Syntheses, structures, near-infrared, and visible luminescence of lanthanide-organic frameworks with flexible macrocyclic polyamine ligands

A series of lanthanide-based MOFs with flexible macrocyclic polyamine ligands, formulated as [Ln(H(2)TETA)]NO(3)center dot 2H(2)O (Ln = Nd (1), Eu (2), Tb (3), Dy (4), Y (5); H(4)TETA = 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid) have been successfully synthesized and characterized. They possess the same 3D architectures and crystallize in triclinic space group P (1) over bar. Their structures are built up from the paddle-wheel SBUs, which lead to 1D inorganic chains and further 3D framework with 13.26 x 10.94 angstrom(2) rhombic channels. The macrocyclic ligand displays special coordination pattern and protonation scheme. Complexes 1-3 exhibit strong fluorescent emissions in the visible and near-infrared region at room temperature. Formation of paddle-wheel structure plays crucial role in realizing efficient fluorescent emissions of complexes 1-3.