An Ni₄ Single‐Molecule Magnet: Synthesis, Structure and Low‐Temperature Magnetic Behavior

Abstract

Abstract The reaction of Ni(NO 3 ) 2 ·6H 2 O with H 3 thme (trihydroxymethylethane) in the presence of NaOMe leads to a tetranuclear Ni 4 complex with a cubane‐like structure. Intramolecular ferromagnetic interactions [ J = 10 cm −1 based on H = − J ( S 1 · S 2 + S 1 · S 3 + S 1 · S 4 + S 2 · S 3 + S 2 · S 4 + S 3 · S 4 )] lead to an S = 4 ground state stabilized by 40 cm −1 from the first S = 3 excited state. Magnetization vs. field studies at different temperatures above 2 K suggest the presence of an axial magnetic anisotropy. Single‐crystal magnetization measurements show a single‐molecule‐magnetic behavior below T = 0.5 K with fast relaxation of the magnetization due to resonant quantum tunneling. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)