objective to develop catalysts having application potential for oxidative coupling of methane (OCM) at relatively lower temperature. A series of Ln2Zr2O7 compounds with varied rareearth A sites have been prepared by a co-precipitation method. XRD and Raman have proved that pure Ln2Zr2O7 compounds have been successfully prepared for all the catalysts. By decreasing the rA/rB ratio, their crystalline structure
Different hydrated forms of the ethylenediaminetetraacetato complexes of the light rare earths
作者:J.Linn Mackey、David E. Goodney、James R. Cast
DOI:10.1016/0022-1902(71)80276-2
日期:1971.11
The reaction between the carbonates of the light rareearths and ethylenediaminetetraacetic acid (EDTA) yields different forms of the protonated 1:1 rare earth-EDTA chelates depending on the temperature. Near room temperature, multihydrates are formed (H[Ln(EDTA)]·nH2O, where n = 7 or 5), while above 45°C H[Ln(EDTA)]·mH2O is formed where m = 1 or 0. These chelates have been characterized by i.r., TGA
轻稀土的碳酸盐与乙二胺四乙酸(EDTA)之间的反应会根据温度产生不同形式的质子化1:1稀土-EDTA螯合物。在室温附近,会形成多水合物(H [Ln(EDTA)]· n H 2 O,其中n = 7或5),而在45°CH以上,会形成多水合物CH [Ln(EDTA)]· m H 2 O,其中m = 1或0。这些螯合物的特征在于ir,TGA和X射线粉末衍射。La,Ce,Pr和Nd的多水合物螯合物H [Ln(EDTA)]·7H 2 O是同构的,而H [Sm(EDTA)]·5H 2 O和H [Eu(EDTA)]·5H 2O形成不同的同构系列。红外光谱和溶解度表明这两个系列的结构不同。根据稀土的配位数,讨论了各种质子化1:1螯合物的稳定性和结构。
Observations on the rare earths—LXX
作者:T. Moeller、E.P. Horwitz
DOI:10.1016/0022-1902(59)80092-0
日期:1959.12
Chelates of the types Ln(HEDTA)·xH2O and Ba[Ln(DCTA)]2·yH2O have been isolated for neodymium, samarium, europium, gadolinium and yttrium by precipitation with alcohols. X-ray diffraction data show isomorphism within each series of compounds. Magnetic susceptibility data for several of these chelates and the corresponding ethylenediaminetetraacetate chelates indicate that the 4f electrons are not involved
已通过乙醇沉淀分离出钕,sa 、,、 euro,g和钇中的Ln(HEDTA)· x H 2 O和Ba [Ln(DCTA)2 · y H 2 O类型的螯合物。X射线衍射数据显示出各系列化合物内的同构。这些螯合物中的几种和相应的乙二胺四乙酸盐螯合物的磁化率数据表明,4 f电子不参与键的形成。吸收光谱数据证实了这一结论,并进一步表明吸收特性的变化与螯合稳定性之间不存在相关性。红外数据和脱水研究表明,Ln(HEDTA)· x H2种O型化合物,螯合剂占据5个配位位置,水占据6个。
Preparation, I.R. and thermogravimetric studies on triglycine rare earth chloride complexes
作者:B.S. Mathur、T.S. Srivastava
DOI:10.1016/0022-1902(70)80211-1
日期:1970.10
Several triglycine complexes of rareearthchlorides have been prepared which have composition RCl32H3N+CH2COO−. 3H2O, where R = Y, La, Ce. Pr, Nd, Sm and Dy. The i.r. spectra of these complexes have been interpreted in terms of zwitterion structure of glycine which is coordinated to rareearth cations through oxygens of carboxylic group. The i.r. data together with thermal behaviour of above complexes
Studies on selenates. V. Thermal decomposition of double selenate hydrates of samarium with sodium potassium and ammonium
作者:M.A. Nabar、S.V. Paralkar
DOI:10.1016/0040-6031(80)87128-0
日期:1980.2
Abstract Thermoanalytical techniques have been used to study the decomposition of double selenatehydrates of samarium with sodium, potassium and ammonium. Interpreting the results obtained, the mechanisms of decomposition have been proposed. The decompositions of non-hydrates of alkali-metal salts exhibit close similarity.