Syntheses, Structures and Luminescence Properties of Ln-Coordination Polymers Based on Flexible Thiodiacetic Acid Ligand

Two novel lanthanide complexes with the. formulas [Ln(2)(tda)(3)(H2O)(2)], [Ln=Sm (1), Dy (2), H(2)tda=thiodiacetic acid] have been prepared by using the corresponding lanthanide salt and H(2)tda under hydrothermal conditions. Single crystal X-ray diffraction studies show that the two compounds are isostructural and present a 2D network based on the I D metallic chain, in which an edge-sharing dinuclear polyhedral [Ln(2)O(16)] was found to be the building unit of the I D chains. Interestingly, in the network, the tda ligands exhibit two different coordination modes, including the mode L-a: bis(syn,syn-bridging bidentate, chelating-bridging tridentate), and mode L-b: bis(chelating-bridging tridentate, syn, anti-bridging bidentate). Furthermore, through the tda ligand in modes La and Lb, the I D metallic chains are cross-linked to generate a 2D network structure with (3,4,5,6)-connected (4(7).6(8))(4(4).6(6))(4(5).6)-(4(6))(4(3) ) topology. Photoluminescence measurements indicate that the dysprosium complex is yellow emitters, and the samarium complex shows salmon pink light emission in the solid state at room temperature.