Synthesis, Structure, Magnetic and Photoluminescent Properties of Lanthanide(III) Complexes with a Ligand Based on 1,10-Phenanthroline and (+)−3-Carene

Ionic complexes of the composition [LnL2(NO3)2]2[Ln(NO3)5]3Me2CO (Ln = Sm (1), Eu (2), Tb (3), Dy (4)) with an optically active ligand L containing 1,10-phenanthroline and (+)−3-carene moieties are synthesized. According to the X-ray crystallographic data, the crystal structure of compound 2 is composed of complex [EuL2(NO3)2]+ cations (N6O4 polyhedron) and complex [Eu(NO3)5]2− anions (O10 polyhedron), and also Me2CO molecules. The L and NO3 ligands perform both tridentate and bidentate chelating functions respectively. Complexes 1–4 are isostructural and crystallize in the non-centrosymmetric space group P1; their magnetic properties are studied in the temperature range 2–300 K. The μeff values for 1–4 at 300 K are 3.14 μB, 6.08 μB, 16.76 μB, and 18.30 μB respectively and are typical of Ln3+ ions. For complex 3 significant anisotropy results in a nonlinear field dependence of the magnetization at 2 K. Complexes 1–4 exhibit metal-centered orange (Sm3+), red (Eu3+), green (Tb3+), and yellow (Dy3+) luminescence in the solid state at room temperature. Luminescence quantum yield decreases for solid samples in the order 2 > 1 > 3 ≈ 4.