COMPARISON OF THE INFLUENCE OF SILVER, IRON(III) AND CHROMIUM(III) ON THE AROMATIC SYSTEM OF BENZOIC AND SALICYLIC ACIDS IN HYDRATED AND ANHYDROUS COMPLEXES

Assignments are proposed for the IR absorption and Raman spectra of silver and iron(III) benzoates and salicylates. Investigations were made of the effect of silver, iron(III) and chromium(III) on the aromatic system of benzoic and salicylic acids by means of IR, Raman and absorption (UV-visible) spectrometry. Comparisons were also made with the effects of lanthanides (Ln) and other metal ions. The influence of hydration on the aromatic properties of the complexes was elucidated. Silver destabilizes and iron(III) and chromium (III) stabilize the aromatic ring of benzoic and salicylic acids. The frequencies and intensities of some oscillation bands of the aromatic system depend systematically on the ionic potentials of the metals within the series of isostructural complexes. In anhydrous complexes the effect of metal ions on the aromatic system of salicylic acid is stronger than that of benzoic acid. Hydrated complexes possess stronger aromatic properties than anhydrous complexes. Water molecules weaken the effect of metal ions on the aromatic system of benzoic and salicylic acids.