Unique Y-shaped lanthanide aggregates and single-molecule magnet behaviour for the Dy4 analogue

Abstract

The assembly of N′-(amino-(pyrimidin-2-yl)methylene)-o-vanilloyl hydrazine ligands (H₂L, Scheme 1) with different lanthanide perchlorates produces novel Y-shaped tetranuclear complexes, [Ln₄(μ₃-OH)(L²⁻)₄(H₂O)₆]·(ClO₄)₃·6H₂O, where Ln = Tb (1), Dy (2) and Ho (3). The formation of this unprecedented Y-shaped topology is largely ascribed to the versatility of the mixed-donor hydrazone ligands in terms of their potential denticity. Analysis of the susceptibility data shows that only the Dy-based molecule features SMM-like behaviour. The synthetic methodology of employing H₂L and related ligands has provided a very promising route towards new families of magnetic coordination clusters with novel metal topologies and properties.