Microporous Lanthanide Metal-Organic Frameworks Containing Coordinatively Linked Interpenetration: Syntheses, Gas Adsorption Studies, Thermal Stability Analysis, and Photoluminescence Investigation

Under solvothermal conditions, the reactions of trigonal-planar ligand, TATB (4,4',4''-s-triazine-2,4,6-triyl-tribenzoate) with Dy(NO(3))(3), Er(NO(3))(3), Y(NO(3))(3), Yb(NO(3))(3), gave rise to four microporous lanthanide metal-organic frameworks (MOFs), designated as PCN-17 (Dy), PCN-17 (Er), PCN-17 (Y), and PCN-17 (Yb), respectively. The four porous MOFs are isostructural, with their crystal unit parameters shrinking in the order of PCN-17 (Dy), PCN-17 (Y), PCN-17 (Er), and PCN-17 (Yb), which also reflects the lanthanides' contraction trend. All of them adopt the novel square-planar Ln(4)(mu(4)-H(2)O) cluster as the secondary building unit and contain coordinatively linked doubly interpenetrated (8,3)-connected nets. In addition to exhibiting interesting photoluminescence phenomena, the coordinatively linked interpenetration restricts the pore sizes and affords them selective adsorption of H(2) and O(2) over N(2) and CO, as well as renders them with high thermal stability of 500-550 degrees C as demonstrated from TGA profiles.