K2Fe(C2O4)(HPO4)(OH2) · H2O: A layered oxalatophosphate hybrid material

One novel layered oxalatophosphate structure K2Fe(C2O4)(HPO4)(OH2) · H2O (1) has been synthesized by hydrothermal method. X-ray crystallography reveals that the complex 1 possesses a 2D layered structure constructed from octahedral FeO6, tetrahedral HPO 4 - moieties and multidentate oxalate ligands with the K+ cations among the layers. It is noteworthy that the oxalate anion as a tetradentate ligand bonds to three iron atoms in bidentate-chelating mode on one side and in monodentate-bridging mode on the other, thus forming a neutral iron oxalate sheet. This new structural feature can be considered as the third role of the oxalate ions in metal oxalatophosphate chemistry.