Recent Developments in Co^III₂Ln^III₂ Single‐Molecule Magnets

Abstract

In this work we review the Co 2 III Ln 2 III family of compounds reported up to date that shows SMM features. The vast majority of them show a butterfly arrangement with Ln III ions placed at the body positions. The number of Dy III examples constitutes the majority, probably because of the intrinsic properties of this lanthanide ion regarding SMMs characteristics. Butterfly complexes have a SAP geometry around Ln III ions with a variety of distortion degrees. However, when looking at the key U eff parameter trend through this family of complexes, it becomes clear that a pure geometrical consideration is not [a] he started his independent research career in the field of molecular magnetism and coordination chemistry. The main research topic of his group is the synthesis, structural characterization and magnetic properties study of molecular nanomagnets.2067 III Ln 2 III unit. As low-spin Co III is a diamagnetic ion, this type of compounds, from the magnetic point of view, are genuine dinuclear lanthanide compounds. Moreover, the inclusion of the Co III coordination spheres offers more synthetic Eur.

Single Molecule Magnet Features in the Butterfly [CoIII2LnIII2] Pivalate Family with Alcohol‐Amine Ligands

“…structural section), that the degree of axiality of the ground KD is controlled by the ligand field perturbation of the axis running along the opposite two shortest LnÀ O bonds. [30] In fact, the ab-initio computations show that the ground KD g-tensor main axis are exactly running along this axis. (Figure S4).…”

“…These bonds are the ones that involve the O alkoxide donor atom of the alcohol-amine ligand. [30] When comparing 1-Ln family with 2-Ln a clear pattern is observed in Ln(III)-O bond distances: while an elongation of these short LnÀ O bonds that involve the alkoxide O atom of dmea 2À or teaH 2À is observed, a compression of the LnÀ O bonds which involve bridging OH À / À OCH 3 ligands and k 2pivalate ligands occurred (Table S2). This trend is tightly observed for all studied Ln(III) ions and may be related to the smaller size of the hydroxide ligand than the methoxide ligand.…”

“…[18,[21][22][23][24][25][26][27][28][29] The SMM behaviour of this particular family of complexes have been recently reviewed by some of us. [30] In this context, we have previously reported the only example of this type of {Co III 2 Ln III 2 } compounds where several Ln(III) ions has been explored in order to analyse the influence of the Ln(III) over magnetic behaviour. [21] This family comprises the system: [Co III 2 Ln III 2 (OCH 3 ) 2 (teaH) 2 (Piv) 6 ] with Ln = 2-Tb, 2-Dy, 2-Ho, 2-Er and 2-Yb while the Gd compound affords a structurally closely related 1D structure.…”

Cobalt and zinc halide complexes of 4-chloro and 4-methylaniline: Syntheses, structures and magnetic behavior

“…1,2,3 Extensive work has been done 1) Present address: Dept. of Chemistry, University of Virginia, 409 McCormick Road, Charlottesville, VA 22904 USA recently, especially in the study of transition metal and lanthanide complexes, as a result of the discovery of single molecule, 4,5,6,7,8 single chain, 9,10,11 and single ion magnets. 12,13,14,15 Recent publications have demonstrated the breadth of interest in studies of molecular magnetic materials employing a wide variety of transition metal and lanthanoid ions.…”

“…The dotted lines and dashed lines are fits using the 1D chain model and 2D rectangle lattice model, respectively. Considering the hydrogen bonding first, there are differences between the metal chloride compounds (1,2,5,6) and the metal bromide compounds (3,4,7,8) CoCl2, 36 and CdI2. 40a However, when the ML2X2 complex is square planar, the phenyl rings orient themselves on opposite sides of the coordination plane and a different type of chain structure is formed where the halide ions exhibit short contacts to two different adjacent molecules.…”