Bis‐Cyclooctatetraenyl Thulium(II): Highly Reducing Lanthanide Sandwich Single‐Molecule Magnets

Abstract

Divalent lanthanide organometallics are well‐known highly reducing compounds usually used for single electron transfer reactivity and small molecule activation. Thus, their very reactive nature prevented for many years the study of their physical properties, such as magnetic studies on a reliable basis. Herein, the access to rare organometallic sandwich compounds of TmII with the cyclooctatetraenyl (Cot) ligand impacts on the use of divalent organolanthanide compounds as an additional strategy for the design of performing Single Molecule Magnets (SMM). The first divalent thulium sandwich complex with f13 configuration behaving as a single‐molecule magnet in absence of DC field is highlighted.

The Archetypal Homoleptic Lanthanide Quadruple‐Decker—Synthesis, Mechanistic Studies, and Quantum Chemical Investigations

“…The trivalent species 2 is subsequently reduced by excess KC 8 to give compound 4 (Scheme 4). A similar reactivity was recently described for the reduction of trivalent [K(thf) 3 Tm(COT) 2 ] [23c] . Likewise, isolated 2 can be reduced by KC 8 to give 4 in an NMR scale reaction.…”

“…Aside from investigations towards the application of complex 4 as novel reducing agent in organic and inorganic transformation, the unprecedented hexa‐decker motif is of great interest in terms of a possible thulium analogue. Especially, considering recent advances in the synthesis of divalent thulium SMMs [23c] …”

Size‐Controlled Hapticity Switching in [Ln(C9H9)(C8H8)] Sandwiches

“…Additionally, because magnetism and luminescent applications often require solid‐state measurements, the understanding of how packing forces influence the inner coordination as well as the exact arrangement of the closest neighbors in the crystal lattice is important. Recent studies led by some of us have underlined the importance of the orientation of the anisotropy axes in a series of binuclear Er(Cot) fragments [11d] as well as the second sphere environment in divalent [Tm(Cot) 2 ] 2− compounds, when designing performing SMMs [11e] …”

“…Recent studies led by some of us have underlined the importance of the orientation of the anisotropy axes in a series of binuclear Er(Cot) fragments [11d] as well as the second sphere environment in divalent [Tm(Cot) 2 ] 2− compounds, when designing performing SMMs. [11e] …”

A Linear "Head-to-Tail" Chlorido-Bridged Didysprosium Single-Molecule Magnet Exhibiting 100-s Blocking Temperature near 8 K

“…One is to create an axial symmetric environment around Dy(III) ions. [19][20][21] Typical examples include the dysprosocenium family [22][23][24] and the pentagonalbipyramidal (PB) family. [25][26][27] Right now, the former system exhibits great success in the combination of magnetic axiality and stiffness of the molecule thanks to the core pentadentate cyclopentadienyl (Cp) ligands.…”