Analyzing the enforcement of a high-spin ground state for a metallacrown single-molecule magnet

Competing Intramolecular Superexchange Interactions in the CuFe4 Metallacrown on Au(111)─An Inelastic Tunneling Spectroscopy Study

“…For a dominant tangential antiferromagnetic superexchange interaction J 2 (Figure b bottom), a low-spin ground state is expected, while a high spin is observed in the case of a pronounced antiferromagnetic exchange interaction J 1 . The latter is the case for CuFe4, as shown by χMT­(T) and XMCD (X-ray magnetic circular dichroism) measurements. , This can be rationalized considering the natural magnetic orbital d x 2 –y 2 of the central Cu­(II) ion which directly point toward the basal O-donor atoms, promoting the central Cu­(II) ion to the role of a magnetic director.…”

“…The latter is the case for CuFe4, as shown by χMT(T) and XMCD (X-ray magnetic circular dichroism) measurements. 21,22 This can be rationalized considering the natural magnetic orbital d xd 2 −yd 2 of the central Cu(II) ion which directly point toward the basal O-donor atoms, promoting the central Cu(II) ion to the role of a magnetic director.…”

The Nature of the Bridging Anion Controls the Single-Molecule Magnetic Properties of DyX4M 12-Metallacrown-4 Complexes

“…Metallacrowns are often thought of as inorganic analogues of crown ethers − and have been especially fruitful in the field of SMMs for their ability to organize metals in a predictable geometry. ,, We have particular interest in working with Mn III -based metallacrowns as high-spin Mn III ions have an S = 2 spin state as well as a magnetoanisotropy vector aligned with the Jahn–Teller axis. Using the ligand salicylhydroximate, we have the ability to isolate selectively Mn III ions in a planar geometry with all of the Mn III ions’ Jahn–Teller distortions aligned in one direction, maximizing the probability of aligning the Mn III ions’ magnetoanisotropy vectors .…”

Synthesis, Structural, and Magnetic Characterization of a Mixed 3d/4f 12-Metallacrown-4 Family of Complexes

“…This family of compounds has been extensively structurally studied but the authors did focus their investigations mainly towards the effect that the Na I or K I ions had on magnetic measurements and not on the pure {Mn 4 III Ln III (µ-NO)4} 11+ magnetic core, without emphasizing on the evaluation of exchange interactions by fitting of the data. Our group has a great interest in the synthesis and magnetic characterization of MCs and so far has dealt with the isolation of homometallic and heterometallic ones based on transition metal ions [29][30][31][32] 4 ]·(ClO 4 )) for 3 in high yields (>59%). The chemical and structural identities of the compounds were confirmed by single-crystal X-ray crystallography, elemental analyses (C, H, N) and IR spectral data (Supplementary Materials).…”