A novel phosphate-based metal-organic framework: Synthesis and comprehensive structural characterization

A novel organic-inorganic metallo-phosphate complex, CoF₂(H₂O)Fe(C₁₀H₈N₂)(HPO₄)₂, obtained through hydrothermal method, was characterized via single-crystal X-ray diffraction, infrared and Raman spectroscopies, and thermogravimetric analysis. UV and photoluminescence spectroscopy were used to determine the optical properties. Structural study revealed a metal-organic framework (MOF), with iron and cobalt octahedra and phosphate tetrahedra, and a (2,2′‒bipyridine) coordinated by Fe octahedron. These moieties form chains, connected via π−π and H bonds. In order to assess the structural stability and interactions between atoms, a crystal contact study was carried out through Hirshfeld surface analysis and 2D fingerprint diagrams, to investigate the tendency of intermolecular interactions to form crystal packing by using enrichment ratio. To better examine the structure, theoretical studies were carried out using density functional theory, followed by a detailed examination of atoms in molecules using the bond critical point approach. The material revealed clear fluorescence after excitation at 285 nm, with intense emission in the violet.