Unveiling new [1+1] Schiff-base macrocycles towards high energy-barrier hexagonal bipyramidal Dy(iii) single-molecule magnets

Abstract

The employment of the [1+1] condensation approach for the preparation of new macrocyclic scaffolds (L^N6 and L^N3O3) towards high-performance Dy(III) single-molecule magnets (SMMs) with pseudo-D_6h symmetry is described. Engineering of the macrocycles denticity from L^N6 to L^N3O3 leads to a mononuclear SMM with a large U_eff value of 1300 K. The experimental results are supported by ab initio calculations, which indicate relaxation of the magnetization via the second-excited state.