scholarly journals Isomeric bis(pyrazolyl)sulfones based on bis(1,1-dihydropolyfluoroalkyl)sulfones. A new type of ligands for metal-polymer complexes with silver cation

Author(s):  
Ya.S. Borodkin ◽  
◽  
E.B. Rusanov ◽  
Yu.G. Shermolovich

The work is devoted to the methods of synthesis of bis(polyfluoroalkenyl)sulfones and bis(polyfluoromethoxyalkenyl)sulfones as well as to the study of their reactions with diazomethane, resulting in the formation of N-methylated bis(pyrazolyl)sulfones isomers. Methods for the preparation of bis(polyfluoromethoxyalkenyl)sulfones not described previously in the literature have been developed by the addition of triethylamine and trimethylchlorosilane to a solution of the respective bis(polyfluoroalkyl)sulfones and methanol in diethyl ether in an argon atmosphere. A new method for the preparation of a previously unknown bis(3,3-difluoro-2,2-dimethoxypropyl)sulfone was suggested. The reaction occurs at room temperature in methanol in the presence of lithium hydroxide monohydrate. It was found that different regioisomeric bis(polyfluoroalkylpyrazolyl)sulfones are formed when using different methoxy derivatives of bis(polyfluoroalkenyl)sulfones in reaction with diazomethane, depending on the length of the polyfluoroalkyl moiety. These experimental data suggest that the attack of the double bond of methoxy-derived bis(polyfluoroalkenyl)sulfones by a molecule of diazomethane is influenced not only by the presence of an alkoxyl group, but also by the length of the polyfluoroalkyl substituent. The obtained bis(pyrazolyl)sulfones were investigated for the possibility of their use as ligands in the chemistry of metal complexes. It was shown that 5,5'-sulfonylbis[4-(difluoromethyl)-1-methyl-1H-pyrazole] forms a polymeric metal complex with silver nitrate. The results of X-ray structural analysis of the prepared coordination compound are presented. According to these results, the silver atom coordinates with two nitrogen atoms of pyrazole cycles of different molecules in the crystal of the obtained metal-complex compound, forming a supramolecular structure. In our opinion, an important role in this arrangement is played by the nitrate group that is coordinated with two silver atoms. As a result, we observed a supramolecular structure in the crystal that had a spiral structure with some free space in the middle. The paper also presents the results of spectral and X-ray diffraction analysis of a new regioisomeric compound of bis(3-hexafluoropropyl-1-methylpyrazolyl)sulfone.

Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.


Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xinzhao Xia ◽  
Lixian Xia ◽  
Geng Zhang ◽  
Yuxuan Jiang ◽  
Fugang Sun ◽  
...  

Abstract In this work, a new type of zinc(II) coordination polymer {[Zn(HIDC)(BBM)0.5]·H2O} n (Zn-CP) was synthesized using 4,5-imidazoledicarboxylic acid (H3IDC) and 2,2-(1,4-butanediyl)bis-1,3-benzimidazole (BBM) under hydrothermal conditions. Its structure has been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The Zn(II) ion is linked by the HIDC2− ligand to form a zigzag chain by chelating and bridging, and then linked by BBM to form a layered network structure. Adjacent layers are further connected by hydrogen bond interaction to form a 3-D supramolecular framework. The solid-state fluorescence performance of Zn-CP shows that compared with free H3IDC ligand, its fluorescence intensity is significantly enhanced.


2012 ◽  
Vol 490-495 ◽  
pp. 3486-3490
Author(s):  
Qiang Yu ◽  
Zhen Chen ◽  
Zhong Cheng Guo

In order to prepare a new type of anode material, stainless steel was selected as substrate material. The β-PbO2 coating on stainless steel substrate was prepared under the appropriate plating solution, and the PbO2-MnO2 coating was prepared with thermal decomposition. The crystal structure was determined by X-ray diffraction; Surface morphology was test by Scanning Electron Microscopy; the energy spectrum was used to determine element mass-fraction and the ratio of atomic number of the coatings.


2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers


2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.


Author(s):  
Yuliya V. Butina ◽  
Elena A. Danilova ◽  
Maxim V. Dmitriev ◽  
Aleksey V. Solomonov

For citation:Butina Yu.V., Danilova E.A., Dmitriev M.V., Solomonov А.V. Crystal structure of bis[1-(diaminomethylene)-thiouron-1-ium] sulfate. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 45-49. In this work crystal data of bis[1-(diaminomethylene)-thiouron-1-ium] sulfate is shown. This compound was characterized by IR spectroscopy and elemental analysis. The monocrystal of this compound was obtained and the structure was confirmed by single X-ray analysis. Moreover, the work describes potential application of synthesized compound. Comparative characteristics of thiourea and its known salts are demonstrated. It is known, that derivatives of thiourea have several tautomeric forms, which can be different in crystalline state or in solution. Therefore, changed scheme of the synthesis of 2-imino-4-thiobiuret is proposed. Elemental cell of crystal consists of two 1-(diaminomethylene)thiouron-1-ium cations and one sulfat anion. A full set of X-ray diffraction data was deposited in the Cambridge Structural Database (deposit CCDC 1421710) and it can be gotten from the site www.ccdc.cam.ac.uk/data_request/cif.


Author(s):  
Marie-Rose Van Calsteren ◽  
Ricardo Reyes-Chilpa ◽  
Chistopher K Jankowski ◽  
Fleur Gagnon ◽  
Simón Hernández-Ortega ◽  
...  

The tropical tree Calophyllum brasiliense (Clusiaceae) grows in the rain forests from Brazil to Mexico. Its leaves, as well as those of other Calophyllum species, are rich sources of chromanone acids, such as apetalic acid, isoapetalic acid, and their derivatives. Apetalic acid has shown significant antimycobacterial activity. The biological activity of apetalic acid has been related to the configuration of three asymmetric centers and the stereochemistry of the molecule; however, the C-19 configuration in the acidic side chain has not been fully resolved. For this reason, the unequivocal determination of the absolute configuration by means of X-ray crystallography in a sample of unique homogeneous apetalic acid stereoisomer was the most important point to start this study. We prepared some chiral amides using the carboxyl group. We determined the C-19 stereochemistry of apetalic acid, and its specific chiral derivatives, using NMR, X-ray diffraction methods, and molecular mechanics. Finally, we observed that steric hindrance in the side chain of apetalic acid leads to restriction of rotation around the pivotal link C-10 and C-19 establishing chiral centers at C2(R), C3(S), and C19(R). We were able to separate derivatives of these two high-rotatory-barrier conformers of apetalic acid by forming diastereoisomeric amides with phenylglycine methyl ester having a chiral center at C-2’. Our results allowed the conclusion of the existence of atropisomerism in the apetalic acid molecule.


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