Complexation and ligand exchange in aqueous of Cu(II) and Ni(II) with hydrazides of some aromatic acids

Afanas'eva, G. V.; Bychkova, T. I.; Штырлин, В. Г.; Шакирова, А. Р.; Garipov, Ruslan; Zyavkina, Yu. I.; Zakharov, A. V.

doi:10.1134/s1070363206030030

Cited by 8 publications

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“…In this case, n,v-coordination should involve donor center with pK a ≈ 2 and σ ≈ 0.6 (these values were calculated using Δ λ-pK a and Δ λ-σ dependences; Table 1). Taking into account that coordination at the nitrogen atom in the pyridine ring contradicts the data of [11] (pK a 3.56 for + HNC 5 H 4 , Hammett constant σ = 0.28 for related CONH 2 group), we ought to presume that the complex with Zn-TPP is formed via coordination of the N 1 atom of the hydrazide group with a pK a value of 1.91 [11], which is fairly similar to the calculated value. X-Ray diffraction data showed the possibility for formation of dative bond with participation of both nitrogen atom in the pyridine ring and CONHNH 2 group.…”

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Complex Formation of Tetraphenylporphyrinatozinc(II) and Nucleophilic Substitution Reactions with Pyridines and Pyridine N-Oxides

et al. 2010

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Thermodynamic parameters of complexation of tetraphenylporphyrinatozinc(II) with pyridines in chloroform at 273-313 K are linearly related to the corresponding shifts of their absorption maxima in the electronic spectra, logarithms of the stability constants of the complexes, pK a values of the ligands in water, and Hammett substituent constants σ provided that steric factors are absent. Linear correlations also exist between thermodynamic and kinetic parameters of some nucleophilic substitution reactions and complex formation of tetraphenylporphyrinatozinc(II) with pyridines and pyridine N-oxides.Processes involving axial coordination of various ligands are responsible for biological activity of many porphyrin metal complexes [1,2]. However, studies on complex formation of metal porphyrins in vivo are very difficult to perform. Therefore, such studies are often carried out in vitro using readily accessible from the synthetic viewpoint 5,10,15,20-tetraphenylporphyrinatozinc(II) (Zn-TPP) whose IR, electronic absorption and emission, and NMR spectra are fairly simple and very sensitive to interactions with nucleophiles, ligands, and bases.We previously showed [3] that shifts of absorption maxima (Δλ) in the electronic spectra of Zn-TPP in chloroform, resulting from interaction with pyridine, quinoline, and acridine N-oxides (provided that steric factors are absent), are linearly related to the logarithms of the stability constants of the complexes, pK a values of the ligands in water and other solvents, and Hammett constants σ of substituents in the heterocycle. In the present article we report on complex formation of Zn-TPP with pyridines containing substituents in positions 3 and 4 of the heteroring.Complex formation of pyridine and its derivatives with zinc porphyrins in various solvents was studied in [4][5][6][7][8], and several complexes with pyridine were isolated as individual crystalline substances and analyzed by X-ray diffraction [9] (CSD refcodes: HPORN10, VIXGEO, PRPHZN, EPOPZN10). The goal of the present work was to determine thermodynamic parameters of coordination of substituted pyridines with Zn-TPP and analyze these parameters in terms of the linear free energy relationship principle.The experimental stability constants K of molecular complexes formed by Zn-TPP with pyridine derivatives in chloroform are concentration parameters. On the other hand, taking into account low concentration of the initial compounds (2 × 10 -5 M for Zn-TPP and 10 -4 -10 -3 M for ligands) and the absence of ionic species in solution, we presume that the obtained experimental values insignificantly differ from thermodynamic. We found that, as with heteroaromatic N-oxides [3], in the absence of steric factors shifts of

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Complex Formation of Tetraphenylporphyrinatozinc(II) and Nucleophilic Substitution Reactions with Pyridines and Pyridine N-Oxides

et al. 2010

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“…Calcd for C 12 N 6 H 14 O 2 Cl 2 Cu (%): C, 33.8; N, 19.7; H, 2.38; Cu, 15.6. Observed: C, 31.8; N, 21.4; H, 2.47; Cu, 15.3 [26].…”

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A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes

et al. 2015

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Abstract:The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II) complexes. New compounds with the general formulae [CuX 2 (INH) 2 ]¨nH 2 O (X = Cl´and n = 1 (1); X = NCS´and n = 5 (2); X = NCO´and n = 4 (3); INH = isoniazid, a drug widely used to treat tuberculosis) derived from the reaction between the copper(II) chloride and isoniazid in the presence or absence of pseudohalide ions (NCS´or NCO´) were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, elemental analysis, melting points and complexometry with 2,2 1 ,2 11 ,2 111 -(Ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA). The characterization techniques allowed us to confirm the formation of the copper(II) complexes. The Cu(II) complexes were loaded into microemulsion (MEs) composed of 10% phase oil (cholesterol), 10% surfactant [soy oleate and Brij 58 (1:2)] and 80% aqueous phase (phosphate buffer pH = 7.4) prepared by sonication. The Cu(II) complex-loaded MEs displayed sizes ranging from 158.0˘1.060 to 212.6˘1.539 nm, whereas the polydispersity index (PDI) ranged from 0.218˘0.007 to 0.284˘0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC 50 ) against the Vero cell line (ATCC CCL-81 TM ) were used to calculate the selectivity index (SI). Among the free compounds, only compound 2 (MIC 500 µg/mL) showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC's 125, 125 and 500 µg/mL, respectively) and S. aureus (MICs 250, 500 and 125 µg/mL, respectively). The loaded compounds were less toxic against the Vero cell line, especially compound 1 (IC 50 from 109.5 to 319.3 µg/mL). The compound 2-and 3-loaded MEs displayed the best SI for E. coli and S. aureus, respectively. These results indicated that the Cu(II) complex-loaded MEs were considerably more selective than the free compounds, in some cases, up to 40 times higher.

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Transformations of Peroxide Products from Ozonolysis of (–)-α-Pinene and (+)-3-Carene by Capric and Benzoic Acid Hydrazides

et al. 2020

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Complexation and ligand exchange in aqueous of Cu(II) and Ni(II) with hydrazides of some aromatic acids

Cited by 8 publications

References 5 publications

Complex Formation of Tetraphenylporphyrinatozinc(II) and Nucleophilic Substitution Reactions with Pyridines and Pyridine N-Oxides

Complex Formation of Tetraphenylporphyrinatozinc(II) and Nucleophilic Substitution Reactions with Pyridines and Pyridine N-Oxides

A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II) Complexes

Transformations of Peroxide Products from Ozonolysis of (–)-α-Pinene and (+)-3-Carene by Capric and Benzoic Acid Hydrazides

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