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51.
Hiléia K. S. Souza V. R. da Silveira F. M. M. Borges Dulce M. A. Melo H. Scatena Jr. O. A. de Oliveira A. G. Souza 《Journal of Thermal Analysis and Calorimetry》2007,87(2):433-436
Thermal behavior of rare earth nitrate complexes
with 2-azacyclononanone (AZA) with Ln(NO3)3·3(AZA)
composition (where Ln=Gd, Er and Ho) was
analyzed in kinetic point of view. Kinetic parameters were calculated from
thermogravimetric data. All obtained results were similar. The first decomposition
step was representative to the loss of ligand and the residue was essentially
Ln2O3. Furthermore, a reaction
path was proposed for the thermal decomposition of the Ln(NO3)3·3(AZA). 相似文献
52.
R. Łyszczek 《Journal of Thermal Analysis and Calorimetry》2007,90(2):533-539
The new 1,2,4-benzenetricarboxylates of lanthanide(III) of the formula Ln(btc)·nH2O, where btc is 1,2,4-benzenetricarboxylate; Ln is La-Lu, and n=2 for Ce; n=3 for La, Yb, Lu; and n=4 for Pr-Tm were prepared and characterized by elemental analysis, infrared spectra and X-ray diffraction patterns. Polycrystalline
complexes are isotructural in the two groups: La-Tm and Yb, Lu. IR spectra of the complexes show that all carboxylate groups
from 1,2,4-benzentricarboxylate ligands are engaged in coordination of lanthanide atoms.
The thermal analysis of the investigated complexes in air atmosphere was carried out by means of simultaneous TG-DTA technique.
The complexes are stable up to about 30°C but further heating leads to stepwise dehydration. Next, anhydrous complexes decompose
to corresponding oxides. The combined TG-FTIR technique was employed to study of decomposition pathway of the investigated
complexes. 相似文献
53.
Four novel 1D lanthanide coordination polymers with formula [Ln(3,4-pybz)3(H2O)2· H2O]n (Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-(pyridin-4-yl)benzoic acid) have been synthesized by hydrothermal reactions of lanthanide oxide and 3-(pyridine-4-yl) benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoclinic system, space group P1. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-(carboxylate)2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied. 相似文献
54.
<正>NMR spectra were recorded in CDCl3 or DMSO-d6 on a Bruker Avance 400 operating at 400 MHz with TMS as internal standard. 1H-benzo[d]imidazol-2(3H)-one(3aa) [1]: 1H NMR(400 MHz, DMSO-d6) δ 10.5(s, 2 H, NH), 6.90(s, 4H)(aromatic CH). 13 C NMR(400 MHz, DMSO-d6) δ 155.7, 130.1, 120.9, 108.9. NH HN O3 aa 1-(2-Aminophenyl)-3-phenylurea(3aa′) [2]: 1H NMR(400 MHz, DMSO-d6) δ 8.75(s, 1H), 7.71(s, 1H)(CONH), 7.44(d, J = 8.0 Hz, 2H), 7.33(d, J = 7.8 Hz, 1H), 7.26(t, J = 7.7 Hz, 2H), 6.94(t, J = 7.4 Hz, 1H), 6.84(t, J = 7.4 Hz, 1H), 6.74(d, J = 7.8 Hz, 1H), 6.57(t, J = 7.4 Hz, 1H)(aromatic CH), 4.78(s, 2H)(NH2). 13 C NMR(400 MHz, DMSO-d6) δ 153.6, 141.4, 140.6, 129.2, 125.2, 124.8, 124.2,121.9, 118.4, 117.3, 116.4. 相似文献
55.
56.
Yiyi Ou Dr. Weijie Zhou Dr. Zece Zhu Dr. Fengkai Ma Dr. Rongfu Zhou Fang Su Dr. Lirong Zheng Prof. Li Ma Prof. Hongbin Liang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):24018-24024
Optical multiplexing based on luminescent materials with tunable color/lifetime has potential applications in information storage and security. However, the available tunable luminescent materials reported so far still suffer from several drawbacks of low efficiency or poor stability, thus restraining their further applications. Herein, we demonstrate a strategy to develop efficient and stable lanthanide coordination polymers (LCPs) with tunable luminescence as a new option for optical multiplexing. Their multicolor emission from green to red and naked-eye-sensitive green emission with tunable lifetime (from ca. 300 to ca. 600 μs) can be controlled by host differential sensitization and energy transfer between lanthanide ions. The quantum efficiencies of developed samples range from around 20 % to 46 % and the luminescence intensity/lifetime appear quite stable in polar solvents up to ten weeks. Furthermore, with the aid of inkjet printing and concepts of luminescence lifetime imaging and time-gated imaging, we illustrate their promising applications of information storage and security in spatial and temporal domains. 相似文献
57.
Anastasia N. GeorgopoulouConstantinos G. Efthymiou Constantina PapatriantafyllopoulouVassilis Psycharis Catherine P. RaptopoulouManolis Manos Anastasios J. TasiopoulosAlbert Escuer Spyros P. Perlepes 《Polyhedron》2011,30(18):2978-2986
The synthetic investigation of the NiII/M(NO3)3·6H2O/di-2-pyridyl ketone [(py)2CO] tertiary reaction system in EtOH has yielded triangular Ni2M cationic complexes (M = lanthanide, Y). The reaction between Ln(NO3)3·6H2O, Ni(ClO4)2·6H2O, (py)2CO and base (1:3:3:3) in EtOH under gentle heating gave the isostructural complexes [Ni2Ln{(py)2C(OEt)(O)}3{(py)2C(OH)(O)}(NO3)(H2O)](ClO4)2 (Ln = Gd, 2; Ln = Tb, 3) in high yields. The ligands (py)2C(OEt)(O)− and (py)2C(OH)(O)− are the monoanions of the hemiketal and gem-diol derivatives of (py)2CO, respectively, formed in situ in the presence of the metal ions. The cations of 2 and 3 consist of one 8-coordinate LnIII and two distorted octahedral NiII atoms in an essentially isosceles, triangular arrangement capped by a central μ3-Ο− atom of the unique 3.3011 (Harris notation) (py)2C(OH)(O)− ligand. Each metal-metal edge is bridged by the deprotonated O atom of one 2.2011 (py)2C(OEt)(O)− ligand. The isostructural complexes [Ni2M{(py)2C(OEt)(O)}4(NO3)(H2O)]2[M(NO3)5](ClO4)2 (M = Y, 4 ; M = Tb, 5 ; M = Dy, 6) were prepared by the 1:1 reaction of the mononuclear “metalloligand” [Ni(O2CMe){(py)2CO}{(py)2C(OH)2}](ClO4) (1) and M(NO3)3·6H2O in EtOH under mild heating in moderate to good yields. The structures of the dications of 4-6 are similar to those in 2 and 3, the only difference being the replacement of the unique 3.3011 (py)2C(OH)(O)− ligand of the latter by one 3.3011 (py)2C(OEt)(O)− group in the former. The YIII, TbIII and DyIII atoms in [M(NO3)5]2− are coordinated by five bidentate chelating nitrato groups. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the ligands. Variable temperature, solid-state direct current magnetic susceptibility and magnetization studies were carried out on dried samples of 2-4. The data indicate ferromagnetic Ni?Ni and Ni?Gd exchange interactions, and an ST = 11/2 ground state for 2. Complex 3 is characterized by a high-spin ground state while the ferromagnetic Ni?Ni interaction for 2 is independently supported by the study of 4. No out-of-phase, alternating current susceptibility signals have been detected for 3 that would be indicative of SMM behavior. 相似文献
58.
Hydrothermal phase equilibria studies have been carried out in the Ln2O3-H2O systems (Ln = La, Pr, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) and the stability fields of the phases Ln(OH)3 LnOOH and Ln2O3-C have been established in the pressure-temperature range of 25000 psi and 900° C. The sequioxides Ln2O3-C are stable only in the last four systems of Er to Lu along with the Ln(OH)3 and LnOOH. The systems from Nd to Ho have only Ln(OH)3 and LnOOH as stable phases and those from La to Pr have only Ln(OH)3 as the stable phase. The unit cell parameters of trihydroxides deviate from the values reported in the literature and this
is attributed to the contamination of CO2 in the starting material. 相似文献
59.
60.
二(2-乙基己基)膦酸从盐酸介质中萃取钪(Ⅲ)、钇(Ⅲ)、镧系离子(Ⅲ)和铁(Ⅲ) 总被引:1,自引:0,他引:1
本文研究了二(2-乙基己基)膦酸(H[DEHP])的正辛烷溶液从盐酸介质中萃取钪(Ⅲ)、钇(Ⅲ)、镧系离子(Ⅲ)和铁(Ⅲ)的平衡规律。结果表明,H[DEHP]对上述离子的萃取次序是Sc3+>Fe3+>Lu3+>Yb3+>Er3+>Y3+>Ho3+。讨论了Sc(Ⅲ)与Fe(Ⅲ)、Y(Ⅲ)、Ln(Ⅲ)(镧系离子)以及Fe(Ⅲ)与重镧系离子(Ⅲ)分离的可能性,并与HEH[EHP]萃取上述离子的性能进行了比较。借助IR、NMR和斜率法,饱和法研究了低酸度下H[DEHP]萃取Sc(Ⅲ)、Y(Ⅲ)和Ln(Ⅲ)的平衡反应,计算了浓度平衡常数和萃取反应的热力学函数。 相似文献