scholarly journals Structures and Spectroscopy Studies of Two M(II)-Phosphonate Coordination Polymers Based on Alkaline Earth Metals (M = Ba, Mg)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kui-Rong Ma ◽  
Chun-Li Wei ◽  
Yu Zhang ◽  
Yu-He Kan ◽  
Ming-Hui Cong ◽  
...  

The two examples of alkaline-earth M(II)-phosphonate coordination polymers, [Ba2(L)(H2O)9]·3H2O (1) and [Mg1.5(H2O)9]·(L-H2)1.5·6H2O (2) (H4L = H2O3PCH2N(C4H8)NCH2PO3H2),N,N′-piperazinebis(methylenephosphonic acid), (L-H2= O3PH2CHN(C4H8)NHCH2PO3) have been hydrothermally synthesized and characterized by elemental analysis, FT-IR, PXRD, TG-DSC, and single-crystal X-ray diffraction. Compound1possesses a 2D inorganic-organic alternate arrangement layer structure built from 1D inorganic chains through the piperazine bridge, in which the ligand L−4shows two types of coordination modes reported rarely at the same time. In1, both crystallographic distinct Ba(1) and Ba(2) ions adopt 8-coordination two caps and 9-coordination three caps triangular prism geometry structures, respectively. Compound2possesses a zero-dimensional mononuclear structure with two crystallographic distinct Mg(II) ions. Free metal cations  [MgO6]n2+and uncoordinated anions(L-H2)n2-are joined together by static electric force. Results of photoluminescent measurement indicate three main emission bands centered at 300 nm, 378.5 nm, and 433 nm for1and 302 nm, 378 nm, and 434.5 nm for2(λex=235 nm), respectively. The high energy emissions could be derived from the intraligandπ∗-ntransition stations ofH4L(310 nm and 382 nm,λex=235 nm), while the low energy emission (>400 nm) of1-2may be due to the coordination effect with metal(II) ions.

Author(s):  
Jeffrey A. Rood ◽  
Ashley L. Huttenstine ◽  
Zachery A. Schmidt ◽  
Michael R. White ◽  
Allen G. Oliver

Reaction of alkaline earth metal salts with diphenylphosphinic acid in dimethylformamide solvent afforded four coordination polymers: [Mg3(O2PPh2)6(DMF)2]·2DMF (I), [Ca(O2PPh2)2(DMF)2] (II), [Sr(O2PPh2)2(DMF)2] (III) and [Ba(O2PPh2)2(DMF)2] (IV) (where DMF isN,N-dimethylformamide). Single-crystal X-ray diffraction revealed that all four compounds produce linear chain structures in the solid state, with the Ca, Sr and Ba forming isostructural crystals. The bulk materials were characterized by FT–IR and1H NMR spectroscopy and elemental analyses.


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.


2019 ◽  
Vol 946 ◽  
pp. 351-356 ◽  
Author(s):  
Olga M. Kanunnikova ◽  
V.V. Aksenova ◽  
G.A. Dorofeev

The present work deals with the investigation of the transformations of the solid and liquid phases at high energy planetary ball milling of toluene together with titanium powder. The sequence of structural toluene transformations using FT-IR spectroscopy was investigated. Phase constitutions and morphology of ball milled titanium powders were studied by X-ray diffraction and scanning electron microscopy. It is shown that mechanically induced destruction of toluene occurs by the mechanism of catalytic cracking. During ball milling, concentration of aromatic hydrocarbons in the liquid phase decreases, at the same time the content of alkenes, cycloalkanes, and isoalkanes increases. The main solid products of the mechanosynthesis were cubic and hexagonal titanium carbo-hydrides.Evolution of lattice parameters, crystallites sizes, and micro-stresses of the solid phases during ball milling as a function of the mechanical energy dose have been discussed.


2011 ◽  
Vol 121-126 ◽  
pp. 3401-3405 ◽  
Author(s):  
Ju Hua Luo

Lithium niobate powders were prepared by mechanochemical treatments using Li2CO3 and Nb2O5 as raw materials. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) were employed to evaluate the morphologies and structures of samples. The mechanism of LiNbO3 formation of the ground mixture samples was discussed. The crystal structure of mixture was collapsed into a disordered structure, which increased with increasing grinding time. At the same time, the specific surface area increase and the bond energy reduction of the mixture occurred. Consequently, high energy ball milling enables increase of the internal energy, reduction of the activation energy, and improvement of the uniform mixing stage, which resulted in direct formation of singal phase LiNbO3 at a low temperature (500°C). However, the temperature must reach 1200°C for the traditional method.


1989 ◽  
Vol 160 ◽  
Author(s):  
L.J. Schowalter ◽  
J.E. Ayers ◽  
S.K. Ghandhi ◽  
Shin Hashimoto ◽  
W.M. Gibson ◽  
...  

AbstractEpitaxial layers of (111) GaAs of approximately 1 µm thickness were grown on epitaxial CaF2 buffer layers which were either 140 or 380 nm thick on Si(111) substrates. The best nucleation temperature for the GaAs on CaF2/Si(111) we have observed was 620 °C. This resulted in high quality GaAs films which exhibited channeling minimum yields of 4%. The density of threading dislocations in the GaAs layers was observed by TEM to be ~108 cm-2. Double-crystal x-ray diffraction measurements showed that the strain (ε┴.) was less than 2.2×10-4 in both sets of GaAs samples. Ion channeling, however, revealed a large tetragonal strain of 3.5×10-3 (ε┴ = 1.7×10-3) in the thinner (140 nm) CaF2 buffer layers. By doing ion channeling with high energy (2.5 MeV) protons, it was possible to determine strain more accurately. Using this technique, we were able to set an upper limit for the tetragonal strain of 2.5×10-4 in both the GaAs (which implies ε┴ < 8×10-5 and CaF2 (ε┴ < 1.5×10-4) layers for the thicker (380 nm) CaF2 buffer layer structure. These results are in good agreement with the strain predicted from previous strain measurements of CaF2 epitaxial layers on Si.


RSC Advances ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 6131-6139 ◽  
Author(s):  
Youzhi Cao ◽  
Qiao Li ◽  
Wei Wang

A novel crossed-layer-structure MoS2/g-C3N4 (graphitic carbon nitride) was synthesized by a facile method, and was characterized by a collection of analytical techniques: X-ray diffraction patterns, FT-IR spectra, SEM, TEM, and XPS.


2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Kavitha Govindarajan ◽  
Vijayarohini Parasuraman ◽  
Parasuraman Perumalswamy Sekar ◽  
Ilhami Colak ◽  
Balkew Zewge Hailemeskel

The synthesis of several metal complexes of d-block elements of hexadecanoic acid (palmitic acid) and its antimicrobial activity was reported in this study. UV-Vis and FT-IR spectroscopy studies were used to characterize and confirm the produced metal complexes by the shift in the absorbance and the formation of M-O linkage. The X-ray diffraction method was mainly used to examine the crystallographic faces of the complexes based on the transition metals. Thermal gravimetric investigation revealed that all metal palmitate complexes had high thermal stability in the range of 250-300°C. The metal complexes of hexadecanoic acid were examined for microbicidal activity against diverse bacterial strains and fungal pathogens using the agar well diffusion method. The copper palmitate complex presented excellent antibacterial activity among the other metal complexes. These outcomes suggest of using fatty acid metal complexes as a suitable candidate in several biomedical applications.


2020 ◽  
Vol 21 (22) ◽  
pp. 8696
Author(s):  
Mateusz Kowalik ◽  
Joanna Masternak ◽  
Iwona Łakomska ◽  
Katarzyna Kazimierczuk ◽  
Anna Zawilak-Pawlik ◽  
...  

Two novel coordination polymers, [Bi2(2,3pydc)2(2,3pydcH)2(H2O)]n (1) and {(Et3NH)2[Bi(2,3pydc)(2,3pydcH)Cl2]}n (2) were prepared using as a prolinker pyridine-2,3-dicarboxylic acid (2,3pydcH2). The obtained complexes were fully characterized by elemental analysis, TG/DTG, FT-IR, solid-state photoluminescence, DFT calculations and single-crystal X-ray diffraction. The obtained complexes crystallized in the triclinic P-1 space group (1) and comprise dimeric units with two crystallographically different Bi(III) centers (polyhedra: distorted pentagonal bipyramid and bicapped trigonal prism) and monoclinic P21/c space group (2) with a distorted monocapped pentagonal bipyramid of Bi(III) center. The various coordination modes of bridging carboxylate ligands are responsible for the formation of 1D chains with 4,5C10 (1) and 2C1 (2) topology. The photoluminescence quantum yield for polymer 2 is 8.36%, which makes it a good candidate for more specific studies towards Bi-based fluorescent materials. Moreover, it was detected that polymer 1 is more than twice as active against H. pylori as polymer 2. It can be concluded that there is an existing relationship between the structure and the antibacterial activity because the presence of chloride and triethylammonium ions in the structure of complex 2 reduces the antibacterial activity.


2015 ◽  
Vol 71 (7) ◽  
pp. 618-622 ◽  
Author(s):  
Shao-Ming Ying ◽  
Jing-Jing Ru ◽  
Wu-Kui Luo

Metal–organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(μ-N-benzyl-L-phenylalaninato-κ4O,O′:O,N)(μ-formato-κ2O:O′)zinc(II)], [Zn(C16H16NO2)(HCOO)]n, (1), and poly[(μ-N-benzyl-L-leucinato-κ4O,O′:O,N)(μ-formato-κ2O:O′)zinc(II)], [Zn(C13H18NO2)(HCOO)]n, (2), and studied by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two-dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region.


2018 ◽  
Vol 74 (2) ◽  
pp. 240-247 ◽  
Author(s):  
Nassima Bendjellal ◽  
Chahrazed Trifa ◽  
Sofiane Bouacida ◽  
Chaouki Boudaren ◽  
Mhamed Boudraa ◽  
...  

In coordination chemistry and crystal engineering, many factors influence the construction of coordination polymers and the final frameworks depend greatly on the organic ligands used. The diverse coordination modes of N-donor ligands have been employed to assemble metal–organic frameworks. Carboxylic acid ligands can deprotonate completely or partially when bonding to metal ions and can also act as donors or acceptors of hydrogen bonds; they are thus good candidates for the construction of supramolecular architectures. We synthesized under reflux or hydrothermal conditions two new alkaline earth(II) complexes, namely poly[(1,10-phenanthroline-κ2N,N′)bis(μ-3-phenylprop-2-enoato-κ3O,O′:O)calcium(II)], [Ca(C10H7O2)2(C10H8N2)]n, (1), and poly[(1,10-phenanthroline-κ2N,N′)(μ3-3-phenylprop-2-enoato-κ4O:O,O′:O′)(μ-3-phenylprop-2-enoato-κ3O,O′:O)barium(II)], [Ba(C10H7O2)2(C10H8N2)]n, (2), and characterized them by FT–IR and UV–Vis spectroscopies, thermogravimetric analysis (TGA) and single-crystal X-ray diffraction analysis, as well as by powder X-ray diffraction (PXRD) analysis. Complex (1) features a chain topology of type 2,4 C4, where the Ca atoms are connected by O and N atoms, forming a distorted bicapped trigonal prismatic geometry. Complex (2) displays chains of topology type 2,3,5 C4, where the Ba atom is nine-coordinated by seven O atoms of bridging/chelating carboxylate groups from two cinnamate ligands and by two N atoms from one phenanthroline ligand, forming a distorted tricapped prismatic arrangement. Weak C—H...O hydrogen bonds and π–π stacking interactions between phenanthroline ligands are responsible to the formation of a supramolecular three-dimensional network. The thermal decompositions of (1) and (2) in the temperature range 297–1173 K revealed that they both decompose in three steps and transform to the corresponding metal oxide.


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