Syntheses, Crystal Structure, Luminescence, Porosity and Magnetic Properties of Three-Dimensional Lanthanide Coordination Polymers with 2-Aminoterepthalic Acid

摘要

Ten isomorphous coordination polymers (CPs) with the formula [Ln_2(ATPA)_3(DEF)_2]_n Ln=Ce (1), Pr(2), Nd (3), Eu (5), Gd (6) and [Ln(ATPA)_(1.5)(DEF)]_n Ln=Sm (4), Tb (7), Dy (8), Ho (9) and Y(10) (H_2ATPA=2-aminoterepthalic acid and DEF=diethyl for- mamide) have been synthesized by the self assembly of Ln(III) ions, 2-aminoterepthalate and DEF under solvothermal con- dition. These polymers have been systematically characterized by single-crystal X-ray diffraction, FTIR, PXRD, thermogravi- metric (TGA) and elemental analyses. Structure analyses of CPs 1–10 reveal that all CPs crystallize in the monoclinic space group C_(2/c) system and form 3D framework with difference in coordination numbers. The CPs 1 & 2 exhibit eight coordina- tion numbers whereas CPs 3–10 show seven coordination number with different geometries. TGA indicate thermal stabil- ity and robustness of the synthesized CPs. The Sm (4), Eu (5), Tb (7) and Dy (8) polymers emit strong ligand sensitized char- acteristic f-f luminescence. Analyses of magnetic susceptibility data of CPs 4, 6, 7 & 8 at variable temperatures and applied magnetic fields reveal weak ferromagnetic interactions at low temperatures.