Spectrophotometric Determination of Stabilities of 2-Furo-and 2-Furanacrylohydroxamic Acid Chelates of Fe(III): A Comparative Study†

Abstract

2-Furohydroxamic acid [FHA] and 2-furanacrylohydroxamic
acid [FAHA] from blue coloured complexes with Fe(IIl) at pH 2.
The metal-ligand ratios of the complexes are found to be 1 : 3 for
both the systems. Beer's law is obeyed over the range of 0-40 ppm
and 0-110 ppm for Fe-FHA and Fe-FAHA systems respectively.
Yatsimirskii's and Leden's methods are adopted to determine the
step-wise stability constants of both the systems. The results reveal
that an introduction of double bond between functional grouping
increases the molar absorptivity,   λ_max,  step-wise and overall
stability constants of the system. The overall stability constant of
the Fe-FAHA system is approximately ten times greater than that
of Fe-FHA system.