Structural, magnetic and theoretical analyses of anionic and cationic phthalocyaninato-terbium(iii) double-decker complexes: magnetic relaxation via higher ligand-field sublevels enhanced by oxidation

Abstract

Crystal structural and magnetic analyses were performed for the anionic (1⁻) and cationic (1⁺) forms of phthalocyaninato-Tb³⁺ double-decker single-molecule magnets (SMMs). Both charged species showed slow magnetic relaxations and magnetic hysteresis characteristics for SMMs. 1⁺ showed longer magnetic relaxation times (τ) and higher activation energy for spin reversal (ΔE) than 1⁻ did. Ligand field (LF) splitting calculated using ab initio methods revealed that the experimental ΔE values in 1⁻ and 1⁺ were considerably larger than the first excited LF levels but rather close to the higher excited ones, indicating the magnetic relaxation via higher excited states.