Tuning the Equatorial Negative Charge in Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets to Improve the Magnetic Behavior.

Taking advantage of the pentaethylene glycol (EO5) and deprotonation of EO5, a family of new structurally hexagonal bipyramidal Dy(III) complexes, [Dy(EO5)(2,6-dichloro-4-nitro-PhO)](2,6-dichloro-4-nitro-PhO) (), [Dy(EO5-BPh)(2,6-dichloro-4-nitro-PhO)] (), and [Dy(EO5-BPh)(2,6-dichloro-4-nitro-PhO)Cl] (), were controbllably synthesized and structurally characterized. Magnetic measurements show that complex is a zero-field SIM and has an observable hysteresis opening up to 4 K. Conversely, only under extra magnetic field is slow magnetic relaxation observed in and .