Dynamic Magnetic and Optical Insight into a High Performance Pentagonal Bipyramidal Dy Single-Ion Magnet.

The pentagonal bipyramidal single-ion magnets (SIMs) are among the most attractive prototypes of high-performance single-molecule magnets (SMMs). Here, a fluorescence-active phosphine oxide ligand CyPh PO (=cyclohexyl(diphenyl)phosphine oxide) was introduced into [Dy(CyPh PO) (H O) ]Br ⋅2 (CyPh PO)⋅EtOH⋅3 H O, and combined dynamic magnetic measurement, optical characterization, ab initio calculation, and magneto-optical correlation of this high-performance pseudo-D Dy SIM with large U (508(2) K) and high magnetic hysteresis temperature (19 K) were performed. This work provides a deeper insight into the rational design of promising molecular magnets.