Coupling Strategies to Enhance Single-Molecule Magnet Properties of Erbium−Cyclooctatetraenyl Complexes

ABSTRACT: Two different coupling strategies were employed to create ErIII single-molecule magnets (SMMs) using high blocking temperature mononuclear precursors. The magnetic properties of three lanthanide−COT complexes, [ErIII2(COT′′)3] (1) (COT′ ′ = 1,4-bis(trimethylsilyl)cyclooctatetraenyl dianion) and K2(THF)4[Ln III 2(COT)4] (Ln = Gd (2), Er (3); THF = tetrahydrofuran, COT = cyclooctatetraenyl dianion), are reported. Both ErIII complexes behave as SMMs and exhibit magnetic hysteresis at 12 K in solid state. In solution compound 1 exhibits hysteresis up to 14 K. Ac susceptibility data indicates a 100 s blocking temperature of 12.5 and 12.9 K for [ErIII2(COT′′)3] an