New Carboxylate Anionic Sm-MOF: Synthesis, Structure and Effect of the Isomorphic Substitution of Sm3+ with Gd3+ and Tb3+ Ions on the Luminescent Properties

Two new compounds, namely {(NMe2H2)}[Ln(TDA)(HCOO)] 0.5H(2)O, Ln = Sm3+ (Sm-TDA) and Gd3+ (Gd-TDA), where TDA(3-) is the anion of 1H-1,2,3-triazole-4,5-dicarboxylic acid (H(3)TDA), were synthesized by the solvothermal method in a DMF:H2O mixture. According to single-crystal X-ray diffraction data, the compounds are 3d-MOFs with an anionic lattice and dimethylammonium cations occupying part of the cavities. Based on these compounds, two series of mixed-metal complexes, [NMe2H2][Sm(x)Ln(1-x)(TDA)(HCOO)], (x = 0.9 (Sm(0.9)Ln(0.1)-TDA), x = 0.8 (Sm-0.8-Ln(0.2)-TDA) horizontal ellipsis Sm(0.02)Ln(0.98)-TDA, Ln = Tb, Gd), were also obtained and characterized by powder XRD. The luminescent properties of the compounds were studied and it was shown that the resulting compounds are two- or three-component emitters with the possibility of fine color tuning by changing the intensities of fluorescence and phosphorescence of the ligand, as well as the luminescence of Sm3+ and Tb3+ f-ions.