10196-18-6Relevant articles and documents
Synthesis of the hydroxide cluster [Al13(μ3-OH) 6(μ-OH)18(H2O)24]15+ from an aqueous solution
Wang, Wei,Wentz, Katherine M.,Hayes, Sophia E.,Johnson, Darren W.,Keszler, Douglas A.
, p. 4683 - 4685 (2011)
A scalable synthesis of the "flat" tridecameric inorganic cluster [Al13(μ3-OH)6(μ-OH)18(H 2O)24]15+ has been realized by treating an aqueous aluminum nitrate solution with a zinc-metal powder at room temperature. Single crystals and polycrystalline samples are readily obtained in yields exceeding 55% relative to the starting reagent Al(NO3)3. Products have been characterized by X-ray diffraction and solid-state 27Al MAS and MQMAS NMR.
Structural, magnetic and M?ssbauer spectral studies of nanocrystalline Ni0.5Zn0.5Fe2O4 ferrite powders
Verma, Seema,Joy,Kurian, Sajith
, p. 8999 - 9004 (2011)
Nanocrystalline Ni0.5Zn0.5Fe2O4 powders, synthesized by a combustion method are investigated by X-ray diffraction, vibrating sample magnetometry and M?ssbauer spectroscopic techniques. We adopt a strategy to systematically control the particle sizes between 4 and 45 nm simply by changing the elemental stoichiometric coefficient, Φe, of the combustion mixture. Curie temperature of the superparamagnetic particles of size 4 nm is higher than that of the bulk particles. Interestingly, bigger particles (45 nm) show a comparable room temperature saturation magnetization and exceptionally very high Curie temperature of 833 K, when compared to that of the bulk Ni0.5Zn 0.5Fe2O4 material (563 K).
Thermal studies on energetic compounds: Part 30. Kinetics and mechanism of bis(diethylenetriamine)metal nitrate complexes
Singh,Pandey
, p. 507 - 519 (2004)
The nitrate complexes of copper, nickel and zinc with diethylenetriamine (dien) i.e. [Cu(dien)2](NO3)2, [Ni(dien) 2](NO3)2·2H2O and [Zn(dien)2](NO3)2 have been prepared and characterised. Thermal studies were undertaken using TG-DTG, DSC, ignition delay (tid) and ignition temperature (IT) measurements. Impact sensitivity was measured using drop mass technique. The kinetic parameters for both non-isothermal and isothermal decomposition of the complexes were evaluated by employing Coats-Redfern (C-R) method and Avrami-Erofeev (A-E) equations (n=2 and 3), respectively. The kinetic analysis, using isothermal TG data, was also made on the basis of model free isoconversional method and plausible mechanistic pathways for their decomposition are proposed. Rapid process was assessed by ignition delay measurements. All these complexes were found to be insensitive towards impact of 2 kg mass hammer up to the height limit (110 cm) of the instrument used. The heat of reaction (ΔH) for each stage of decomposition was determined using DSC.
Ewing, W. W.,Brandner, J. D.,Guyer, W. R. F.
, p. 260 - 265 (1939)
Local investigation of hyperfine interactions in pure and Co-doped ZnO
Mercurio,Carbonari,Cordeiro,Saxena,D'Agostino
, p. 1195 - 1197 (2010)
In the present work bulk samples of pure as well as Co-doped ZnO with different concentrations were prepared by sol-gel method from highly pure metallic Zn (99.9999%) and Co (99.9999%). The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray microanalysis (EDS) and perturbed gamma-gamma angular correlation (PAC) spectroscopy. Carrier-free 111In nuclei were introduced during preparation of the samples and used as probe nuclei at Zn sites for PAC measurements. PAC results show that both pure and Zn1 - x Cox O (x ≤ 0.15) samples have the same electric quadrupole frequency when Co-doped samples are annealed in air, argon or nitrogen atmosphere at 1173 K. SEM and EDS results showed that Co-doped samples are homogeneous without any secondary Co phases. These observations indicate that Co ions are substituted for Zn ions and have a similar electronic structure of Zn ions. A weak local magnetism was observed at temperatures below about 300 K for Co concentration of 10% when sample was annealed in Nitrogen.
Is it possible the substitution of Cr cations from spinel-type oxides with bulky rare-earth cations by sol-gel auto-combustion method?
Borhan,Samoila,Gherca,Iordan,Palamaru
, p. 200 - 207 (2015)
Rare-earth La3+ cations, with large ionic radii, substituted ZnCr2-xLaxO4 nanoparticles with x ranging from 0.0 to 0.50 were synthesized by sol-gel auto-combustion technique. Effect of La substitution on structural and magnetic properties of ZnCr2O4 spinel oxide is reported. The phase composition of the obtained powders was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Magnetic measurements were made using a SQUID magnetometer. FT-IR and X-ray diffraction revealed the transition of spinel structure to perovskite structure because of the exchange of Zn2+ and La3+ cations among constituent A-sites. The particle size were estimated from the SEM micrographs and were found to increase with the La ions substitution from 48 to 80 nm. It was revealed from the magnetic measurements that magnetization follow a decreasing trend with substitution of Cr3+ ions by paramagnetic La3+ ions. Also, the magnetization showed a drastic decrease with increase of temperature from 2 K to 300 K because of enhanced domain pinning effect, due to the La3+ substitution.
Kinetics and mechanism of Copper(II), Zinc(II), and Cadmium(II) Incorporation into 5,10,15,20-Tetraphenylporphine and N-Methyl-5,10,15,20-tetraphenylporphine in N,N-Dimethylformamide
Funahashi, Shigenobu,Yamaguchi, Yushi,Tanaka, Motoharu
, p. 204 - 208 (1984)
The kinetics of reactions of 5,10,15,20-tetraphenylporphine (H2(tpp)) and N-methyl-5,10,15,20-tetraphenylporphine (H(metpp)) with CuII, ZnII, and CdII ions was studied spectrophotometrically in N,N-dimethylformamide.The rate of incorporation of metal ions (M2+: Cu2+, Zn2+, Cd2+) into H(metpp) is first order with respect to both H(metpp) and metal ion: d+>/dt = k2+> with k(25 deg C)=11.5 +/- 0.5 mol-1 dm3 s-1 for Zn2+ and (5.8 +/- 0.8)x102 mol-1 dm3 s-1 for Cd2+.The rate of incorporation of copper and zinc into H2(tpp) is first order in H2(tpp) and the conditional first-order rate constants are expressed as follows: k0(M)=K2+>(1+K2+>)-1(k1+k22+>) where for Cu2+ and Zn2+ K/mol-1 dm3, k1/s-1, and k2/mol-1 dm3 s-1 at 25 deg C are (1.6 +/- 0.2)x104 and (7.2 +/- 1.5)x102, (1.2 +/- 0.1)x10-4 and (3.5 +/- 0.7)x10-5, and (5.2 +/- 0.2)x10-2 and (8.6 +/- 0.2)x10-4, respectively.Metal ion incorporation into H2(tpp) proceeds through the formation of intermediates prior the rate-limiting step.For the H(metpp) system, the methyl group on the pyrrole in H(metpp) prevents the formation of such an intermediate.On the other hand, the rate of cadmium incorporation into H2(tpp) is first order with respect to Cd2+ and H2(tpp) and its second order rate constant k is (6.5 +/- 1.0)x10-3 mol-1 dm3 s-1.The large cadmium(II) ion can not fit into the porphyrin nucleus and its reaction proceeds through a pathway involving a mononuclear activated complex.
