Synthesis, structure and magnetic properties of [FeIII4LnIII2] (Ln = Gd, Tb, Dy, Ho) and [FeIII4YIII2] clusters

The use of 2-(hydroxymethyl)pyridine in Fe/Ln (Ln = lanthanide) and Fe/Y reactions has afforded a new family of Fe4Ln(Y)2 clusters with a chair conformation. The central Fe4 rectangle has an S = 0 ground state due to strong Fe⋯Fe interactions (J1 = −20.5 cm−1, J2 = −41.3 cm−1), so at low temperatures the two LnIII ions are magnetically isolated.