Second structural directing agent induces the formation of 1D organic templated terbium sulfate

Two organic amine templated 1D terbium sulfates (H₃O) ₂(C₂H₈N)[Tb(SO₄)₃] 1 and 3D (C₂H₈N)₉[Tb₅(SO₄) ₁₂]·2H₂O 2 have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 1D anionic chain structure compensated by protonated dimethylamine and water cations occluded in the helical [Tb-O-S]_n chains, while the 3D inorganic framework of 2 contains extra-large 20-membered ring channels. The synthesis of both compounds demonstrates that a large organic amine (1,3,5-triazine-2,4,6-triamine) may be used as the second structural directing agent (SDA) to prevent the formation of a high dimensional inorganic framework as well as inducing crystal growth of 1D structural terbium sulfate chain of 1. Because of the excellent luminescent properties of Tb³⁺, compounds 1 and 2 were investigated. The very strong luminescence in the green light region indicates 1D compound 1 is an excellent candidate for green fluorescent materials.