Metallofullerenes
Definition and meaning of Metallofullerenes in chemistry.
Metallofullerenes are fullerene molecules containing one or more metal atoms trapped inside a carbon cage. The encapsulated metal atoms remain completely enclosed within the fullerene structure, altering the compound's electronic and chemical properties.
In more detail
The metal atom is stabilized by the surrounding carbon framework and shielded from external reactions. This endohedral structure is denoted M@Cn, where M represents the metal and Cn the carbon cage (typically C60 or larger). The encapsulated metal fundamentally changes the compound's electron transfer properties, reactivity, and electronic behavior compared to empty fullerenes. Metallofullerenes show significant promise in medical imaging contrast agents, molecular magnetism and spintronics, and advanced nanoelectronic applications.
Key facts
| Field | Inorganic Chemistry |
|---|---|
| Chemical formula | M@Cn (M = metal; n = number of carbons, typically 60-110) |
| First metallofullerene isolated | La@C82, isolated in bulk (weighable) quantities in 1991 |
| Key applications | Medical imaging contrast agents, molecular magnetism/spintronics, nanoelectronics |
La@C82 is a well-studied metallofullerene in which a lanthanum atom is enclosed within an 82-carbon cage. The encaged lanthanum atom transfers electrons to the carbon cage, giving the molecule unusual electronic and magnetic properties compared to empty C82.
Frequently asked questions
How does the metal atom remain trapped inside the carbon cage?
The carbon cage completely encloses the metal atom, which is too large to escape through the carbon framework. Strong interactions between the metal and the cage structure provide thermodynamic stabilization.
What does the '@' symbol mean in metallofullerene notation?
The '@' symbol denotes 'inside' or 'encapsulated within,' so La@C82 means lanthanum enclosed in an 82-carbon cage, distinguishing endohedral fullerenes from surface-substituted derivatives.