Acid Metal Salts Research Articles

Synthesis and characterization of a new organic–inorganic Pb 2+ selective composite cation exchanger acrylonitrile stannic(IV) tungstate and its analytical applications

A new polymeric–inorganic cation exchanger acrylonitrile stannic(IV) tungstate composite was synthesized by sol–gel technique by incorporating stannic(IV) tungstate precipitate with acrylonitrile. Composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic polymers (acrylonitrile, cellulose acetate, polyaniline, polypyrrole, polythiophene, etc.), providing a new class of ‘organic–inorganic’ composite exchangers with better mechanical and granulometric properties, good ion exchange capacity, higher stability, reproducibility and selectivity for heavy metals. The physico-chemical characterization was carried out by elemental analysis, TGA, SEM, XRD, FTIR and TEM studies. Ion exchange capacity, pH titrations, elution and distribution behavior were also carried out to understand the ion exchange behavior of the material. The adsorption behavior of heavy metal ions has been reported in nitric acid and two surfactants media by batch processes. The analytical applications of the material have been explored by achieving some analytically important binary separations from aqueous solution on its columns. The practical applicability of acrylonitrile stannic(IV) tungstate was demonstrated in the quantitative separation of Fe 3+and Zn 2+ contents of a commercially available pharmaceutical sample namely Fefol-Z.

Synthesis, spectral characterization and antimicrobial studies of some new binuclear complexes of CuII and NiII Schiff base

Heterobinuclear alkali metal complexes of Cu II or Nu II with Schiff base derived from condensation of 1,2-propylenediamine with o-hydroxyacetophenone in 1: 2 molar ratio have been synthesized. They were characterized by elemental analysis, IR spectra, UV-Visible spectral analysis, magnetic and molar conductance measurements. The synthesized binuclear Cu II and Ni II complexes of Schiff base are found to have square planar geometry. No change in the stereochemistry of Cu II and Ni II complexes was observed after formation of adduct with the alkali metal salts of the organic acids. The antimicrobial activity of some of the heterobinuclear complexes are assayed which demonstrated inhibitory effect against some bacteria and fungi.

Silane-Derived SEI Stabilization on Thin-Film Electrodes of Nanocrystalline Si for Lithium Batteries

Effects of trimethoxy methyl silane additive on solid electrolyte interphase (SEI) layer formation on nanocrystalline Si thin-film electrode in ∕ethylene carbonate:diethyl carbonate(1:1) electrolyte were studied using attenuated total reflection Fourier transform infrared (IR) spectroscopy. IR analyses indicated that silane effectively protected the Si surface, which produced a stable SEI layer composed of organics with alkyl carbonate and carboxylic acid metal salt functionalities, and PF-containing species, leading to a stable cycling at vs delivering over . The film surface obtained after cycling without silane, however, showed primarily PF-containing species, which is responsible for inefficient passivation of the Si surface, resulting in a rapid capacity fade.

Complexes of triethanolamine with aroxyacetic acids and their metal salts as a new class of biologically active compounds

A series of complexes of triethanolamine with metal salts of aroxyacetic acids has been prepared. The complexes are perspective biologically active compounds for search for new immunomodulating, antistress, anti-inflammatory and other types of agents. The structure and acid-base properties of these compounds were studied by NMR and IR spectroscopy and potentiometric titration.

Soap: The Polymorphic Genie of Hierarchically Structured Soft Condensed-Matter Products

More than 5 million tonnes of metal salts of fatty acids are manufactured and used worldwide every year, to create a range of soft condensed-matter products such as bar soaps, stick deodorants, personal care creams, toothpastes, and lubricant greases. These molecules, popularly known as soaps, are capable of forming a plethora of states and self-assembled aggregates such as micelles, liquid crystals, solid crystals, and gels, whose characteristic sizes or domain sizes can span from nanometers to centimeters. The type and mix of the phases formed, their morphologies, and their states of dispersion or the nature of their further supra-assemblies dictate the underlying micromechanical structures of products, which, in turn, are responsible for their optical, structural, and rheological properties. Developing processing guidelines to manipulate characteristic micromechanical structures is therefore key to obtaining the desired look, touch, feel, and function of these products. The article discusses a few illu...

Sorptive Removal of Dyes Using Titanium Phosphate

Basic dyes have been found to be the most soluble dyes used in textile industries that, with their tinctorial values being high and even in small quantities, produce obvious coloration. Adsorption has often been used as a method to remove dissolved contaminated organic compounds because of simplicity of design, ease of operation, and insensitivity to toxic substances. When a cation-exchange material is used as a sorbent, it is believed that the interaction of the functional groups present in the dye with the matrix material (sorbent) being used could be anywhere from covalent to Coulombic, hydrogen bonding, or weak van der Waals forces. In the present study, titanium phosphate (TiP), an inorganic ion-exchange material of the class of tetravalent metal acid salt has been synthesized by sol−gel method, characterized, and used as a sorbent. The sorption behavior of cationic dyes Crystal Violet (CV), Rhodamine 6G (R6G), Methylene Blue (MB), and Pink FG (PFG) toward TiP has been studied, based on thermodynamic parameters evaluated and adsorption isotherms (Langmuir and Fruendlich). Breakthrough capacity and elution behavior of dyes have also been studied. Sorption affinity of dyes toward TiP is found to be MB > CV> R6G > PFG.

Synthesis, characterization and analytical applications of a new composite cation exchanger cellulose acetate-Zr(IV) molybdophosphate

A new composite cation exchanger cellulose acetate-Zr(IV) molybdophosphate was synthesized because composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic polymers (cellulose acetate, polyaniline, polythiophene, polypyrrole, Nylon 6,6, etc.), providing a new class of ‘organic–inorganic’ composite ion exchangers with better mechanical and granulometric properties, good ion exchange capacity, reproducibility, higher stability and selectivity for heavy metals. The physico-chemical properties of this material were determined using some instrumental analyses viz. FTIR, X-ray, TGA–DTA and SEM. Ion exchange capacity, pH titrations, elution and distribution behavior were also carried out to understand the ion exchange behavior of the material. Its selectivity was examined by achieving some important binary separations like Mg(II)–Ca(II), Zn(II)–Ca(III), Fe(III)–Cr(III), Zn(II)–Cr(III), Cd(II)–Hg(II), Cd(II)–Cr(III) on its column. This new exchanger was offered a variety of technological opportunity for quantitative determination and separation of Cr 3+ from a synthetic mixture of metal ions and Ca 2+ from commercially available vitamin and minerals formulation namely Recovit.

Cooperative Effect of 3,3′,4,4′-Benzophenonetetracarboxylic Acid and 1,10-Phenanthroline under Solvothermal Conditions to Afford Two Novel Zinc(II) and Cadmium(II) Complexes

Rational self-assembly of a flexible ligand 3,3′,4,4′-benzophenonetetracarboxylic acid and d10 transition metal salts in the presence of rigid bidentate ligand 1,10-phenanthroline yields two novel helical coordination polymers with different structural motifs; i.e., [Zn(H2bbtc)(phen)2 · 2H2O] n (1) and [Cd2(bbtc)(phen)4 · 2.25H2O] n (2) (H4bbtc = 3,3′,4,4′-benzophenonetetracarboxylic acid, phen = 1,10-phenanthroline), under solvothermal condition. One is hydrogen bonded and π–π stacked together into a network, and the other is a covalently coordinated 3D framework. The coordination polymers were characterized by FT-IR, UV/VIS and fluorescent spectroscopy, single crystal X-ray diffraction, elemental analysis and differential thermal analysis/thermogravimetry (DTA/TG). The most intriguing structural feature is that each complex exhibits novel helical-spaced chains by reason of two different ligands coordinating to the metal centers. Additionally, compounds 1 and 2 showed good fluorescence properties compared to the free ligands.

Synthesis, characterisation and curing of furan resins

The furan resins have been synthesized by condensation of furfuryl alcohol with anisaldehyde/salicyldehyde and furfuraldehyde with furfuryl alcohol/p-cresol using acid or base or metal salt as catalyst. These resins have been characterized by Fourier Transform Infra-red spectra (FTIR) and cross-linking of these resins are accomplished by using various curing agents. These resins find extensive application in spandex fibers, laminates, lining for rocket fuels, abrasive wheels etc.

Metal catalyzed rearrangement of a 2,2′-bipyridine Schiff-base ligand to a quaterpyridine-type complex

A Co(II) quaterpyridine-type complex has been prepared via a one-pot transformation of a 2,2'-bipyridine Schiff-base ligand in the presence of a Lewis acidic metal salt.

Effects of Metal Salts of Organic Acids and Fired Temperature on Coloring of Hematite Pigments

Effects of Metal Salts of Organic Acids and Fired Temperature on Coloring of Hematite Pigments

Preparation of Bi2Sr2Can−1CunOy/NiO/Ni tapes by chemical solution method

We have prepared high quality Bi2Sr2Ca1Cu2Oy (Bi-2212) tapes on polished NiO/Ni or Ag substrates using a chemical solution method of acetic acid metal salts, and investigated an optimum condition for the preparation of Bi-2212/NiO/Ni tapes with c-axis orientation. From the results, we found that zero-resistance temperature (TC) of the 35μm thick tapes was about 72K, and its critical current (IC) increased with the thickness of the tapes. The TC and IC of the Bi-2212 tapes were improved by increasing their thickness. The IC of the 28μm thick Bi-2212 tape was more than 800mA at 30K and 0T. However, the TC of Bi-2212/Ag tapes was about 84K, and decreased on the nickel plate. Since the decrease of TC may be due to nickel magnetization effect, the use of the nickel substrates in the preparation of Bi-2212 tapes is thought to be disadvantageous.

Cytochemical Differences in Bacterial Glycocalyx

To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

“Micro-Pottery”Marangoni Effect Driven Assembly of Amphiphilic Fibers

We report spontaneous supra-assembly of fibrous surfactant crystallites at the air-solution interface resulting in spectacular arrays of two-dimensional spiral and three-dimensional "micro-pottery"-like superstructures. Surface pressure differential driven bending of the embryonic fiber nuclei and Marangoni convection driven fiber migration/alignment appear to be the causal factors behind this phenomenon. The assemblies form at specific crystal-growth velocities dictated by the relative time scales for fiber bending/alignment and their rigidification/immobilization as they grow. Although our studies are restricted to a specific class of amphiphiles, namely, alkaline metal salts of linear fatty acids, the phenomenon should be generic to amphiphilic molecules that crystallize into flexible fibers.

Preparation of Bi 2Sr 2Ca n−1 Cu nO y thick films by chemical solution deposition

We prepared Bi 2Sr 2Ca n−1 Cu n O y ( n=2: Bi-2212) thick films on MgO (1 0 0) substrates by a chemical solution deposition of acetic acid metal salts, where a partial melt-process was included. From the X-ray diffraction results, we found that the optimum maximum temperature ( T max) and period of sintering for obtaining c-axis-oriented Bi-2212 thick films were 910 °C and 15 min, respectively. The film showed a metallic temperature dependence of resistance in the normal state, and its T c (critical temperature) was about 88 K, which became about 90 K by annealing at 700 °C.

Enantioselective Diels-Alder reactions catalyzed by hydrogen bonding.

Like molecules of life (e.g., proteins and DNA), many pharmaceutical drugs are also asymmetric (chiral); they are not superimposable on their mirror images. One mirror image form (enantiomer) of a drug can have desirable activity, the other not. Consequently, the development of methods for the selective synthesis of one enantiomer is of great scientific and economic importance. We report here that a simple, commercially available chiral alcohol, alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-dimethanol (TADDOL), catalyzes the all-carbon Diels-Alder reactions of aminosiloxydienes and substituted acroleins to afford the products in good yields and high enantioselectivities (up to 92% enantiomeric excess). It is remarkable that the reactions are promoted by hydrogen bonding, the ubiquitous "glue" that helps to keep water molecules together and holds up the 3D structures of proteins. Hydrogen bond catalysis is little used in chemical synthesis, wherein most reactions are promoted by complexes of Lewis acidic metal salts coordinated to chiral ligands. As it does for enzymes, hydrogen bonding not only organizes TADDOL into a well defined conformation, but, functioning as a Brønsted acid catalyst, it also activates the dienophile toward reaction with the diene. The gross structure of the TADDOL has been found to have a profound influence on both the rate and the enantioselectivity of the cycloadditions. These structure-function effects are rationalized by evaluating the conformation adopted by the TADDOLs in the crystal state. It is suggested that pi,pi-stacking plays an central role in the overall catalytic cycle, in particular, the enantioselective step.

Tetravalent Metal Acid Salts: Solid Acid Catalysts for Hydration of Nitriles to Amides.

For Abstract see ChemInform Abstract in Full Text.

A New Route to Alumoxane Gel: A Versatile Precursor to γ‐Alumina and Alumina‐Based Ceramic Oxides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Glycocalyx morphology of Candida albicans.

In this study, we examine new cytochemical aspects of the fimbria-mediated adhesion of the oral facultative pathogen Candida albicans. A wild-type strain of the yeast was grown with and without sucrose supplementation for 8 days. Osmium tetroxide, uranyl acetate (UA), ruthenium red (RR), and cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs) and tannic acid-metal salt technique (TAMST) were applied to specimens separately or in combination for transmission electron microscopy (TEM) examination. Cytochemically, two types of fimbriae of C. albicans were distinguished: RR-positive fimbriae of polyanionic glycoconjugates and CB-positive fimbriae with a ceasing point of 0.3 M MgCl2 where no staining of sulfated carboxyl-rich and/or phospho-glycoconjugates occurred. Additionally, CB-positive intercellular fibers were observed, which seemed to be involved in intercellular adhesion. The present protocol enables, for the first time, a partial cytochemical differentiation between at least two kinds of yeast fimbriae.

Synthesis, characterization and analytical applications of a new and novel ‘organic–inorganic’ composite material as a cation exchanger and Cd(II) ion-selective membrane electrode: polyaniline Sn(IV) tungstoarsenate

Composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic conducting polymers (polyaniline, polypyrrole, polythiophene, etc.), providing a new class of ‘organic–inorganic’ hybrid ion exchangers with better mechanical and granulometric properties, good ion-exchange capacity, higher stability, reproducibility and selectivity for heavy metals. Such a type of ion exchanger ‘polyaniline Sn(IV) tungstoarsenate’ was developed by mixing polyaniline into inorganic precipitate of Sn(IV) tungstoarsenate. This material was characterized using atomic absorption spectrometry, elemental analysis, Fourier transform infrared spectroscopy, simultaneous thermogravimetry–differential thermogravimetry, X-ray and scanning electron microscopy studies. Ion-exchange capacity, pH-titrations, elution and distribution behavior were also carried out to characterize the material. On the basis of distribution studies, the material was found to be highly selective for Cd(II) and its selectivity was tested by achieving some important binary separations like Cd(II)–Zn(II), Cd(II)–Pb(II), Cd(II)–Hg(II), Cd(II)–Cu(II), etc., on its column. Using this composite cation exchanger as electroactive material, a new heterogeneous precipitate based selective ion-sensitive membrane electrode was developed for the determination of Cd(II) ions in solutions. The membrane electrode is mechanically stable, with a quick response time, and can be operated within a wide pH range. The selectivity coefficients for different cations determined by mixed solution method were found to be less than unity. The electrode was also found to be satisfactory in electrometric titrations.