scholarly journals Crystallization Induced Enhanced Emission in Two New Zn(II) and Cd(II) Supramolecular Coordination Complexes with the 1-(3,4-Dimethylphenyl)-5-Methyl-1H-1,2,3-Triazole-4-Carboxylate Ligand

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1756
Author(s):  
Pilar Narea ◽  
Jonathan Cisterna ◽  
Alejandro Cárdenas ◽  
Pilar Amo-Ochoa ◽  
Félix Zamora ◽  
...  

Two new d10 metal supramolecular metal–organic frameworks (SMOFs) with general formula [ML2(H2O)2]n (M = Zn, Cd) have been synthetized using the sodium salt of the anionic 1-(3,4-dimethylphenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylate ligand (Na+L−). Both SMOFs have been structurally characterized by single-crystal X-ray diffraction analysis and IR spectroscopy. The compounds are isostructural and form supramolecular aggregates via hydrogen bonds with the presence of less common dihydrogen bonds. Interestingly, they show ionic conductivity and porosity. The luminescent properties have been also studied by means of the excitation and emission spectra. Periodic DFT and molecular TD-DFT calculations have been used to unravel the emergence of luminescence in the otherwise non-emitting 1-(3,4-dimethylphenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylate ligand once incorporated in the SMOFs. Our results also illustrate the importance of considering the dielectric environment in the crystal when performing excited state calculations for isolated fragments to capture the correct electronic character of the low-lying states, a practice which is not commonly adopted in the community.

2011 ◽  
Vol 64 (1) ◽  
pp. 104 ◽  
Author(s):  
Chunfeng Yan ◽  
Qihui Chen ◽  
Lian Chen ◽  
Rui Feng ◽  
Xiaochen Shan ◽  
...  

Six d10 metal–organic complexes with multipyridine ligands, [Cd(terpy)2](NO3)2·2H2O (1), [Cd(terpy)(NO3)2(H2O)] (2), [Hg(terpy)I2] (3), [Zn(tpt)(NO3)(H2O)2]NO3 (4), [Zn2(tpt)2(4,4′-bipy)(4H2O)](NO3)4·4H2O (5), [Zn(tpt)(OAc)2]·5H2O (6) (terpy = 2,2′:6′,2′-terpyridine, tpt = 2,4,6-tri(2-pyridyl)-1,3,5-triazine, 4,4′-bipy = 4,4′-bipyridine) were synthesized and structurally characterized. The abundant hydrogen-bonding interactions extend complex 2 into ladder-like 1D chains, discrete molecules of 4 into a 2D layer structure, complex 5 into a 2D hydrogen-bonded network through linking the hydrogen-bonded ribbons with hexagonal and four-sided rings, and complex 6 into a 3D hydrogen-bonded network through combining water helical chains. Fluorescence analyses of 1–6 in the solid state are investigated at both room temperature and 10 K. The emission spectra of 1–2 show a large red shift, which is ascribed to ligand-to-ligand charge transfer combined with ligand-to-metal charge transfer, whereas emissions of 4–6 all originate from intraligand π-π* transitions. In organic solvents, 1–6 behave very differently and their emission spectra exhibit various luminescences, with an obvious blue shift indicating strong solvent effects. The X-ray diffraction and thermal gravimetric analyses for complexes 1–6 are also reported.


2021 ◽  
Author(s):  
Qing-Xia Yao ◽  
Miaomiao Tian ◽  
Jun Zheng ◽  
Jintang Xue ◽  
Xuze Pan ◽  
...  

A series of microporous Ln(III)-based metal-organic frameworks (1-Ln) have been hydrothermally synthesized by using 4,4',4''-nitrilotribenzoic acid (H3NTB). Single crystal X-ray diffraction analyses show 1-Ln are isostructural and have 3D porous...


2021 ◽  
Vol 9 ◽  
Author(s):  
Wang Xie ◽  
Jie Wu ◽  
Xiaochun Hang ◽  
Honghai Zhang ◽  
Kang shen ◽  
...  

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(μ2-H2O)]}n (1), {[Cd(BDAB)]∙2H2O∙DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O}n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4′-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2–4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+via quenching effect.


2010 ◽  
Vol 663-665 ◽  
pp. 332-335
Author(s):  
En Guo Wang

Eu3+-doped La2Mo2O9 phosphor was fabricated by sold-state reaction method. The as-prepared samples were characterized by the application of X-ray diffraction (XRD), scanning electron microscopy (SEM), and emission spectra. The effect of the sintering temperature and doping amount of europium ion on the luminescent properties of La2Mo2O9:Eu3+ was investigated. The results show that the luminescent intensity will reach the strongest when the sintering temperature is equal to 1073 K. The Eu3+ doping amounts also have obvious effect on the luminescent properties.


2018 ◽  
Vol 10 (3) ◽  
pp. 409-412
Author(s):  
Shihua Zhao

ZnO/AAM (anodic alumina membrane) arrays were prepared by an electrodeposition method and X-ray diffraction (XRD) patterns show that the characteristic diffraction peaks of ZnO appear, such as the lattice planes of (100), (002), and (102), moreover, the diffraction peaks of Al2O3 are dominated. Scanning electron microscopy (SEM) images show that the average sizes of the ZnO particles are about 100 nm corresponding to the channel diameters of AAM, and the ZnO arrays are composed of those close particles linked together. The photoluminescence emission spectra express that the as-prepared ZnO arrays can give out relatively pure ultraviolet light (395 nm) from the excitons.


2013 ◽  
Vol 652-654 ◽  
pp. 563-566
Author(s):  
Xia Wang ◽  
Chang Cheng Liu ◽  
Zhen Hua Liang ◽  
Gui Hua Peng ◽  
Xiao Bao Han

Hollow spherical CaMoO4:Eu3+, Li+red phosphors have been successfully synthesized by spray pyrolysis method. The crystalline phase, morphology and luminescent properties of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence emission spectra (PL). The XRD results demonstrated that all the diffraction peaks of the samples can be well indexed to the tetragonal phase of CaMoO4. The SEM images showed that the particles were composed of hollow spheres, whose diameters are about 1.4 μm. The as-prepared CaMoO4:Eu3+, Li+hollow spheres show a strong red emission corresponding to the5D0-7F2transition of the Eu3+ ions under ultraviolet light.


2016 ◽  
Vol 35 (9) ◽  
pp. 963-966
Author(s):  
Yanzhi Meng ◽  
Xiaomin Wang ◽  
Yi Shen ◽  
Xiaoli Wei ◽  
Liying Han ◽  
...  

AbstractThe red long-lasting phosphors (LLPs) ZnxCa1–xTiO3:yPr3+ (ZCTP) were successfully prepared via the sol–gel method. The effects of Zn2+ content and Pr3+ molar concentration on the luminescent properties of ZCTP LLPs were characterized by X-ray diffraction, excitation and emission spectra, long-lasting decay curves and thermoluminescence (TL) curves. In this study, the results indicated that luminescent properties of Zn0.2Ca0.8TiO3:0.2 %Pr3+ phosphor was the best. In addition, when Pr3+ molar concentration reached 0.8 mol %, concentration quenching effect was obvious.


2018 ◽  
Vol 32 (04) ◽  
pp. 1850047 ◽  
Author(s):  
Jianlin Zhong ◽  
Lixin Yu ◽  
Songchu Li ◽  
Xiaoqin Man ◽  
Wei Sun

The BaZr[Formula: see text]Si2O[Formula: see text]: Eu[Formula: see text]/Eu[Formula: see text] phosphors were prepared with different concentrations of Eu2O3 by a self-reduction method under air condition. The X-ray diffraction and the photoluminescence properties of the prepared samples were analyzed. The emission spectra consisting of a broadband emission from the 4f[Formula: see text]5d transitions of Eu[Formula: see text] and sharp emissions from 5D0-7F[Formula: see text] (J = 0, 1, 2, 3, 4) transitions of Eu[Formula: see text] are observed. The different luminescent colors can be obtained and modulated by doping different concentrations of Eu2O3 and the white light emission can be observed as the concentration of europium is 6%.


2008 ◽  
Vol 8 (3) ◽  
pp. 1410-1413 ◽  
Author(s):  
Shaozhe Lü ◽  
Jishen Zhang

La3PO7:Eu3+ samples were prepared by combustion and annealing and characterized by X-ray diffraction and transmission electron microscopy. It was found that the average size of the particles is about 80 nm. The red emission from the 5D0 → 7F2 transition of the Eu3+ ions under ultraviolet light excitation is much stronger than the orange emission from the 5D0 → 7F1 transition. The emission spectra, charge transfer band, laser selective excitation spectra, and time-resolved spectra indicate that symmetry of the local environment of Eu3+ lacks an inversion center and Eu3+ ions occupy at least two types of sites in the La3PO7 crystal. The superior color chromaticity compared to other phosphates and borates doped with Eu3+ means La3PO7:Eu3+ may have potential as a luminescent material.


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