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Miroslava Puchoňová, Milan Mazúr and Dušan Valigura

Abstract

As a part of our systematic study of copper(II) complexes in presence of biologically active ligands, we concluded to realize experiments with methyl- or methoxysalicylatocopper(II) complexes in presence of 2-aminomethylpyridine (ampy) ligand. This has resulted in four new complexes of the formula Cu(XSal)2(ampy) (where XSal are 3-MeSal = 3-methylsalicylate, 4-MeSal = 4-methylsalicylate, 5-MeSal = 5-methylsalicylate, or 4-MeOSal = 4-methoxylsalicylate anions). The synthesis, elemental analysis and spectral properties (EPR, electronic and infrared) are reported. The Cu(II) atom in all four complexes is probably coordinated by two nitrogen atom of the bidentate chelating ampy as well as monodentate and/or highly asymmetrically chelating salicylate anions. Based on the analyses it was concluded that the structure of these new compounds could be similar to [Cu(HCOO)2(ampy)], or [Cu(CH3COO)2(ampy)] that are reported in the literature.

Open access

Miroslava Puchoňová, Vladimír Kuchtanin, Milan Mazúr and Dušan Valigura

Abstract

Four new compounds of formulae [Cu(3-Mesal)2(etbzim)2] (1), [Cu(4-Mesal)2(etbzim)2] (2), [Cu(4-MeOsal)2(etbzim)2] (3), [Cu(5-MeOsal)2(etbzim)2] (4) where 3- or 4-Mesal = 3- or 4-methylsalicylate anionic ligand, 4- or 5-MeOsal = 4- or 5-methoxysalicylate anionic ligand, etbzim = 2-ethylbenzimidazole) have been prepared and characterised by elemental analysis and available spectral methods (EPR, UV-vis and IR spectra). EPR spectra of all measured complexes are axial symmetry. Other spectral methods led to conclusion that all prepared complexes probably contain the etbzim ligand coordinated in equatorial plane together with the asymmetrically bonded salicylato anions thus giving {CuN2O2O’O”} chromophore. The supposed structural motive for all prepared complexes might be simmilar to those benzoate complexes with benzimidazole [Cu(4-OHbz)2(bzim)2] and [Cu(4-Mebz)2(bzim)2] (4-OHbz = 4-hydroxybenzoate, 4-Mebz = = 4-methylbenzoate), but similarity with polymeric salicylate complex [Cu(sal)2(bzim)2]n cannot be excluded.

Open access

Josef Malach, Kateřina Kostolánová, Milan Chmura, Anna Szafrańska-Gajdzica and Ewa Ogródska-Mazur

Abstract

The comparative study defines the terms electronic learning environment and smart learning environment with their components and contribution to university education. Moreover, it introduces identified trends that are expected to emerge in the next five years. The research on a representative sample of the University of Ostrava students and the University of Silesia students, which was carried out within the scope of the 7th RP IRNet project, was aimed at how the individual components of the electronic learning environment can be used, the reasons for their use and the related needs of students.

Open access

Flóra Jozefíková, Milan Mazúr, Miroslava Puchoňová and Dušan Valigura

Abstract

Three new nitrosalicylatocopper(II) complexes have been prepared and characterized. Compounds of the composition Cu(5-NSal)2(2-ampy)2 (1), Cu(5-NSal)2(2-hmpy)2 (2) and Cu(3,5-DNSal)2(2-hmpy)2 (3), where 2-ampy = (2-aminomethyl)pyridine, 2-hmpy = (2-hydroxymethyl)pyridine, 5-NSal = 5-nitrosalicylate anion and 3,5-DNSal = 3,5-dinitrosalicylate anion, were characterized by elemental analyses, EPR and IR spectroscopy. EPR spectra are consistent with the dx2-y2ground electronic state. Spectral properties have shown “classic” monodentate coordination of 5-nitrosalicylate anion. Similarly, bonding mode of the 3,5‑dinitrosalicylate anion in (3) is assumed to be unidentate via the carboxyl group, which is surprising compared with the previously studied complex, where the preferred coordination via the phenolate group anion was observed.

Open access

Jozef Miklovič, Dušan Valigura, Ingrid Svoboda, Ján Moncol and Milan Mazúr

Abstract

The synthesis and characterization of nine new copper(II) complexes [Cu(2-Clnic)2L2] (where 2-Clnic is 2-chloronicotinate anion, L is imidazole – Im, benzimidazole – Bim, furo[3,2-c]pyridine – FP, 2-methylfuro[3,2-c]pyridine – MFP, or [1]benzofuro[3,2-c]pyridine – BFP), [Cu(2-Clnic)2(INA)] (where INA is isonicotinamide), [Cu(2-Clnic)2(4-py)]·H2O (where 4-py is 4-methylpyridine) and [Cu2(2-Clnic)4(IQ)2] (where IQ is isoquinoline) are reported. The characterizations were based on elemental analysis, infrared, electronic and EPR spectra. The dimeric character of [Cu2(2-Clnic)4(IQ)2] is assumed on the EPR spectrum and the other spectral methods. The crystal structure of the [Cu(2-Clnic)2(Bim)2] and [Cu(2-Clnic)2(FP)2] complexes have been determined by X-ray crystal structure analysis. Both complexes exhibit the hexacoordination coordination polyhedra around copper atom that lies in the crystallographic center of symmetry. The distorted tetragonal-bipyramidal (4+2) arrangement is in good agreement with spectral data that have suggested an asymmetric chelate coordination of the carboxylic group.