Thermal behaviour of a few lanthanide complexes of the type ML3(I) [M=Eu, Gd; HL=4,4,4-trifluoro-1-(2-napthyl)-1,3-butanedione and EuL(3)0.5dmm dmm=2,6-dimethylmorpholine(II)], has been investigated. From thermogravimetric (TG) curves, the decomposition pattern of the compounds has been analysed on the basis of mass loss data. The order and activation energy of the thermal decomposition reactions have been elucidated. From differential thermal analysis (DTA) studies, the heat of reaction and rate of thermal decomposition reaction have been enumerated.
Thermal behaviour of a few lanthanide complexes of the type ML3(I) [M=Eu, Gd; HL=4,4,4-trifluoro-1-(2-napthyl)-1,3-butanedione and EuL(3)0.5dmm dmm=2,6-dimethylmorpholine(II)], has been investigated. From thermogravimetric (TG) curves, the decomposition pattern of the compounds has been analysed on the basis of mass loss data. The order and activation energy of the thermal decomposition reactions have been elucidated. From differential thermal analysis (DTA) studies, the heat of reaction and rate of thermal decomposition reaction have been enumerated.
Preparation of Nanosized Perovskite-type Oxides via Polyol Method
作者:M. Siemons、Th. Weirich、J. Mayer、Ulrich Simon
DOI:10.1002/zaac.200400300
日期:2004.10
Several perovskite-typenanosizedoxides were prepared via polyol-mediated synthesis. The crystallinity of the materials was analysed by X-ray diffraction (XRD). While the “as synthesized” materials are amorphous or show very poor crystallinity, highly ordered materials could be obtained by annealing at 700 °C. Morphology of the materials was analysed by scanning electron microscopy (SEM) and transmission
通过多元醇介导的合成制备了几种钙钛矿型纳米氧化物。通过X射线衍射(XRD)分析材料的结晶度。虽然“合成”材料是无定形的或显示出非常差的结晶度,但通过在 700 °C 下退火可以获得高度有序的材料。通过扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析材料的形态。材料的粒径介于 20 和 200 nm 之间。Darstellung nanopartikularer Oxide des Perowskittyps uber die Polyol-Methode Uber eine Polyol-vermittelte Synthese wurden mehrere nanoskalige Oxide mit Perowskitstruktur hergestellt。Die Kristallstruktur der Materialien wurden mittels Rontgendiffraktometrie
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。
Coordination equilibria and water exchange kinetics of lanthanide(III) propylenediaminetetraacetates and other magnetic resonance imaging related complexes
including the reaction volume, for these equilibria were determined. 17O NMR transverse relaxation rates and chemical shifts were measured for aqueous solutions of the eight-coordinate complexes [Ln(PDTA)(H2O)2]− (LnTb, Dy, Er, Tm, Yb) and [Er(EDTA)(H2O)2]− as a function of temperature, pressure and magnetic field. The results were analysed in terms of the water exchange kinetics on the complexes. The water
测量了Eu 3+与六齿聚氨基羧酸酯配体EDTA 4-,CDTA 4-,HDTA 3-和PDTA 4-的配合物水溶液的UV-Vis吸收光谱随温度和压力的变化,对应于Eu 3+的7 F 0 → 5 D 0转变。结果可以用九坐标和八坐标物种之间的平衡来解释,其中八坐标物种的内球水分子比九坐标物种少一个。确定了这些平衡的热力学参数,包括反应体积。17种测量的氧气NMR横向弛豫率和化学位移为八坐标复合物的水溶液[LN(PDTA)(H 2 O)2 ] -(LnTb,镝,铒,铥,镱)和[二( EDTA)(H 2 O)2 ] -作为温度,压力和磁场的函数。根据复合物上的水交换动力学分析了结果。LnTb到k时,[Ln(PDTA)(H 2 O)2 ] -上的水交换速率随着整个镧系元素上离子半径的减小而急剧减小,从k ex 298 =(2.4±0.1)×10 7 s -1对于LnYb,ex 298 =(2
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。