- Influence of the spatial structure of the alkyl chain on the composition of the product of the direct neutralization reaction between aliphatic carboxylic acids and zinc hydroxide
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A study was launched to clarify the influence of the spatial structure of the alkyl chain on the products of the direct neutralization reactions between zinc hydroxide and several non-cyclic saturated carboxylic acids in the presence of an excess of either the carboxylic acid or zinc hydroxide. The species formed were identified on the basis of their FT-IR spectra in the mid-IR region. Straight-chain acids produced the corresponding zinc bis-carboxylates with polymeric sheet structure under all circumstances. The species present in the products of the branched-chain carboxylic acids depended strongly on the nature of the component in excess and the bulk of the alkyl group. Besides the starting materials the reaction mixtures contained two carboxylate species in various ratios. One of them was the zinc bis-carboxylate of the branched-chain carboxylic acid, characterized by an additional νC=O band at around 1630 cm-1, above the usual two strong carboxylate stretching bands. The other species was the corresponding complex Zn4O(RCOO)6. The conditions of formation of these three forms of zinc carboxylates were formulated on the basis of the decreasing possibility of interaction between the neighbouring alkyl chains to form a polyethylene subcell in the sequence of: Zn(RCOO)2 (polymeric sheet) > Zn(RCOO)2 (intermediate form) > Zn4O(RCOO)6 (tetranuclear complex).
- Dreveni,Berkesi,Andor,Mink
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- Thermal properties of zinc butyrate complex compounds. II. Caffeine, nicotinamide and theobromine
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The new zinc(II) complexes of general formula Zn(CH3CH2CH2COO)2·nL (where L = caffeine, nicotinamide, theobromine; n = 1 or 2) were prepared and identified. Thermal properties of these compounds were investigate
- Gyoryova,Balek,Behrens,Matuschek,Kettrup
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- Anion Directed Selective Synthesis of Supramolecular Metallocycles and Related Coordination Dimers
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The reaction of C3-symmetric tris-(2-pyridinylene-N-oxide)triaminoguanidinium salts ([H3L]X) and zinc(II) in presence of thiocyanate and different carboxylate ions as co-ligands yields in a series of different coordination compounds. Supramolecular metallocycles and carboxylate-bridged dimers are defined by two fundamentally different binding motifs. By adjusting the co-ligands’ stoichiometry, metallocycles and carboxylate-bridged compounds can be synthesized selectively. Furthermore, the occupation of the metallocycles with co-ligands can also be controlled that way. Directed synthesis of these metallocycles is essential for further application in host-guest chemistry due to their cavities and porosity in the solid state.
- Sturm, Lisa,G?b, Christian R.,Oppel, Iris M.
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- Structurally diverse coordination compounds of zinc as effective precursors of zinc oxide nanoparticles with various morphologies
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The structurally diverse coordination compounds of zinc were designed and synthesized using two types of building blocks: short-chain carboxylate ions and hexamethylenetetraamine. They were characterized by X-ray crystallography, infrared spectroscopy and thermal analysis. The studied compounds were used as precursors for production (via controlled thermal conversion) of zinc oxide nanoparticles. The conversion process was optimized in terms of two parameters (heating rate and maximum temperature). Such an approach, combined with proper design of the precursor structure, allows fabrication of various zinc oxide micro- and nanoparticles. The influence of a precursor structure and modifications of conversion parameters on size and morphology of ZnO particles were studied and discussed.
- Swiatkowski, Marcin,Kruszynski, Rafal
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- Thermal, spectral and biological properties of Zn(II) complex compounds with phenazone
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The thermal decomposition of the complexes Zn(form)2 2phen (I), Zn(ac)2 2phen (II), Zn(prop)2 2phen (III), Zn(but) 2 2phen (IV), where phen=phenazone, form=formiate, ac=acetate, prop=propionate, but=butyrate has
- Szunyogova, Erika,Gyoeryova, Katarina,Hudecova, Daniela,Piknova, Lenka,Chomic,Vargova, Zuzanna,Zelenak
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- Room temperature molecular and lattice structures of a homologous series of anhydrous zinc(II) n-alkanoate
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The room temperature structures and lattice arrangements of a homologous series of zinc(II) n-alkanoates from chain length, nC = 4-20, inclusive, have been studied using infrared spectroscopy, X-ray diffraction and polarizing light microscopy. Lattice parameters from single crystal and powder diffraction data, for zinc(II) hexanoate, are compared to validate the use of the powder method. Since they are in excellent agreement, the powder data are analyzed by a software programme to determine lattice parameters for all the homologues. These are used, in conjunction with infrared, X-ray, density and molecular model calculations to determine molecular and lattice structures. The compounds are isostructural, in that, each zinc atom is tetrahedrally coordinated to oxygen atoms from four different carboxylate groups and each ligand forms a Z,E-type bidentate bridge with two tetrahedral zinc atoms resulting in a syn-anti arrangement. The hydrocarbon chains are in the fully extended all-trans configuration and are tilted at an average angle of 60° to the zinc basal plane. For the short chain length compounds with nC ≤ 8, a double bilayer in-plane-perpendicular-perpendicular-in-plane arrangement of hydrocarbon chains, with two molecules per unit cell, is indicated. For the others, an interdigitating in-plane-in-plane bilayer with head-to-tail interactions, with one molecule per unit cell, is proposed. A geometric model is presented to account for odd-even chain effects and to explain the differences in melting points and densities between these adducts. All the compounds crystallize in the monoclinic space group with P symmetry and are arranged in a two-dimensional network along the ac plane within the unit cell.
- Taylor, Richard A.,Ellis, Henry A.
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- METHOD FOR THE PRODUCTION OF METAL CARBOXYLATES AND THE METAL AMINOATE OR METAL HYDROXY ANALOGUE METHIONATE DERIVATIVES THEREOF, AND USE OF SAME AS GROWTH PROMOTERS IN ANIMAL FEED
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A method of production of metal carboxylates and of their metal carboxylate-aminoate or metal carboxylate-methioninate hydroxy analog derivatives, and their use as growth promoters in animal nutrition. It comprises mixing stoichiometric quantities of formic or butyric acid and oxide and of the dry basic salt of divalent metal, the oxide or hydroxide of Zn2+ or Cu2+, to give an exothermic reaction, without addiction of solvents, giving rise to a dry carboxylate of divalent metal that is easy to use. It also describes the use of a stage of mixing with metal aminoates or hydroxy analogs of methionine in the process, for forming either a carboxylate-aminoate of divalent metal or a carboxylate-methioninate hydroxy analog of divalent metal, products that are finally obtained in a dry form that is easy to use. Finally it describes the use of the compounds that can be obtained in the feeding of monogastric animals for improving the productivity, the bioavailability of the metals, and achieve a reduction of their emission to the environment, owing to the growth-promoting effect that they all display.
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Page/Page column 4-5
(2008/06/13)
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- Decomposition of organic salts of some d and f metals: Non-isothermal kinetics and FT-IR studies
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The thermal decomposition in non-isothermal conditions of formates, acetates, propionates and butyrates of Mn, Co, Zn, Cd, Eu, Sm and Ni was studied. The observed compensation effect allows us to calculate the isokinetic temperature. A selective activation mechanism was suggested. This leads to a good agreement between kinetic and spectroscopic data.
- Vlase,Vlase,Chiriac,Doca
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p. 839 - 845
(2008/10/08)
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- Meso Phase and Glass Formation in Binary Systems of Thallium Butyrate with Magnesium, Calcium, or Zinc Butyrate
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Phase equilibria in the binary systems thallium butyrate-divalent metal (Mg, Ca, Zn) butyrate were studied by differential thermal analysis and polythermal polarizing microscopy from 20 to 400°C. In all systems, the smectic A phase was induced due to the
- Mirnaya,Yaremchuk,Dradrakh,Volkov
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p. 775 - 778
(2008/10/08)
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