Pyrene Tetraphosphonate‐Based Metal‐Organic Framework: Structure and Photoluminescence

The synthesis of pyrene‐1,3,6,8‐tetrayltetrakis(phosphonic acid) (H8ptp) and its use in the preparation of a new isotypical family of Metal‐Organic Frameworks (MOF) using oxalic acid as secondary linker are reported. This new family, generally formulated as [Ln2(H4ptp)(ox)(H2O)6]·5H2O [where Ln3+ = Ce3+ (1Ce), Pr3+ (1Pr), Nd3+ (1Nd), Sm3+ (1Sm), Eu3+ (1Eu), Gd3+ (1Gd), Tb3+ (1Tb) and Dy3+ (1Dy)], were prepared under hydrothermal conditions and fully characterized using different techniques. The photoluminescence properties of 1Eu were studied, showing emission lifetimes of 0.27 ± 0.01 ms and 0.33 ± 0.01 ms at 294 K and 12 K, respectively. This family of materials, based on a fully hydrolysed tetraphosphonate pyrene ligand, constitutes the first example of MOFs obtained using this highly fluorescent organic ligand. A tetraphosphonic acid organic linker based on a pyrene core was used as the main ligand to design and prepare via hydrothermal synthesis a series of isotypical metal‐organic frameworks (MOFs). Oxalic acid was used as a secondary linker. The Eu3+‐based material showed photoluminescence in the visible region, both at ambient and low temperatures.