Synthesis, Structure, Luminescence, and Magnetic Properties of a Single-Ion Magnet “mer”-[Tris(N-[(imidazol-4-yl)-methylidene]-dl-phenylalaninato)terbium(III) and Related “fac”-dl-Alaninato Derivative

Two TbIII complexes exhibiting different coordination geometries “fac”-[TbIII(HLdl-ala)3]·7H2O and “mer”-[TbIII(HLdl-phe)3]·7H2O were synthesized. Magnetic data were analyzed by a spin Hamiltonian including the crystal field effect on the TbIII ion. The resultant energy patterns indicate easy-axis and -plane anisotropies for “mer” and “fac” complexes, respectively. The “mer” complex showed an onset of out-of-phase alternating current magnetic susceptibility on cooling down to 1.9 K and magnetic hysteresis in the pulsed-field magnetization measurements below 1.6 K, but the “fac” complex did not. Both complexes showed efficient luminescence.