626 research outputs found
New copper(II) 1D polymer containing dimethyl(phenylsulfonyl)amidophosphate: Synthesis, crystal structure and magnetic properties
No full textThe reaction of sodium dimethyl(phenylsulfonyl)amidophosphate NaL (HL=C(6)H(5)SO(2)NHP(O)(OCH(3))(2)) with Cu(NO(3))(2) center dot 6H(2)O and o-bpe (1,2-bis(pyridine-2-yl)ethane) in appropriate ratios, afford the formation of 1D coordination polymer [Cu(L)(2) center dot o-bpe](n) in good yield. The crystal structures of HL (1) and [Cu(L)(2) center dot o-bpe](n) (2) are reported. In the crystal package the molecules of 1 are linked by intermolecular hydrogen bonds formed by the phosphoryl oxygen atoms which serve as acceptors and nitrogen atoms of amide groups as donors. The crystal structure of 2 indicates the presence of unsaturated Cu(L)(2) unit bridged by o-bpe ligand in the one-dimensional polymeric chain. The Cu(II) atoms have distorted 4 + 2 octahedral CuO(4)N(2) environment formed by the oxygen atoms belonging to the sulfonyl and phosphoryl groups of two deprotonated chelate ligands and nitrogen atoms of the bridging o-bpe ligands. The magnetic study of 2 has revealed the presence of a weak intrachain antiferromagnetic exchange interaction between copper ions. (C) 2009 Elsevier Ltd. All rights reserved.Fundamental Researches State Fund of Ukraine [F25/193 - 2008
One-Pot Synthesis of a New Magnetically Coupled Heterometallic Cu2Mn2 [2 x 2] Molecular Grid
No full textThe heterometallic [2 x 2] grid-type complex [Cu2Mn2(pop)(4)(OAc)(4)]center dot 7H(2)O (1) has been selectively synthesized in a targeted one-pot reaction. Single-crystal X-ray analysis shows the expected structure with identical metal ions located at diagonal vertices of the grid. Magnetochemical studies reveal that 1 has a ferrimagnetic spin ground state with some admixture of low-lying excited states.DFG [SFB 602
Regular High-Nuclearity Species from Square Building Blocks: A Triangular 3 x [2 x 2] Ni-12 Complex Generated by the Self-assembly of Three [2 x 2] Ni-4 Molecular Grids
No full textA dodecanuclear 3 x [2 x 2] nickel(II) complex has been obtained via the self-association of three tetranuclear [2 x 2] molecular grids. X-ray diffraction shows a "propeller-like" structure of the [Ni-4](3) scaffold with a central mu(3)-hydroxide. The dodecanuclear species remains stable in solution and can be deposited without decomposition on highly ordered pyrolytic graphite surfaces
Synthesis and structure of [2 x 2] molecular grid copper(II) and nickel(II) complexes with a new polydentate oxime-containing Schiff base ligand
No full textA new polynucleating oxime-containing Schiff base ligand, 2-hydroxyimino-N'-[1-(2-pyridyl)ethylidene]propanohydrazone (Hpop), has been synthesized and fully characterized. pH potentiometric, electrospray ionization mass spectrometric, and spectrophotometric studies of complex formation in H(2)O/DMSO solution confirmed the preference for polynuclear complexes with 3d metal ions. Single-crystal X-ray diffraction analyses of [Ni(4)(pop)(4)(HCOO)(4)]center dot 7H(2)O (1), [Cu(4)(pop-H)(4)(HCOOH)(4)] center dot H(2)O (2), and [Cu(4)(pop-H)(4)(H(2)O)(4)] center dot 9H(2)O (3) indicated the presence of a [2 x 2] molecular grid structure in all three compounds but distinct configurations of the cores: a head-to-tail ligand arrangement with overall S(4) symmetry of the grid in the Cu(2+) complexes as opposed to a head-to-head ligand arrangement with (noncrystallographic) O(2) grid symmetry for the Ni(2+) complex. A cryomagnetic study of 3 revealed intramolecular ferromagnetic exchange between copper ions in the grid, while in 1, antiferromagnetic interactions between the metal ions were observed
"Re-creating" Tadeusz Konwicki’s fiction : "Little apocalypse" and Yurii Andrukhovych’s "Moscoviad"a
Get PDFOn the basis of a comparative analysis of the worlds presented in Moscoviada by Yurii Andrukhovych and in the Little Apocalypse by Tadeusz Konwicki the article demonstrates the meaning of "metaphorical translation". Using the category proposed by Joseph Brodsky, the author of the article shows how similar characters, who search for their identities, are presented in both books
Growth of nanoparticles in liquid medium using magnetron sputtering technique
No full textTitle: Growth of nanoparticles in liquid medium using magnetron sputtering technique Author: Josef Kučera Department: Department of Surface and Plasma Science Supervisor: Mgr. Yurii Yakovlev, Ph.D., Department of Surface and Plasma Science Abstract: This thesis investigates the preparation of platinum and platinum-ruthenium alloy nanoparticles using magnetron sputtering method on a liquid substrate. Polypropylene glycol with three different molecular weights of 425, 1000, and 4000 was chosen as the liquid substrate. The influence of the different viscosities of these substrates on the size and morphology of the nanoparticles produced in the magnetron was investigated. Dynamic light scattering and transmission electron microscopy methods were used to determine the size of the nanoparticles. Furthermore, the catalytic activity of the produced nanoparticles in an alkaline environment was investigated using the rotating disk electrode technique. Keywords: Nanoparticles, Magnetron Sputtering, Polypropylene glycol, Hydrogen Fuel Cells, Water Electrolyzers, Hydrogen oxidation/reduction reactions
George Yurii Shevelov as a master of academic writing
No full textУкраїнськомовні лінгвістичні праці Юрія Шевельова свідчать про нього як про яскраву авторську індивідуальність. У статті проаналізовано стильові та художні засоби, якими він послуговується, щоб дієвіше впливати на читачів. Зроблено висновок про актуальність його мовної практики для вдосконалення й уточнення сучасних норм українського наукового стилю.Ukrainian linguistic papers by George Yurii Shevelov are evidence of his outstanding author individuality. The article deals with analysis of some stylistic and expressive means, which he uses for more effective influence upon his readers. The conclusion of the study reveals that his language practice is topical for development and improvement of modern standards of Ukrainian academic discourse
George Yurii Shevelov as a master of academic writing
No full textУкраїнськомовні лінгвістичні праці Юрія Шевельова свідчать про нього як про яскраву авторську індивідуальність. У статті проаналізовано стильові та художні засоби, якими він послуговується, щоб дієвіше впливати на читачів. Зроблено висновок про актуальність його мовної практики для вдосконалення й уточнення сучасних норм українського наукового стилю.Ukrainian linguistic papers by George Yurii Shevelov are evidence of his outstanding author individuality. The article deals with analysis of some stylistic and expressive means, which he uses for more effective influence upon his readers. The conclusion of the study reveals that his language practice is topical for development and improvement of modern standards of Ukrainian academic discourse
Information Systeems and Technologies in Agronomy and Business^ Employers Requirements-Oriented Study in Agricultural Universities
No full textOlena Kopishynska, Yurii Utkin, Viktor Lyashenko, Olha Barabolia, Olena Kalashnik, Svitlana Moroz,Olga Kartashova. Information Systeems and Technologies in Agronomy and Business^ Employers Requirements-Oriented Study in Agricultural Universities. The 25 th World Multi-Conference on Systemics, Cybernetics and informatics juiy 18-21 2021 - Virtuai Conference. Florida U.S.A
Novel pyrazolate-based copper(II) [2 x 2] grid complexes: Synthesis, structure and properties
No full text5-Acetyl-substituted pyrazole-3-carboxylic acid (H2L) forms [2 x 2] grid-like tetranuclear Cu(II) complexes with four five-coordinated copper(II) ions bridged by pyrazolate groups. Despite a significant dissociation of [Cu4L4(H2O)(4)]center dot 4H(2)O (1) in aqueous solution(1), it was possible to substitute the coordinated water molecules by pyridine ligands or azide anions. The resulting tetranuclear complexes [Cu4L4Py4]center dot 2H(2)O (2) and Na-4[Cu4L4(N-3)(4)]center dot 7MeOH (3) were isolated and studied by X-ray diffraction analysis. In 2 and 3 the azide anions or pyridine molecules complete the distorted square-pyramidal coordination of each copper(II) center. Magnetic susceptibilities of the obtained compounds have been measured by SQUID techniques. Simulation of the data using a Heisenberg spin Hamiltonian approach showed that the bridges between the metals mediate weak intramolecular antiferromagnetic coupling (J in the range -13.3 to -17.1 cm (1)) and lead to a singlet ground state in all cases. (C) 2012 Elsevier B.V. All rights reserved
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