(NO₃)₂-Mg(NO₃)₂-CO(NH₂)₂-H₂O system with different component ratios were studied in the temperature interval from 0 to −40°C. A series of nitrate and nitrate-carbonate reagents that are promising for the creation of anti-acing reagents were found, which form eutectics with ice at temperatures from −25 to −39°C. Their properties, viz., melting properties with respect to ice and corrosiveness on metals and alloys, were determined. An effective corrosion inhibitor was selected.     

Crystal structure of new compound (Rb,K)<Subscript>2</Subscript>Cu<Subscript>3</Subscript>(P<Subscript>2</Subscript>O<Subscript>7</Subscript>)<Subscript>2</Subscript>

A new compound of (Rb,K)₂Cu₃(P₂O₇)₂ is obtained by high-temperature reactions from a mixture of RbNO₃, KNO₃, Cu(NO₃)₂, and (NH₄)₄P₂O₇. The crystal structure was solved by direct methods and refined to R ₁ = 0.056 for 5022 independent reflections. The compound belongs to a rhombic crystal system, P2₁2₁2₁, Z = 8, a = 9.9410(7) Å, b = 13.4754(6) Å, c = 18.6353 (3) Å, and R = 0.056. The basis of the structure is a complex copper-phosphate skeleton of the composition of [Cu₃(P₂O₇)₂]^2–, which can be regarded as consisting of two types of heteropolyhedral layers parallel to the (001) plane. The layers are alternated with each other, forming a frame, in the cavities of which the positions of alkali cations are located, statistically populated with K⁺ and Rb⁺ ions. Based on the refined populations of the positions of alkali cations, an exact chemical formula of the compound can be written as Rb_1.28K_0.72Cu₃(P₂O₇)₂. The compound is the most complex among those known to this day of the composition of A₂ ^IB₃ ^II(P₂O₇)₂ (A = Li, Na, K, Rb, or Cs; B = Ni, Cu, or Zn).