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Alejandro Pérez

Bio: Alejandro Pérez is an academic researcher from Simón Bolívar University. The author has contributed to research in topics: Amino acid & Stability constants of complexes. The author has an hindex of 6, co-authored 13 publications receiving 71 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the formation of ternary complexes with their respective formation constants in the systems formed by copper (II), picolinic acid and the amino acids was studied.
Abstract: In this work, the formation of ternary complexes with their respective formation constants in the systems formed by copper (II), picolinic acid and the amino acids = histidine (His), aspartic acid ...

17 citations

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TL;DR: Binary and ternary complexes of nickel(II) with dipicolinic acid (H 2 dipic) and the amino acids serine (Hser), threonine(Hthr), methionine (MHmet) and phenylalanine (PHphe) have been investigated in aqueous solutions at a 1.0 mol·dm − − 3 NaCl ionic strength and 25 °C as mentioned in this paper.

14 citations

Journal ArticleDOI
TL;DR: In this paper, the binary and ternary complexes of Nickel(II) with picolinic acid (Hpic) as a primary ligand and the small blood serum bioligands lactic acid, oxalic acid, citric acid, and phosphoric acid as biologically relevant secondary ligands were studied.

14 citations

Journal ArticleDOI
TL;DR: In this paper, the results of the speciation of the ternary vanadium(III)-1,10-Phennanthroline(Phen) and the amino acids glycine (HGly), proline (HPro), α-alanine (αAla), and β-ala (HβAla) by means of potentiometric measurements in 3.0 -mol −m −m−m−3 KCl at 25 −°C were presented.

11 citations

Journal ArticleDOI
TL;DR: In this paper, the ternary Nickel(II) complexes with salicylic acid and the amino acids were studied in aqueous solution at 25°C and 1.0 ǫ − 3 NaCl as the ionic medium.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: A bibliographical research emphaticizing the chemical speciation of the vanadium with different amino acids and reviewing also some other important aspects such as its chemistry and therapeutical applications of several vanadium complexes.

76 citations

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TL;DR: Analysis of the equilibrium constants of the reactions and spectroscopic data has allowed determination of the type of coordination and effectiveness of the carboxyl groups in the process of complex formation.

60 citations

Journal ArticleDOI
TL;DR: A series of mixed ligand complexes were prepared from the Schiff base (L 1 ) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1, 10-phen) as a secondary ligand as mentioned in this paper.

50 citations

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TL;DR: Third-order NLO properties of nitrogen containing phenanthroline based compound 9 were observed to be several times higher than those of the compounds 7 and 8, justify the design approach.

26 citations

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TL;DR: In this paper, the effect of chelating agents (citrate and EDTA) on the visible light photocatalytic activity of natural pyrite for the inactivation of Escherichia coli ATCC 25922 (E. coli) was investigated.
Abstract: The effect of chelating agents (citrate and EDTA) on the visible light photocatalytic activity of natural pyrite for the inactivation of Escherichia coli ATCC 25922 (E. coli) was investigated. The influence of various parameters, such as chelating agent and H2O2 concentration, light intensity and aeration rate, was evaluated experimentally and through kinetic models. The presence of a chelating agent enhanced the photocatalytic activity of natural pyrite, and citrate was more effective than EDTA, considerably improving bacteria inactivation in natural pH and reducing the drawbacks of the photocatalytic inactivation system. For both citrate-pyrite and EDTA-pyrite, the inactivation rate went through a maximum for a concentration of the chelating agent of 0.5 mM. The increase of the light intensity (10–60 mW cm−2), H2O2 concentration (10–25 mg L-1) and aeration rate (2-8 L min-1) improved the radical generation, resulting in a high inactivation effect. The low effect of H2O2 on the catalytic activity of pyrite in the presence of EDTA was likely due to the inhibition of the hydrogen peroxide-to-hydroxyl radical conversion by EDTA. On the other hand, degradation of citrate at high aeration rate occurred, decreasing the catalytic activity of the citrate-pyrite system. Scavenging tests indicated that the bulk hydroxyl radicals are the most reactive radical species in the bacterial inactivation, closely followed by valence band holes, while conduction band electrons play a less important role. In addition, in order to generate predictions and to better understand the process, artificial neural networks were used as models for the considered process: the obtained performance indexes indicated a good correlation between experimental and predicted values.

22 citations