Structure endohedral fullerenes

A. L. Balch, FuUerenes as encapsulating hosts preparation, detection, and structures of endohedral fullerenes, in Encyclopedia of Supramolecular Chemistry (eds J. L. Atwood and J. W. Steed), Marcel Dekker, New York, 2004, p. 579. 

Figure 15.30 X-ray crystal structure of a derivative of the endohedral fullerene complex Sc3N C80 (Sc and N atoms shown as large spheres).51...

Figure 1 The structures of endohedral fullerenes with encapsulated tetrahedral MX molecules and...

Figure 6 The structures of endohedral fullerene clusters with linear tri- and tetraatomic guest molecules inside C70 ( >5/, ).

Figure 7 The structure of endohedral fullerene clusters with benzene and borazole molecules encapsulated into Cs4 ( >6a).

Research on modeling of endohedral fullerenes within single-walled carbon nanotubes (SWNTs) has received increased attention towards the understanding of their electronic and structural properties [304-307]. However, very recently particular emphasis was given to the endohedral fullerenes N C60 [308-313] and P C60 [314] due to the electron spin on the nitrogen or phosphorus site, respectively. Having an extremely long decoherence time the unpaired electron spin could be used as a qubit within a quantum computer. 

The monometalhc endohedral fullerenes are typified by M C82 (M = Sc, Y, La), and ESR studies of these molecules indicate that they are best described as the charge-separated species M + C82 For all three species, two distinct signals are seen, indicating the presence of two isomers of M C82, although it is not known whether these correspond to any of the observed isomers of the parent ffillerene C82 EXAFS studies of Y Cs2 indicate that each yttrium atom has seven nearest neighbor carbon atoms at 2.35 A as well as another yttrium atom at 4.05 A. These data are not consistent with a simple endohedral structure and further studies are required to clarify this apparent contradiction. 

Figure 6.29. Images of the calculated structures involved in the hole-repairing mechanism for endohedral fullerene growth. Shown from left to right are the Cyg open cage, top and side views of the CgY fragment, and the final Y Cg2 metallofullerene. Reproduced with permission from Gan, L.-H. Wang, C.-R. J. Phys. Chem. A 2005,109, 3980. Copyright 2005 American Chemical Society.

Olmstead, M.H., de Bettencourt-Dias, A., Duchamp, J.C. etal. (2001) Isolation and structural characterization of the endohedral fullerene Sc2N C-i%. Angewandte Chemie International Edition, 40, 1223-1225. 

Kobayashi, K., Nagase, S., Yoshida, M. et al. (1997) Endohedral metallofullerenes. Are the isolated pentagon rule and fullerene structures always satisfied Journal of the American Chemical Society, 119, 12693—12694. 

Mercado, B.Q., Beavers, C.M., Olmstead, M.M. et al. (2008) Is the isolated pentagon rule merely a suggestion for endohedral fullerenes The structure of a second egg-shaped endohedral fullerene-Gd3 N C(s)(39663)-C82. Journal of the American Chemical Society, 130, 7854-7855. 

Zuo, T.M., Olmstead, M.M., Beavers, C.M. etal. (2008) Preparation and structural characterization of the 7h and the Dsh isomers of the endohedral fullerenes TmsNOCgo icosahedral Cgo cage encapsulation of a trimetallic nitride magnetic cluster with three uncoupled Tm + ions. Inorganic Chemistry, 47, 5234-5244. 

Guha, S., and Nakamoto, K. 2005. Electronic structures and spectral properties of endohedral fullerenes. Coordination Chemistry Reviews 249, 1111-1132. 

Endohedral fullerenes, which contain metal atoms or small molecules inside the carbon cages, hold great promise for application in optoelectronic devices because of their fullerene-like and metallic properties. However, their investigations are limited by extremely low yields of these fullerenes (mg pg range). IR and Raman studies of endohedral fullerenes are important in elucidating the nature of interaction between the carbon cage and encapsulated species. Electronic structures and spectroscopic properties of endohedral fullerenes have been reviewed by Guha and Nakamoto [1549]. 

Compounds of Carbon ) has been expanded to show significant applications of vibrational spectroscopy to the structural determination of fullerences, endohedral fullerenes, and carbon nanotubes. Vibrational data on a number of novel inorganic compounds prepared most recently have been added throughout Chapter 2. 

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