Trimetasphere carbon nanomaterials (TMS), also known as trimetallic nitride endohedral metallofullerenes, are a family of endohedral metallofullerenes (EMF). The first TMS adduct, a Diels-Alder cycloadduct of Sc3N by C80, was reported by Dorn et al. in 2002. It was not until 2005 that other derivatives were reported[1][2][3]. The most abundant TMS consist of 80 carbon atoms encompassing and forming a complex with three metal atoms and a nitrogen atom (trimetallic nitride clusters, M3N).
Examples of metals forming trimetallic nitride clusters include [4]: