Biomimetic control of iron oxide and hydroxide phases in the iron oxalate system*

Abstract

The syntheses of mineral phases of iron formed under hydrolytic conditions have been studied using ambient and hydrothermal methods in the presence and absence of the oxalate (ox) template. A systematic survey of experimental parameters revealed how the oxolate template can influence crystal morphology, iron oxidation state and the nature of the phase formed. In addition to observing biomimetic control over crystal morphology of magnetite, two iron(II) hydrolytic oxalate phases were observed, humboldtine, Fe^II(ox)(H₂O)₂, and the new phase, Fe^II₂(ox)(OH)₂, which was identified by single-crystal X-ray diffraction.