Slow Relaxation of the Magnetization in Bis-Decorated Chiral Helicene-Based Coordination Complexes of Lanthanides

The complexes [Ln2(hfac)6(L)]·nC6H14 (Ln = Dy (1) n = 0, Yb (2) n = 1) with the L chiral 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) have been synthesized in their racemic form and structurally and magnetically characterized. Both complexes behave as field-induced single molecule magnets in the crystalline phase. These magnetic properties were rationalized by ab initio calculations.