Syntheses and Solvent Extractive Properties of Three Hydroxamic Acids at Different Levels of Acidity

Abstract

The aim of this research is to study the extractive ability of some hydroxamic acids. Thus monoesters of this acid were synthesised and employed for preparation of the corresponding hydroxamic acid. Three compounds were prepared (succinohydroxamic acid, phthalohydroxamic acid, N-p-aminophenylbenzohydroxamic acid). They were identified by vanadium solution and ferric (III) solution, m.p., infrared, nuclear magnetic resonance and G.C- mass spectra. The extractive properties of these compounds towards the metals: Fe (III), Cu (II), Ni (II), Co (II), Mo (VI), V (V) and Cr (VI) were studied under different pH values. Cr (VI) is determined by spectrophotometric method while the other metals were determined by atomic absorption spectroscopy. The extractability of the synthesized hydroxamic acids, towards the studied metals were as follows:- Succinohydroxamic acid was found to have a maximum extraction for Fe (III) 33.979% at pH 4, Cu(II) 0.64% at pH 3, Ni (II) 12.7% at pH 5, Co (II) 1.2% at pH 9, V (V) 3.7% at pH 2, Mo (VI) 2% at pH 1 and Cr (VI) 73.9 at pH 1. Phthalohydroxamic acid was found to have a maximum extraction for Fe (III) 89.5% at pH 6, Cu (II) 48.0% at pH 6, Ni (II) 24.4% at pH 6, Co (II) 35.5% at pH 9, V (V) 75% at pH 2, Mo (VI) 60.4% at pH 2 and Cr (VI) 84.5% at pH 1. N-p-aminophenylbenzohydroxamic acid was found to have a maximum extraction for Fe (III) 81.7% at pH 6, Cu (II) 73.4% at pH 7, Ni (II) 32.2% at pH 6, Co (II) 47.4% at pH 10, V (V) 18.5% at pH 5 and Cr (VI) 89.4% at pH 1.