Potentiometric and spectroscopic studies with chromium(III) complexes of hydroxysalicylic acid derivatives in aqueous solution

Abstract

The stoichiometries and stability constants of the chromium(III) complexes of hydroxysalicylic acid ligands (2,x-dihydroxy benzoic acids; 2,x-DHBA, x=4-6)(H3L) were determined in aqueous solution by potentiometry and spectroscopy at 25degreesC and at an ionic strength of 0.1 mol L- (KNO3). The existence of Cr(HL)(+) type complex was verified. The stability constants of coordination species that exist in Cr(III):2,x-DHBA systems were defined. In the acidic medium the major coordination species involve salicylate type coordination. The formation of monohydroxo complexes was observed at higher pH values.