Hidrólisis del Ion V(III) a pH mayores de 3 en KCl 3M a 25 °C

Se estudio la hidrólisis del ion Vanadio (III) por medio de medidas de fem (H) a 25 ºC en KCl 3,0 M (M = mol/ dm3) como medio iónico, para un rango de concentración total de Vanadio (III) entre 8 y 31,5 mM a pH mayores de 3. El análisis de los datos potenciométricos realizado mediante el programa computacional de mínimos cuadrados generalizados LETAGROP, indica la formación de las siguientes hidroxoespecies y constantes de estabilidad (-log ßpq): VOH2+ (3,13 ± 0,08), V2(OH)24+ (3,76 ± 0,06), V(OH)2+ (6,86 ± 0,02) y V3(OH)8+ (27,47 ± 0,04).51-56cuatrimestreVanadium (III) ion Hydrolysis at pH higher than 3 in KCl 3M at 25 °C. The Vanadium (III) hydrolysis has been studied at 25 ºC in 3.0 M KCl as ionic medium for a range of total Vanadium concentration between 8 and 31,5 mM at pH higher than 3. The analysis of the potentiometric data by means of least-squares computational program LETAGROP, indicated the formation of the following hydroxospecies and their stability constants (-log ßpq): VOH2+ (3.13 ± 0.08), V2(OH)24+ (3.76 ± 0.06), V(OH)2+ (6.86 ± 0.02), and V3(OH)8+ (27.47 ± 0.04)

Complejos de V (III) en solución acuosa con el ácido aminopolicarboxílico CDTA

Se estudió mediante medidas de fuerzas electromotrices fem(H), la formación de los complejos de V(III) con el ácido aminopolicarboxílico trans-1,2-diaminociclohexano-N,N,N',N'-tetraetanoico (CDTA, H4L) en solución acuosa a 25°C y en KCl 3,0mol.L-1 como medio iónico. El análisis de los datos potenciométricos mediante el programa computacional de mínimos cuadrados generalizados LETAGROP, indica la formación de cantidades significativas de los complejos [VHL], [VL]- y [V(OH)L]2- con las respectivas constantes de estabilidad para cada complejo. Además del análisis por LETAGROP se realizaron mediciones espectrofotométricas en el UV-Vis para realizar una caracterización de manera cualitativa a las especies formadas en solució[email protected] forces measurements emf (H) were employed to study the formation of the Vanadium(III) complexes with the aminopolycarboxylic acid trans-1,2-diaminocyclohexane-N,N,N',N'-tetraethanoic (CDTA, H4L) in aqueous solution at 25 °C in 3.0mol.L-1 KCl as the ionic media. The analysis of the potentiometric data by means of the least-squares computational program LETAGROP, indicates the formation of significant quantities of the complexes [VHL], [VL]- and [V(OH)L]2- together with their respective stability constants of each complex. In addition to the LETAGROP analysis UV-Vis spectrophotometric measurements were done in order to make a qualitative characterization of the complexes formed in aqueous solution

Estudio de la hidrólisis del ion Niquel(II) y de la formación de los complejos de Niquel(II) con los ácidos Picolínico y Dipicolínico en NaCl 1,0 mol.dm-3 a 25°C

Estudio de la hidrólisis del ion Niquel(II) y de la formación de los complejos de Niquel(II) con los ácidos Picolínico y Dipicolínico en NaCl 1,0 mol.dm-3 a 25°[email protected] productos de hidrólisis (formación de compuestos hidroxilados) del ion Níquel(II) y de las especies complejas formadas entre el Ni(II) y los ligandos ácido picolínico (Hpic) y ácido dipicolínico (H2dipic), se han estudiado potenciométricamente en solución acuosa (a 25ºC, en medio iónico de NaCl I = 1,0 mol.dm-3). En la aplicación del programa informático de mínimos cuadrados generalizados, LETAGROP, a la data experimental de fem(H), se observó la formación de los productos de hidrólisis [Ni(OH)]+, [Ni(OH)2] y [Ni4(OH)4]4-. Adicionalmente, se ha detectado la formación de los complejos [Ni(pic)]+, [Ni(pic)2] y [Ni(pic)3]- con ácido picolínico y de las especies [Ni(dipic)] y [Ni(dipic)2]2- con ácido dipicolínico. Las constantes de estabilidad de los complejos formados fueron determinadas por mediciones potenciométricas

Speciation study and biological activity of copper (II) complexes with picolinic and 6-methylpicolinic acid with different components of blood serum of low molecular mass in KNO3 1.0 mol·L−1 at 25 °C

In the present work, the chemical speciation of ternary complexes of copper (II) with picolinic acid and 6-methylpicolinic acid and different ligands, such as, components of the blood plasma of low molecular mass (lactic acid, oxalic acid, citric acid, and phosphoric acid) were studied by measurements of emf(H) in KNO3 1.00 molL- 1. Potentiometric studies showed a predilection towards the formation of ternary species in solution, except for the copper (II)-picolinate-phosphate systems. The biological activity of the binary and ternary complexes isolated in situ, against reactive oxygen species was studied showing a concentration-dependent effect due to a possible mechanism of electron transfer. Finally, for the complexes Cu(Pic)2 and for the ligands were studied the ligand-receptor interaction on a PI3k of human origin by molecular docking, showing that, by themselves, the ligands are not capable of interacting with the active site of the enzyme. The metallic center is fundamental to generate reversible electrostatic interactions, that can be key to the indirect hypoglycemic effect exhibited by the Cu(Pic)2 complex reported in the literature

Chemical speciation, antioxidant activity and molecular docking of copper(II) complexes with pyridinedicarboxylic acids and different ligands of low molecular mass

Analyses of potentiometric measurements were conducted on ternary complexes of copper(II) with dipicolinic acid and quinolinic acid, as well as lactic acid, oxalic acid, citric acid, and phosphoric acid, which are components of blood plasma. Studies on chemical speciation showed that ternary compounds were more likely to be formed. In systems with quinolinic acid, the solubility was small, and most complexes precipitated at pH <= 2. In situ isolated ternary and binary complexes of CuDiPic(H2O)(2) were evaluated for antioxidant activity, as shown by their inhibiting activity of superoxide anion (O-2.(-)), which demonstrates copper(II) complexes provide protective effects. Docking studies of ligands with a protein kinase revealed that the Cu(II) metal centre is crucial for the successful interaction of the complex with the receptor's active site

Potentiometric determination of stability constants for ternary Vanadium(III) complexes with dipicolinic acid and the amino acids serine, threonine, methionine and phenylalanine/ Determinación potenciométrica de constantes de estabilidad para complejos de

In this work, we present the results of the speciation of the ternary complexes formed between vanadium(III), dipicolinic acid (H2Dipic) and the amino acids serine (Ser, HL), threonine (Thr, HL), methionine (Met, HL) and phenylalanine (Phe, HL), in aqueous solution at 25.0(1)&deg;C using 3.0 mol.dm-3 KCl as the ionic medium. The analysis of the potentiometric data using the least squares computational program LETAGROP, indicates the formation of the species [V(Dipic)(HL)]+, V(Dipic)(L), [V(Dipic)(L)(OH)]- and [V(Dipic)(L)(OH)2]2-, in the ternary V(III)-H2Dipic-Amino acids (HL) systems studied. The values of &Delta; log K&rsquo;&rsquo; for ternary systems involving amino acids have been evaluated and discussed. The species distribution diagrams as a function of pH were briefly discussed. The spectrophotometric spectra were done in order to get a qualitative characterization of the complexes formed in aqueous solution, indicates that the dipicolinate is acting as a tridentade ligand and the complexes formed are all heptacoordinated