Calixarenes are versatile ligands, capable of supporting the formation of a wide variety of polymetallic clusters comprising 3d, 4f or 3d–4f metal ions. Calixarene-based metal ion fragments act as both bridging and structure capping moieties in these systems, and this behaviour is systematically extended upon moving to bis-calixarene, a relatively new ligand in which two calixarenes are tethered at the methylene bridge position. N,O-Ligands greatly influence cluster formation with bis-calixarene, affording a remarkable mixed-valence [MnIV2MnIII10MnII8] cluster that displays coordination chemistry typical of each ligand type, but also new structure capping behaviour for the latter.
Coletta, M., Sanz, S., McCormick, L. J., Teat, S. J., Brechin, E. K., & Dalgarno, S. J. (2017). The remarkable influence of N,O-ligands in the assembly of a bis-calixarene-supported [MnIV2MnIII10MnII8] cluster. Dalton Transactions, 46(48), 16807-16811. https://doi.org/10.1039/C7DT04233G