Studies in amine-amino acid mixed ligand chelates—I

Chemistry Department, Faculty of Science, M.S. University of Baroda, Baroda-2, India
Journal of Inorganic and Nuclear Chemistry 01/1970; 32(10):3271-3275. DOI: 10.1016/0022-1902(70)80210-X

ABSTRACT Irving-Rossotti technique has been applied to study the formation constant of the reaction (Cu A)2+ + L− ⇌ (Cu AL)+ where A = dipyridyl and L = Glycine, α or β-alanine. Copper dipyridyl 1 : 1 is known to form at lower pH and is stable at higher pH when the secondary ligand gets bound. The values of the formation constant obtained in the mixed ligand systems are little less than the first formation constant of Cu-amino acid simple systems.

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    ABSTRACT: Complexing behaviour of three dihydroxyben-zenes (DHB) namely, hydroquinone, resorcinol and catechol with Th(IV) along with their protonation constants were studied in 1 M NaClO 4 medium at 23 ± 0.5 • C, using pH titra-tion technique. Both protonation and metal-ligand equilibrium constants of dihydroxybenzenes were computed using advance software suite of program HYPERQUAD. Logarithmic values of overall protonation constants (log β 1H and log β 2H) were found to be 11.47 ± 0.05 and 21.45 ± 0.06, for hydroquinone, 11.76 ± 0.04 and 20.98 ± 0.04 for resorcinol and 12.58 ± 0.03 and 21.87 ± 0.08 for catechol respectively. Complex forma-tion has been investigated in the pH range 2 to 4. The logarithmic values of metal-ligand equilibrium constants ob-tained in the present work were β 1 3 −1 = 48.51 ± 0.67 and β 1 4 −1 = 64.86 ± 1.25 for hydroquinone, β 1 1 0 = 16.98 ± 0.16, β 1 3 −1 = 46.46 ± 0.18 and β 1 4 −2 = 59.65 ± 0.20 for resorcinol and β 1 1 −1 = 14.06 ± 0.10 for catechol. The literature values were reviewed.
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    ABSTRACT: Ternary 1:1:1 complexes of Pd(II) with dipicolinic acid (DPA) or iminodiacetic acid (IDA) as primary ligands and some selected mono- and dicarboxylic amino acids (glycine, α-alanine, leucine, valine, phenylalanine, tryptophan, methionine, histadiene aspartic acid, and glutamic acid), aromatic carboxylic acids (salicylic and phthalic), and aliphatic carboxylic acids (succinic, oxalic, malic, maleic, malonic, and tartaric) as secondary ligands have been investigated by using the potentiometric technique at T = 30 °C and I = 0.1 mol·dm−3. The ternary complexes are formed in a stepwise mechanism. Confirmation of the ternary complexes in solution has been carried out using conductometric measurements.
    Journal of Chemical and Engineering Data - J CHEM ENG DATA. 10/2009; 55(2).
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    ABSTRACT: A new series of novel mixed‐ligand complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III) and U(VI)O2 with the Schiff base derived from salicylaldehyde and the sulfa drug sulfamerazine, [N‐(salicylidene)‐sulfamerazine] (LH) and the heterocyclic base 2,2′‐bipyridine (bpy) have been synthesized and characterized by IR, NMR, diffuse reflectance spectra and magnetic, thermal, and molar conductance measurements. The coordination by the azomethine nitrogen is inferred by the downfield shifting of the –CH=N– signal in the NMR spectra and the shift of ν(C=N) to lower frequencies by 15–40 cm–1 in the IR spectra upon complexation. Conductance measurements confirm the non‐electrolytic nature of these complexes. The presence of lattice and coordinated water molecules are indicated by thermograms of the complexes. The general compositions of the complexes were found to be [M(L)(bpy)(OAc)(H2O) {where M = Cu(II), Ni(II), Co(II) or Zn(II) and HOAc = acetic acid} and [Sm(L)(bpy)(OAc)2(H2O)·2H2O and [UO2(L)(bpy)(OAc)(H2O)·H2O.