The influence of cage size on the reactivity of trimetallic nitride metallofullerenes: a mono- and bis-methanoadduct of Gd_3N@C_(80) and a monoadduct of Gd_3N@C_(84)

摘要

A reactivity study of the higher TNT EMFs of gadolinium is reported here showing that the reactivity substantially decreases when the fullerene cage gets larger.rnThe trimetallic nitride templated endohedral metallofullerenes (TNT EMFs) have emerged as unique compounds with a wide range of potential applications. Specifically, gadolinium nitride cluster fullerenes have proven to be better contrast agents for magnetic resonance imaging (MRI) than the Gd~(3+)-based complexes currently in commercial use. The functionalization of TNT EMFs is a key requirement in order to take full advantage of these compounds for MRI applications. To date many different reactions have been reported for TNT EMFs of general formula M_3N@C_(80), and these have led to completely characterized monoadducts. In the case of Gd_3N@C_(80) derivatives the characterization has been limited to mass spectrometry and HPLC. Nothing is currently known about the reactivity of TNT EMFs with cages larger than C_(80) due to the scarce amounts of the larger metallofullerenes obtained during the arc synthesis. There is therefore great interest to understand how the reactivity of TNT EMFs is influenced by the size of the cage.