Complexes of Cu(II) with D-aldonic and D-alduronic acids in aqueous solution

Abstract

[Traduit par la redaction]

Kinetics of Sn(II) reduction in acid sulphate solutions containing gluconic acid

“…The dissociation of carboxylic group has been much studied. The protonization constants of gluconate anion (L À ), presented in different references, are in a sufficiently good agreement, though they depend on the ionic strength, temperature and nature of supporting electrolyte [22][23][24][25][26][27][28][29]. Recently the second constant, attributed to the dissociation of OH-group at the 4th carbon atom, has also been estimated [25].…”

Codeposition of copper and tin from acid sulphate solutions containing gluconic acid

“…Formation of complexes CuL + and CuL 2 in acidic solution is commonly reported [2,3], but few in number data concerning their stability constants are rather discrepant. Particularly stable Cu(II)-gluconate complexes are formed in strongly alkaline solutions due to the dissociation of OH À groups in the ligand [1,4].…”

Accumulation mechanisms and subcellular distribution of Cu in maize grown on soil treated with [S, S]-ethylenediamine disuccinic acid

“…This difference can be attributed mainly to the stability constants between Cu and EDDS, glucuronic acid, or galacturonic acid (cell wall components) and to chemical properties of the Cu-EDDS complex. As the stability constant of Cu for EDDS (log K 18.4) (Orama et al 2002) is far greater than that for galacturonic acid (log K 1.8-3.4) (Escanda and Sala 1992;Rosen and Williams 1978) or for glucuronic acid (the stability constant of which is slightly smaller than that of galacturonic acid) (Escanda and Sala 1992), the complex cannot be retained in roots as Cu forms of glucuronic acid or galacturonic acid. Furthermore, because of the negative charge carried by Cu-EDDS 2-, the complex cannot be electrostatically bound to root tissues (Tandy et al 2006b), and most of the complex absorbed by roots is translocated to shoots.…”