Chelation behaviour of lanthanides with somethio-Schiff bases

Issa, Y. M.; Fattah, Hoda M. Abdel; Omar, M. M.; Soliman, Ahmed A.

doi:10.1007/bf00812245

Cited by 13 publications

(5 citation statements)

References 7 publications

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“…Compound 3b was studied potentiometrically by Issa et al using the Calvin-Bjerrum titration technique as modified by Irving and Rossotti at 25 • C and an ionic strength of 0.1 M (NaCl) in 70% (v/v) aqueous ethanol and dissociation constant of -SH group was determined as 10.12. 5 This value is the same as that found in our study (10.12). Dissociation constants of 3a were studied by Geary et al, Gürkan et al, and Sengupta et al in 50% (v/v) aqueous methanol and 50% (v/v) aqueous dioxin, respectively.…”

Section: Dissociation Constantssupporting

confidence: 91%

Comparison of chelating ability of NO-, NS-, ONS-, and ONO-type Schiff base derivatives and their stability constants of Bis-complexes with copper(II)

Atabey¹,

Fındık²,

Sarı³

et al. 2014

Turk J Chem

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Abstract:The present study includes important findings relating to the number of donor atoms, species of ligands, and stabilities of complexes. Stabilities of complexes between Cu(II) ion and NO-, NS-, ONS-, and ONO-type Schiff bases were compared. Acid-base properties of the Schiff bases were explained at 25 ± 0.1• C and ionic strength ( I) of 0.1 M supported by NaCl. The Hyperquad computer program was used for calculation of dissociation and stability constants.The overall stability constants of their Cu(II) complexes were calculated and the various formed complexes between the Schiff bases with Cu(II) ion formulated as CuL 2 , CuHL 2 , CuH 2 L 2 , and CuH −1 L 2 (Cu (OH) L 2) . The complexes of ONS-and ONO-type tridentate ligands were more stable than those of NO-and NS-type bidentate ligands.

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Section: Dissociation Constantssupporting

confidence: 91%

Comparison of chelating ability of NO-, NS-, ONS-, and ONO-type Schiff base derivatives and their stability constants of Bis-complexes with copper(II)

Atabey¹,

Fındık²,

Sarı³

et al. 2014

Turk J Chem

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“…This could indicate that the two CO groups are bound cis ‐ to each other in a distorted octahedral arrangement. The distortion of the octahedral arrangement may be explained as based on the noncoplanar characteristics of the Schiff base molecule 20. In the far IR spectrum of the complex compound, the nonligand bands observed at 510.7 and 453.7 cm −1 due to Ru‐O and Ru‐N bond giving rather a conclusive evidence for the bonding of azomethine nitrogen and enolic oxygen, i.e., the ligand to the metal ion 20, 21.…”

Section: Resultsmentioning

confidence: 99%

“…The distortion of the octahedral arrangement may be explained as based on the noncoplanar characteristics of the Schiff base molecule 20. In the far IR spectrum of the complex compound, the nonligand bands observed at 510.7 and 453.7 cm −1 due to Ru‐O and Ru‐N bond giving rather a conclusive evidence for the bonding of azomethine nitrogen and enolic oxygen, i.e., the ligand to the metal ion 20, 21. Therefore, it can be concluded that acacenH 2 ligand probably coordinated to ruthenium atom through enolic oxygen and azomethine nitrogen and acting as a tetradentate ligand.…”

Section: Resultsmentioning

confidence: 99%

Selectively crosslinked hyaluronic acid hydrogels for sustained release formulation of erythropoietin

Motokawa¹,

Hahn

Nakamura³

et al. 2006

J Biomedical Materials Res

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A novel sustained release formulation of erythropoietin (EPO) was developed using hyaluronic acid (HA) hydrogels. For the preparation of HA hydrogels, adipic acid dihydrazide grafted HA (HA-ADH) was synthesized and analyzed with (1)H NMR. The degree of HA-ADH modification was about 69%. EPO was in situ encapsulated into HA-ADH hydrogels through a selective cross-linking reaction of bis(sulfosuccinimidyl) suberate (BS(3)) to hydrazide group (pK(a) = 3.0) of HA-ADH rather than to amine group (pK(a) > 9) of EPO. The denaturation of EPO during HA-ADH hydrogel synthesis was drastically reduced with decreasing pH from 7.4 to 4.8. The specific reactivity of BS(3) to hydrazide at pH = 4.8 might be due to its low pK(a) compared with that of amine. In vitro release of EPO in phosphate buffered saline at 37 degrees C showed that EPO was released rapidly for 2 days and then slowly up to 4 days from HA-ADH hydrogels. When the hydrogels were dried at 37 degrees C for a day, however, longer release of EPO up to 3 weeks could be demonstrated. According to in vivo release test of EPO from HA-ADH hydrogels in SD rats, elevated EPO concentration higher than 0.1 ng/mL could be maintained from 7 days up to 18 days depending on the preparation methods of HA-ADH hydrogels. There was no adverse effect during and after HA-ADH hydrogel implantation.

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“…The electronic spectra of 1b, 2b, and 3b have revealed essentially two absorption bands. The first is located in the wavelength range 260-280 nm [33]. By considering the electron density of this transition, it is concluded that this transition is essentially related to the delocalization of the electrons from phenyl rings of the pyrrolic compounds to the C=O moiety.…”

Section: Spectroscopic Datamentioning

confidence: 96%

Synthesis and spectral analysis of N-substituted pyrrole salicylaldehyde derivatives-electropolymerization of a new nickel(II)-Schiff base complex derived from 6-[3′-N-pyrrolpropoxy]-2-hydroxyacetophenone and 1,2-diaminoethane

Ourari

Aggoun

2015

J IRAN CHEM SOC

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parameters such as the nature of the electrode material, the number of voltammetric scans, and the scan rate dependence. The electrodeposited poly(pyrrole) films onto ITO surface was characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). This poly(pyrrole) matrix, containing metallic centers, was found to have good catalytic properties towards the reduction of iodobenzene and carbon dioxide CO 2 . Graphical abstractAbstract Three dihydroxylated acetophenone derivatives 2,6-(1a), 2,5-(2a), and 2,4-dihydroxyacetophenone (3a) were O-monoalkylated at moderate temperature (50 °C) using 3-bromopropyl-N-pyrrole. These monomers 6-(3′-N-pyrrolpropoxy)-2-hydroxyacetophenone (1b), 5-(3′-N-pyrrolpropoxy)-2-hydroxyacetophenone (2b), and 4-(3′-N-pyrrolpropoxy)-2-hydroxy acetophenone (3b) were isolated with acceptable yields (59-70 %). Their characterization was carried out with usual spectroscopic methods such as UV-vis, FTIR, NMR 1 H, 13 C, Dept135, and elemental analysis. These pyrrolic compounds were deliberately chosen as electropolymerizable monomers to elaborate poly(pyrrole) films containing metallic centers useful as redox mediators covalently grafted on the surfaces of modified electrodes. Accordingly, we have initiated the synthesis of an original pyrrole-Ni(II)-Schiff base complex derived from 2,6-(1b) and 1,2-diaminoethane. This pyrrolic complex was electropolymerized onto glassy carbon (GC), platinum disk (Pt), and indium tin oxide (ITO) electrode surfaces. This electropolymerization was performed in acetonitrile via anodic oxidation of pyrrolic moieties by cyclic voltammetry. The efficiency of the electrochemical polymerization was investigated as a function of several * Djouhra Aggoun

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Chelation behaviour of lanthanides with somethio-Schiff bases

Cited by 13 publications

References 7 publications

Comparison of chelating ability of NO-, NS-, ONS-, and ONO-type Schiff base derivatives and their stability constants of Bis-complexes with copper(II)

Comparison of chelating ability of NO-, NS-, ONS-, and ONO-type Schiff base derivatives and their stability constants of Bis-complexes with copper(II)

Selectively crosslinked hyaluronic acid hydrogels for sustained release formulation of erythropoietin

Synthesis and spectral analysis of N-substituted pyrrole salicylaldehyde derivatives-electropolymerization of a new nickel(II)-Schiff base complex derived from 6-[3′-N-pyrrolpropoxy]-2-hydroxyacetophenone and 1,2-diaminoethane

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