Chelates du manganese(II) avec des coordinats phenoliques: Partie I. complexes simples binaires

The complex formation of simple binary species of manganese(II) with five phenolic ligands has been studied by a potentiometric method at 25°C and at ionic strength of 1 M NaClO₄. Experiments were carried out in an inert atmosphere to avoid any oxidation to manganese(III), especially in the case of o-diphenolic ligands. New results are reported for some systems and the stability constants of all the species formed are computed. The data show that the Tiron and 3,4-dihydroxybenzoic acid-manganese(II) chelates are among the most stable complexes formed by bidentate ligands with manganese(II).