Crystal Structures and Luminescence Behaviour of d10 Metal - Organic Complexes with Multipyridine Ligands

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.

2014 ◽  
Vol 69 (6) ◽  
pp. 681-690
Author(s):  
Guo-Cheng Liu ◽  
Nai-Li Chen ◽  
Ju-Wen Zhang ◽  
Yun Qu ◽  
Hong-Yan Lin ◽  
...  

Four new d10 metal-organic coordination polymers, [Zn(L)(phen)(H2O)] (1), [Cd(L)(phen)] (2), [Zn(L)(bppdc)]·3H2O (3), and [Cd(L)(bppdc)]·3H2O (4) [L=2-carboxymethylsulfanyl nicotinic acid, phen=1,10-phenanthroline, bppdc=N;N`-bis(pyridin-3-yl)pyridine-2,6-dicarboxamide], have been obtained from hydrothermal reactions of zinc(II)=cadmium(II) nitrates with the semi-rigid N-= S-containing dicarboxylate L, and the two structurally disparate neutral N-donor ligands phen and bppdc. Single-crystal X-ray diffraction analysis has revealed that compound 1 is a one-dimensional (1- D) helical coordination polymer linked by ZnII atoms and L spacers. Compound 2 features a doublechain structure connected via binuclear CdII units and pairs of L linkers. Adjacent chains of 1 and 2 are packed into 3-D supramolecular networks by hydrogen bonds and p-p stacking interactions. Compounds 3 and 4 exhibit similar 2-D (4,4)-connected wave-like networks based on linear [M-L]n and zigzag [M-bppdc]n metal-organic chains (M=ZnII for 3 and CdII for 4). The effects of metal ions and N-donor ligands with different coordination characters are discussed. Moreover, the photoluminescence properties and photocatalytic activities of compounds 1 - 4 were investigated.


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.


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.


2015 ◽  
Vol 68 (2) ◽  
pp. 307 ◽  
Author(s):  
Guo-Xia Jin ◽  
Jian-Ping Ma ◽  
Chuan-Zhi Sun ◽  
Yu-Bin Dong

Four new CuI coordination polymers, [(CuCl)L]n (1), {[(CuCl)2L2]·(H2O)}n (2), [(CuBr)L]n (3), and {[(CuBr)2L2]·(H2O)}n (4), were obtained from a new ligand 4,4′-bis(3-pyridyl)-2,2′-bis(hydroxylmethyl) biphenyl (L) and characterized by single-crystal X-ray diffraction. In 1 and 3, the rhombic [Cu2(μ-X)2] units are connected to each other by the bidentate linkers to form an infinite 1D double chain (X = Cl, Br). Such 1D chains are arranged into a 2D sheet through inter-chain π···π interactions. In 2 and 4, there are similar 1D double chains, but different inter-chain arrangement. Such 1D chains are connected into a 2D layer and further arranged in an ABAB fashion through O–H···X hydrogen bonds. The emission spectra and lifetimes in the microsecond range were measured at room temperature and at 77 K. Complexes 1 and 3 exhibit strong orange and yellow–orange emission in the solid state at room temperature, and were assigned to X-and M-to-ligand charge transfer excited states based on density functional theory calculations. The emission property of 2 and 4 was distinctly different from that of 1 and 3, probably due to the difference in coordination environments of the CuI centres as well as the dissimilar intermolecular arrangement.


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.


2020 ◽  
Vol 76 (2) ◽  
pp. 177-185
Author(s):  
Dan-Dan Wang ◽  
Jian-Teng Wang ◽  
Li Song ◽  
You-Yu Wang ◽  
Wen-Xiang Chai

Luminescent cuprous complexes are an important class of coordination compounds due to their relative abundance, low cost and ability to display excellent luminescence. The heteroleptic cuprous complex solvate rac-(acetonitrile-κN)(3-aminopyridine-κN)[2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl-κ2 P,P′]copper(I) hexafluoridophosphate dichloromethane monosolvate, [Cu(C5H6N2)(C2H3N)(C44H32P2)]PF6·CH2Cl2, conventionally abbreviated as [Cu(3-PyNH2)(CH3CN)(BINAP)]PF6·CH2Cl2, (I), where BINAP and 3-PyNH2 represent 2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl and 3-aminopyridine, respectively, is described. In this complex solvate, the asymmetric unit consists of a cocrystallized dichloromethane molecule, a hexafluoridophosphate anion and a complete racemic heteroleptic cuprous complex cation in which the cuprous centre, in a tetrahedral CuP2N2 coordination, is coordinated by two P atoms from the BINAP ligand, one N atom from the 3-PyNH2 ligand and another N atom from a coordinated acetonitrile molecule. The UV–Vis absorption and photoluminescence properties of this heteroleptic cuprous complex have been studied on polycrystalline powder samples, which had been verified by powder X-ray diffraction before recording the spectra. Time-dependent density functional theory (TD-DFT) calculations and a wavefunction analysis reveal that the orange–yellow phosphorescence emission should originate from intra-ligand (BINAP) charge transfer mixed with a little of the metal-to-ligand charge transfer 3(IL+ML)CT excited state.


2021 ◽  
Vol 33 (12) ◽  
pp. 2972-2976
Author(s):  
Anju Bala ◽  
Rajeev Sehrawat ◽  
Renu Bala ◽  
Ashutosh Dixit

Organically functionalized manganese doped zinc sulfide (ZnS/Mn) quantum dots were prepared by simple chemical method with polypyrrole (PPy) used as a capping agent. Prepared quantum dots were characterized with Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction microscope (XRD), UV-visible spectroscopy and photoluminescence spectroscopy. Crystalline size of PPy capped ZnS/Mn quantum dots for various concentrations of PPy were approximate 2 nm as analyzed by XRD and TEM analysis. The absorption spectra revealed the occurrence of a blue shift in the peak of absorption and an increase in the band gap value due to the quantum confinement effect. FTIR spectroscopy confirmed that shifting of broad peak at 2335.8 cm–1 was due to S-H stretching vibrations, which confirmed interaction of hydrogen and sulphur in ZnS/Mn/PPy nanocomposites. Uncapped ZnS/Mn and PPy capped ZnS/Mn quantum dots reveal the effective photoluminescence emission spectra in the range of 300-700 nm. With increase the value of capping agent in ZnS/Mn quantum dots, photoluminescence spectra going to red shifting. The photoluminescence properties of the organically functionalized ZnS nanoparticles are favourable for the application in optoelectronic devices.


2019 ◽  
Vol 205 ◽  
pp. 09009 ◽  
Author(s):  
Li Liu ◽  
Damianos Agathangelou ◽  
Thomas Roland ◽  
Olivier Crégut ◽  
Thibaud Duchanois ◽  
...  

We demonstrate the implementation of a broadband fluorescence up-conversion set-up with high signal-to-noise ratio and dynamic range allowing for the detection of weak luminescence from triplet states in Fe(II) NHC complexes. Based on the experimentally determined radiative rates and the emission spectra, these states have dominant MLCT character.


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