A comparative study of magnetization dynamics in dinuclear dysprosium complexes featuring bridging chloride or trifluoromethanesulfonate ligands

We utilized a rigid ligand platform PyCp (PyCp = [2,6-(CH C H ) C H N] ) to isolate dinuclear Dy complexes [(PyCp )Dy-(μ-O SOCF )] (1) and [(PyCp )Dy-(μ-Cl)] (3) as well as the mononuclear complex (PyCp )Dy(OSO CF )(thf) (2). Compounds 1 and 2 are the first examples of organometallic Dy complexes featuring triflate binding. The isolation of compounds 1 and 3 allows us to comparatively evaluate the effects of the bridging anions on the magnetization dynamics of the dinuclear systems. Our investigations show that although the exchange coupling interactions differ for 1 and 3, the dynamic magnetic properties are dominated by relaxation via the first excited state Kramers doublet of the individual Dy sites. Compounds 1 and 3 exhibit barriers to magnetization reversal (U = 49 cm ) that can be favorably compared to those of the previously reported examples of [Cp Dy(μ-Cl)] (U = 26 cm ) and [Cp Dy(thf)(μ-Cl)] (U = 34 cm ).