When metal clusters meet carbon cages: endohedral clusterfullerenes

Abstract

Fullerenes have the characteristic of a hollow interior, and this unique feature triggers intuitive inspiration to entrap atoms, ions or clusters inside the carbon cage in the form of endohedral fullerenes. In particular, upon entrapping an otherwise unstable metal cluster into a carbon cage, the so-called endohedral clusterfullerenes fulfil the mutual stabilization of the inner metal cluster and the outer fullerene cage with a specific isomeric structure which is often unstable as an empty fullerene. A variety of metal clusters have been reported to form endohedral clusterfullerenes, including metal nitrides, carbides, oxides, sulfides, cyanides and so on, making endohedral clusterfullerenes the most variable and intriguing branch of endohedral fullerenes. In this review article, we present an exhaustive review on all types of endohedral clusterfullerenes reported to date, including their discoveries, syntheses, separations, molecular structures and properties as well as their potential applications in versatile fields such as biomedicine, energy conversion, and so on. At the end, we present an outlook on the prospect of endohedral clusterfullerenes.

Hybrids of Fullerenes and 2D Nanomaterials

“…[94] An experimental report on a hybrid of an endohedral fullerene and graphene has yet to be published. [94] Since a large variety of EMFs with different types of endohedral species transferring different numbers of electrons to the carbon cage have been isolated, [3,95] experimental studies of hybrids of endohedral fullerenes with graphene are eagerly needed and expected to fulfill unique properties that are not accessible by hollow fullerenes. The Sc 3 N@C 80 -graphene noncovalent hybrid model was constructed, for which the simulated graphene nanoflake, composed of 96 C and 24 H atoms (C 96 H 24 ) with symmetric hexagonal units, served as a support for the deposition of fullerenes in the center.…”

Strain Release of Fused Pentagons in Fullerene Cages by Chemical Functionalization

“…In addition to nitrogen and carbon atoms, sulfur atoms have also been encapsulated along with metal atoms into fullerene cages to form metal sulfide clusterfullerenes (SCFs), with Sc 2 S@ C 3 v (8)‐C 82 being the first member . In 2012, Echegoyen and co‐workers synthesized a series of Sc‐based SCFs by introducing SO 2 as a sulfur source, and succeeded in isolating Sc 2 S@C 72 as the first non‐IPR SCF by using multistage HPLC.…”

“…Analogous to CNCFs, the metal cyanide clusterfullerenes (CYCFs) contained an encapsulated [CN] moiety, but this is bonded with only one metal atom . In 2017, Yang and co‐workers reported the first non‐IPR CYCF MNC@C 76 (M=Tb, Y), whereby the cage structure was elucidated by means of single‐crystal X‐ray diffraction to be C 2 v (19138)‐C 76 bearing a pair of DFPs (Figure b) .…”

Freisetzung der Spannung kondensierter Fünfringe des Fullerenkäfigs durch chemische Funktionalisierung

“…Neben dem Stickstoff‐ und Kohlenstoff‐ wurde auch das Schwefelatom zusammen mit Metallatomen im Fullerenkäfig eingeschlossen, um Metallsulfidclusterfullerene (SCFs), mit Sc 2 S@ C 3 v (8)‐C 82 als erstem Vertreter, zu bilden . 2012 synthetisierten Echegoyen und Mitarbeiter eine Reihe von SCFs auf Basis von Scandium durch Einleiten von SO 2 als Schwefelquelle und konnten durch mehrstufige HPLC Sc 2 S@C 72 als erstes Nicht‐IPR‐SCF isolieren.…”