Slow Magnetization Relaxation in a Family of Triangular {Co<sup>III</sup><sub>2</sub>Ln<sup>III</sup>} Clusters: The Effect of Diamagnetic Co<sup>III</sup> Ions on the Ln<sup>III</sup> Magnetic Dynamics
Alexandros S. Armenis, Vikram Vipanchi, Konstantinos N. Pantelis, Luı́s Cunha-Silva, Kuduva R. Vignesh, Dimitris I. Alexandropoulos, Theocharis C. Stamatatos
Abstract
Abstract The first use of the Schiff base chelate N ‐naphthalidene‐ o ‐aminophenol (naphH 2 ) in Co/Ln chemistry has afforded a family of isostructural [Co III 2 Ln III (OMe) 2 (naph) 2 (O 2 CMe) 3 (MeOH) 2 ] (Ln=Tb, Dy and Er) complexes, revealing a rare {Co III 2 Ln(μ 3 ‐OMe)} 8+ triangular core composed of two diamagnetic Co III ions and a 4f‐ion with slightly distorted square antiprismatic geometry. Alternating current ( ac ) magnetic susceptibility studies revealed that {Co 2 Dy}, and its magnetic diluted analogue {Co 2 Dy 0.05 Y 0.95 }, behave as mononuclear single‐molecule magnets (SMMs) with similar energy barriers for the magnetization reversal, U eff , of ~85‐90 K. SMM properties were also detected for {Co 2 Er}, with the compound exhibiting a U eff of 18.7 K under an applied magnetic field of 800 Oe. To interpret the experimental magnetic results, ab initio CASSCF/RASSI‐SO and DFT calculations were performed as a means of exploring the single‐ion characteristics of Ln III ions and comprehend the role of the diamagnetic Co III ions in the magnetization relaxation of the three heterometallic compounds.