title: Crystal field splitting of the ground state of terbium(III) and dysprosium(III) complexes with a triimidazolyl tripod ligand and an acetate determined by magnetic analysis and luminescence.
abstract: Terbium(III) and dysprosium(III) complexes with a tripodal N7 ligand containing three imidazoles (H3L) and a bidentate acetate ion (OAc(-)), [Ln(III)(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 Tb(III) and Dy(III) complexes have an isomorphous structure, and each Tb(III) or Dy(III) 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 Tb(III) ion (4f(8), J = 6, S = 3, L = 3, g(J) = 3/2, (7)F6) and the Dy(III) ion (4f(9), J = 15/2, S = 5/2, L = 5, g(J) = 4/3, (6)H(15/2)). The Stark splittings of the ground states (7)F6 of the Tb(III) ion and (6)H(15/2) of the Dy(III) 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 (5)D4 → (7)F6 transition for 1 and the (6)F(9/2) → (6)H(15/2) 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.
authors.affiliation: Department of Chemistry, Faculty of Science, Kumamoto University , Kumamoto 860-8555, Japan.
authors.forename: Seira
authors.initials: S
authors.lastname: Shintoyo
authors.forename: Keishiro
authors.initials: K
authors.lastname: Murakami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujinami
authors.forename: Naohide
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Naotaka
authors.initials: N
authors.lastname: Mochida
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ishida
authors.forename: Yukinari
authors.initials: Y
authors.lastname: Sunatsuki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Masanobu
authors.initials: M
authors.lastname: Tsuchimoto
authors.forename: Jerzy
authors.initials: J
authors.lastname: Mrozinski
authors.forename: Cecilia
authors.initials: C
authors.lastname: Coletti
authors.forename: Nazzareno
authors.initials: N
authors.lastname: Re
mesh_terms: D000085:Acetates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004419:Dysprosium / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence; D060328:Magnetic Phenomena; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D013725:Terbium / Q000737:chemistry*
chemical_list: D000085:Acetates; D007093:Imidazoles; D008024:Ligands; D009942:Organometallic Compounds; D013725:Terbium; D004419:Dysprosium