Formation constants of chromium(III), scandium(III) and yttrium(III) complexes of some hydroxy naphthoic acids


Aksoy M. S. , Aydin R. , Turkel N., Ozer U.

CHEMICAL & PHARMACEUTICAL BULLETIN, vol.53, no.5, pp.471-475, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 53 Issue: 5
  • Publication Date: 2005
  • Doi Number: 10.1248/cpb.53.471
  • Title of Journal : CHEMICAL & PHARMACEUTICAL BULLETIN
  • Page Numbers: pp.471-475
  • Keywords: chromium scandium, yttrium, naphthoic acid, formation constant, water pollutant, AQUEOUS-SOLUTION, CARBOXYLIC-ACIDS, SALICYLIC-ACID, HYDROXYAROMATIC LIGANDS, DISSOCIATION-CONSTANTS, DERIVATIVES, STABILITIES, COPPER(II), BERYLLIUM(II), EQUILIBRIUM

Abstract

The complexes of chromium(III), scandium(III) and yttrium(Ill) formed by 1-hydroxy-2-naphthoic acid (1,2-HNA: H2L) and 3-hydroxy-2-naphthoic acid (3,2-HNA: H2L) were investigated by potentiometry and spectroscopy at 25 +/- 0.1 degrees C and at an ionic strength of 0.1 m KNO3 in 50% ethanol-water (v/v) medium. The stoichiometries of these three M(III) complexes formed with these hydroxy-naphthoic acids and with hydroxo ion were defined and their formation constants were determined and compared. Thus, the removing capacities of these ligands could be examined by calculating the equilibrium concentration of Cr(III) that exists in the discharge water of various industries since Cr(III) ions are the main pollutants present during waste water treatment in our city, Bursa.