Chiral Homodinuclear Dysprosium Macrocyclic Complexes with Single-Molecule Magnetic Behaviours

A pair of enantiomerically chiral dysprosium homodinuclear complexes: [(acac)4Dy2(R,R,R,R-L)] (R-Dy) and [(acac)4Dy2(S,S,S,S-L)] (S-Dy) (Hacac=acetylacetone) have been synthesized based on macrocyclic chiral ligands (R,R,R,R-H2L or S,S,S,S-H2L), derived from the [2+2] template condensation of 4-tert-butyl-2,6-diformylphenol, dysprosium acetylacetonate and (1R,2R)-/(1S,2S)-1,2-cyclohexanediamine, respectively. Circular dichroism spectra confirms their enantiomeric chirality. Single-crystal structures show two crystallographic independent dysprosium(III) ions have square antiprismatic coordination with different D4d local symmetry. Furthermore, the selected R-Dy complex owns the slow magnetic relaxation behaviour with the ferromagnetic Dy3+& sdot;& sdot;& sdot;Dy3+ coupling. image