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Classification and Construction of Topologically Nontrivial
Graphitic MaterialsBih-Yaw Jin
Department of ChemistryNational Taiwan University
ACS meeting, Washington DC, Aug.20, 2009
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Classification
Polygonal TorusTamura, R. et al. Phys. Rev. B. 2005, 71, 045418.
Chuang, Fan & Jin, J.Chem.Inf & Model 2009, 49, 361
A family of achiral TCNTs with Dnh symmetry can be systematically constructed by polygonal prisms defined by four parameters, (n75, n77, n55, s).
Series I : the increasing of n75 while keeping other parameters, n77, n55, and s, constant. Series II : varying (n77, n55). Series III : the increasing of s.
Evolution of TCNTs as a function of certain indices among the four parameters, (n75, n77, n55, s)
B
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Construction of Fullerenes
("=?$<+#&=":+7/40
9>?+#&,$G40
Beads and beadworks
1-D
2-D
3-D
Beaded Buckyball
• Bead Representation = Bond Representation
• 90 beads are needed for C60
• Beaded fullerene represent the pi-bond network.
60× 3/2 = 90
Weaving code �Spiral Code
9•C60: [1 7 9 11 13 15 18 20 22 24 26 32 ]
566666565... planar graph
7 Isomers of C80
• [1 7 9 11 13 15 28 30 32 34 36 42]
•[1 7 9 11 13 18 25 30 32 34 36 42]
• [1 7 9 11 14 22 27 30 34 36 38 40]
•[1 7 9 11 14 23 28 30 33 35 37 39]
•[1 7 9 12 14 20 26 28 32 34 39 42]
•[1 7 10 12 14 19 26 28 32 34 39 42]
•[1 8 10 12 14 16 28 30 32 34 36 42]
P. W. Fowler, An Atlas of FullerenesSpiral Codes
Structures of Fullerenes
P. W. Fowler, An Atlas of Fullerenes Point group: D5d�D2�C2v�D3�C2v�D5h�Ih
Advantages of Beaded Models
• The shapes of the beaded fullerenes are in good agreement with the optimized geometries based on more sophisticated molecular force fields since the mechanical interactions among three neighbored beads can effectively mimic the steric repulsion in the sp2-hybridized fullerenes.
• Beaded fullerenes can be constructed systematically based on the spiral codes together with simple construction rules.
Minimal Length of String Required
•What is the minimal length of string to weave
a particular fullerene?
•Hamiltonian Circuits or Paths
Lmin = 2sNd + Lext
• d : diameter of bead.
• s = 1.1
• Lex: extra length
Truncated Icosahedron
C60 C80 C140 C180 C240 C280
Truncated Tetrahedron
End-capped CNT
17
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Classification
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(HIJ&5B:
(IKJ5B:
Beaded Models
TCNT 240 (T240) Construction Procedure of T240
Helically Coiled CNTsHorizontal shifting
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(IK&L$4/<&,+77
(MJL$4/<&,+77
Beaded Model for HCCNT
More beaded models for HCCNT Triple Stranded Carbon Helix
L.P. Hwang, Phys. Chem. Comm.(2002)
Helicity of 2nd Kind: Vertical Shifting
Combination of Two Kinds of Helicities: CNT Space Curves
Carbon Trefoil Knots
Carbon Nanotube Torus Knot
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Classification
Neck Structure: Construction of High Genus Fullerenes
Chuang & Jin, J.Chem.Inf & Model 2009, 49, 1664
D5h Necks
High Genus Fullerenes
Chuang & Jin, J.Chem.Inf & Model 2009, 49, 1664
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Chuang & Jin, J.Chem.Inf & Model 2009, 49, 1664
(BIK3+4$%&P!:
(IJKJ3+4$%&HQR1
Beaded models for High-Genus Fullerenes
Superbuckyball
C60
C70
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Chuang & Jin, submitted
Doubly periodic graphitic structures
)+,-&E<#$,<$#+&"4&S#,1/=+:+>4&!/7/40 Triply Periodic Minimal Surfaces
P-Type Minimal Surface
D-Type TPMS Gyroidal Minimal Surfaces
C168 Pseudo P-Type surface
H-Type Surface Sierpinski buckyball
D=log 90/log scaling factor = log(90)/log(7) ~ log(90)/log(6.5) = 2.3 ~ 2.4
Hausdorff (fractal) dimension
Sierpinski's pyramid
http://commons.wikimedia.org/wiki/Image:Sierpinski_pyramid.png
Conclusion
• The shapes of the beaded fullerenes are in good agreement with the optimized geometries based on more sophisticated molecular force fields since the mechanical interactions among three neighbored beads can effectively mimic the steric repulsion in the sp2-hybridized fullerenes.
• Beaded fullerenes can be constructed systematically based on the spiral codes together with simple construction rules.
• Bead is a versatile low-cost high quality material for creating various complicated 3D structures of sp2-hybridized carbon nanostructures.
• Beaded molecules are aesthetically pleasing artworks.
Advantages of Beaded Models
KM
Blog for Beaded Fullereneshttp://thebeadedmolecules.blogspot.com/
C. Chuang
NSC, TaiwanCTS and CQSE, NTU