Since their initial discovery, fullerenes have been a source of major interest due to their unique structure, reactive properties, and crystallographic challenges. The high rotational symmetry of empty cage leads to disorder in crystal structures, further leading to difficulty in locating atoms and uncertain bond lengths. This is especially troublesome when a higher fullerene has multiple possible cage isomers. A clever solution to the problem can be found using a technique known as cocrystallization – where harnessing the non-covalent interaction between the fullerene and a second molecule (the cocrystallization agent) to reduce the disorder of the fullerene. A unique cocrystal was discovered with an asymmetric unit cell of 12 C70 fullerene molecules, 12 NiII(OEP) molecules, and 18 para-xylene molecules, and its subsequent phase transition as the crystal is warmed from 90 K to 190 K. This cocrystal was also compared to other C70 fullerene and MII(OEP) cocrystals to systematically determine the effects of the cocrystallization agent and solvent arrangement within the crystal. In addition to the crystallographic discoveries made, there are ongoing experiments on using functionalized fullerenes as building blocks for fullerene polymers. Fullerene polymers are highly sought after due to displaying a number of potentially useful functions including catalytic activity and energy storage. However, the formation of polymers containing fullerenes that are structurally well-defined is challenging, due in part to the low-yield functionalization reactions. The other obstacle is finding the right molecular bridge between the fullerenes. This new work aims to use bimetallic coordination complexes as bridges for functionalized fullerenes to create polymer chains.

Fullerene nanostructures: Examining fullerene cocrystals and using bimetallic complexes to create fullerene polymers

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.