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FULLERENES Aaron Koga May 1, 2007 Physics 441. OUTLINE Introduction to Fullerenes Some properties A few different fullerenes, applications, interesting.

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Presentation on theme: "FULLERENES Aaron Koga May 1, 2007 Physics 441. OUTLINE Introduction to Fullerenes Some properties A few different fullerenes, applications, interesting."— Presentation transcript:

1 FULLERENES Aaron Koga May 1, 2007 Physics 441

2 OUTLINE Introduction to Fullerenes Some properties A few different fullerenes, applications, interesting things C 60 Endoheral fullerenes, bucky onions Fullerite Medicine

3 INTRODUCTION (History) Discovered 1985, Kroto, Smalley, and Curl Nobel Prize chemistry, 1996: 3 scientists for discovery of Fullerenes Named after Richard Fuller (Architect) Montreal Biosphere by Fuller

4 INTRODUCTION (What is a Fullerene?) Carbon allotropes Hollow sphere (buckyball), ellipsoid, tube (buckytube, nanotube) Similar structure to graphite: Hexagons Pentagons (curvature) Euler: 12 pentagons to make sphere

5 INTRODUCTION (Production) Before: vaporization laser 1990 Graphite electrodes Fill chamber with He (inert gas), ~100 torr Run current through graphite Get black soot ~10% C 60 Some larger fullerenes

6 PROPERTIES (Structure) Stable, but not totally unreactive In graphite: sp 2 bonding Planar, 120 o Fullerenes: [6,6] double bonds, hexagons [6,5] single bonds, pentagons to hexagons [6,6] are shorter than [6,5] Sphere, so not planar angle strain Estimated that 80% of E-formation due to strain Strain concentrated on pentagons structures with out touching pentagons are more stable (C 60 )

7 PROPERTIES (Other) Slightly soluble in some solvents Toluene, carbon disulfide, etc. In water: large clusters (nC 60 ) of 250-350 nm Toxic? 2004: found increase in cellular damage to fish with ~.5ppm in water 2005: computer simulation found deformation of DNA by C 60 in water Wave-particle duality with λ=3pm, 1999

8 C 60 Buckminster Fullerene Smallest structure with no pentagons touching ~.7 nm diameter Melting point ~ 550K

9 Endohedral Fullerenes Have atoms, clusters, molecules inside Endohedral Metallofullerenes: Metals with the fullerene 1985: La@C 60 (@ for inside) Electrons donated by metal to C 60 Different size charge transfers ex. La 2 @C 80 (2 e - ) vs. Sc 3 N@C 80 (6 e - ) Non-metal doped fullerenes: Ex. He@C 60, Ne@C 60 Forms when fullerene in ~3 atm of noble gas Noble gas is exactly in center of structure

10 Bucky Onions One fullerene inside another Up to 70 layers observed Nanotube generation normally produces some onions

11 Fullerite Bulk solid C 60 FCC structure Ultrahard Fullerite: 310±40 GPa hardness Diamond: <240 GPa (sometimes 150 GPa)

12 Fullerite A 3 C 60, A 6 C 60 Alkali metal cations for each sphere 3 metal holes (grey) per sphere (blue) A 3 C 60 : conductor A 6 C 60 : insulator at room temp

13 Fullerite A 3 C 60 becomes super conducting Lattice constant, a o, changes to accommodate the metal cation Different T c

14 Fullerenes in Medicine Useful because of size, stability, hydrophobia HIV (Human Immunodeficiency Virus) inhibitor HIVP has cylindrical active site with hydrophobic amino acids C 60 is about same size as the cylinder Possible inhibiting of HIVP Drug delivery, attach to outside of cage Improve MRI (Magnetic Resonance Imaging): Gd 3+ used to improve imaging, but toxic metal When in fullerene even safer than current method Stabilize other reactive species (not only in medicine)

15 References Fullerene. http://en.wikipedia.org/wiki/Fullerenehttp://en.wikipedia.org/wiki/Fullerene Unwin, Peter. Fullerenes (an overview). http://www.ch.ic.ac.uk/local/projects/unwin/Fullerenes.html http://www.ch.ic.ac.uk/local/projects/unwin/Fullerenes.html Bleeke, John R. and Frey, Regina F. Fullerene Science Module. http://www.chemistry.wustl.edu/~edudev/Fullerene/fullerene.html http://www.chemistry.wustl.edu/~edudev/Fullerene/fullerene.html Bucky Onion. http://www.3dchem.com/molecules.asp?ID=218http://www.3dchem.com/molecules.asp?ID=218 Diffraction and Interference with Fullerenes. http://www.quantum.univie.ac.at/research/matterwave/c60/ http://www.quantum.univie.ac.at/research/matterwave/c60/ Dagani, Ron. Cage Chemistry. http://pubs.acs.org/cen/coverstory/8024/8024fullerenes.html http://pubs.acs.org/cen/coverstory/8024/8024fullerenes.html


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