These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
DyD6h-ChemRxiv .pdf (931.1 kB)
Air-Stable Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets with Nearly Perfect D6h Local Symmetry
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
Local eight-coordination of the Dy(III) with D6h
symmetry receives much expectation for high-performance single-molecule magnets
(SMMs) due to the simultaneous fulfillment of the magnetic axiality and high
coordination number (a requisite for the air stability). But the experimental
realization is challenging due to the required restriction of six coordination
atoms in the equatorial plane of the hexagonal-bipyramid, which is usually too
crowded for the central Dy(III) ion. Here we show by using the hexaaza
macrocyclic Schiff base ligand and fine-tuning the axial
alkoxide/phenol type ligands, a family of hexagonal-bipyramidal Dy(III) complexes, namely [DyIII(L)(Cl)2(H2O/CH3OH)]Cl
1, [DyIII(L)(C6F5O)2(H2O)](BPh4)·2, [DyIII(L)(PhO)2](BPh4)
5 and [DyIII(L)(Ph3SiO)2](BPh4)
be isolated. Among them, complexes
3, 4 and 5 possess nearly perfect D6h
local symmetry. Complex 4
shows the highest effective magnetic reversal barrier 1338 K and an open hysteresis temperature 6 K at the field sweeping
rate of 1.2 mT/s, which represents a new record for D6h SMMs.