Chemistry Reference
In-Depth Information
Table 8.4
Energetic data (DFTB) for some C
20
-based hyper-graphenes HG (reference C
60
H
60
)
C
20
_hyper-graphene
C atoms
E
tot
(au)
E
tot
/C (au)
Gap (eV)
−
−
C
20
HG_11_90H
60
i.e. (C
20
)
6
_90H
60
90
178.393
1.982
8.992
C
20
HG_22_252H
136
252
−
487.798
−
1.936
8.447
C
20
HG_44_780H
360
780
−
1487.55
−
1.907
8.191
C
20
HGCor_621_384H
192
384
−
737.736
−
1.921
8.307
C
20
HGCor_631_882H
396
882
−
1678.02
−
1.903
8.155
C
60
H
60
60
−
125.584
−
2.093
10.412
Table 8.5
Energetic data (DFTB) for some small fullerenes and hyper-cycles
C
20
_hyper-graphene
C atoms
E
tot
(au)
E
tot
/C (au)
Gap (eV)
−
102.185
−
1.703
C
60
60
1.930
C
20
20
−
33.429
−
1.671
0.731
C
24
24
−
40.142
−
1.673
1.667
C
28
28
−
47.101
−
1.682
0.351
(C
24
)
5
_90
90
−
152.998
−
1.700
1.634
(C
20
C
28
)
3
_114
114
−
192.488
−
1.688
0.166
(C
20
)
5
_75H
50
75
−
146.956
−
1.959
9.969
(C
24
)
5
_90H
60
90
−
175.282
−
1.948
9.103
(C
28
)
5
_110H
80
110
−
220.185
−
2.002
9.270
−
178.393
−
1.982
(C
20
)
6
_90H
60
90
8.992
(C
20
C
28
)
3
_114H
84
114
−
226.346
−
1.985
10.278
C
60
H
60
60
−
125.584
−
2.093
10.412
C
20
H
20
20
−
41.659
−
2.083
12.295
C
24
H
24
24
−
49.752
−
2.073
12.247
C
28
H
28
28
−
58.301
−
2.082
12.384
cyclo-adducts but this is just the beginning of a more complex process that in-
volves the coalescence of quasi-spherical units of C
60
to form oligomers and finally
a polymer (see Figs.
8.6
and
8.7
); Table
8.6
supports this idea.
Let us detail the structures participating to such a process. Two dimers with
joint face for C
60
units can be designed (Fig.
8.6
, top): C
60
P2J5_115 (J5 meaning a
pentagon identification) and C
60
P2J6_114 (J6 representing a hexagon identification).
These two dimers have the total energy per C atoms comparable to C
60
; the HOMO-
LUMO gap of “J5”- dimer is larger than that of “J6”-dimer (even “J5” dimer has no
Kekulé structures).
