Dysprosium Triangles Showing Single‐Molecule Magnet Behavior of Thermally Excited Spin States

Abstract

Dedicated to Professor Dante Gatteschi on the occasion of his 60th birthdayThe study of paramagnetic metal-ion aggregates has been of increasing interest since the observation that such molecules can exhibit magnetic memory effects. [1][2][3] Termed singlemolecule magnets or SMMs, the important factors leading to such properties derive from the combination of a large ground-state spin and a large magnetic anisotropy of the Ising (easy-axis) type. Studies have largely been based on transition-metal compounds since they typically exhibit both of the aforementioned features. The incorporation of lanthanides into these complexes has been investigated to take advantage of the potentially large number of unpaired f-electrons available. [4][5][6][7] However, very little work has been done to date on purely lanthanide-based systems. [8,9] The origin of SMM behavior in lanthanide-containing compounds is more complicated than that of d-block transition-metal ions since there is likely to be a significant orbital component. In the lanthanide-containing phthalocyanine complexes reported in the literature the ligand environment induces a large splitting of the ground J manifold, whereas in SMMs large-spin ground states arising from magnetic interactions between the metal centers of the cluster can enhance the weaker single-ion

The Origin of Nonmagnetic Kramers Doublets in the Ground State of Dysprosium Triangles: Evidence for a Toroidal Magnetic Moment

“…identical, [19] we can conclude that substitution of the water molecule by a chloride ion on the Dy(3) site does not change the magnetic properties of the Dy 3 unit, therefore below we consider the complex with the Dy(3) unit coordinated by two chloride ions (Figure 1). We performed complete active space self-consistent-field (CASSCF) calculations for each dysprosium fragment of this unit and included the effects of spinorbit coupling by mixing all terms with energies lower than 50 000 cm À1 (see the Supporting Information for computational details).…”

“…[18] Generally, however, the origin of SMM behavior of complexes at the weak exchange limit is difficult to elucidate. [19] [Dy 3 [19] [20] have recently been synthesized and investigated. All these compounds show slow relaxation of magnetization.…”

Construction of Nitronyl Nitroxide‐Based 3d–4f Clusters: Structure and Magnetism

“…Recently, significant efforts have been devoted to construct SMMs by means of 4f ions owing to the strong magnetic anisotropy of 4f ions. [3,4] In this regard, 3d-4f heterometallic compounds are excellent candidates for SMMs because a favorable combination of magnetic couplings between the metal ions and the local magnetic anisotropy carried by lanthanide ions can be achieved within the same molecular entity. [5, 6] Indeed, this promising way has led to the observation of an improved energy barrier for magnetization reversal and blocking temperature [5b, 7] and has encouraged chemists to explore various synthetic strategies to obtain 3d-4f clusters with high-performance SMM behaviors.…”

Direct measurement of dysprosium(III)˙˙˙dysprosium(III) interactions in a single-molecule magnet

“…F ascinating physics has been observed in lanthanide-based molecules ranging from single nuclear spin detection and manipulation 1,2 , blocking of magnetization at unprecedentedly high temperatures for a molecule 3,4 , magnetic memory in chiral systems with a non-magnetic ground state 5,6 and energy barriers for loss of magnetization, U eff , an order of magnitude higher than observed for polymetallic d-block cages 7,8 . A diverse range of applications has been envisioned for lanthanide (Ln) containing molecules, including use as qubits for quantum information processing 9,10 and prototype devices such as molecular spin valves 11 and transistors 1 have been reported.…”