Open-Cage Fullerene as a Macrocyclic Ligand for Na, Pt, and Rh Metal Complexes

An open-cage [60]fullerene derivative was prepared throughMalapradeoxidation of a vicinal triol moiety as the key step. Above the 17-memberedorifice, there is one carboxyl group. Three ketone carbonyl groupsand one lactone carbonyl group are located on the rim of the orifice.The carboxylic and carbonyl oxygen atoms around the orifice act asstrong polydentate ligands for a sodium ion. These oxygen atoms alsoreact with [Rh(CO)(2)Cl](2) to form various isomericrhodium complexes with comparable stability. The fullerene C Cbond on the rim of the orifice forms a stable platinum complex whentreated with Pt(PPh3)(4). Single crystal X-raydiffraction data reveal that one of the carboxylic oxygen atoms abovethe orifice forms a H-bond with the water molecule trapped in thecage.

Automated summary

An open-cage fullerene derivative was prepared by Malaprade oxidation of a vicinal triol moiety. The orifice above the 17-membered ring contains a carboxyl group, and there are three ketone carbonyl groups and one lactone carbonyl group on the rim of the orifice. The carboxylic and carbonyl oxygen atoms around the orifice act as strong polydentate ligands for a sodium ion and also form various isomeric rhodium complexes with comparable stability when reacted with [Rh(CO)(2)Cl](2). The fullerene C=C bond on the rim of the orifice forms a stable platinum complex when treated with Pt(PPh3)(4), and one of the carboxylic oxygen atoms above the orifice forms a H-bond with the water molecule trapped in the cage as revealed by the single crystal X-ray diffraction data.