Solvent Effects of the Electronic Absorption Spectrum of Ferroin Molecule

Abstract

In order to explore the role of the solvents on one of the best
indicators, 1: 10-phenanthroline ferrous sulphate, i.e., ferroin,
through ultraviolet spectroscopy, λ_max, ε_max and oscillator strength
have been determined at room temperature. The present results
together with values obtained from the experiments in water,
methanol, acetone and orthophosphoric acid have been discussed
in terms of ion-solvent interactions and solvent polarity. The intense
long wavelength band which appears at about 510 nm in the visible
region is referred to as the ¹A  → ¹A₁ or V ← N band. It is
expected that the interaction affects the symmetry of the bidentate
ligand with Fe²⁺ ion in the molecule to some extent depending on
its nature.