Synthesis of some salicylic acid derivatives and studies of their interaction with uranyl ion

1991 ◽  
Vol 56 (7) ◽  
pp. 1446-1453 ◽  
Author(s):  
Evgenija A. Djurendić ◽  
Terézia M. Surányi ◽  
Dušan A. Miljković

Some unsubstituted and substituted bis-derivatives of salicylic acid have been synthesized and their acidity constants determined spectrophotometrically in 61.10% aqueous ethanol. The stability constants of complexes these compounds from with UO22+-ion were determined spectrophotometrically using the method of continuous variation under following conditions: pH 3.58 and 3.98, 61.10% aqueous ethanol, μ = 0.5 (LiCl), 25 ± 1 °C.

1995 ◽  
Vol 60 (3) ◽  
pp. 464-472 ◽  
Author(s):  
Terézia M. Surányi ◽  
Evgenija A. Djurendić ◽  
Gyöngyi Gy. Vastag

The stoichiometric ratio and stability constants of iron(III) complexes with 1,n-di-O-salicyloylalkane-1,n-diols (n = 2 - 8) and N,N'-disalicyloyl-1,n-alkanediamines (n= 2 - 4) were determined spectrophotometrically. In 61.10% aqueous ethanol, the iron-to-ligand ratio is 1 : 1 (FeL+). The stability constants of the complexes were measured at 298 K and μ = 0.5 mol dm-3 (LiCl). Since the determination was performed in a glycinate buffer, the constants were corrected for the side reaction of iron(III) with glycine.


1990 ◽  
Vol 55 (7) ◽  
pp. 1763-1768 ◽  
Author(s):  
Evgenija A. Djurendić ◽  
Terézia M. Surányi ◽  
Dušan A. Miljković

Several derivatives of salicylic acid have been synthesized by the condensation reaction of methyl salicylate with α,ω-diols and α,ω-diamines, and the acidity constants of five newly prepared derivatives have been determined in 61.10% aqueous ethanol using potentiometric titration method. In order to avoid calibration of pH-meter, the standard potential of glass electrode was determined from the titration data. The results obtained are discussed with regard to different resonance effects of the ester oxygen and the amide nitrogen atoms.


1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.


Environments ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 69
Author(s):  
Spencer Steinberg ◽  
Vernon Hodge ◽  
Luis Becerra-Hernandez

Gd3+ forms a strongly colored complex with 4-(2-pyridylazo)-resorcinol (PAR) in aqueous solutions. We characterized the Gd3+-PAR complex in order to use it as a probe of Gd3+ speciation in the presence of environmentally relevant ligands. The formation of the Gd3+-PAR complex was investigated from pH 5 to 8 in the presence of excess PAR. The absorbance of the Gd3+-PAR complex dramatically increased from pH 5 to 8 and application of the method of continuous variation indicates that the complex was primarily 1:2 Gd(PAR)2 at pH 8. Stability constants for Gd3+ with other ligands can be quantified by competitive displacement of the PAR ligand. To establish the viability of this approach, we measured the stability constants between Gd3+ and several organic acids and carbonate. Our measurements show reasonable agreement with the literature values. We used the competitive displacement approach to establish that humic acids can competitively displace PAR from the Gd(PAR)2 complex.


1970 ◽  
Vol 48 (16) ◽  
pp. 2574-2586 ◽  
Author(s):  
W. A. E. McBryde ◽  
Janet L. Rohr ◽  
J. S. Penciner ◽  
J. A. Page

Stability constants of the iron(III) complexes of salicylic acid, sulfosalicylic acid, and 4-aminosalicylic acid, together with several of the acidity constants of these, have been determined at 25 °C and in solutions with 0.5 M background electrolyte. For the spectrophotometric measurement of the stability constants improved methods for determining the extinction coefficients of the first and second complexes are described. Protonated species appear only with the aminosalicylate complexes, and the site of this protonation is discussed. Previous values of these equilibrium constants have been collected and critically assessed.


RSC Advances ◽  
2015 ◽  
Vol 5 (48) ◽  
pp. 38435-38442 ◽  
Author(s):  
Natalia Gutowska ◽  
Piotr Seliger ◽  
Grzegorz Andrijewski ◽  
Mariola Siwy ◽  
Magdalena Małecka ◽  
...  

Two new single and double P-pivot lariat ethers have been synthesized and the stability constants of their complexes with silver(i) ions were determined in acetonitrile and methanol solutions.


1969 ◽  
Vol 47 (12) ◽  
pp. 2320-2323 ◽  
Author(s):  
Vedula S. Sastri ◽  
Keijo I. Aspila ◽  
Chuni L. Chakrabarti

Studies on the solvent extraction of morpholine dithiocarbamic acid complexes of divalent metal ions Mn, Fe, Co, Ni, Cu, Zn, Pb, Cd, Hg, and Sn were carried out, and the extraction constants and the overall stability constants were determined. The stability constants of complexes of Cu(II) formed with various substituted dithiocarbamic acids, showed a variation of the stability constants with the basicity of the nitrogen and sulfur atoms in the reagents.


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