Unprecedented magnetic relaxation via the fourth excited state in low-coordinate lanthanide single-ion magnets: a theoretical perspective

Four low-coordinate SIMs have been studied to probe their relaxation dynamics using ab initio calculations. Our calculations reveal that both the symmetry and the equatorial ligand field play a key role in controlling the barrier heights in three-coordinate [Ln(III)(NSiMe3)3] complexes (Ln = Dy/Er). This study reveals an unprecedented blockade of magnetization up to three excited states for the Er(III) complex.