Sonochemical Synthesis and Characterization of the New Plate-Shaped Lead(II)–Iodo Coordination Polymer: A Precursor to Produce a Pure Phase Nano-Sized Lead(II) Oxide

Preparation of plate-shaped nanostructures of a new 1D polymeric lead(II) complex containing the Pb₂-(μ-I)₂ motif, [Pb(neo)I₂] _n ,(1) where neo is the abbreviation of neocuproine, using a sonochemical method is described. The new coordination polymer is characterized by scanning electron microscopy, X-ray diffraction (XRD), elemental analysis and infrared spectroscopy. The single crystalline material is obtained using a heat gradient applied to a solution of the reagents. Single-crystal XRD analysis indicates that a coordination number of six for Pb^II ions, (i.e., PbN₂I₄) with an asymmetrical coordination sphere and “stereo-chemically active” electron lone pairs. They also show that the chains interact with each other through π–π stacking interactions creating a 3D framework. PbO nanoparticles are obtained by thermolysis of 1 at 180?°C with oleic acid as a surfactant. Scanning electron microscopy confirms formation of PbO particles with a size of ~25?nm.     

A New Metal–Organic ZnII Supramolecular Assembled via Hydrogen Bonds and N···N Interactions as a New Precursor for Preparation Zinc(II) Oxide Nanoparticles, Thermal, Spectroscopic and Structural Studies

A new 1D supramolecular involving two different ligands, {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O (GB = 2-guanidinobenzimidazole and bpe = 1,2-bis(4-pyridyl)ethylene, has been synthesised, characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR spectroscopy. The thermal stability of compound {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O was studied by thermal gravimetric and differential thermal analyses. The single crystal X-ray analysis shows that the complex is a one-dimensional polymer involving macrocycle rings as a result of non-covalent bridging bpe ligands via N–H···N and N···N interactions, N–H···bpe···bpe···H–N, with the basic repeating {[Zn(GB)₂](μ-bpe)₃}(ClO₄)₂·H₂O units and by connecting [Zn(GB)₂]²⁺ nodes. ZnO nanoparticles were obtained by calcination of compound {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O at 500 °C in air. The nanoparticles were characterized by X-ray diffraction and scanning electron microscopy.     

Simultaneous Growing of Two New Cd(II) Metal–Organic Frameworks with 2,6-Naphthalendicarboxylic Acid as New Precursors for Cadmium(II) Oxide Nanoparticles: Thermal, Topology and Structural Studies

Crystal structure and thermal stability of two new 3D Cd(II) metal–organic frameworks (MOF) containing 2,6-naphthalenedicarboxylate, [Cd(NDC)(DMF)], 1, and [Cd₃(NDC)₄], 2 (H₂NDC = 2,6-naphthalenedicarboxylic acid; DMF = N,N-dimethylformamide) have been studied. These two MOFs grow simultaneously within the same solution to give multiple crystals that are due to the general lability of Cd(II) complexes. Structure 1 shows a 3D neutral metal–organic framework with PtS topology and crystallizes in the triclinic system, space group P-1 (No. 2), whilst 2 crystallizes in the orthorhombic system, space group Fdd2 (No. 43) with body-centered cubic bcu-(4²⁴.6⁴) topology. The elongated nature of NDC results in large cavities in both compounds; however, the pores are filled by coordinated DMF molecules in 1. The thermal stability of 1 and 2 were studied by thermogravimetry and show stability to 400 °C for 1 and continuous weight loss for 2. CdO nanoparticles were prepared by direct calcination of 1 and 2 at 600 °C. The CdO nanoparticles were characterized by X-ray powder diffraction and its morphology were studied by scanning electron microscopy. The results show that the CdO is pure and has a uniform morphology.     

A Novel Copper(II)–Hydrogen Oxalate Coordination Polymer Showing a New Coordination Mode

A novel Cu(II) coordination polymer of general empirical formula {[Cu(μ-HC₂O₄)₂(H₂O)₂][Cu(HC₂O₄)₂]∙6H₂O} _n (1) has been synthesized and characterized by single-crystal X-ray diffraction technique. The complex (1) crystallizes in the triclinic form with P-1 space group. It is quite surprising that single crystal X-ray analysis of 1 illustrates the presence of hydrogen oxalate ligand in the coordination environment of Cu(II) ion. Because oxalate is not present in the starting reaction mixture, it may be derived from the reduction of squarate ligand. In 1, Cu(II) ions exhibit two different coordination environments, forming a distorted octahedral geometry. The Cu1 is coordinated with six oxygen atoms from two bidentate HC₂O₄ ⁻ and two aqua ligands, while Cu2 is coordinated with six oxygen atoms from four HC₂O₄ ⁻ ligands. The HC₂O₄ ⁻ ligand acts in two different coordination modes, as a bidentate and an unprecedented tridentate bridging coordination mode.     

Synthesis, Structural Investigation and DFT Calculations of Cadmium (II) Fluorine-Substituted β-Diketonate: A Precursor to Producing Pure Phase Nano-Sized Cadmium (II) Oxide

A novel aza-aromatic base adduct of a cadmium(II) fluorine-substituted β-diketonate, [Cd(dmp)(ttfa)₂]_n(1), (“dmp” is an abbreviation for 2,9-dimethyl-1,10-phenanthroline and “ttfa” is an abbreviation for thenoyltrifluoroacetonate) was synthesised and characterised by elemental analysis and IR, ¹H NMR and ¹³C NMR spectroscopy and studied by thermal as well as X-ray crystallography. The single-crystal structure of this complex shows that the coordination number of the Cd²⁺ ion is six with two N-donor atoms from the dmp ligand and four O-donors from ttfa. Self-assembly of this complex was mediated by CH···F–C and π–π stacking interactions. The supramolecular features of these complexes are controlled by weak directional intermolecular interactions. The structural energy of the title complex was determined by density functional theory calculations. The calculated HOMO–LUMO gap is 0.131 a.u. (3.474?eV). The CdO nano-particles were obtained by thermolysis of 1 at 180?°C with oleic acid as the surfactant. Scanning electron microscopy showed that the size of the CdO particles is ~35?nm.     

Mullite–Cobalt (II,III) Oxide System: Preparation of Ceramic Pigment Using Recycling of Fly Ash

Silicon - The present work depends on recycling of fly ash by preparation of stoichiometric mullite containing various amounts of Co3O4; 0, 5, 10, 15 wt.% to obtain pigment ceramic materials. The...     

Mass Transfer and Immobilized Organic Phase Instability Studies for Cobalt(II)–Nickel(II) Separation by PEHFSD

Pseudo-emulsion-based hollow-fiber strip dispersion (PEHFSD) technique was examined as an alternative to solvent extraction for simultaneous separation and concentration of cobalt(II)–nickel(II) mixture using Cyanex-272 as the extractant. Experiments were carried out by continuous recirculation of the feed and pseudo-emulsion phases through a hollow-fiber module. The separation factor increased rapidly after 60 min of operation. The maximum value after 120 min of operation was ～128 (pH = 6.5) for the operating conditions studied. The mass transfer resistance from the extraction reaction appeared to be dominant. The results of mathematical modeling of the mass transfer process indicated that higher separation factor and extraction rate can be achieved using PEHFSD in comparison to solvent extraction. Mixing of the stripping and the feed solution was observed at high dispersed phase volume fraction in the pseudo-emulsion and low flow rate of this phase. The maximum value of backtransport flux from the stripping phase due to mixing was estimated to be approximately two orders lower than the initial extraction rates.     

Synthesis and Characterization of Silica–Polymer Nanocomposites Functionalized with Piperazine for the Synthesis of β-Nitro Alcohols

Abstract  

In order to compare the activity and selectivity for the synthesis of β-nitro alcohols, piperazine was functionalized directly and after surface modification into the ordered mesoporous SBA-15 framework. The materials were characterized by powder X-ray diffraction, N₂-adsorption–desorption isotherm, FT-IR, SS-NMR and scanning electron microscopy. The catalyst synthesized via surface modification under solvent free conditions showed very high activity and selectivity of β-nitro alcohols compared to the one synthesized by direct functionalization of SBA-15. Finally the possible reaction pathways were explained mechanistically.     

Hydrothermal Synthesis, Crystal Structure and Characterization of New Coordination Polymer [Co2(pydc)2(H2O)6] n ·2nH2O

A coordination polymer of cobalt(II) containing the pyridine-2,5-dicarboxylate (pydc) ligand and having the composition [Co₂(pydc)₂(H₂O)₆] _n ·2nH₂O was prepared by the hydrothermal method. The coordination polymer was characterised by FTIR, single crystal XRD, SEM, TGA–DTA, and N₂ Temperature Programmed Desorption, Brunauer, Emmett and Teller surface area. The polymer contains two cobalt(II) ions with slightly distorted octahedral geometry. The carboxylate group at the 2-position of pyridine acts as a bridging ligand between two cobalt metal ions and this expansion leads to formation of a 1-D chain-like coordination polymer. The coordination polymer chains are packed together by well-directed hydrogen bonds to generate a three dimensional mesoporous network. The N₂ TPD study shows that the polymer is mesoporous in nature and possesses slit-shaped mesopores with average pore size diameter of 17.78 nm. SEM micrographs show well-defined channels in the solid crystals confirming the porosity of polymer. Thermogravimetric studies indicate the robust nature of the polymer. The polymer undergoes thermal decomposition in well-defined steps leading to the formation of cobaltous oxide as the end-product.     

Synthesis and Characterization of Biodegradable Polymer – Used as a Pour Point Depressant for Lubricating Oil

Additives based on polymers of alkyl methacrylate used in lubricant composition improve the viscometric and rheological properties of the lubricant and provide fuel economy. They are also looked upon to provide additional performance characteristics such as improved low temperature fluidity, dispersancy and thickening. However, the recent demand for eco-friendly technology guided us to incorporate the sunflower chemistry into the acrylate skeleton through the process of copolymerization in anticipation of getting an ideal blend of performance as well as eco-friendly chemistry. The present investigation comprises the homo and copolymerization of sunflower oil with different mass fraction of methyl methcrylate (MMA), decyl acrylate (DA) and styrene, characterizations and their evaluations as a pour point depressant in base oils.     

Synthesis and Characterization of β-Cyclodextrin Functionalized Ionic Liquid Polymer as a Macroporous Material for the Removal of Phenols and As(V)

β-Cyclodextrin-ionic liquid polymer (CD-ILP) was first synthesized by functionalized β-cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (βCD-BIMOTs) and was further polymerized using a toluene diisocyanate (TDI) linker to form insoluble CD-ILP (βCD-BIMOTs-TDI). The βCD-BIMOTs-TDI polymer was characterized using various tools and the results obtained were compared with those derived from the native β-cyclodextrin polymer (βCD-TDI). The SEM result shows that the presence of ionic liquid (IL) increases the pore size, while the thermo gravimetric analysis (TGA) result shows that the presence of IL increases the stability of the polymer. Meanwhile, Brunauer-Emmett-Teller (BET) results show that βCD-BIMOTs-TDI polymer has 1.254 m²/g surface areas and the Barret-Joyner-Halenda (BJH) pore size distribution result reveals that the polymer exhibits macropores with a pore size of 77.66 nm. Preliminary sorption experiments were carried out and the βCD-BIMOTs-TDI polymer shows enhanced sorption capacity and high removal towards phenols and As(V).     

Attenuation of Combined Nickel(II) Oxide and Manganese(II,III) Oxide Nanoparticles’ Adverse Effects with a Complex of Bioprotectors

Stable suspensions of NiO and Mn₃O₄ nanoparticles (NPs) with a mean (±s.d.) diameter of 16.7 ± 8.2 and 18.4 ± 5.4 nm, respectively, purposefully prepared by laser ablation of 99.99% pure nickel or manganese in de-ionized water, were repeatedly injected intraperitoneally (IP) to rats at a dose of 2.5 mg/kg 3 times a week up to 18 injections, either alone or in combination. A group of rats was injected with this combination with the background oral administration of a “bio-protective complex” (BPC) comprising pectin, vitamins A, C, E, glutamate, glycine, N-acetylcysteine, selenium, iodide and omega-3 PUFA, this composition having been chosen based on mechanistic considerations and previous experience. After the termination of injections, many functional and biochemical indices and histopathological features (with morphometric assessment) of the liver, spleen, kidneys and brain were evaluated for signs of toxicity. The Ni and Mn content of these organs was measured with the help of the atomic emission and electron paramagnetic resonance spectroscopies. We obtained blood leukocytes for performing the RAPD (Random Amplified Polymorphic DNA) test. Although both metallic NPs proved adversely bio-active in many respects considered in this study, Mn₃O₄-NPs were somewhat more noxious than NiO-NPs as concerns most of the non-specific toxicity manifestations and they induced more marked damage to neurons in the striatum and the hippocampus, which may be considered an experimental correlate of the manganese-induced Parkinsonism. The comparative solubility of the Mn₃O₄-NPs and NiO-NPs in a biological medium is discussed as one of the factors underlying the difference in their toxicokinetics and toxicities. The BPC has attenuated both the organ-systemic toxicity and the genotoxicity of Mn₃O₄-NPs in combination with NiO-NPs.     

Electrochemical Synthesis of Cu (II) Coordination Polymer Coatings Based on 2,2′-Thiodiacetic Acid and 1,2,4,5-Benzenetetracarboxylate

Electrochemical synthesis of coordination polymers of Cu(II), [Cu(TDA)]_n and [Cu₂(BTC)(H₂O)₆?6H₂O]_n in which H₂TDA is 2,2′-thiodiacetic acid and BTC stands for 1,2,4,5-benzenetetracarboxylate was carried out by the electrochemical oxidation of Cu anode in the presence of H₂TDA (a flexible ligand), and 1,2,4,5-benzentetracarboxylic acid (H₄BTC) (a rigid ligand) in aqueous solutions. The structure of coordination polymers were characterized by scanning electron microscopy, X-ray powder diffraction, elemental analysis, thermal gravimetric and differential thermal analyses. The crystal structure of the compounds consists of one-dimensional cubical crystal polymeric units of [Cu(TDA)]_n and [Cu₂(BTC)(H₂O)₆?6H₂O]_n. Furthermore, the coordination number of Cu (II) ions in synthesized coordination polymers to be found five. The main advantages of electrosynthesis are the minor synthesis time, the milder conditions and the facile synthesis of coordination polymer coatings.     

Architectural View of Flexible Aliphatic –OH Group Coordinated Hemi-Directed Pb(II)-Salen Coordination Polymer: Synthesis,Crystal Structure,Spectroscopic Insights,Supramolecular Topographies,and DFT Perspective

Journal of Inorganic and Organometallic Polymers and Materials - We serendipitously designed one novel 1D hetero-binuclear Zn(II)-Pb(II) coordination polymer, namely...     

Preparation and Characterization of Nano-Sized Iron–Titanium Mixed Oxide for Removal of Some Lanthanides from Aqueous Solution

Nano-structured iron(III)–titanium(IV) mixed oxide, Fe–O–Ti, was prepared by co-precipitation technique and characterized using Transmission Electron Microscopy, Fourier Transform Infra Red, Energy Dispersive X-ray spectroscopy, and Thermal Analysis. The particle size of the prepared material was found to be 10–15 nm. The sorptive potential of nano-composite, Fe–O–Ti, for the removal of some lanthanide elements (including, Ce, Nd, and Gd) was assessed in this work. The percent uptake was found to be 95.6%, 89.5, and 81.9 for Ce³⁺, Nd³⁺, and Gd³⁺ ions, respectively. Three kinetic models, pseudo-first-order, pseudo-second-order, and intra particle diffusion models, were tested. The results indicated that the pseudo-second-order model is more applicable for the sorption process. The experimental equilibrium data were tested for the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models; it was well predicted by the Freundlich model. The thermodynamic parameters were calculated. The results indicated that the nano-sized iron-titanium mixed oxide can be considered as a promising material for the removal of some lanthanides from aqueous solution.     

Syntheses and Characterization of New Nano-porous Soft Copper(II) Metal–organic Framework and Nano-porous Two-dimensional Manganese(II) and Zinc(II) Coordination Polymers with 4,4′-Bipyridine and 2-Sulfobenzoic Acid

Three new Cu(II), Mn(II), and Zn(II) coordination polymers with 4,4′-bipyridine (4,4′-bipy) and 2-sulfobenzoic acid (2-H₂sb) ligands, [M(4,4′-bipy)(2-sb)(H₂O)]_n, have been synthesized and characterized by IR spectroscopy and elemental analyses. The structures were determined by single-crystal X-ray crystallography. The structural studies show that the metal atoms have six-coordinate geometry with a distorted octahedral environment constructed with 4,4′-bipy and 2-sb²⁻ linkers stacked over each other to generate a two-dimension motif. Self-assembly of these compounds in the solid state is likely caused by coordination and hydrogen-bonds. While polymers containing Zn(II) and Mn(II) have analogous structures, the Cu(II)-containing nano-porous soft metal–organic framework presents a different structure.     

Synthesis of a New Interpenetrated Mixed Ligand Ni(II) Metal–Organic Framework: Structural, Thermal and Fluorescence Studies and its Thermal Decomposition to NiO Nanoparticles

Reaction of terephthalic acid and pyrazine with nickel nitrate under hydrothermal conditions forms a 3D metal–organic framework with the composition of [Ni(μ₃ ? tp)(μ₂ ? pyz)]_n (1), where H₂tp = 1,4-benzenedicarboxylic acid (terephthalic acid) and pyz = pyrazine. X-ray single crystal analysis reveals that Ni(II) centers adopt a distorted octahedral geometry which are surrounded by four oxygen atoms from three tp groups and two nitrogen atoms of pyrazine molecules in equatorial and axial positions, respectively. Coordination of Ni(II) centers by terephthalate linkers in ac plane forms infinite (4, 4)-connected 2D layers, which are further joined together by pyrazine groups to form an interlocked 3D structure. Topological studies show a two-fold interpenetrated uninodal 3D network with point symbol of (4¹²·6³). The polymer shows a blue emission band at 467 nm in the solid state at room temperature. The X-ray power diffractions (PXRD) and thermal gravimetric analysis of 1 are also presented and discussed. NiO nanoparticles have been prepared via direct calcination of 1 at 600 °C, with sizes of about 35–45 nm. Nanoparticles were further characterized by IR, scanning electron microscopy equipped with energy dispersive X-ray analyses and PXRD technique.     

Surface Modification of Luminescent LnIII Fluoride Core–Shell Nanoparticles with Acetylsalicylic acid (Aspirin): Synthesis,Spectroscopic and in Vitro Hemocompatibility Studies

Luminescent lanthanide fluoride core–shell (LaF₃:Tb³⁺,Ce³⁺@SiO₂-NH₂) nanoparticles, with acetylsalicylic acid (aspirin) coated on the surface have been obtained. The synthesized products, which combine the potential located in the silica shell with the luminescent activity of the core, were characterized in detail with the use of luminescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) methods. The in vitro effects of the modified luminescent nanoparticles on human red blood cell (RBC) membrane permeability, RBC shape, and sedimentation rate were investigated to assess the hemocompatibility of the obtained compounds. This study demonstrates that LaF₃: Tb³⁺ 5 %, Ce³⁺ 10 %@SiO₂-NH₂ nanoparticles with acetylsalicylic acid (aspirin) coated on the surface are very good precursors for multifunctional drug-delivery systems or bio-imaging probes that can be used safely in potential biomedical applications.