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Tuning single-molecule magnetism in Dy3+ complexes via a tris(aryl)alkoxide ligand
Gautier Félix1, Alexander N Selikhov2,3, Max Kallio4
1ICGM, Univ. Montpellier, CNRS, ENSCM, Montpellier, France. gautier.felix@umontpellier.fr.
None:
We report the synthesis, structures, and magnetic properties of two Dy3+ complexes supported by a tripodal tris(aryl)alkoxide ligand (Me2NCH2-o-C6H4)3CO-. The mononuclear complex [κ3-O,N,N-(Me2NCH2-o-C6H4)3CO]DyCl2(THF) (1) adopts a distorted octahedral geometry, while its reaction with a dipotassium dicarbollide K2[7,8-Me2C2B9H9] affords a heterobimetallic coordination polymer {[K(μ-Cl)Dy(κ3-O,N,N-(Me2NCH2-o-C6H4)3CO)(μ-2,3-Me2C2B9H9)]·0.5THF}n (2·0.5THF) featuring a layered structure. Both compounds exhibit single-molecule magnet (SMM) behavior, with effective barriers of 344 K (240 cm-1) for 1 and 133 K (92.5 cm-1) for 2. Ab initio calculations indicate that 1 relaxes via the third excited Kramers doublet (KD), while 2 likely relaxes through the second KD. The relaxation pathways observed experimentally for 2 do not correspond to the computed KDs, possibly due to experimental limitations at high temperatures or fast relaxation rates undetectable by alternating current susceptibility.
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