Luminescence spectra of chelate compounds of europium in aqueous methanol solutions

Davidenko, N. K.; Goryushko, A. G.; Naboikin, Yu. V.; Zholdakov, A. A.

doi:10.1007/bf00938155

Cited by 1 publication

(2 citation statements)

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“…This agreement in behaviour of the studied ligands with those cited in literature (17)(18)(19)(20) may be due to the similarity of the coordination sites of the ligands.…”

Section: Lu) As a Results Of Complex Formationsupporting

confidence: 87%

“…In terms of electrostatic considerations, the gadolinium break may be attributed to the discontinuity of the crystal radius at gadolinium (16). The deviation of the ligand stability constants from linearity is not peculiar, but seems to be common for most rare earth complexes with several chelating agents, such as 2,4-pentanedione (17), 1 -phenyl-1,3 -butane dione (18) and N-hydroxyethylenediamine triacetic acid (14).…”

Section: Lu) As a Results Of Complex Formationmentioning

confidence: 99%

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Formation constants of trivalent lanthanide metal ions and hydrazone β-diketones in 75% dioxane – water solvent

El‐Shetary¹,

Stefan²,

Abdel-Moez³

et al. 1988

Can. J. Chem.

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A new series of hydrazone P-diketone organic ligands were prepared: 3-(2-acetylpheny1hydrazone)pentane-2,4-dione (2-APHA), 2-(2-acetylpheny1hydrazone)-1-phenyl-1,3-butane dione (2-APHB), 2-(2-acetylpheny1hydrazone)-1,3-diphenyl-1,3-propane dione (2-APHDB), 3-(2-acetylphenylhydrazone) 1,1,1-trifluoropentane-2,4-dione (2-APHTA) and 2-(2-acetylpheny1hydrazone)-5,5-dimethyl-1,3-cyclohexane dione (2-APHDm). The step formation constants of their 1:l and 1:2 rare-earth complexes were determined at 30°C by pH titration in 75% (v/v) dioxane-water solvent. The ionization constant of ligands were also measured. A curious odd-even stability differential was apparent in the (2-APHDm) ligand with the heavier rare earths Gd-Lu. The differential was apparent in both log K , and log P values and may be sufficient to cause reversal of the usual ion-exchange elution sequence. On a prCparC une nouvelle skrie de ligands organiques dCrivts d'hydrazones de P-dicttones : (acCtyl-2 phCny1hydrazone)-3 pentanedione-2,4 (2-APHA), (acCtyl-2 phCny1hydrazone)-2 phtnyl-1 butanedione-1,3 (2-APHB), (acttyl-2 phCny1hydrazone)-2 diphCnyl-1,3 propanedione-1,3 (2-APHDB), (acCtyl-2 phtny1hydrazone)-3 trifluoro-1 , 1 , 1 pentanedione-2,4 (2-APHTA) et (acCtyl-2 phCny1hydrazone)-2 dimkthyl-5,5 cyclohexanedione-1,3 (2-APHDm). Operant a 30°C, dans un mClange dioxanneleau i 75% (v/v), on a dCterminC les constantes de formation par ttape de leurs complexes I: 1 et 1:2 avec des terres rares. On a aussi mesurC la constante d'ionisation des ligands. On a determink qu'il existe une curieuse de stabilitt diffkrentielle dans les complexes pair et impair du ligand 2-APHDm avec les terres rares plus lourdes de la strie Gd a Lu. On peut remarquer les differences tant dans les valeurs du log K , que du log P et ces differences sont telles qu'elles peuvent &tre suffisantes pour renverser la stquence habituelle d'Clution lors de l'tchange d'ions.[Traduit par la revue] P-Diketones are well-known chelating agents, capable of forming stable complexes with metal ions. Lanthanide Pdiketones have also been found to have wide application (2), including chromatographic separation of the lanthanide series (3). Azo compounds are also used as complexing agents (4), and the combination of azo compounds and P-diketones are good ligands (5). The chelation between similar ligands and lanthanide metal has been studied (6, 7).The coupling product of the diazonium salt of 2-aminoacetophenone with-different P-diketones such as acetylacetone, benzoylacetone, dibenzoyl methane, trifluoroacetylacetone, and 5,5-dimethylcyclohexane-1,3-dione (dimedone) produces a series of 3-(2-acetylphenylhydrazone)diketone ligands. T h e present study determined the acid dissociation constants of these ligands and the formation constants of their trivalent lanthanide complexes. The structure and basicity effects of the ligands on the stability of the formed complexes are discussed and some correlations attempted. These complexing agents may be useful in the separation of the lanthanides. Experimental (i) Ma...

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“…This agreement in behaviour of the studied ligands with those cited in literature (17)(18)(19)(20) may be due to the similarity of the coordination sites of the ligands.…”

Section: Lu) As a Results Of Complex Formationsupporting

confidence: 87%

Section: Lu) As a Results Of Complex Formationmentioning

confidence: 99%