Single-Ion Magnet and Photoluminescence Properties of Lanthanide(III) Coordination Polymers Based on Pyrimidine-4,6-Dicarboxylate

Herein, we report the magnetic and photoluminescence characterization of coordination polymers (CP) built from combination lanthanide(III) ions, pyrimidine-4,6-dicarboxylate (pmdc) ligand a co-ligand with formula {[Dy(μ-pmdc)(μ-ox)0.5(H2O)3]·2H2O}n (1-Dy), {[Dy(μ3-pmdc)(μ-ox)0.5(H2O)2] ~2.33H2O}n (2-Dy), {[Dy2(μ3-pmdc)(μ4-pmdc)(μ-ox)(H2O)3]·5H2O}n (3-Dy), {[Ln(μ3-pmdc)(μ-ox)0.5(H2O)2]·H2O}n (where Ln(III) = Nd (4-Nd), Sm (4-Sm), Eu (4-Eu) Dy (4-Dy)) {[Dy(μ4-pmdc)(NO3)(H2O)]·H2O}n (5-Dy). It must be noted presence oxalate anion acting as ditopic in compounds 1-Dy, 2-Dy, 3-Dy 4-Ln, whereas 5-Dy nitrate plays role terminal co-ligand. Direct current measurements carried out for dysprosium-based CPs reveal almost negligible interactions between Dy3+ ions within crystal structure, which is confirmed by computed values exchange parameters J. In addition, alternating show field-induced single-molecule magnet (SMM) behavior 4-Dy 5-Dy, slight-frequency dependence also observed 3-Dy. Solid state emission spectra performed at room temperature those emitting visible region confirm occurrence significant ligand-to-lanthanide charge transfer view strong characteristic emissions all lanthanide ions. Emission decay curves were recorded to estimate lifetimes reported compounds, addition absolute quantum yields. Among them, high yield 25.0% measured 4-Eu highlighted representative example good emissive properties materials.