Model compounds for microbial iron-transport compounds. Part 3. Solution chemistry and Mössbauer study of iron(II) and iron(III) complexes from 2,3-dihydroxypyridine and 2-mercapto-3-pyridinol

Abstract

The iron complexes found in solutions containing FeCl 3 and 2,3-dihydroxypyridine and 2-mercapto-3-pyridinol have been studied by pH and conductance titrations together with Mössbauer spectroscopy. Some of these complexes are identified as Fe II species not unlike Fe II catechol and Fe II enterobactin complexes. Black precipitates formed in these systems give evidence for the presence of radicals and such radicals are offered as an explanation for the presence of Fe II. It is proposed, in view of the findings of this paper that 2,3-dihydroxypyridine and 2-mercapto-3-pyridinol are unsuitable as analytical agents for iron analysis.