Figure 1: Preparation and characterization of dysprosocenium
(2 ): a) synthetic procedure; b) molecular structure; c)
hysteresis loop at 2 K; d) CASSCF-SO energy level
diagram.[14a]
[Dy(Cpttt)2][B(C6F5)4]
was not just the best performing SMM reported at the time; it also
allowed the Chilton Group, newly established in 2016, to theorize that
magnetic relaxation in the high-temperature regime (Orbach) was effected
by specific Cp ring distortions, which opened the door to further design
criteria through the consideration of ligand, and molecular, vibrational
modes.[14a] These criteria were later adopted by
other research groups to achieve dysprosocenium-based SMMs with even
high U eff, T b andT H values.[14b-c]