The Johnson research group has developed a high-yielding synthetic strategy for preparing discrete polynuclear inorganic clusters containing 13 Group 13 metals (Al, Ga, In). The Keggin-like structures consist of 7 of the metals in an interior core arranged in a flat hexagonal disc through bridging hydroxo ligands with 6 M(H2O)4 bound to the core by two -OH bridges. Examples of higher nuclearity metal cation clusters of any morphology with mixed metal components are fairly rare, and control of the metal stoichiometry is desirable. Compositions have been made containing 13 Ga ions, 13 Al ions, or a combination of these metals.
These inorganic aggregates are useful either as the discrete cluster or as synthons. Applications range from Ga-67 contrast agents for PET or SPECT medical diagnostic imaging, to synthons for other nanomaterials, to oxide precursors in the fabrication of electronic devices. For more information see Dr. Johnson's web site.