A New Family of Nonanuclear Lanthanide Clusters Displaying Magnetic and Optical Properties

Abstract

The initial employment of 2-(hydroxymethyl)pyridine in 4f metal chemistry has afforded a new family of Ln(III)(9) clusters with a sandglass-like topology and dual physical properties; the Dy(III) member shows single-molecule magnetism behavior, while the Eu(III) analogue exhibits intense red photoluminescence.

Rare‐Earth Metal Oxo/Hydroxo Clusters – Synthesis, Structures, and Applications

“…The resulting nonanuclear cluster compounds are stabilized by oxo-or hydroxo groups in the inner coordination sphere and by various ligands in the outer coordination sphere (Figure 2). Examples with alkoxides, [39] -diketonates, [7,52,57,58] and pyridine derivatives [59] are known in the literature. Hydrogen atoms are omitted for clarity.…”

Twists to the Spin Structure of the Ln9-diabolo Motif Exemplified in Two {Zn2Ln2}[Ln9]{Zn2} Coordination Clusters

“…This nonanuclear motif is often referred to as "diabolo" shaped and has been identified in several compounds. 14,16,[30][31][32][33] The diabolo description derives from the similarity to the topology of a double spinning top which a player performs tricks with using a twohandled rope. In the compound we describe here, the hands and rope are provided by the "handlebar unit", corresponding to Zn2 and Ln6 and their symmetry equivalents, respectively, the diabolo is provided by the Ln9 core, where Ln2, Ln3, Ln4 and Ln5 (and their symmetry related counterparts) form two square planes arranged as a square antiprism with Ln1 in the middle.…”

“…This is in contrast to other "diabolo" shaped Gd9 or Dy9 cores reported in the literature, which are found to be antiferromagnetically coupled. 14,16,32,41 We believe this is the result of the presence of the tetranuclear [ZnLn2Zn(HL2)2(µ2-MeO)3Cl2(MeOH)2] 3+ "handlebar" unit ( Figure 3), containing a dimeric triplyoxygen bridged Ln III motif and the chiral HL2 ligand, with the C2 axis lying between the two lanthanide metal centers. The field dependence of the magnetization (see Figure 5) was measured between 2.0 to 5.0 K. For Although a frequency-dependent signal is observed without the application of an external field at 1.8 K (Figure 6), the maximum in the out-of-phase signal is not within the measurable frequency range.…”

“…This motif can be envisaged as the vertex sharing fusion of two square-based pyramid units and for both motifs and the spin structures have always proved to be often intriguing although also ambiguous. 12,[14][15][16][17][18] So far no one has succeeded in combining the diabolo motif into a 3d/4f system. We have previously demonstrated that it is possible to combine Zn II and 4f ions using the ligand H2L1 (Scheme 1, left) to give a series of "butterfly" Zn II 2Ln III 2 CCs showing excellent catalytic efficiency.…”

Field‐Induced SMM and Visible/NIR‐Luminescence Behaviour of Dinuclear LnIII Complexes with 2‐Fluorobenzoate

“…Multifunctional molecular materials can be defined as compounds that involve coexistence, interplay or synergy between multiple physical properties , . Restricting the discussion to the combination of luminescence and single‐molecule magnet (SMM) properties, the Ln III coordination compounds are ideal candidates for the construction of this kind of hybrid molecular material . On the one hand, the 4f–4f electronic transitions (responsible for the light emission) are narrow and characteristic for each Ln III , and the emitting excited states are long‐lived.…”