Supramolecular open-framework based on 1-D iron phosphate–diphosphate chains assembled through hydrogen bonding

Fe(H2PO4)(H2P2O7)·C5H5N, a new iron(III) phosphate with an open-framework has been synthesized hydrothermally using pyridine as organic template. The crystal structure was solved ab initio using conventional powder X-ray diffraction data. The unit cell is orthorhombic, a=9.5075(2), b=10.1079(1), c=13.3195(2) Å, space group P212121, Z=4. The structure consists of FeO6 octahedra joined by H2PO4 and H2P2O7 groups forming linear chains interconnected by hydrogen bonding to give rise to a supramolecular framework enclosing tunnels in which the pyridine molecules reside.

The low temperature hydrothermal synthesis offers many possibilities in the preparation of new materials with mixed octahedral–tetrahedral open-frameworks. Fe(H2PO4)(H2P2O7)·C5H5N is constituted by linear chains of FeO6 octahedra joined through of both dihydrogenphosphate and dihydrogendiphosphate bridges, interconnected by hydrogen bonds, originating channels where the pyridine molecules are located.Figure optionsDownload as PowerPoint slide