A molecular [Mn₁₄] coordination cluster featuring two slowly relaxing nanomagnets

Abstract

An extended polypyrazolyl ligand has been used to assemble Mn ions into high spin entities, in the form of one stable molecule composed of two well defined clusters. The slow relaxation of the magnetisation observed is demonstrated to arise from each "half-SMM" composing this molecular cluster pair.

Linear or Cyclic Clusters of Cu(II) with a Hierarchical Relationship

“…22 However, its structure shows some flexibility, which allows for the observation of a variety of cluster topologies, compatible with maintaining certain structural motifs. 23,24 We show now that, when fully deprotonated, H 4 L has a tendency to form a remarkable cyclic [Cu 16 L 8 ] cluster that can be reproducibly isolated and fully characterized. Interestingly, small variations in reaction conditions have allowed the crystallographic characterization of its building blocks, as well as one closely related product, [Cu 11 L 5 (OH) 2 (py) 12 ].…”

Supramolecular aggregates of single-molecule magnets: exchange-biased quantum tunneling of magnetization in a rectangular [Mn3]4 tetramer

“…Only a few of these exhibit SMM behavior and none display exchanged-biased QTM steps in hysteresis loops, probably due to the SMM subunits interacting too strongly causing the oligomer to behave magnetically like a single molecule, 54 or individual SMM subunits having low lying excited states that interfere with the quantum tunneling process, resulting in stepless hysteresis loops even when the interactions between the subunits are weak. 60 …”

Influence of Tuned Linker Functionality on Modulation of Magnetic Properties and Relaxation Dynamics in a Family of Six Isotypic Ln2(Ln = Dy and Gd) Complexes

“…The breakthrough revelation of single-molecule magnet (SMM) feature in Mn 12 acetate complex − proved to be a giant quantum leap, since it triggered a rapid development behind exploring the different intriguing facets of magnetic properties for nanoscale magnetic coordination complex or cluster-based materials of varied nuclearity, over the span of last two decades. − SMMs are molecular species typically possessing the unmatched combination of high-spin ( S ) and uniaxial Ising-like magnetic anisotropy ( D ), leading to an anisotropy energy barrier ( U ) for the concomitant reversal of magnetization vector S 2 | D |. − Majority of these efforts had been primarily aimed at the development of novel molecular magnets for miniaturizing devices in the nanoregime, involving the exciting facets of high-density information storage, quantum computing, and molecule spintronics. − Barring the initial focus that seemingly converged on polynuclear 3d metal aggregates, particularly large manganese clusters, − the following years until now have witnessed stupendous enthusiasm toward the development of mixed 3d–4f complexes as well as 4f-based lanthanide clusters. ,,− Particularly, the attainment of maximum relaxation energy barrier and the highest blocking temperature for Ln­(III)-based multinuclear clusters deserves special attention. ,− The crucial, rather imperative involvement of L...…”