Synthesis, Crystal Structure, and Photoluminescent Properties of a Series of LnIII–CuI Heterometallic Coordination Polymers Based on Cu4I3 Clusters and Ln–ina Rod Units

2017 ◽  
Vol 70 (8) ◽  
pp. 943 ◽  
Author(s):  
Chengcai Xia ◽  
Gang Xiong ◽  
Lixin You ◽  
Baoyi Ren ◽  
Shuju Wang ◽  
...  

A novel series of LnIII–CuI heterometallic coordination polymers (HCPs) {[Ln2Cu4I3(ina)7(DMA)2]n·nDMA, Ln = La (1), Ce (2), Pr (3) Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9) Ho (10), Er (11), Yb (12), Hina = isonicotinic acid, DMA = N,N-dimethylacetamide} were synthesised by a solvothermal reaction. The structures of compounds 1–12 were characterised by elemental analysis, FT-IR spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. Single crystal X-ray diffraction studies revealed that 1–12 are isomorphous and are 3D heterometallic coordination polymers based on inorganic Cu4I3 clusters and Ln2(ina)7(DMA) rod units. In addition, the luminescent properties of compounds 5–9 have been investigated in detail. All of them exhibited green light emission due to the synergistic effects of characteristic emissions of lanthanide ions and iodide-to-copper charge transfer.

2020 ◽  
Vol 73 (1) ◽  
pp. 16
Author(s):  
Shu-Ju Wang ◽  
Yi-Hui Jiang ◽  
Han-Lin Wu ◽  
Li-Xin You ◽  
Gang Xiong ◽  
...  

Three new coordination polymers, {[Ln(cbb)(Hcbb)(DMF)·H2O]n, Ln=Sm (1), Eu (2), Tb(3), H2cbb=2-(4-carboxybenzyloxy) benzoic acid, DMF=N,N-dimethylformamide}, have been synthesised by a solvothermal reaction and structurally characterised by infrared spectroscopy, elemental analysis, thermogravimetry analysis, and X-ray single-crystal diffraction. The results of single-crystal X-ray diffraction indicate that the coordination polymers 1–3 are isostructural, belong to a triclinic system, space group P-1, and show 1D chain structures through the H2cbb ligands connecting adjacent lanthanide ions. In addition, the fluorescence properties of polymers 1–3 were also investigated.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Li Tian ◽  
Zhi Long Ma ◽  
Mengchen Wang ◽  
Jian Yun Shi

Solvothermal reaction of a novel multidentate ligand 2,5-bis-(1,2,4-triazol-1-yl)-terephthalic acid (H2TTPA), with MnCl2 afforded three structurally different coordination polymers with the similar formula [Mn(TTPA)•H2O]n (Mn-(1-3)). Single-crystal X-ray diffraction analyses show that...


2011 ◽  
Vol 279 ◽  
pp. 161-165
Author(s):  
Xing Yuan Guo ◽  
Jing Zhou ◽  
Zhan Hui Ding ◽  
Yan Feng Xue ◽  
Bin Yao

Hexagonal ZnO whiskers were prepared by using an optical floating zone furnace. Most of the as-grown whiskers have diameters of about 20-30 µm and lengths of about 2~3 mm. The characteristic peaks of X-ray diffraction (XRD) verify that the as-grown ZnO whiskers have excellent hexagonal wurtzite phase and (001) orientation. The room-temperature photoluminescence spectra show a near-UV emission band located at 380 nm and a green light emission band centered at 515 nm. The threshold of near-UV emission and lasing were observed.


2016 ◽  
Vol 69 (8) ◽  
pp. 846 ◽  
Author(s):  
Xiu-Li Wang ◽  
Xiao-Mei Wu ◽  
Guo-Cheng Liu ◽  
Nai-Li Chen ◽  
Hong-Yan Lin ◽  
...  

Six new coordination polymers [Zn2(L)(chdc)2]·2H2O (1), [Zn(L)(mip)]·3H2O (2), [Zn(L)(bdc)]·H2O (3), [Cd2(L)(chdc)2]·2H2O (4), [Cd(L)(mip)]·2H2O (5), and [Cd(L)(bdc)]·2H2O (6) (L = N,N′-bis(pyridine-3-yl)-4,4′-oxybis(benzoic) dicarboxamide, 1,4-H2chdc = trans-1,4-cyclohexanedicarboxylic acid, H2mip = 5-methylisophthalic acid, 1,3-H2bdc = 1,3-benzenedicarboxylic acid) have been synthesized from ZnII/CdII ions and L ligands in the presence of auxiliary dicarboxylates via hydrothermal or solvothermal reaction. The coordination polymers have been fully characterized by infrared spectroscopy, powder X-ray diffraction, thermogravimetric analyses, and single-crystal X-ray diffraction analysis. Complex 1 contains a 1D [Zn4(chdc)4]n wave-like chain, which is connected by the μ2-bridging ligand L, affording a 3,4-connected 2D polymeric network. Complexes 2 and 3 both possess similar 2D 4-connected square grid-like layers, which are based on Zn-carboxylates linear chains and left-handed [Zn(L)]n helix chains. The structure of complex 4 is very similar to that of 1. Complexes 5 and 6 demonstrate a similar 2D 3,5-connected channel-level network, which is constructed from a pair of Cd-carboxylates linear chains and 1D [Cd2(L)2]n cyclic chains. The effects of the central metal ions and different dicarboxylates on the formation and structures of the title coordination polymers have been discussed. In addition, the fluorescence and photocatalytic properties of the title complexes have been investigated.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Nuengruethai Ekthammathat ◽  
Titipun Thongtem ◽  
Anukorn Phuruangrat ◽  
Somchai Thongtem

Aligned hexagonal ZnO nanorods on pure Zn foils were hydrothermally synthesized in 30 mL solutions containing 0.05–0.50 g KOH. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. In this research, wurtzite hexagonal ZnO nanorods grown along the [002] direction with green light emission at 541 nm caused by singly ionized oxygen vacancies inside were detected.


Author(s):  
Dmytro Vlasyuk ◽  
Renata Łyszczek

AbstractThe impact of different synthetic procedures such as: hydrothermal, mechanochemical and precipitation on the structure and thermal properties of coordination polymers of 1H-pyrazole-3,5-dicarboxylic acid (H3pdca) with selected lanthanide ions was determined. The prepared complexes of the general formula: Ln2(Hpdca)3⋅nH2O, where Ln = Eu(III), Nd(III), Tb(III) and Er(III); n = 6 or 7 were fully investigated by: elemental analysis, Energy-Dispersive X-Ray (ED-XRF) and infrared (ATR-FTIR) spectroscopy, powder as well as single-crystal X-ray diffraction methods and thermal analysis (TG-DSC and TG-FTIR) in various atmospheres. It was proved that all used strategies offer high yields of reactions along with crystallinity of the obtained products. The X-ray diffraction methods allowed to conclude that the complexes with the same metal ions exhibit the same crystal structure despite different synthesis routes. On the other hand, the coordination polymers of Eu(III), Tb(III) and Er(III) prepared under different conditions are isomorphous. Only neodymium(III) compounds have a different crystal structure. Thermal stability of the produced complexes was correlated with the synthesis conditions, in particular with the way of energy supply. It was found that the highest thermal stability was exhibited by the complexes prepared under the hydrothermal conditions. Additionally, based on the volatile products of metal complexes decomposition, the mechanism of their pyrolysis was proposed in relation to their structures.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Yu Li ◽  
Chumin Liang ◽  
Xunzhong Zou ◽  
Jinzhong Gu ◽  
Marina V. Kirillova ◽  
...  

Three 2D coordination polymers, [Cu2(µ4-dpa)(bipy)2(H2O)]n∙6nH2O (1), [Mn2(µ6-dpa)(bipy)2]n (2), and [Zn2(µ4-dpa)(bipy)2(H2O)2]n·2nH2O (3), were prepared by a hydrothermal method using metal(II) chloride salts, 3-(2′,4′-dicarboxylphenoxy)phthalic acid (H4dpa) as a linker, as well as 2,2′-bipyridine (bipy) as a crystallization mediator. Compounds 1–3 were obtained as crystalline solids and fully characterized. The structures of 1–3 were established by single-crystal X-ray diffraction, revealing 2D metal-organic networks of sql, 3,6L66, and hcb topological types. Thermal stability and catalytic behavior of 1–3 were also studied. In particular, zinc(II) coordination polymer 3 functions as a highly active and recoverable heterogeneous catalyst in the mild cyanosilylation of benzaldehydes with trimethylsilyl cyanide to give cyanohydrin derivatives. The influence of various parameters was investigated, including a time of reaction, a loading of catalyst and its recycling, an effect of solvent type, and a substrate scope. As a result, up to 93% product yields were attained in a catalyst recoverable and reusable system when exploring 4-nitrobenzaldehyde as a model substrate. This study contributes to widening the types of multifunctional polycarboxylic acid linkers for the design of novel coordination polymers with notable applications in heterogeneous catalysis.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.


Hydrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-21
Author(s):  
Youyi Sun ◽  
Alexey Y. Ganin

Metal alloys have become a ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes, making the search for earth-abundant and cheaper alternatives important. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co7Mo6 alloys. The single-phased nature of the alloys is confirmed by X-ray diffraction and electron microscopy. When electrochemically tested, they achieve competitively low overpotentials of 115 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 0.5 M H2SO4, and 120 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 1 M KOH. Both alloys outperform Co and Mo metals, which showed significantly higher overpotentials and lower current densities when tested under identical conditions, confirming the synergistic effect of the alloying. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring, polycrystalline bimetallic electrocatalysts could challenge the dominance of Pt in acidic media if ways for improving their stability were found.


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