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Molekularne materiały magnetyczne

Löffler M., Gałkowska A., Korabik M., Utko J., Lis T.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

523--541

EN

The „molecular” term appears more and more often in the materials chemistry. The Nobel Prize in 2016 was awarded to Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard R. Feringa „for the design and synthesis of molecular machines”. Magnetism in molecular scale, also known as molecular nanomagnetism, has been developing intensively since the second half of the last century. This branch of science involves the magnetic properties of coordination compounds of d- and f-electron metals. The paper presents results of the magnetic studies of molecular magnets of copper(II) and dysprosium(III), which have been pursuing in two doctoral thesis. The compounds form trinuclear and triangular molecules. The spin frustration phenomenon observed in the triangular relationship of copper(II) has been described. Since dysprosium(III) ion is characterized by a large magnetic anisotropy, the triangular, trinuclear coordination compound of dysprosium(III) of the formula [Dy3L5HLCl4]∙HL (where HL = 2-methoxyethanol) presents the characteristic properties of molecular magnets (SMMs) behavior. Two values of the energy barier were determined as Ueff/kB = 84,6 K and 31,2 K with the corresponding relaxation times τ0 = 1,82·10-6 s and 5,19·10-5 s. The data are probably attributed to different geometry of the coupled dysprosium ions.

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Farmakologiczna aktywność flawonoidów i aminoflawonów

Szeliga D., Korabik M., Ochocki J.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

563--583

EN

Aminoflavones belong to a group of flavonoids, compounds commonly found in nature. Their pharmacological and biochemical effects include cytotoxic, antioxidant and antitumor properties. The studies have shown that complexes of aminoflavons with metal ions can be potential drugs and seem to be promising in the treatment of ovarian cancer, breast cancer, lung adenocarcinoma and melanoma. In addition aminoflavones have a lower cytotoxic activity towards healthy cells than another compounds. In the view of their wide pharmacological and biological actions, they seem to have great therapeutic potential.

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The Evaluation of an Artificial Infiltration and Groundwater Recharge Project in the Well Field in Rožnov pod Radhoštěm (Czech Republic)

Heviankova S., Marschalko M., Malikova P., Drabinova S., Kyncl M., Korabik M., Kubac J.

Inżynieria Mineralna

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2018

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R. 20, nr 2

311--320

EN

The article analyses the permeability of ground surface in order to implement artificial surface infiltration and groundwater recharge by means of surface spraying near the well field, from where groundwater is pumped using a collection gallery in the fluvial gravel terrace. The artificial groundwater recharge project was implemented in order to deal with the periods of drought and related lack of water to be pumped from the fluvial terrace. The area of interest was divided into quasi-homogeneous blocks of surface permeability. Surface spraying was applied in the permeable quasi-homogeneous block. The other low permeable quasi- homogeneous blocks were unsuitable for the application of spraying and groundwater recharge. In the research, two methods were applied to evaluate the ground surface permeability. The first method was in-situ measurements of surface permeability using a two-cylinder infiltrometer in a regular network of points near the collection gallery (drainage channel). The second method was used to evaluate the ground permeability based on soil grain-size curves, where the soil samples were drawn from the same network of points as in the first method. It showed that the majority of the area of interest is sufficiently permeable for the puposes of artificial groundwater recharge, except for three polygons, where the soils were low permeable and where ponds used to occur in the past. Based on the study, surface spraying using water from nearby ponds was applied via an irrigation system, which resulted in increased groundwater levels. In the future, artificial infiltration and groundwater recharge may be applied in analogous geological conditions.

PL

W artykule przedstawiono analizę wpływu oprysków rolniczych na wody powierzchniowe i infiltrację do gruntów w strefie ochronnej wód obszaru Rožnov pod Radhoštěm (Czechy), gdzie wody są odprowadzane do rzeki. Projekt sztucznego dostarczania wód do wód gruntowych został wdrożony, aby rozwiązać problem małej ilośi wód w okresach suszy. Obszar zainteresowania podzielono na quasi-homogeniczne bloki o okreslonej przepuszczalności powierzchni. Natryskiwanie powierzchniowe zastosowano w przepuszczalnym quasi-homogenicznym bloku. W badaniach zastosowano dwie metody oceny przepuszczalności powierzchni gleby. Pierwszą metodą były pomiary percepcji powierzchniowej in-situ za pomocą dwu-cylindrycznego infiltrometru w regularnej sieci punktów w pobliżu miejsca nawadniania (kanał odwadniający). Drugi sposób zastosowano do oceny przepuszczalności gruntu w oparciu o krzywe wielkości ziarna gleby, gdzie próbki gleby pobrano z tej samej sieci punktów jak w pierwszej metodzie. Wykazano, że większość badanego obszaru jest dostatecznie przepuszczalna dla sztucznego uzupełniania wód podziemnych, z wyjątkiem trzech wielokątów, gdzie gleba była słabo przepuszczalna i gdzie kiedyś występowały stawy. Na podstawie przeprowadzonych badań zastosowano natryskiwanie powierzchniowe przy użyciu wody z pobliskich stawów za pomocą systemu nawadniającego, co spowodowało zwiększenie poziomu wód gruntowych. W przyszłości sztuczne infiltracje i uzupełnianie wód gruntowych mogą być stosowane w analogicznych warunkach geologicznych.

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Vibrational spectra, electronic excited states and magnetic properties of the copper(II) ions in alkylaminoacetylurea complexes

Ciurla H., Hanuza J., Talik Z., Korabik M., Mrozinski J.

Materials Science Poland

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2009

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Vol. 27, No. 1

5--21

EN

Copper(II) complexes with alkylaminoacetylurea ligands were synthesized and studied by means of IR, Raman, electron absorption and luminescence spectroscopies, as well as by ESR and magnetic methods. The spectroscopic and magnetic studies were performed in the 4-300 K and 1.9-300 K temperature ranges, respectively. The Cu2+ ions in these complexes are four coordinated having distorted squareplanar surroundings. The dependence of the spectroscopic parameters on the alkyl radical of the ligand is discussed. At low temperatures, very weak ferromagnetic interactions are observed for the C3 and C5 alkyls, and an antiferromagnetic one is observed for the remaining complexes, with C4 and C6-C18 alkyls.

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Magnetyczne oddziaływania nadwymienne przez wiązania wodorowe

Korabik M.

Wiadomości Chemiczne

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2008

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[Z] 62, 5-6

449-478

EN

Hydrogen bonds play a key role in interactions in biological structures, supramolecular chemistry, and crystal engineering [28, 29]. The development of supramolecular structure created by hydrogen bonds is a new challenge for the synthesis of materials, in order to study their magnetic behaviour [59, 62]. A role played by hydrogen bonds in the transmission of magnetic interactions is still not fully understood, but the number of magnetically coupled hydrogen-bonded systems is growing. The present paper describes magnetic properties of copper(II) complexes [33] with nitrobenzoate and salicylate ligands where the system of hydrogen bonds O-HźźźO is the only path of magnetic interaction. Magnetic measurements in the temperature range 1.8-300 K show magnetic phase-transition at 6 K to antiferromagnetically coupled CuII dimers with singlet-tryplet energy gap 2J = -6.26 cm-1. A variety of different supramolecular hydrogen bond structures [27, 33-52, 57-62] and significant changes in their magnetic properties were analyzed to show the role of hydrogen bonds in magnetic interactions. Magnetostructural correlation has been made taking into account both covalently bridging ligand and the existence of intermolecular hydrogen bonds. An evidence for hydrogen-bond-mediated exchange coupling has been observed in magnetic study as well as in DFT calculations [40, 48]. Intermolecular interaction has been generally treated as a nuance, but today, it has established itself as an important functional tool, tunable at will [59] in the design of nanosized magnetic materials and their dimensionally-expanded compounds [57-62]. Intermolecular magnetic exchange interactions through hydrogen bonds, can have a large influence on the quantum properties of single molecular magnets SMMs [59]. Hydrogen bonding leads to coupling of the magnetic effects of individual SMMs units and to different quantum behaviour. Even very weak hydrogen bond inter-molecular interactions demonstrate a possibility of switching from an original nanosized magnetic system to a correlated system, for example, from single molecule magnet SMM to single chain magnet SCM or from such nanosized magnets to a bulk magnet [59].

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Magnetic, Electrochemical and Antimicrobial Properties of Some Cu(II) Complexes with TPMC

Vuckovic G., Antonijevic-Nikolic M., Korabik M., Mroziński J., Manojlovic D., Gojgic-Cvijovic G., Matsumoto N.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 4

679-687

EN

Three complexes: [Cu2(C6H5COO)tpmc](ClO4)3.CH3OH, (A), (tpmc = N,N',N'',N'''- tetrakis(2-pyridilmethyl)-1,4,8,11-tetraazacyclotetradecane), [Cu2(Hpht)tpmc](ClO4)3.3H2O (H2pht = phtalic acid) (B) and [Cu4(ipht)(tpmc)2](ClO4)6_NaClO4_2CH3CN (H2ipht = isophtalic acid) (C) previously described were investigated by magnetic measurements, cyclic voltammetry (CV) and were tested towards some strains of microorganisms. It is found that all three complexes were electrochemically stable in the investigated ranges. The least stable was mi-iphtcomplex (C) due to the reaction of central ion, which is seen from weak peaks in its cyclic voltammogram. Complexes were characterized by variable temperature magnetic measurements (4.2-300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H= - 2JSS1 2, giving the ferromagnetic exchange parameters J = 0.92 cm-1 forA, J = 0.55 cm-1 forB and J= 0.65 cm-1for C. For the complex C model of molecular magnet with two magnetically isolated dimeric subunits was used. These results indicate the presence of weak ferromagnetic spin exchange interaction between the CuII magnetic centers within each molecule.

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Copper(II) Pyridine-2,6-dicarboxylates. Coordination and Distortion Isomers of [Cu(pydca)(H2O)2]

Koman M., Moncol J., Hudecová D., Dudová B., Melnik M., Korabik M., Mroziński J.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 7

957-964

EN

Copper(II) pyridine-2,6-dicarboxylate dihydrate and its ronicol (ron), nicotinamide (nia) and caffeine (caf) complexes were prepared and their spectral, magnetic as well as their bio-activites were studied. X-ray analysis of [Cu(pydca)(H2O)2] (pydca = pyridine- 2,6-dicarboxylate) shows, that the complex exists in two isomeric forms: monoclinic and triclinic and it is an example of the coordination isomerism. Triclinic forms also exists in two isomeric forms, differing mostly by degree of distortion and being an example of the distortion isomerism. On the basis of spectral and magnetic properties for Cu(pydca)L (L = ron, nia or caf) a square-pyramidal coordination of the copper(II) ion can be proposed. Highest bio-activity shows [Cu(pydca)(H2O)2].