Tuning the Equatorial Crystal-Field in Mononuclear DyIII Complexes to Improve Single-Molecule Magnetic Properties.

Two DyIII complexes, [Dy(bbpen-F)X] [X = Cl (1), Br (2); H2bbpen-F = N,N'-bis(2-hydroxybenzyl)-N,N'-bis(5-fluoro-2-methylpyridyl)ethylenediamine], have been synthesized that show remarkable single-molecule-magnet behavior with effective barriers of magnetic reversal of 837.7 K for 1 and 1149.7 K for 2 under zero direct-current field and hysteresis loops up to 20 K for 1 and 30 K for 2, as confirmed by magnetic properties and ab initio calculations.