557-28-8Relevant articles and documents
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.
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.
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.
