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Updated: May 29, 2025
Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Metal-Dilution Effect on Spin Transition Behavior of Solvated/Desolvated Hydrogen-Bonded Cobalt(II)-Organic
Keisuke Yamato1, Takuya Kanetomo1, Masaya Enomoto1
1Department of Chemistry, Faculty of Science Division I, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
Abstract:
Terpyridine-based cobalt(II) complex, [CoII(HL)2] (1; H2L = 2,2':6',2″-terpyridine-5,5″-diyl dicarboxylic acid), forms a hydrogen-bonded diamond framework with solvent absorption and desorption capabilities. The desolvated form (1·desolv) exhibits spin transition (ST) behavior accompanied by thermal hysteresis. To investigate the effect of metal-dilution, an Fe2+ center, which has a low-spin state (S = 0) and coordinates to two terpyridine moieties, was introduced. The resulting complexes, [CoII FeII 1- (HL)2], where x = 0.88 (2), 0.55 (3), and 0 (4), demonstrated a significant influence of metal-dilution on the desolvated forms, but not on the solvated forms. Namely, the spin state is more strongly affected by the presence of solvent than by metal-dilution. However, in the absence of solvent, the Fe2+ ratio significantly impacts the ST behavior.
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