Fullerenes encapsulation

Acknowledgements—This work was supported by the Office of Naval Research, the National Science Foundation, the Robert A. Welch Foundation, and used equipment designed for study of fullerene-encapsulated catalysts supported by the Department of Energy, Division of Chemical Sciences. 

Soon after the discovery of the buckminsterfullerene (Qo), it was hypothesized that the diameter of this molecule was large enough to encapsulate a variety of atoms inside the carbon cage (Kroto et al. 1985). Indeed, the first stable metaUofuIlerene based on the bucky ball (La Cgo) was detected in the same year as the initial discovery (Heath et al. 1985), and some years later the formation of higher fullerenes encapsulating a lanthanum atom, such as La C7o, La C74, and... 

If the atomic model were rigorously correct, a lanthanide element would have the same magnetic moment in every material and crystalline environment. Of course, this is not the case, and more advanced methods have to be employed to determine the effect of the crystalline and chemical environment on magnetic moments with numerical precision. Examples of materials where the theory described above fails to give an accurate value for the lanthanide ion magnetic moment are ubiquitous. They include NdCos (Alameda et al., 1982), fullerene encapsulated lanthanide ions (Mirone, 2005), and lanthanide p)TO-chlores (Hassan et al., 2003). 

Figure 9 Recently developed tripod systems for fullerene encapsulation. 8 is a tripod on a rigid scaffold. 9 is a cyclic trimer. 10 is a trimer with flexible arms.

Simon F, Kuzmany H, Rauf H, Pichler T, Bemardi J, PeterUk H, Korecz L, Fulop F, Janossy A. Low temperature fullerene encapsulation in single-wall carbon nanotubes synthesis of N C , SWCNT. Chem Phys Lett 2004 383 362-7. 

Recently [78b], the solid-state stracture of the CeoZ/ -Bu -calixlSlarene complex has been studied through characterization techniques such as SEM, TEM, AFM, XRD, and Raman spectroscopy. Interestingly, these studies evidenced the existence of a layered tetragonal array of fullerenes encapsulated by calixarenes [78b],... 

Kataura, H., Maniwa, Y, Kodama, T., Kikuchi, K., Hirahara, K., Suenaga, K., lijima, S., Suzuki, S., Achiba, Y. and Kratschmer, W., High-yield fullerene encapsulation in single walled carbon nanotubes. Synthetic Metals, 121,2001,1195-1196. 

If the orifice of an open-cage fullerene encapsulating a guest species can be completely closed while retaining the guest inside, the molecular surgery approach toward the synthesis of endohedral fullerenes is actualized. In 2005, Komatsu and co-workers reported such closure of the orifice of H2 56 by a four-step sequence of... 

Robert J. Poreda of the University of Rochester seem to strongly support the impact theory. Examining sediment from China and Japan, the team found fullerenes encapsulating argon and helium gas atoms whose isotopic composition indicates that they are extraterrestrial in origin. For example, the ratio of He to He found in the fullerenes is 100 times greater than the ratio for helium found in the earth s atmosphere. Likewise, the isotopic composition of the fullerene-trapped argon atoms is quite different from that found on earth. 

The most novel fullerene derivatives are the metallofullerenes where the fullerene encapsulates a transition metal atom within the closed carbon cage structure. While the air sensitivity and small available quantities of metallofullerenes has hindered the electrochemical studies of metallofullerenes, the electrochemistry of some of the more stable metallofullerenes has been observed [104-107]. This unique combination results in a completely new electrochemical behavior for the derivative that is different from that of all other... 

Figure 6.1 Schematic illustration of fullerene-containing helical polymers, (a) and (b), and fullerene-encapsulated helical polymers (c).

SEMO calculations nsing the AMI Hamiltonian have been used to study the structure and energetics of freestanding and fullerene-encapsulated Mo nanoclusters. It was observed that freestanding nanoclusters of Mo and Mo< . are always amor-... 

J. A. Elliott and Y. Shibuta. A semi-empirical molecular orbital study of freestanding and fullerene-encapsulated Mo nanoclusters. Mol. Simul. 34, 2008, 10-15. 

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