SPECTROPHOTOMETRIC STUDIES OF TERNARY COMPLEXES OF VANADYL, MANGANESE, AND IRON WITH o-PHENANTHROLINE AND EOSIN

ABSTRACT The reaction of Vanadyl(II), Manganese(II) and Iron(III) as metal ion with 1,10-phenanthroline as primary ligand and eosin as secondary ligand was examined spectrophotometrically. The solution spectra of mixed ligand complexes formed are characterized by an absorption band with λmax at 550 nm for VO(II), 560 for Mn(II) and 555 nm for Fe(III) at pH 6.0, 5.2 and 5.6, respectively. These association complexes obey Beer's Law over the concentration range 3.0–12.0, 0.4–2.0 and 0.5–2.0 ppm with molar absorption coefficient of 1.73 × 104, 1.95 × 104 and 2.80 × 104 L mole−1 cm−1, respectively. Stability constants and diverse ion effects on these complexes have also been investigated.