Potentiometric investigations of some catechol derivatives of scandium

Abstract

The equilibrium reactions of scandium(III) with some triprotic catechol derivatives (H 3 L) were studied. The selected ligands that are 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3.4-dihydroxyhydrocinnamic acid (3,4-DHHCA), and 3,4-dihydroxyphenylacetic acid (3,4-DHPA) were investigated in aqueous solution by means of potentiometry in 0.1 M ionic medium at 25 ° C. The stability constants are reported for the ScL and ScL ( H 2 L ) -mononuclear complexes. 2,3-DHBA can bind to Sc 3+ ion strongly and the salicylate mode (COO -, O -) is effective over the acidic pH range. But in higher pH range, 3,4-DHBA, 3,4-DHHCA, and 3,4-DHPA act more efficiently through catecholate groups (O -, O -).

Chemical speciation of 2,3-dihydroxybenzoic acid complexes with some biologically essential metal ions in 1, 2-propanediol–water mixtures

“…Equilibrium reactions of 2,3-dihydroxybenzoic acid (2,3-DHBA) with Sc(III), La(III) and Y(III) ions in aqueous medium have been investigated by potentiometric and and spectrophotometric methods (Sahoo et al, 2008;Aydin and Özer, 2004;Türkel and Özer, 2005). The aqueous chemistry of 2,3-DHBA complexes with metal ions, such as iron(III), copper(II), nickel(II) and manganese(II) have also been studied (Gerard et al, 1987;Jeżowska-Bojczuk et al 1990;Casale et al, 1992).…”

Stabilities of Scandium(III)- and Yttrium(III)-Tiron Chelates and their hydrolytic behavior

“…Tiron (H 2 L 2-) is a versatile chelating agent, whose coordination ability was investigated by several authors for various techniques [11,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Several authors were interested in the polymerization and hydrolysis of -and Th(IV)-Tiron chelates [14][15][16][17].…”

Potentiometric and Spectroscopic Studies on Yttrium(III) Complexes of Dihydroxybenzoic Acids

“…7) Measurements were made at 25.0Ϯ0.05°C and the ionic strength was maintained at approximately 0.1 M, by the addition of NaClO 4 solution to Y(III) solution, as a background electrolyte. Purified nitrogen was circulated through the jacketed titration cell under slight pressure to exclude carbon dioxide.…”

“…The preferences of Sc(III) and Y(III) towards catechol, salicylic acid and their derivatives were investigated by Özer and coworkers. [5][6][7] Thus, the hydrolytic tendencies of Y(III) ion were decreased by an increase in the number of binding sites of phenolates and or carboxylate donors.…”