Single-molecule magnet behavior in heterolopetic Dy3+-chloro-diazabutadiene complexes: influence of the nuclearity and ligand redox state

Abstract

We report the synthesis, structure and magnetic properties investigations of a series of new dysprosium heteroleptic mono- and dinuclear complexes based on the association of chloride and different diazabutadiene (DAD^2R = [2,6-iPr₂C₆H₃N–CRCR–NC₆H₃iPr₂-2,6]; R = H, Me) ligands showing different redox states. While using dianionic DAD^2R ligands affords the formation of dichloro-bridged dinuclear complexes [Dy₂(DAD^2R)(μ-Cl)₂(THF)₂] (R = H (1), Me (2)), two different mononuclear complexes of general formula [DyCl₂(DAD^2R)(THF)₂] (R = H (3), Me (4)) could be obtained with either a radical monoanionic and a monoanionic DAD^2R state, respectively. Remarkably, all the complexes exhibit a slow relaxation of their magnetization where the relaxation dynamics depends on both the nuclearity of the system and the DAD^2R redox state.