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 FeCl₃ 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.