Fullerenes 5

Transcription

Fullerenes 5

Fullerenes 5
Mircea V. Diudea
Faculty of Chemistry and Chemical Engineering
Babes-Bolyai University
400028 Cluj, ROMANIA
diudea@chem.ubbcluj.ro
1
Contents

Fullerene – Physico-Chemical properties

Addition Reaction

Stone-Wales Reactions
2
Fullerenes in Nature

Fullerenes were found in the natural
environment, but only in the ppm-range.
Some places are Shunga/Russia,1 New
Zealand2 and Sudbury/Canada.3
1. P.R. Busek, S.J. Tsipursky, R. Hettich, Science 257 (1992) 215
2. D. Heymann, L.P.F. Chibante, R.R. Brooks, W.S. Wolbach, R.E. Smalley,
Science 265 (1994) 645
3. L. Becker, J.L. Bada, R.E. Winans, J.E.Hunt, T.E. Bunch, B.M. French,
Science 265 (1994) 642
3
Isolated Fullerenes
C60
C70
4
Fullerenes – physico-chemical
properties

Good solvents for fullerenes are CS2, toluene, xylene, and odichlorobenzene while they are insoluble in water and stable at air.
Thin layers of fullerenes and solutions are coloured, because of ππ*electron transitions:1
- C60 purple/violetred
- C70 brick-red
- C76 light yellow-green
- C2v-C78 maroon, D3-C78 golden,
- C84 brown and
- C86 olive-green.
1. A.F. Hollemann, Lehrbuch der anorganischen Chemie, 101. Auflage (1995),
de Gruyter, 843.
5
Chemical Reactions of Fullerenes

Fullerenes are not “aromatic” compounds.1
No reactions with “reversion to type” (preserving e.g., the π
-electron distribution, as the substitution reactions of
benzene - like molecules, i.e., aromatic species) occur.
The general addition chemistry of C60 is closer to “super
alkenic” than “super aromatic”.2
1. J. Castels, Some comments on fullerene terminology, nomenclature,
and aromaticity. Fullerene Sci. Technol. 1994, 2, 367-379.
2. P. W. Fowler, D. J. Collins, and S. J. Austin, J. Chem. Soc., Perkin
Trans., 1993, 2, 275-277.
6
Addition Reactions

Fullerenes are electron-defficient molecules.1
They form multiple-charged anions with electron
donating species, e.g., the alkaline or alkaline-earth
metals.
Endohedral complexes, like La@C82 , are formed when the
metal was catalysed the fullerene growth.
Exohedral derivatives are synthesized by addition
reactions.
1. P. J. Fagan, J. C. Calabrese, and B. Malone, Acc. Chem. Res.,
1992, 25, 134-142
7
Endohedral (a) and exohedral (b)
derivatives
(a) La@C82
(b) C60Cl6
8
Addition Reactions

Although C60 has 12500 Kekule structures,1 its addition
reactions, in which it shows an electron-deficient alkenic
character, are oriented by the Fries Kekule structure;
recall that, in this unique structure, all p (5,6) edges are
formal single bonds while all h (6,6) are formally double.
The highest bond order (i.e., the 2-order) is reached by the
Stone-Wales formal double bonds, located at the centre of
pyracylene-like patches.
All 30 double bonds of C60 (among 90 edges) while in C70
(among 105 edges) only 20 are of this type. The addition
reaction will occur, most probably, at these electron-rich
bonds.
1. H. W. Kroto, J. R. Heath, S. C. O’Brian, R. F. Kurl and R. E. Smalley,
Nature, 1985,318, 162.
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Stone-Wales isomerisation1
pyracylenic patch
The bold edge shares two cycles
of size (sm, sn) to be reduced,
after rotation, to (sm-1, sn-1).
The two cycles joined by this edge
will increase their size from (sp, sr)
to (sp+1, sr+1)
1. A. J. Stone and D. J. Wales, Chem.Phys. Lett., 1986, 128, 501.
10
Stone-Wales isomerisation1
pyracylenic patch
Most often, the edge flipping
runs as a cascade SW
transformation
1. A. J. Stone and D. J. Wales, Chem.Phys. Lett., 1986, 128, 501.
11
Stone-Wales isomerisation

SW Isomerization by a concerted
mechanism, with a diradical transition
state.
=
12
Stone-Wales isomerisation

SW Isomerization involving a carbene as
the intermediate.
13
Enantiomers by SW: C28:1
14
A SW Family - C30
C30 : 1
C30 : 2
C30 : 3
15
Coalescence of Nanostructures
SW edges
M. V. Diudea, Cs. L. Nagy, O. Ursu, and T. S. Balaban,
Fuller. Nanotub. Carbon Nanostruct., 2003, 11, 245-255.
16
ta-Tubulenes
17
ta –Tubulenes1
CN (k 5k 7k (56)k-A[2k,n]) ; N = 8k +p
2C24(6 5616- A[12,0]) + A[12,4]
C96(6 5676(5,6)6(6,5)6765 66) (C2)
1. M. V. Diudea, Stability of tubulenes, Phys. Chem., Chem. Phys., 2004, 6, 332-339
18
fa -Tubulenes
fa –Tubulenes from ta -Tubulenes by SW isomerization 1
C96(6 66(5,6)6(6,6)6(6,5)6666) (D6d)
Geodesic Projection
1. A. J. Stone and D. J. Wales, Chem. Phys. Lett., 1986, 128, 501-503.
19
kfz-peanut Tubulenes
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Peanut 1 kf –Tubulenes CNN’ (k-Z[2k,n])
C168(6 66(5,6)6(6,5)676666676)
C168(6 66(5,6)6(6,5)676(5,7)3(7,5)376)
1. D. L. Strout, R.L. Murry, C. Xu, W.C. Eckhoff, G. K. Odom, and G. E. Scuseria,
Chem. Phys. Lett. 1993, 214, 576-582.
21
Peanut kf-Tubulenes
Isomerization of the distancing nanotube by SW edge rotations1
C72(76666676)
Geodesic projection
1. M. V. Diudea et al., Periodic Cages, Croat. Chem. Acta, 2004 (in press)
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Peanut kf-Tubulenes
C72(76 5 64 7 7 64 5 76)
Geodesic projection
23
Peanut kf-Tubulenes
C72(76 5 62 7 5 72 62 5 7 5 76)
Geodesic projection
24
Peanut kf-Tubulenes
C72(76 5 62 7 5 72 62 5 7 5 76)
Geodesic projection
25
Energetic and Spectral Properties of
Peanut kfz –Tubulenes CN (k…Z[2k,n])
Cage
Sym
PM3
HF/at
PM3
Gap
Spectral Data
λN/2
λN/2+1 Gap Shell
3
C168(6 66(5,6)6(6,5)676666676)
D6d
11.927
5.11
-0.023
-0.023
0
OP
4
C168(6 …765 647 7 645 76)
C2
12.261
5.16
-0.013
-0.023
0.01
MC
5
C168(6 … 765 627 5 72 625 7 5 76)
C2
12.452
5.19
0.009
-0.040
0.05
PC
6
C168(6 …76(5,7)3(7,5)376)
S6
12.553
5.43
0.162
-0.040
0.20
PC
26
Tubulene (left) and peanut z -tubulenes (mean)
corresponding to the multi-peanut (C60)n (right)
27
HOMO eigenvalues of multi peanut
z -tubulenes (C60)4
0.2
0.15
0.1
λ 0.05
0
0
0.5
1
1.5
2
2.5
3
3.5
-0.05
-0.1
no. necks
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((5,7)3) kz-peanut
Tubulenes
29
Rearrangement of (4, 6) pairs to (5, 5) ones
by SW edge rotation1
C84(7 5777(4,6)777577)
C84(7 577751477577); (Ci )
1. A. J. Stone and D. J. Wales, Chem. Phys. Lett., 1986, 128, 501
30
Rearrangement of all (5, 7) cages
to the classical C12k fullerenes by SW1
C60(5 557551075555) (Ci )
C60(5 65(5,6)5(6,5)5655) (Ih )
1. A. J. Stone and D. J. Wales, Chem. Phys. Lett., 1986, 128, 501
31
Semiempirical and spectral data
for ((5,7)3) periodic cages
(5,7) Cage
Sym
CN (k 5k(7k52k7k)r5kk)
PM3
HF/at
PM3
GAP
λN / 2
ΛΝ/2
Spectral
λ N / 2 +1 Data
ΛΝ/2+1
GAP
Shell
1
60 ; 5; 1
Ci
21.158
5.623
0.3797
0.2290
0.1507
PSC
2
100; 5; 2
Ci
18.906
5.592
0.2785
0.2785
0
OP
3
140; 5; 3
-
-
-
0.2979
0
0.2979
PSC
4
84; 7; 1
Ci
16.249
4.538
0.2452
0.2311
0.0141
PSC
5
140;7; 2
Ci
15.828
5.114
0.2231
0.2231
0
OP
6
196; 7; 3
-
-
-
0.2199
0.0155
0.2044
PSC
32
((5,7)3) Periodic Cages

The ((5,7)3) periodic cages tend to
isomerize to the more stable fa-tubulenes
33
ISOMERIZATION OF (5, 7) PERIODIC CAGES
to fa-Tubulenes
C100(k 5k(7k52k7k)r5k k); k = 5; r = 2
C100(5 65(5,6)5-A[10,2])
34
C100(k 5k7k52k8k(5,6)k(5,7)k5k k);
k=5
C100(k 5k7k(5,6)k(6,6)k(6,5)k7k 5kk);
k=5
35
C100(k 6k(5,6)k(5,7)k7k(5,6)k(5,6)kk); C100(k6k(5,6)k(5,8)k(5,6)k(6,5)k6k k);
k=5
k=5
36
Data for some ((5,7)3) peanut cages
and their isomerization to fa-tubulenes
Cage
1
C100(k 5k(7k52k7k)r5k k);
Sym
PM3
HF/at
PM3
GAP
λ
Ci
18.906
5.592
0.279
0.279
0
OP
N / 2 +1
Spectral Data
λN / 2
GAP
Shell
k = 5; r = 2
2
C100(k 6k(5,6)k (5,7)k7k
D5d
15.146
5.546
0.311
0.311
0
OP
3
C100(k6k(5,6)k(5,8)k(5,6)k
C5v
13.966
5.770
0.391
0.020
0.371
PSC
4
C100(k 5k7k52k8k (5,6)k
C1
18.260
5.404
0.414
0.147
0.267
PSC
5
C100(k 5k7k(5,6)k(6,6)k
D5d
15.205
3.849
0.247
0.239
0.008
PSC
6
C100(5 65(5,6)5-A[10,2])
D5d
10.876
5.045
0.350
0
0.350
PC
k
k
(5,6) (5,6) k)
k k
(6,5) 6 k)
k k
(5,7) 5 k)
k k k
(6,5) 7 5 k)
37
Functionalization of
fullerenes
38
The study of 1,3-bipolar nitrilimines and
fullerene C60 cycloaddition

During the study of 1,3-disubstituted nitrilimines and
fullerene cycloaddition reaction a model set of
fullerenepyrazolines containing various substituents
including heterocyclic fragments and CF3 group was
synthesized. Stable [6,6]-closed adducts 1, 2, 3, 4, 5, 6,
and 7 were synthesized by 1,3-bipolar cycloaddition of
fullerene and nitrilimines, generated in situ from the
corresponding
hydrazonoil
halogenides
and
threethylamine.
39
Functionalization of fullerenes
Methanofullerenes
These compounds represent the most versatile and widely studied class of
fullerene adducts. In theory, there exist four possible isomers: 6-5-open,
6-5-closed, 6-6-open, 6-6-closed, depending on wherther addition takes
place at 6-6 or 6-5 bonds and whether the bridgehead C atoms are at
nonbonding distance or are connected by a transannular bond.
6-5-closed
6-5-open
6-6-closed
6-6-open
40

Formation of the parent 6-5-open (1) and 6-6-closed (2)
methanofullerene (C61H2) isomers by 1,3-dipolar cycloaddition of
diazomethane to C60 to give a 6-6-fused pyrazoline intermediate
followed by thermal or photochemical extrusion of N2.
41
6-6-fused pyrazoline intermediate
42

1,3-Dipolar cycloaddition of tertbutyl (t-Bu) diazoacetate yields a mixture of
two diastereomeric 6-5-open (kinetic) and one 6-6-closed (thermodinamic)
products.
43

The optically active fullerene-sugar conjugate 4 is obtained by the
attack of a nucleophilic glycosylidene carbene (formed from the
corresponding diazirine) to C60.
44

In the Bingel reaction, ∝-bromo-malonates are deprotonated by a base
and react as nucleophiles with C60 to give an intermediate anion, which,
by displacement of the halide, closes the methano bridge to diesters
such as 5.
45

Trimethylsilyl-protected 3-bromopenta- 1,4- diyne reacts in the
presence of bases with trimethylsilylethyne affords 7, which, upon
electrolysis, yields a conducting polymeric film at the cathode
(TMEDA, N,N,N’,N’-tetramethylethylenediamine; Ph, phenyl; and Me,
methyl).
46
Formation of methanofullerenes by nucleophilic addition
of a phosphonium ylide, a Wittig reagent.
47

A fullerene-dendrimer
48
49
50
Cyclopropanation Reactions1
Trans-4-[60]fullerene bis-adducts –fluorescence studies
1. J-. Y. Zheng, Sh. Noguchi, K. Miyauchi, M. Hamada, K. Kinbara, and
K. Saigo, Tether-linked [60]fullerene-donor dyads. Fullerene Sci.
Technol. 2001, 9, 467-475.
51
Dimeric C60; a [2 +2] cicloadduct
C5-c2-2_7(all sp2); 120; D5d; HF = 10.625 kcal/mol
C120 - (hh)
C120- (pp-c)
S. Lebedkin, A. Gromov, S. Giesa, R. Gleiter, B. Renker
H. Rietschel and W. Krätschmer, Raman scattering study of
C120, a C60 dimer. Chem. Phys. Lett, 1998, 285, 210-215.
52
Cycloaddition [2 +3] = C120O
Epoxi-[60]fullerene
C120 - O (hh)
A. Gromov, S. Lebedkin, S. Ballenweg, A. G. Avent, R. Taylor and
W. Krätschmer, C120O2: The first [60]fullerene dimer with cages bislinked by furanoid bridges, Chem. Commun. 1997, 209-210.
53
Fullerenes – physical properties

The discovery of superconductivity in alkali doped fullerides at
moderately high temperatures (1991).
The chemistry of fullerenes also includes the synthesis of
endohedral fullerenes having the formula M@Cn , where M stands
for a metal atom inside the fullerene cage.
These studies have suggested enormous potential and a wide range
of applications for carbon-based materials, thanks to the possibility
of tailoring their physical properties and performances.
It was suggested that the superconducting critical temperature of
doped fullerite increases with the curvature of fullerene cages,
namely with the reduction of the cluster size from C60 down to C36,
and perhaps C28 and C20.
Moreover, an unexpected ferromagnetic behavior has been recently
described in fullerenic materials.
54
Utilizations of Fullerenes

Soft ferromagnetics,
Organic conductors,
Lubricant materials,
Superconductivity, discovered in fullerene films
dopped with alkaline metals. The temperature of
transition into this state, at 45 K is exceeded
only by ceramic superconductors, but fullerene
films have higher critical- current values.
Applications in catalysis is also of interest.
55
References
1. Diudea, M. V.; Graovac, A.; Generation and Graph-Theoretical
Properties of C4-Tori. Commun. Math. Comput. Chem. (MATCH),
2001, 44, 93-102
2. Diudea, M. V.; Silaghi-Dumitrescu, I.; Parv, B. Toranes versus
Torenes.Commun. Math. Comput. Chem. (MATCH), 2001, 44, 117133
3. Diudea, M. V.; John, P. E. Covering Polyhedral Tori. Commun. Math.
Comput. Chem. (MATCH), 2001, 44, 103-116
4. Diudea, M. V.; Kirby, E. C. The Energetic Stability of Tori and
Single-wall Tubes. Fullerene Sci. Technol. 2001, 9, 445-465.
56
References
5. Diudea, M. V. Graphenes from 4-Valent Tori. Bull. Chem. Soc.
Japan, 2002, 75, 487- 492.
6. Diudea, M. V.; Silaghi-Dumitrescu, I.; Pârv, Toroidal Fullerenes. Ann.
West Univ.Timisoara, 2001, 10, 21-40
7. Diudea, M. V.; Silaghi-Dumitrescu, I.; Pârv, B. Toroidal Fullerenes
from Square Tiled Tori. Internet Electronic Journal of Molecular
Design. 2002, 1, 10-22.
8. Diudea, M. V. Hosoya Polynomial in Tori. Commun. Math. Comput.
Chem. (MATCH), 2002, 45, 109-122.
57
References
9. Diudea, M. V. Phenylenic and Naphthylenic Tori. Fullerenes,
Nanotubes Carbon Nanostruct., 2002, 10, 273-292.
10. Diudea, M. V.; Parv, B.; Kirby, E. C. Azulenic Tori. Commun. Math.
Comput. Chem. (MATCH), ( in press).
11. Diudea M. V., Periodic 4,7 cages. Bul. Stiint. Univ. Baia Mare Ser. B
2002, 18, 000-000.
12. Diudea M. V. Topology of Naphthylenic Tori. PCCP 2002, 4, 47404746.
13. Diudea, M. V., Ed., Nanostructures – Novel Architecture,
Nova Science, Huntington, New York, (in preparation).
58