Roland Bircher, Brendan F. Abrahams, Hans U. Güdel and Colette Boskovic
Synthesis, structure and magnetic properties of a novel Tb₄ spin cluster and synthesis of a Tb chain
Polyhedron 26, 3023-3028 (2007)                       

Abstract: The syntheses of two new polynuclear Tb^III compounds are reported. A tetranuclear complex [Tb₄(H₂L)₂(H₄L)₂(OAc)₈] (1), with H₄L = 2-((2-hydroxy-benzylidene)-amino)-2-hydroxy-methyl-propane-1,3-diol, has a butterfly-type structure, while [Tb(OAc)₃MeOH]_∞ (2) is a linear chain. A novel binding mode for H₂L^2– is observed in 1, with two alkoxides each bridging three Tb^III ions. The magnetic properties of 1 are determined by the superposition of the ligand field split ⁷F₆ states of Tb^III single-ions located on two crystallographically distinct sites. Weak antiferromagnetic exchange interactions possibly contribute to the lowering of the magnetic moment at the lowest temperatures.

Graphical Abstract: The syntheses of a tetranuclear terbium complex incorporating the ligand 2-((2-hydroxy-benzylidene)-amino)-2-hydroxy-methyl-propane-1,3-diol and of a linear terbium chain are reported. The magnetic properties of the tetranuclear complex were investigated by variable temperature magnetic susceptibility and magnetization measurements.