Chemische, elektrochemische und Struktureigenschaften von endohedralen Metallofullerenen

Abstract

Seit dem ersten Fund von endohedralen Metallofullerenen (EMFs) hat sich die Suche nach Kohlenstoffkäfigen mit eingeschlossenen Metallen oder kleinen Molekülen rasch zu einem sehr aktiven Forschungsgebiet entwickelt. EMFs weisen besondere elektronische und Struktureigenschaften auf und finden vielfache Anwendungsmöglichkeiten. Noch mehr Potenzial bieten funktionalisierte EMFs, die besser löslich sind und durch Röntgenkristallographie und andere Techniken leicht charakterisiert werden können. Wir geben hier eine Übersicht über das allgemeine Gebiet der EMFs und insbesondere der funktionalisierten EMFs. Wir befassen uns in diesem Aufsatz mit der Struktur und den (elektrochemischen) Eigenschaften dieser faszinierenden Verbindungen und werden auch auf Anwendungen eingehen.

Urea as a New and Cheap Nitrogen Source for the Synthesis of Metal Nitride Clusterfullerenes: The Role of Decomposed Products on the Selectivity of Fullerenes

“…This indicates the high selectivity of Sc-based NCFs under these conditions. This behavior is actually similar to the cases with either gaseous NH 3 (the reactive gas atmosphere route [1,3,5] ) or guanidinium thiocyanate (the selective organic solid route [25] ) as the nitrogen source (see Figure 5 and Figure S2 in the Supporting Information). Therefore, it is reasonable to conclude that NH 3 generated in situ from the decomposition of COA C H T U N G T R E N N U N G (NH 2 ) 2 through steps i and/or ii is mainly responsible for the formation of Sc-based NCFs when using only one rod.…”

“…[1,3,25] However, for the present method, metal oxide Sc 2 O 3 , COA C H T U N G T R E N N U N G (NH 2 ) 2 , and graphite are simply mixed and subjected to arc discharging directly without any additional heating pretreatment, thus the method is simplified and much more facile than the two commonly used methods. With such advantages, COA C H T U N G T R E N N U N G (NH 2 ) 2 as the new nitrogen source is expected to be established as a general route for NCFs based on other metals, studies into which are underway in our lab.…”

“…Assuming that the decomposition process of C 3 H 6 N 6 during discharging is similar to that under conventional heating conditions, for both COA C H T U N G T R E N N U N G (NH 2 ) 2 and C 3 H 6 N 6 , NH 3 generated in situ clearly primarily contributes to the formation of NCFs by following the reported reactive gas atmosphere route. [1,3,5] Although COA C H T U N G T R E N N U N G (NH 2 ) 2 decomposes into C 3 H 6 N 6 upon heating, which eventually releases NH 3 during discharging, additional NH 3 and CO 2 are generated simultaneously (see step 5 in Scheme 2), while the influence of CO 2 generated in situ upon the discharging process is as yet unknown. Therefore, the differences in selectivity and yield of Sc NCFs between COA C H T U N G T R E N N U N G (NH 2 ) 2 and C 3 H 6 N 6 is believed to be due to differences in the concentration of NH 3 generated in situ during discharging and/or the influence of CO 2 .…”

“…[2] Thanks to the establishment of synthetic methods for NCFs, a wealth of new NCFs have been isolated in the past decade by means of either tuning the encaged metal atoms or stabilizing a large variety of cage sizes, including different isomeric structures. [1, To date, all of the isolated NCFs have been synthesized primarily by two methods: the "trimetallic nitride template" (TNT) process reported by Dorn et al in 1999 [4] and the "reactive gas atmosphere" route developed by Dunsch et al in 2003, [5] with gaseous N 2 and NH 3 as the nitrogen source, respectively. As a modification of the TNT process, Stevenson et al used gaseous N 2 from air as the nitrogen source and CuA C H T U N G T R E N N U N G (NO 3 ) 2 ·2.5 H 2 O as an additive for the selective synthesis of Sc 3 N@C 80 NCF.…”

“…[1] Among the endohedral fullerenes, metal nitride clusterfullerenes (NCFs) exhibit a variety of new structural and electronic properties for potential applications in electronics and biomedicines. [2] Thanks to the establishment of synthetic methods for NCFs, a wealth of new NCFs have been isolated in the past decade by means of either tuning the encaged metal atoms or stabilizing a large variety of cage sizes, including different isomeric structures.…”