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  • Author: Miroslava Puchoňová x
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Miroslava Puchoňová, Jozef Švorec and Dušan Valigura

Abstract

A systematic study of the preparation of methylsalicylatocopper(II) complexes with or without N-donor ligand has resulted in three new dimeric complexes formation. The investigation has been targeted to two main aspects: the conditions of dimeric complexes preparation and the properties of obtained products. The common stoichiometric formula for all three complexes is Cu(x-MeSal)2(H2O)(ACN)z (where x-MeSal = 3- or 4-methylsalicylate anion, ACN = acetonitrile and z = 0, 1). Used spectral measurements mainly EPR spectroscopy gave the proof about the existence of dimeric “paddle-wheel” units in all three complexes. Moreover, it was concluded that acetonitrile molecules are more probably bonded to copper(II) atoms in apical positions of dimeric units. The water molecules are in coordination sphere only in the case when acetonitrile is not present. However data show that presence of 4-methylsalicylate anions led to strengthening of Cu-N bonds.

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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

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.