Session: Undergraduate Research Posters: Inorganic Chemistry:

Metallacrowns (MCs) with a [M-N-O] repeat unit in a ring are the inorganic analogues to crown ethers. Metallacrowns come in various sizes such as 12-MC-4, where 12 refers to the total number of atoms in the ring and 4 refers to the number of oxygen atoms. Two metallacrowns can be linked by bridging organic ligands such as isophthalate to form a dimer or ‘sandwich’. Due to the high density of the metal ions in the molecules, metallacrowns can be highly magnetic or luminescent depending upon the identity of the metal ions in the MC ring and the ions bound to the central cavity. Indeed, MCs have proven to display single-molecule magnet properties when the ring metals are paramagnetic transition metal ions and paramagnetic lanthanide ions are captured in the central cavity. Luminescent MCs have typically been produced when central lanthanide ions are paired with spectroscopically silent ring metal ions such as gallium. A modified bridging ligand was used to allow additional bonding sites for transition metal ions. Transition metals such as cobalt, copper, and nickel were used to increase the MCs magnetic properties when bound to the bridging ligands. Herein we report the results of modified metallacrown dimers with bridging ligands that bind additional metal ions.

Curtis Zaleski

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