Inorganic–Organic Hybrid Structures: Open-Framework Iron Phosphite–Oxalates of Varying Dimensionality

Inorganic–organic hybrid structures belonging to the family of iron phosphite–oxalates have been prepared by employing hydrothermal methods. Their structures, determined by single-crystal X-ray diffraction, show a hierarchy within the family. While compounds I and II are low dimensional, III–VI have three-dimensional structures. Compound I has edge-shared ladders of iron phosphite with oxalate units hanging from the iron centers. Compound II has a layer structure with a honeycomb-like arrangement. The three- dimensional hybrid structures have the oxalate units connected in both in-plane and out-ofplane modes. A newly identified secondary building unit (SBU-7) and the oxalate units satisfying the valence and coordination requirements in the structure of V are novel and noteworthy structural features. Magnetic studies show that the dominant interactions between the iron centers are antiferromagnetic. Similar to other known hybrid structures, the phosphite–oxalate structures appear to show wide compositional and structural diversity