Construction of lanthanide single-molecule magnets with the “magnetic motif” [Dy(MQ)4]−

Abstract

A dinuclear complex (HNEt₃)[Dy₂(MQ)₄(NO₃)₃]·EtOH·H₂O (HMQ = 2-methyl-8-hydroxyquinoline) was prepared and proved to have no observable single-molecule magnet (SMM) behaviour. With increasing NEt₃ in the reaction, two coordinated NO₃⁻ units in the {(NO₃)₃} pocket were replaced by an additional “magnetic motif” [Dy(MQ)₄]⁻. In this way, the unfavourable interactions between the two dysprosiums were diminished and a trinuclear complex [Dy₃(MQ)₈(NO₃)] was obtained, which behaves as an SMM with an efficient energy barrier of 244(21) K for the full temperature range and 150(12) K for the high-temperature region. It is suggested that introduction of a “magnetic motif” is a feasible strategy for modulating the magnetic behaviour of polynuclear systems.