557-28-8Relevant academic research and scientific papers
Combinatorial nanopowder synthesis along the ZnO-Al2O 3 tie line using liquid-feed flame spray pyrolysis
Kim, Min,Lai, Samson,Laine, Richard M.
, p. 3308 - 3318 (2011)
Liquid-feed flame spray pyrolysis (LF-FSP) of mixtures of alumatrane [Al(OCH2CH2)3N]/zinc acetate dihydrate [Zn(O2CCH3)2·2(H2O)] or zinc propionate [Zn(O2CCH2CH3)2]/aluminum acetylacetonate [Al(Acac)3] dissolved in EtOH in known molar ratios can be used to combinatorially generate nanopowders along the ZnO-Al 2O3 tie-line. LF-FSP was used to produce (ZnO) x(Al2O3)1-x powders with x=0-1.0. Powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, thermal gravimetric analysis, differential thermal analysis, and BET. The resulting powders had average particle sizes (APSs) 2O3 the particle morphologies are combinations of plates and rods that grow with c/a ratios close to 1. The spinel phase dominates at (ZnO)x(Al 2O3)1-x (x=0.5 and 0.3). In the latter case, the currently accepted phase diagram for the ZnO-Al2O3 couple indicates that phase separation should occur to form zinc spinel (ZnAl2O4) and α-alumina. It appears that the rapid quenching during LF-FSP helps to preserve the spinel phase at ambient temperature giving rise to kinetic nanopowder products along the ZnO 2-Al2O3 tie-line. Finally, the solubility of ZnO in Al2O3 and vice versa in the materials produced by LF-FSP suggest apparent flame temperatures reached before quenching are 1700°-1800°C. Efforts to re-pass the spinel phase powders, (ZnO) x(Al2O3)1-x, x=0.5 and 0.3 through the LF-FSP system were made with the hope of generating core shell materials. However, instead the x=0.5 material generated materials closer to the x=0.3 composition and pure ZnO nanoparticles that coat the former materials. These results suggest that at LF-FSP flame temperatures ZnO remains in the vapor phase for sufficient times that Al3+ oxy-ions generated promote nucleation of finer particles leaving essentially phase pure ZnO still in the vapor phase to condense giving the two distinct particle morphologies observed.
Ultrasonic Absorption Study of the Complex Formation of Zinc(II) Carboxylates in Aqueous Solution
Tamura, Kiyoshi
, p. 7358 - 7362 (1989)
Ultrasonic absorption of aqueous zinc(II) formate, acetate, and propionate is measured in the metal-rich concentration regions with a pulse technique over the frequency range 3-260 MHz.The single relaxations observed in all cases are attributed to the complex formation of zinc(II) carboxylates via the Eigen-Tamm mechanism of stepwise association.The reaction parameters are determined from the concentration dependences of the relaxation frequency and amplitude.Both the association constant of outer-sphere complex and the rate constant of ligand substitution indicate ligand dependences; the former is larger while the latter is smaller with the higher carboxylate.However, the uncertainties involved in these reaction parameters prevent the elucidation of the above feature.The volume changes of the outer-sphere complexing are substantially less than those of the ligand substitution; the volume change of the latter is larger for the higher carboxylate.
Anion Directed Selective Synthesis of Supramolecular Metallocycles and Related Coordination Dimers
Sturm, Lisa,G?b, Christian R.,Oppel, Iris M.
supporting information, p. 1050 - 1056 (2021/02/01)
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.
Structurally diverse coordination compounds of zinc as effective precursors of zinc oxide nanoparticles with various morphologies
Swiatkowski, Marcin,Kruszynski, Rafal
, (2019/04/01)
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.
Thermal characterization of new complexes of Zn(II) and Cd(II) with some bipyridine isomers and propionates
Czakis-Sulikowska,Radwannska-Doczekalska,Markiewicz,Pietrzak
, p. 789 - 794 (2009/02/07)
New mixed ligand complexes of the following stoichiometric formulae: M(2-bpy)2(RCOO)2?nH2O, M(4-bpy)(RCOO) 2?H2O and M(2,4'-bpy)2(RCOO) 2?H2O (where M(II)=Zn, Cd; 2-bpy=2,2'-bipyridine, 4-bpy=4,4'-bipyridine, 2,4'-bpy=2,4'-bipyridine; R=C2H5; n=2 or 4) were prepared in pure solid-state. These complexes were characterized by chemical and elemental analysis, IR and conductivity studies. Thermal behaviour of compounds was studied by means of DTA, DTG, TG techniques under static conditions in air. The final products of pyrolysis of Cd(II) and Zn(II) compounds were metal oxides MO. A coupled TG/MS system was used to analyse of principal volatile products of thermal decomposition or fragmentation of Zn(4-bpy)(RCOO)2?H2O under dynamic air and argon atmosphere. The principal species correspond to: C+, CH+, CH3 +, C2H2+, HCN+, C 2H5+ or CHO+, CH2O + or NO+, CO2+, 13C 16O2+ and 12C16O 18O+ and others; additionally CO+ in argon atmosphere.
Metal carboxylate salts
-
Page/Page column 3, (2008/06/13)
A dietary source of mineral in the form of a metal carboxylate is prepared using the acid-base-like reaction. A salt of a carboxylate anion and a by-product cation is reacted in aqueous solution with a salt of a metal cation and a by-product anion under conditions which form a metal carboxylate and the by-product salt. Solutions formed in the reaction may be applied directly to a dry carrier to produce a dry dietary supplement or, alternatively, the solutions may be filtered to remove precipitated by-product salt and the filtrate used as a liquid dietary supplement. Preferably, a reducing agent, such as ascorbic acid, is added to help prevent the oxidation of divalent to trivalent form of a metal salt, when an easily oxidized divalent metal is used as starting material.
Thermal, spectral and biological properties of Zn(II) complex compounds with phenazone
Szunyogova, Erika,Gyoeryova, Katarina,Hudecova, Daniela,Piknova, Lenka,Chomic,Vargova, Zuzanna,Zelenak
, p. 219 - 223 (2008/10/09)
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
Comparison on thermal decomposition of propionate, benzoate and their chloroderivative salts of Zn(II)
Skorsepa,Godocikova,Cernak
, p. 773 - 780 (2008/10/09)
The thermal decompositions of propionates, benzoates Zn(II), their chloroderivate and complexes with thiourea have been studied by the means of TG, DTG, DTA, IR and XRD-powder diffraction methods. The investigated decompositions are compared and the resul
Decomposition of organic salts of some d and f metals: Non-isothermal kinetics and FT-IR studies
Vlase,Vlase,Chiriac,Doca
, p. 839 - 845 (2008/10/08)
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.
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
Dreveni,Berkesi,Andor,Mink
, p. 17 - 23 (2008/10/08)
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).
