A Brucite-Like Mixed-Valent Cluster Capped by [MnIIIp-tBu-calix[4]arene]− Moieties

Abstract

p-tBu-calix[4]arene (H4TBC[4]) has proven to be an incredibly versatile ligand for the synthesis of 3d- and 3d/4f- clusters, in particular those containing mixed-valent Mn ions. These are of interest to the magnetochemist for the diversity of magnetic behaviours that can be shown, along with a huge variety of nuclearities and topologies accessible, which allow one to outline magneto-structural correlations and a quantitative understanding of their properties. This contribution reports the synthesis, analysis and magnetic properties of a Brucite-like Mn-oxo/hydroxo octanuclear fragment encapsulated within/capped by four [MnIII-TBC[4]]− moieties. A diol coligand in the reaction mixture plays a seemingly important role in determining the outcome, though it is not incorporated in the final structure.

Supramolecular Chemistry in the 3rd Millennium

“…Supramolecular interactions are critical to selective binding within receptor molecules and host-guest chemistry, and several papers illustrate these principles using hydroquinonebased anion receptors (Gale and coworkers) [3], cucurbit [7]uril (Redshaw and coworkers) [4] and self-assembled n-alkyl-benzoureido-15-crown-5-ethers as selective ion-channels for K + cations (Barboiu and coworkers) [5]. Dalgarno and coworkers contribute with a fascinating investigation of cage assembly using p-t Bu-calix [4]arene building blocks [6]. Catalysis carried out within the confines of molecular or supramolecular cages is a topical area, and Ward and his coauthors describe a beautiful example exploiting a cubic M 8 L 12 coordination cage [7].…”