Synthesis and Magnetic Properties of a Metallacryptate that Behaves as a Single-Molecule Magnet

✍ Scribed by Catherine Dendrinou-Samara; Maria Alexiou; Curtis M. Zaleski; Jeff W. Kampf; Martin L. Kirk; Dimitris P. Kessissoglou; Vincent L. Pecoraro

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 208 KB
• Volume: 42
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.200351246

✦ Synopsis

Metallamacrocyles have been intensively studied over the past decade. These molecules have already been used in applications as diverse as catalysis, [1] sensors, [2] or as chiral building blocks for two-and three-dimensional solids. [3] Metallamacrocyles include complexes such as metallacrowns, [3, 4] molecular squares, [1,2] metallacalixarenes, [5] and metallahelicates. [6] Metallacrowns (MC), the inorganic structural and functional analogs to crown ethers, are usually formed with transition-metal ions incorporated into the metallamacrocyclic ring, thus providing the attractive feature that they concentrate a large number of metal ions per unit volume. This large metal-ion concentration may lead to interesting magnetic behavior. [4,7] Since the recognition of single-molecule magnets (SMMs) in 1993, the field has gained considerable attention as a study of both classical and quantum effects. [8,9] SMMs of cobalt, [10] vanadium, [11] nickel, [12] iron, [13] and a mixed-metal system [14] have been studied. However, the best known and most intensely studied SMMs are the manganese carboxlyate clusters, which range in size from Mn 4 to Mn 30 . [15] Herein we report the synthesis (Scheme 1) and characterization of the second [16] known Mn 26 complex [Mn II 4 Mn III 22 (pdol) 12 (m 3 -CH 3 O) 12 (m 3 -O) 10 (m 4 -O) 6 (N 3 ) 6 ] (1; pdol 2À = dipyridylketone-[