A hybrid open-framework iron phosphate-oxalate with a large unidimensional channel, showing reversible hydration

Abstract

A novel inorganic-organic hybrid iron phosphate-oxalate material has been synthesized hydrothermally in the presence of ethylenediamine as the structure-directing agent. The three-dimensional solid possesses neutral iron phosphate layers built up by strictly alternating FeO₆ octahedra and PO₄ tetrahedra creating large voids of similar to 5 Angstrom free diameter bound by 12 T atoms (T=Fe, P). The oxalate units act as pillars holding the layers apart, and together. The positions of the oxalate units and the amine are such as to give rise to a large one-dimensional channel. The solid orders antiferromagnetically with a Neel temperature of 31 K. The solid undergoes reversible dehydration and shows adsorptive properties.