Crystal structures and luminescent properties of two novel coordination polymers containing Ln3+ and image

Two novel lanthanide–sulfate coordination polymers with chelidamic acid (H3CAM): {[Ln2(HCAM)2(H2O)2SO4] · 2.5H2O}n (Ln = Dy (1) and Tb (2)) have been synthesized under hydrothermal condition. 1 and 2 crystallize in the monoclinic space group P21/c. An intriguing bowl-like structure was constructed by three Ln3+ ions, one image anion and carboxylate O bridges, in which the pentadente mode of image anion are observed, and the structure as a repeating unit was assembled into a 1D chain. The luminescent properties of 1 and 2 are studied and exhibit the characteristic bands of the corresponding lanthanide ions.