10361-79-2Relevant articles and documents
Praseodymium hydroxide and oxide nanorods and Au/Pr6O 11 nanorod catalysts for CO oxidation
Huang,Wu,Zhu,Li,Wang,Gao,Zhu,Yan,Huang,Zhang,Song
, p. 1614 - 1620 (2006)
Praseodymium hydroxide nanorods were synthesized by a two-step approach: First, metallic praseodymium was used to form praseodymium chloride, which reacted subsequently with KOH solution to produce praseodymium hydroxide. In the second step the hydroxide was treated with a concentrated alkaline solution at 180°C for 45 h, yielding nanorods as shown by the scanning and transmission electron microscopy images. The results of X-ray diffraction and energy-dispersive X-ray spectroscopy experiments indicate that these nanorods are pure praseodymium hydroxide with a hexagonal structure, which can be converted into praseodymium oxide (Pr6O11) nanorods of a face-centered cubic structure after calcination at 600°C for 2 h in air. Gold was loaded on the praseodymium oxide nanorods using HAuCl4 as the gold source, and NaBH4 was used to reduce the gold species to metallic nanoparticles with sizes of 8-12 nm on the nanorod surface. These Au/Pr6O11 nanorods exhibit superior catalytic activity for CO oxidation.
The dependence of persistent phosphorescence on annealing temperatures in CaTiO3:Pr3+ nanoparticles prepared by a coprecipitation technique
Zhang, Xianmin,Zhang, Jiahua,Ren, Xinguang,Wang, Xiao-Jun
, p. 393 - 398 (2008)
Red emitting phosphors of CaTiO3:Pr3+ nanoparticles with size ranging from 6 to 95 nm have been prepared by a coprecipitation technique and structurally characterized by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The fluorescence and phosphorescence of CaTiO3:Pr3+ nanoparticles as a function of annealing temperature are investigated. It is found that fluorescence intensities monotonously increase with increasing temperature. However, a maximum in phosphorescence with the increase of annealing temperature occurs for the sample prepared at 700 °C. Based on the measurement of fluorescence emission, fluorescence excitation and reflectance spectra as well as time decay patterns of fluorescence and phosphorescence, it is demonstrated that the dependence of fluorescence and phosphorescence on annealing temperature originates from the decrease of surface defects with the increase of temperature.
Pr6C2-bitetrahedra in Pr6C 2Cl10 and Pr6C2Cl5Br 5
Schaloske, Manuel C.,Mattausch, Hansjuergen,Kienle, Lorenz,Simon, Arndt
, p. 1493 - 1500 (2008)
The compounds Pr6C2Cl10 and Pr 6C2Cl5Br5 are prepared by heating stoichiometric mixtures of Pr, PrCl3, PrBr3 and C in sealed Ta capsules at 810-820°C. They form bulky transparent yellow to green and moisture sensitive crystals which have different structures: space groups C2/c, (a = 13.687(3) A, b = 8.638(2) A, c = 15.690(3) A, β = 97.67(3)° for Pr6C2Cl10 and a = 13.689(1) A, b = 10.383(1) A, c = 14.089(1) A, β = 106.49(1)° for Pr6C2Cl5Br5). Both crystal structures contain C-centered Pr6C2 bitetrahedra, linked via halogen atoms above edges and corners in different ways. The site selective occupation of the halogen positions in Pr 6C2Cl5Br5 is refined in a split model and analysed with the bond length-bond strength formalism. The compound is further characterized via TEM investigations and magnetic measurements (μeff = 3.66 μB).
Meyer, Gerd,Ax, Peter
, p. 1447 - 1456 (1982)
Thermal and spectroscopic studies on solid Ketoprofen of lighter trivalent lanthanides
Galico, D. A.,Holanda, B. B.,Perpetuo, G. L.,Schnitzler, E.,Treu-Filho, O.,Bannach, G.
, p. 371 - 380 (2012/04/23)
Solid-state Ln(L)3 compounds, where Ln stands for trivalent La, Ce, Pr, Nd, Sm, Eu, and L is ketoprofen have been synthesized. Thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC) as well as X-ray diffraction powder (DRX) patterns, Fourier transformed infrared spectroscopy (FTIR), and other methods ofanalysis were used to study solid Ketoprofen of lighter trivalent lanth anides. The results provided information of the composition, dehydration, coordination mode, structure, thermal behavior, and thermal decomposition. The theoretical and experimental spectroscopic study suggests that the carboxylate group of ketoprofen is coordinate to metals as bidentatebond.
Comparison of covalency in the lanthanide chloride and nitrate complexes based on the adsorption data on zeolite y
G?adysz-P?aska, Agnieszka,Majdan, Marek,Ferenc, Wies?awa,Sarzyński, Jan
, p. 469 - 474 (2012/03/22)
The changes of the distribution constants Kd of lanthanide chlorides in the system: zeolite Y (solid phase)-sodium chloride (aqueous phase) were investigated. The evident tetrad effect in the change of log Kd values within the lantha
Lanthanide carbonates
Janicki, Rafal,Starynowicz, Przemyslaw,Mondry, Anna
, p. 3601 - 3616 (2011/10/11)
The crystal and molecular structures of the rare earth carbonates with the general formulae [C(NH2)]3 [Ln(CO3)4 (H2O)]·2H2O (where Ln = Pr3+,Nd 3+,Sm3+,Eu3+,Gd3+,Tb 3+)and [C(NH2)]3 [Ln(CO3) 4]·2H2O (where Ln = Y3+,Dy 3+,Ho3+,Er3+, Tm3+,Yb 3+,Lu3+) were determined. The crystals consist of monomeric [Ln(CO3)4 (H2O)] 5-or [Ln(CO3)4] 5-complex anions in which the carbonate ligands coordinate to the Ln3+ion in a bidentate manner. The spectroscopic (UV/Vis/NIR and IR) properties of the crystalline lanthanide carbonates, as well as their aqueous solutions, were determined. Correlation between the spectroscopic and the structural data enabled us to conclude that the [Ln(CO3)4 (OH)]6-and [Ln-(CO 3)4]5- species predominate in the light and heavy lanthanide solutions, respectively. The nature of the Ln-O interaction was also discussed. The experimental data, as well as the theoretical calculations, indicated that the Ln-O(CO3 2-) bond is more covalent than the Ln-O(OH2) bond. Moreover, the covalency degree is larger for the heavy lanthanide ions. Inspection of the NBO results revealed that the oxygen hybrids, with the approximate composition sp4, form strongly polarized bonds with the 6s6p5d4 hybrids of lutetium. 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
