Preparation and characterization of iron(III) phosphate-oxalate using 1,2-diaminopropane as the structure-directing agent

Abstract

Iron(III) phosphate-oxalate (FePO-DAP) crystallizes from a clear solution containing 1,2-diaminopropane (DAP) and oxalic acid at 120 degreesC under hydrothermal conditions. Doubly protonated DAP is present inside a large one-dimensional 12-membered channel in a disordered manner, its presence creating different environments for the Fe atoms situated across one another at the sides of the channel. This is evident by Mossbauer spectroscopy: the spectrum at 4.2 K exhibits two sextets with an identical isomer shift of about 0.42 mm/s. FePO-DAP undergoes magnetic ordering at a low temperature (19 K).