Stability constant glycolate

Chaput, Jeminet and Juillard measured the association constants of several simple polyethylene glycols with Na", K", Cs", and Tl". Phase transfer catalytic processes and most biological processes are more likely to involve the first two cations rather than the latter two, so we will confine the discussion to these. Stability constants for the dimethyl ethers of tetra-, penta-, hexa-, and heptaethylene glycols were determined poten-tiometrically in anhydrous methanol solution and are shown in Table 7.1. In the third column of the table, the ratio of binding constants (Ks/K s) is calculated. Note that Simon and his coworkers have referred to this ratio as the selectivity constant. ... 

The enthalpies and entropies of formation of mono-mandelato-complexes have been determined and, in comparison with other hydroxycarboxylic acid complexes, the enthalpy order of stabilization is lactate > a-hydroxyiso-butyrate mandelate > glycolate, whereas the entropy order of stabilization is glycolate > a-hydroxyisobutyrate > mandelate > lactate. The stability constants and enthalpy of formation of mono- and di-malonate complexes have also been measured.The mono-1,1-cyclopentanedicarboxylato-complexes are less stable than the corresponding malonate species. 

The glycolate Cr(C2H303)2-H20,213 salicylate Cr(C6H4(0)C02)-3H20 and tartrate Cr(C02CH0HCH0HC02)3 have been prepared. Stability constants have been determined for complexation of Cr11 with salicylate and 5-sulfosalicylate (Table 39). 

Recently, Grenthe [407] compared the stability constants for the acetate, glycolate and thioglycolate (mercaptoacetate) complexes of Eu3+ and Am3+ (fi — 0.5 at 20° C), and obtained the following log k values... 

Table 28. Stability constants of some rare eartha glycolate complexes [406]...

Absorption spectra in the f-f region are in general not very sensitive to the ligand environment unlike the transition metal ions. In spite of this difficulty, the absorption spectroscopic method has been used in the determination of stability constants of Er(III) acetate [197] and Nd(III) glycol ate complexes [198]. For complexes of low stability, a... 

The interaction of olefins with silver salts in solution has been thoroughly investigated and frequently reviewed (47, 268). Distribution (237, 288, 578, 621) and solubility (40, 77,193, 235, 237) data from aqueous systems, as well as retention data obtained from glycol solutions of AgNOg on gas chromatographic columns (154, 236, 240, 243, 296, 416, 548), have been employed for determination of stability constants for... 

L. Bulgariu, D. Bulgariu, Extraction of metal ions in aqueous polyethylene glycol—inorganic salt two-phase systems in the presence of inorganic extractants correlation between extraction behaviour and stability constants of extracted species, J. Chromatogr. A 1196—1197 (2008) 117. 

Examination of Table 8.9 reveals that aminopolycarboxylic adds complex Am(iii) more strongly than do either hydroxycarboxylic or aminoalkylpolyphos-phoric adds (e.g. ethyIenediaminebis(methyIene)phosphonic add). Keller [3] observes that in the series of a-hydroxycarboxylic adds (e.g. glycolic and lactic) the stability of the ameridum complex decreases with increasing number of carbon atoms. The logarithm of the stability constant of the complexes of Am with aminopolycarboxylic adds increases linearly (Fig. 8.9) with the number of bound donor atoms of the ligand. 

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