[en] The results on the potentiometric studies of the ternary systems: Zn(II)/Cd(II)-8. HQS-HA (where 8-HQS =8-hydroxyqinoline, 5-sulphonic acid; HA= quinaldinic acid (QUINA) or picolinic acid (PIC)) have been discussed. (auth.)

[en] Formation of 1:1:1:1 quaternary complexes of dioxouranium(VI) ion with dibasic acids such as oxalic (OX), malonic (MALN), phthalic (PHA) and maleic (MA) acids has been inferred from pH metric studies and the stability constants of the resulting species have been evaluated. (author)

[en] The interaction of vanadyl ion with 2,2'-bipyridyl and some dicarboxylic or hydroxy acids (where dicarboxylic acid = oxalic (OX), malonic (MALN), phthalic (PHA), maleic (MAL) acids; hydroxy acids salicylic (SA), 5-sulfosalicylic (5-SSA), mandelic (MAND) and glycollic (HG) acids was studied potentiometrically. pH-titrations of the reaction mixtures containing vanadyl sulphate, 2,2'-bipyridyl and one of the dicarboxylic or hydroxy acids (OX, MALN, PHA, MAL, SA, 5-SSA, MAND and HG acids) in equimolar ratio exhibited the formation of 1:1:1 mixed ligand chelates. The formation constants of the resulting biligand chelates were calculated, at 35⁺-1⁰ and 45⁺-1⁰ and also the thermodynamic functions viz. ΔF, ΔH and ΔS (μ=0.1M KNO₃) (auth.)

[en] The formation of quaternary complexes of dioxouranium(VI) with three different organic acids (OX, MALN and SA, SSA, TAR or TMA) has been inferred from the potentiometric studies. The formation constants for the resulting triligand complexes have been evaluated. (auth.)

[en] 1:1:1, rare earth ions-CDTA-hydroxy acids ternary systems have been studied pH-metrically. The formation constants log Ksub(MLL') and free energies of formation (ΔF⁰) of the resulting octa-coordinated metal ion mixed-ligand complexes have been calculated. The order of stability in terms of metal ions has been reported as: La < Pr < Nd < Gd < Dy and in terms of hydroxy acids as: TAR < MAL. (author)

[en] The interaction of vanadyl ion with IMDA and some dicarboxylic or hydroxy acids (where dicarboxylic acids = oxalic (OX), malonic (MALN); hydroxy acids = salicylic (SA), 5-sulfosalicylic (SSA), mandelic (MAND) and glycolic (HG) acids) was studied potentiometrically. The formation constants of the resulting biligand chelates and Gibbs free energies of formation (G⁰) were calculated. (author)

[en] Mixed-ligand complex formation in the systems : M(III)-CDTA-dicarboxylic acids (H₂A) [where M(III) = La(III), Pr(III), Nd(III), Gd(III) or Dy(III); CDTA = cyclohexanediamine-tetraacetic acid and dicarboxylic acids (H₂A) = phthalic acid (PHA) or malonic acid (MLA)] has been discussed and the formation of 1:1:1 M(III)-CDTA-PHA/MLA species evidenced. The formation constants(log Ksub(MLL')) and free energies of formation (ΔG⁰) for the resulting ternary chelates have been evaluated. The relative order of stabilities in terms of metal ions : La(III)< Pr(III)< Nd(III)< Gd(III)< Dy(III) and in terms of dicarboxylic acids, PHA>MLA has been observed. (author)

[en] Mixed ligand ternary complexes of La(III), Pr(III), Nd(III), Gd(III), and Dy(III) with iminodiacetic acid (IMDA) and citraconic (CCA) or maleic acid (MIA), have been studied pH-metrically. Their formation takes place through the stepwise addition of the secondary ligand (IMDA) to the initially formed 1 : 1, Ln(III) - CCA/MIA binary species. The resulting ternary complexes undergo hydrolysis to form their hydroxo derivatives simultaneously. The stability constants of the hydroxo species are calculated for constant temperature (27 +- 1deg C) and ionic strength (I = 0.1M KNO₃). The relative order of stability is: La(III) < Pr(III) < Nd(III) < Gd(III) < Dy(III). (Author)

No abstract available

[en] Mixed-ligand complexes of the type MAB where M = La^III, Pr^III, Nd^III, Gd^III and Dy^III; A = TAR (tartaric acid)/MAL (malic acid); B = HQ (8-hydroxyquinoline) have been investigated potentiometrically. During the formation of above spiecies ligand B coordinates to the initially formed 1:1, MA complexes in the second step. IR spectra and elemental analyses of the isolated complexes have also been carried out in support of the potentiometric results. The resulting complexes and involved ligands have been studied to find out the percentage inhibition (at 200 ppm) on some selected fungi and bacteria. (author)