Red (Eu3+), Green (Tb3+) and Ultraviolet (Gd3+) Emitting Nitrilotriacetate Complexes Prepared by One-step Synthesis

2014 ◽  
Vol 69 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Ivan G. N. Silva ◽  
Hermi F. Brito ◽  
Ernesto R. Souza ◽  
Danilo Mustafa ◽  
Maria C. F. C. Felinto ◽  
...  

The [RE(NTA)(H2O)2]⋅(H2O) rare-earth complexes (RE3+: Eu, Gd, Tb and NTA: nitrilotriacetate) were synthesized and characterized by elemental analysis, thermogravimetry, X-ray diffraction, and infrared spectroscopy. The complexes show high crystallinity and thermostability. The photoluminescence behavior was studied based on the excitation and emission spectra, and luminescence decay curves. The compounds exhibit red (Eu3+), green (Tb3+) and UV (Gd3+) monochromatic emissions under UV excitation. The NTA ligand acts as luminescence sensitizer in the ligand-to- RE3+ intramolecular energy transfer process, owing to the fact that the first excited triplet state (T1: 29 000 cm−1) is located above of the 5D0 (Eu3+) and 5D4 (Tb3+) emitting levels. The experimental intensity parameters Ωλ (λ: 2 and 4) for the Eu3+ NTA complex were calculated, and the results are discussed. The Gd3+-NTA complex exhibits a high-intensity emission band in the UV region (32 000 cm−1) assigned to the 6P7/2→8S7/2 intraconfigurational transition.

2008 ◽  
Vol 8 (3) ◽  
pp. 1443-1448 ◽  
Author(s):  
Qingyu Meng ◽  
Baojiu Chen ◽  
Xiaoxia Zhao ◽  
Xiaojun Wang ◽  
Wu Xu

Y2O3:Ln3+ (Ln = Eu or Tb) nanocrystals with different Ln3+ doping concentrations and average sizes were prepared by chemical self-combustion. The corresponding bulk materials with various doping concentrations were obtained by annealing the nanomaterials at high temperature. The emission spectra, excitation spectra, and X-ray diffraction spectra were used in this study. It was found that the charge transfer band of Y2O3:Eu3+ red-shifted as particle size decreased, and the charge transfer band in the 5-nm particles obviously broadened toward the long wavelength. It was also found that the profile of excitation spectra corresponding to the 4f5d (4f8 → 4f75d1) transition changed a lot with the variation of the particle size. The dependence of the excitation spectra of Y2O3:Ln3+ on particle size was investigated.


2016 ◽  
Vol 16 (4) ◽  
pp. 3857-3860 ◽  
Author(s):  
Siling Guo ◽  
Chunyan Cao ◽  
Renping Cao

Through a hydrothermal method, 1 mol% Eu3+ doped NaYF4 and KYF4 micro/nanocrystals have been synthesized. The materials were characterized by X-ray diffraction (XRD) patterns, field emission scanning electron microscopy (FE-SEM) images, room temperature photoluminescence (PL) excitation and emission spectra, and luminescent dynamic decay curves. The XRD analysis suggested the crystalline structures of the obtained samples. The FE-SEM images indicated the morphology and size of the obtained samples. The PL spectra illustrate the optical properties of Eu3+ in the two samples. Since it is sensitive to the local environment of the ion, the Eu3+ presents different optical properties in the NaYF4 and KYF4 materials.


2019 ◽  
Vol 75 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Ya-Li Xue ◽  
Dan Zhao ◽  
Shi-Rui Zhang ◽  
Ya-Nan Li ◽  
Yan-Ping Fan

For the first time, a new langbeinite-type phosphate, namely potassium terbium tantalum tris(phosphate), K2Tb1.5Ta0.5(PO4)3, has been prepared successfully using a high-temperature flux method and has been structurally characterized by single-crystal X-ray diffraction. The results show that its structure can be described as a three-dimensional open framework of [Tb1.5Ta0.5(PO4)3]∞ interconnected by K+ ions. The TbIII and TaV cations in the structure are disordered and occupy the same crystallographic sites. The IR spectrum, the UV–Vis spectrum, the morphology and the Eu3+-activated photoluminescence spectroscopic properties were studied. A series of Eu3+-doped phosphors, i.e. K2Tb1.5–x Ta0.5(PO4)3:xEu3+ (x = 0.01, 0.03, 0.05, 0.07, 0.10), were prepared via a solid-state reaction and the photoluminescence properties were studied. The results show that under near-UV excitation, the luminescence colour can be tuned from green through yellow to red by simply adjusting the Eu3+ concentration from 0 to 0.1, because of the efficient Tb3+→Eu3+ energy-transfer mechanism.


2012 ◽  
Vol 554-556 ◽  
pp. 485-488
Author(s):  
De Kang Xu ◽  
Sheng Hong Yang ◽  
Yue Li Zhang

A series of NH4Y3F10 sub-microcrystals had been prepared by a one-step hydrothermal route. The morphological and structural properties of the sub-microcrystals were studied by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The results of SEM and XRD suggested that NH4Y3F10 sub-microcrystals have irregular shapes with their sizes varying from 100nm to 500nm and the structures of obtained NH4Y3F10 sub-microcrystals are cubic phase. Additionally, the down-converting(DC) phenomenon have been observed under UV excitation in (Yb3+, Nd3+) co-doped NH4Y3F10. It is found that luminescent efficiency of 10%Yb, 1%Nd co-doped NH4Y3F10 sub-microcrystals is stronger than that of 10%Yb, 5%Nd co-doped NH4Y3F10 sub-microcrystals. The energy transfer mechanism of the emission spectra of (Yb3+, Nd3+) co-doped NH4Y3F10 is discussed.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 593
Author(s):  
Juan Miranda-Pizarro ◽  
Macarena G. Alférez ◽  
M. Dolores Fernández-Martínez ◽  
Eleuterio Álvarez ◽  
Celia Maya ◽  
...  

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.


2016 ◽  
Vol 30 (26) ◽  
pp. 1650328
Author(s):  
Yan Dong ◽  
Aimin Sun ◽  
Bin Xu ◽  
Hongtao Zhang ◽  
Meng Zhang

In this paper, the effect of tiny Y2O3 addition in (Bi,[Formula: see text]Pb)-2223 superconductor prepared by solid state reaction technique was studied. The properties of samples have been investigated via X-ray diffraction (XRD), resistance–temperature ([Formula: see text]–[Formula: see text]) curve, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). XRD data indicated that all samples are multiphase and the major phases are high-temperature phases and low-temperature phases. The volume fraction of (Bi,[Formula: see text]Pb)-2223 is not great change with tiny Y2O3 addition. All samples exhibit superconducting phase with the critical transition temperature and one-step transition, however, the transition width was decreased with the Y2O3 addition up to 0.04 wt.% and sharp increased with the excessive oxide addition. SEM pictures show that the Y2O3 appeared on the flake-type grains surface obviously, but the number and size of the hole between grains are decreased in the 0.04 wt.% addition.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.


1996 ◽  
Vol 11 (1) ◽  
pp. 9-12
Author(s):  
W. Wong-Ng

Calculated patterns for the BaR2PdO5 series, in which X is Pd and R=Nd, Sm, Eu, or Gd, have been prepared for materials characterization until experimental patterns can be determined. These compounds are isostructural to the superconductor related “brown phases” BaLa2CuO5 and BaNd2CuO5, which are tetragonal with space group P4/mbm, Z=4. The cell parameters of the Eu and Gd compounds were derived from the La and Nd analogs. The calculated patterns of these four compounds compared well to an experimental pattern of BaNd2CuO5.


2019 ◽  
Vol 75 (9) ◽  
pp. 1220-1227 ◽  
Author(s):  
Mei-rong Han ◽  
Shao-dong Li ◽  
Ling Ma ◽  
Bang Yao ◽  
Si-Si Feng ◽  
...  

A new mononuclear europium complex incorporating the (+)-di-p-toluoyl-D-tartaric acid (D-H2DTTA) ligand, namely, catena-poly[tris{μ2-3-carboxy-2,3-bis[(4-methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3] n , (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one-dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six D-HDTTA− ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The D-H2DTTA ligand is partially deprotonated and adopts a μ1,6-coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one-dimensional propeller-shaped coordination polymer chain along the c axis, with an Eu...Eu distance of 7.622 (1) Å. Moreover, C—H...π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid-state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single-ion magnetic behaviour. The spin-orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm−1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical-magneto bifunctional material.


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