A Linear "Head-to-Tail" Chlorido-Bridged Didysprosium Single-Molecule Magnet Exhibiting 100-s Blocking Temperature near 8 K

Although single-molecule magnets (SMMs) have been considered as the smallest entity to store binary information, the ability to retain the magnetization in one direction for more than 100 seconds is still below liquid nitrogen boiling point (77 K). One of the effective ways to enhance the magnetic blocking temperature is to couple the anisotropic magnetic centers in a proper manner. However, this has been only succeeded in the radical-bridged SMMs so far. For non-radical bridges the 100-second blocking temperature is still not seen. Here we report the best non-radical bridged dimeric SMM - {[Dy(OtBu)(4-NH2py)5]2(µ-Cl)}[BPh4]3 1 - with an energy barrier to magnetization reversal of 1302(6) K and 100-second blocking temperature near 8 K. Compared to the similar local C5v symmetric mononuclear complex [Dy(OtBu)Cl(py)5]BPh4 2, the much higher performance of dimeric 1 is attributed to the pseudo-D5h symmetry and "head-to-tail" linked Dy(III) principle magnetic via the collinear Dy‒Cl‒Dy exchange-coupling pathway.