Terbium(III) and dysprosium(III) complexes with a tripodal N7 ligand containing three imidazoles (H3L) and a bidentate acetate ion (OAc-), [LnIII(H3L)(OAc)](ClO4)2·MeOH·H2O (Ln = Tb, 1; Ln = Dy, 2), were synthesized and studied, where H3L = tris[2-(((imidazol-4-yl)methylidene)amino)ethyl]amine. The TbIII and DyIII complexes have an isomorphous structure, and each TbIII or DyIII ion is coordinated by the tripodal N7 and the bidentate acetate ligands, resulting in a nonacoordinated capped-square-antiprismatic geometry. The magnetic data, including temperature dependence of the magnetic susceptibilities and field dependence of the magnetization, were analyzed by a spin Hamiltonian, including the crystal field effect on the TbIII ion (4f8, J = 6, S = 3, L = 3, gJ = 3/2, 7F6) and the DyIII ion (4f9, J = 15/2, S = 5/2, L = 5, gJ = 4/3, 6H15/2). The Stark splittings of the ground states 7F6 of the TbIII ion and 6H15/2 of the DyIII ion were evaluated from the magnetic analyses, and the energy diagram patterns indicated an easy axis (Ising type) anisotropy for both complexes, which is more pronounced for 2. The solid-state emission spectra of both complexes displayed sharp bands corresponding to the f-f transitions, and the fine structures assignable to the 5D4 → 7F6 transition for 1 and the 6F9/2 → 6H15/2 transition for 2 were related to the energy diagram patterns from the magnetic analyses. 1 and 2 showed an out-of-phase signal with frequency dependence in alternating current (ac) susceptibility under a dc bias field of 1000 Oe, indicative of a field-induced SIM.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry