Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) complexation with sterically hindered 4,6-di- <i>tert</i>-butyl-2,3-dihydroxybenzaldehyde derivatives
Based on the results of potentiometric titration, the acid and base ionization constants for sterically hindered derivatives of 4,6-di- <i>tert</i>-butyl-2,3-dihydroxybenzaldehyde were calculated. It was found that in water-ethanol solution these compounds form complexes with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) ions, the metal/ligand ratio being 1 : 1 and 1 : 2. Overall and stepwise stability constants of these metal complexes were determined. It was shown that the sequence of variation of values of the constants depending on the metal ion nature for most of the complexes with the same ligands corresponds to the Irving - Williams series, thus making it possible to predict the comparative complex stability when modifying the ligand structures