Syntheses and crystal structures of azafulleroid and aziridinofullerene bearing silyl or germyl benzene

Article abstract of DOI:10.1016/j.jorganchem.2008.11.049

Addition of silyl and germylmethyl azides (1) to fullerene C₆₀ at 50 °C through [2+3] cycloaddition led to the formation of the triazoline adducts (2). Subsequently, heating 2 at 100 °C in the solid state, caused N₂ extrusion produci

Full text of DOI:10.1016/j.jorganchem.2008.11.049

Journal of Organometallic Chemistry 694 (2009) 630–636
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Syntheses and crystal structures of azafulleroid and aziridinofullerene
bearing silyl or germyl benzene
*
Houjin Hachiya, Toshiyuki Kakuta, Makoto Takami, Yoshio Kabe
Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 6 October 2008
Received in revised form 13 November 2008
Accepted 18 November 2008
Available online 30 November 2008
Addition of silyl and germylmethyl azides (1) to fullerene C60 at 50 °C through [2+3] cycloaddition led to
the formation of the triazoline adducts (2). Subsequently, heating 2 at 100 °C in the solid state, caused N2
extrusion producing two different isomers, [5,6]-azafulleroid (3) and [6,6]-aziridinofullerene (4). The 13
C
NMR spectrum of 3 had an absence of resonances in the aliphatic region for the fullerene C60 cage, show-
ing a fulleroid with CS symmetry. In contrast, 4 exhibited one sp3 resonance in the aliphatic region for the
fullerene C60 cage, indicative of an aziridinofullerene with C2V symmetry. However, MALDI-TOF mass
characterization was hampered because ion peaks corresponding to the bis-adduct are detected in posi-
tive ion mode measurements, whereas the ion peaks [MꢀN2]ꢀ for 2a as well as [M]ꢀ for 3a and 4a are
observed in negative ion measurements. In an effort to obtain X-ray data, silyl and germylphenyl groups
were introduced to form intermolecular complexes with fullerene C60. The X-ray structures of 3c and 3d
revealed a strong enhancement of homoconjugation in the bridged annulene moiety based on POAV anal-
ysis. The X-ray structures of 3c,d and 4c were confirmed with the detection of silyl and germylphenyl-C60
interactions, similar to dimethoxyphenyl-C60 interactions.
Keywords:
Fullerene
Silicon
Germanium
X-ray structure
POAV analysis
Ó 2008 Elsevier B.V. All rights reserved.
1. Introduction
2. Results and discussion
Among the various fullerenes and fullerene derivatives, only a
limited number of X-ray structures have been reported. Crystals
of fullerenes and many chemically modified fullerenes suitable
for X-ray diffraction studies have been difficult to obtain due to
poor crystal quality and high symmetry. In order to synthesize
acceptable crystalline compounds, cocrystallization with porphy-
rin, benzene and other such compounds has been important [1].
Another method involves, appending a bulky metal complex to
the fullerene or inclusion into bowl-shaped molecules such as
cyclodextrin, calixarene and cyclotriveratrylene which lowers the
symmetry and can also produce ordered structures [2]. Of note is
the fact that some of the methoxybenzenes and benzylether fuller-
ene derivatives showed interesting intermolecular donor–acceptor
interactions, that is, close contact between the methoxybenzene or
benzylether and a neighboring C60, thus forming a chain of inter-
acting fullerene cages in the crystal. To further evaluate this, the
structures of cycloadducts, methanofullerenes and endohedral
methallofullerenes were successfully characterized [3]. It was
found that the silyl and germyl derivatives of fullerenes formed
intermolecular complexes, enabling the structures of silyl- and ger-
mylphenyl-substituted azafulleroid and aziridinofullerene to be
characterized by X-ray analysis [4].
A mixture of fullerene C60 and trimethylsilylmethylazide (1a) in
o-dichlorobenzene (ODCB) was heated at 50 °C for 6 h to give a
dark brown solid triazoline adduct (2a) in 28% yield, as shown in
Scheme 1. The 13C NMR spectrum of 2a exhibited the presence of
2 sp3 resonances for the fullerene C60 cage, indicative of a methan-
ofullerene, i.e., the triazoline derivative with CS symmetry. Subse-
quently heating 2a at 100 °C for 33 h in the solid state produced
a mixture of the corresponding [5,6]-azafulleroid (3a) and [6,6]-
aziridinofullerene (4a). The isomers were separated by column
chromatography (silica gel: CS2) to give dark brown solid 3a in
19% yield, and 4a in 1% yield, with 33% of the C60 recovered. The
13C NMR spectrum of 3a had an absence of resonances in the ali-
phatic region for the C60 cage, typical of a fulleroid with CS symme-
try. In contrast, 4a exhibited one sp3 resonance in the aliphatic
region for the C60 cage, indicative of a methanofullerene with C2V
symmetry (see Fig. 1). Moreover, heating of either 2a or 3a at
170 °C in ODCB affords 4a.
These chemical correlations and the symmetries of the products
based on the 13C NMR data are consistent with the reported reac-
tion: [2+3] addition of azide followed by loss of N2 producing two
different isomers, the azafulleroid and aziridinofullerene [5].
However, MALDI-TOF mass characterization is hampered because
the ion peaks corresponding to the bis-adduct are detected in po-
sitive ion mode measurements, whereas the ion peaks [MꢀN2]ꢀ
for 2a as well as [M]ꢀ for 3a and 4a are observed in negative ion
* Corresponding author. Tel./fax: +81 0463 59 4111.
E-mail address: kabe@kanagawa-u.ac.jp (Y. Kabe).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.11.049

H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
631
ceeds the reported value of 0.32 b for C60NH, evidence of a strong
enhancement of homoconjugation in the bridged annulene moiety.
The C1–C6 addition geometry and distance (1.590 (4) Å) for 4c sug-
gests the presence of a [6,6] transannular bond between C1 and C6,
and the aza-cyclopropane (aziridine) structure shown in Fig. 3. The
distance is of the same order of magnitude as in C60CPh(Ph-
(OMe)2) methanofullerene (1.614 (7) Å) and C60C(Ph-OMe)2 met-
hanofullerene (1.625 Å). B3LYP/6-31G** calculations were also in
good agreement with the transannular bond length: 2.157 Å for
3c, 2.160 Å for 3d, and 1.592 Å for 4c.
Inspection of the crystal packing of 3c ꢁ toluene shown in Fig. 5
(top), shows that one of silylphenyl rings is positioned close to a
neighboring fullerene molecule by face-to-face (p–p) interaction.
The shortest distance between one silylphenyl ring and the C60
moiety is in the 3.384 Å range. These interactions continue on to
the next molecule, resulting in an infinite chain. A second type of
interaction places a silylphenyl hydrogen atom close to the edge-
Scheme 1. Syntheses of azafulleroid 3 and aziridinofullerene 4.
measurement, as shown in Fig. 2. In an effort to obtain X-ray data,
silyl and germylphenyl groups were introduced, forming intermo-
lecular complexes with C60, similar to methoxybenzene deriva-
tives. Instead of trimethylsilylmethylazide (1a), dimethylph
enylsilylmethylazide (1b), triphenylsilylmethylazide (1c) and trip-
henylgermylmethylazide (1d) were employed, affording three ad-
ducts, 2b–d (36%, 31% and 26% yield), 3b–d (22%, 41% and 41%
yield) and 4b–d (4%, 3% and 9% yield), respectively, with some
C60 recovered (42%, 27% and 33% yield). Yields of 4b–d increased
upon heating a solution of 2b–d or 3b–d in ODCB at 170 °C for
24 h. This thermal dependence of yield shows that the aziridino-
fullerenes 4a–d are more stable than the corresponding azafulle-
roids 3a–d. To further clarify the thermal isomerization, the
relative stabilities of 3a–d and 4a–d were calculated at the
B3LYP/6-31G** level (see Scheme 2 and Table 1). The theoretical
calculations were in good agreement with the experimental
results.
Finally, proving the hypothesis valid, 3c,d and 4c were isolated
as black prismatic single crystals by diffusion crystallization from
toluene/CS2 or benzene/CS2. The crystal structures of 3c, 3d and
4c with partial atomic numbering are shown in Fig. 3. These com-
ꢀ
pounds crystallize in space group P1 with one Ph3SiCH2NC60 or
Ph3GeCH2NC60 molecule and one solvent molecule (toluene or
benzene) in the unit cell. The C1–C5 addition regiochemistry for
3c and 3d is [5,6] as seen in the crystal structures shown in Figs.
3 and 4. The C1–C5 distances (2.134 and 2.141 Å) for 3c and 3d
are clearly non-bonded. This distance is of the same order of mag-
nitude as in C70CCl2 fulleroid (2.135 (1) Å) and C60C3NPyPh2 bis-
fulleroid (2.279 (4) Å) [6]. For 3c and 3d, the C5–C6 (1.380 (3)
and 1.384 (3) Å), C7–C8 (1.401 (3) and 1.406 (3) Å) and C9–C1
(1.386 (3) and 1.391 (3) Å) bonds possess double bond character,
whereas the others are single bonds (1.451 (3)–1.486 (3) and
1.444 (3)–1.483 (3) Å, respectively). Thus, 3c and 3d have an
open-bridged annulene structure as shown in Scheme 1. The fulle-
roid preserves 60p electrons, similar to C60, which depends on the
presence of a homoconjugate interaction in the bridged annulene
moiety. The pyramidalization angles based on X-ray geometry for
3c and 3d are 7.1° and 7.3° (C1, C5), 9.5° and 9.6° (C2, C4), 10.5°
and 10.6° (C3), 10.0° and 9.9° (C6, C9), and 11.0° and 11.0° (C7,
C8), which are similar to the reported values for C60NH (8.1°,
10.0°, 10.4°, 10.2° and 10.9°, respectively) (see Fig. 3 and Table 2)
[7c]. The pyramidalization angle for normal fullerene C60 is 11.6°,
and therefore, the values for 3c and 3d indicate that the azafulle-
roid preserves the structure of fullerene C60. The 3D-HMO reso-
nance integral b1.5 equals 0.39 b and 0.38 b for 3c and 3d,
respectively (C1 and C5 averaged for X-ray crystal data), which ex-
Fig. 1. 13C NMR spectra in a CS2: CDCl3 = 3:2 solution; (a) 2a, (b) 3a and (c) 4a.

632
H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
Fig. 2. MALDI-TOF mass spectra of 2a in a 1,1,4,4-tetraphenyl-1,3-butadiene matrix; (a) positive ion reflectron mode and (b) negative ion reflectron mode.
In order to insure that the silylphenyl group alone is capable of
interacting with neighboring fullerenes, single crystal growth of 3c
from CH2Cl2/CS2 solvent resulting in crystallization without sol-
vent inclusion was attempted, as shown in Fig. 5 (bottom). The
crystal packing of 3c shows no face-to-face contacts between the
silylphenyl groups and C60, but has three edge-to-face silylphe-
nyl-C60 interactions in the 2.632–2.855 Å range. The crystal pack-
ing of 4c ꢁ benzene and 3d ꢁ toluene showed additional
interactions, specifically four (4c) and two (3d) edge-to-face inter-
actions between silylphenyl groups, and two (4c) and four (3d)
edge-to-face silylphenyl group-C60 interactions in the 2.845–
2.854 Å and 2.780–2.862 Å range, respectively. Thus, interactions
Scheme 2. Isomerization of azafulleroid 3 to aziridinofullerene 4.
occur with and without participation of solvent, a likely explana-
tion for the ordered structures of these crystals.
In conclusion, the X-ray structures of azafulleroid 3c, 3d and
aziridinofullerene 4c have been obtained with the help of effective
silyl and germylphenyl-C60 interactions. These results suggest that
the introduction of silyl and germylphenyl groups can be useful in
obtaining crystals of chemically modified fullerenes [12].
Table 1
Relative energies (kcal molꢀ1) of 3a–d and 4a–d calculated at the B3LYP/ 6-31G**
basis set.
Azafulleroid (3)
Aziridinofullerene (4)
a: E = Si, R1 = R2 = R3 = Me
+0.69
+0.78
+0.95
+0.87
+1.23
+0.43
0.00
0.00
0.00
0.00
0.00
0.00
b-1: E = Si, R1 = Ph, R2 = R3 = Me
b-2: E = Si, R1 = Me, R2 = Ph, R3 = Me
b-3: E = Si, R1 = R2 = Me, R3 = Ph
c: E = Si, R1 = R2 = R3 = Ph
3. Experimental
3.1. General data
d: E = Ge, R1 = R2 = R3 = Ph
1H and 13C NMR spectra were recorded on a JEOL JNM-ECP500
operating at 500 or 125 MHz, respectively. IR spectra were re-
corded on a JASCO FT/IR-4100. MALDI-TOF mass spectra were re-
to-face on another C60 in the next infinite chain. These edge-to-face
(CH/ ) silylpheny-C60 interactions are in the 2.733–2.892 Å range.
p
corded on
a Shimadzu AXIMA-CFR. EI mass spectra were
Although toluene solvent molecules are omitted for clarity, toluene
also contacts with C60 in the next infinite chain, face-to-face, in the
3.290–3.394 Å range.
recorded on a JEOL JMS-AX505H. UV spectra were recorded on a
JASCO V-550. GPLC (gel permeation liquid chromatography) was
performed on an LC-908 (Japanese Analytical Industry, Co., Ltd.)

H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
633
Fig. 3. X-ray crystal structures of 3c ꢁ toluene (left), 3d ꢁ toluene (middle) and 4c ꢁ toluene (right).
Fig. 4. The partial atomic numbering of azafulleroid
aziridinofullerene 4 ([6,6]close, right).
3 ([5,6]open, left) and
Table 2
Pyramidalization angles (°) of 3c and 3d based on X-ray and calculated geometries.
C1, C5
C2, C4
C3
C6, C9
C7, C8
3ca
7.1
7.6
7.3
7.6
8.1
9.5
9.6
9.6
9.6
10.0
10.5
10.5
10.6
10.5
10.4
10.0
10.0
9.9
9.9
10.2
11.0
10.9
11.0
10.9
10.9
3cb
3da
3db
C60NHc
a
Geometry of X-ray crystal data.
Geometry optimized using B3LYP/6-31G** basis set.
See Ref. [7c].
b
c
Fig. 5. Crystal packing of 3c ꢁ toluene (top) and 3c (bottom), with close contacts
among silylphenyl groups and neighboring fullerenes shown in dashed lines.
equipped with JAIGEL 1H and 2H columns (eluent: toluene). Melt-
ing points were determined on a Yanaco MP-S3.
Yield: 76% (yellow oil). 1H NMR (500 MHz, CDCl3) d 0.40 (6H, s),
2.98 (2H, s,), 7.38–7.54 (5H, m); 13C NMR (125 MHz, CDCl3) dꢀ4.14,
3.2. Azide compounds 1b–d
41.43, 128.04, 129.73, 133.64, 136.07; IR (neat)
t
= 2083 cmꢀ1; MS
(EI) calcd. for C8H11Si ([MꢀCH2N3]+), 135, found, 135.
3.2.1. Typical procedure: dimethylphenylsilylmethylazide (1b)
A mixture of Me2PhSiCH2Cl (5.18 mmol) and NaN3 (6.23 mmol,
1.2 equiv.) in DMPU (15 ml) was stirred heating at 80 °C for 14 h
under argon atmosphere. The reaction mixture was washed with
water, extracted with toluene and hexane, and dried over Na2SO4.
The solvent was removed under reduced pressure, and the crude
product was purified by GPLC (eluent: toluene) to afford
Me2PhSiCH2N3.
3.2.2. Triphenylsilylmethylazide (1c)
Yield: 76% (colorless crystals). m.p. 99 °C; 1H NMR (500 MHz,
CDCl3) d 3.61 (2H, s), 7.39–7.57 (15H, m); 13C NMR (125 MHz,
CDCl3)
= 2098 cmꢀ1
([M+H]+), 316, found, 316.
d
39.59, 128.15, 130.21, 132.35, 135.70; IR (KBr)
t
;
MS (MALDI-TOF mass) calcd. for C19H18N3Si

634
H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
3.2.3. Triphenylgermylmethylazide (1d)
by column chromatography (eluent: CS2) to afford the azafulleroid
Me3SiCH2NC60 (3a) as the major product, and the aziridinofulle-
rene Me3SiCH2NC60 (4a) as the minor. Aziridinofullerene Me3-
SiCH2NC60 (4a) (0.019 mmol) was also obtained by heating a
solution of Me3SiCH2N3C60 (2a) in ODCB (2 ml) at 170 °C for 24 h
under argon atmosphere. The crude product was purified by col-
umn chromatography (eluent: CS2) or GPLC (eluent: toluene) to af-
ford 4a as the major product.
Yield: 63% (colorless crystals). m.p. 92 °C; 1H NMR (500 MHz,
CDCl3) d 3.68 (2H, s), 7.40–7.52 (15H, m); 13C NMR (125 MHz,
CDCl3)
t
found, 305.
d 39.78, 128.49, 129.58, 134.90, 135.37; IR (KBr)
= 2089 cmꢀ1; MS (EI) calcd. for C18H15Ge ([MꢀCH2N3]+), 305,
3.3. Triazoline adducts 2a–d
3a: yield: 19% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 0.38 (9H, s), 3.44 (2H, s); 13C NMR (125 MHz,
CS2:CDCl3 = 3:2) d ꢀ1.63, 43.00, 133.47, 135.28, 135.91, 136.76,
136.98, 137.55, 137.79, 138.24, 138.94, 140.42, 140.98, 142.27,
142.47, 142.54, 142.64, 142.83, 143.12, 143.37, 143.55, 143.88,
143.93, 144.01, 144.07, 144.19, 144.23, 144.50, 144.79, 147.59,
149.00; MS (MALDI-TOF mass) calcd. for C64H10NSi ([MꢀH]ꢀ),
821, found, 821.
4a: yield: 17%: when obtained as the major product (black so-
lid). m.p. >300 °C; 1H NMR (500 MHz, CS2:CDCl3 = 3:2) d 0.49
(9H, s), 3.25 (2H, s); 13C NMR (125 MHz, CS2:CDCl3 = 3:2) d
ꢀ1.91, 41.91, 86.69, 140.53, 141.87, 142.09, 142.61, 142.80,
143.54, 144.22, 144.27, 144.33, 144.84; MS (MALDI-TOF mass)
calcd. for C64H10NSi ([MꢀH]ꢀ), 821, found, 821.
3.3.1. Ttypical procedure: [6,6]-(1-N-trimethylsilylmethyl-triazoline)-
C60 (2a)
A mixture of fullerene C60 (0.500 mmol) and (1a) (0.501 mmol,
1.0 equiv.) in ODCB (36 ml) was stirred heating at 50 °C for 6 h un-
der argon atmosphere. The solvent was removed under reduced
pressure, and the crude product was purified by GPLC (eluted tol-
uene) to afford Me3SiCH2N3C60 (2a) as a black solid.
Yield: 28% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 0.50 (9H, s), 3.62 (2H, s); 13C NMR (125 MHz,
CS2:CDCl3 = 3:2) d ꢀ1.43, 38.59, 83.17, 103.99, 135.64, 136.44,
139.96, 140.40, 140.43, 141.59, 141.78, 141.92, 142.19, 142.25,
142.39, 142.53, 142.68, 142.80, 143.61, 144.13, 144.75, 144.78,
144.85, 145.00, 145.10, 145.42, 145.58, 145.78, 145.87, 145.93,
147.06, 147.25; MS (MALDI-TOF mass) calcd. for C64H10N3Si
([MꢀN2ꢀH]ꢀ), 821, found, 821; UV–Vis (toluene) kmax/nm (
e) 427
3.4.2. [5,6]-(1-N-dimethylphenylsilylmethyl-azafulleroid)-C60 (3b)
and [6,6]-(1-N-dimethylphenylsilylmethyl-fulleroaziridine)-C60 (4b)
3b: yield: 22% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 0.66 (6H, s), 3.62 (2H, s), 7.36–7.76 (5H, m);
13C NMR (125 MHz, CS2:CDCl3 = 3:2) d ꢀ3.26, 42.62, 127.97,
129.48, 133.50, 133.84, 134.15, 135.31, 135.96, 136.91, 136.97,
137.56, 137.80, 138.26, 138.95, 140.46, 141.02, 142.29, 142.50,
142.57, 142.67, 142.82, 142.88, 142.96, 143.15, 143.31, 143.39,
143.56, 143.91, 144.01, 144.09, 144.22, 144.52, 144.81, 147.60,
148.72; MS (MALDI-TOF mass) calcd. for C69H12NSi ([MꢀH]ꢀ),
883, found, 883.
4b: yield: 19%: when obtained as the major product (black so-
lid). m.p. >300 °C; 1H NMR (500 MHz, CS2:CDCl3 = 3:2) d 0.76
(6H, s), 3.42 (2H, s), 7.36–7.77 (5H, m); 13C NMR (125 MHz,
CS2:CDCl3 = 3:2) d ꢀ3.62, 41.49, 86.41, 127.36, 127.70, 129.55,
129.83, 134.11, 134.76, 136.18, 140.33, 141.87, 142.05, 142.58,
142.78, 143.54, 144.24, 144.27, 144.29, 144.86; MS (MALDI-TOF
mass) calcd. for C69H12NSi ([MꢀH]ꢀ), 883, found, 883.
(2900).
3.3.2. [6,6]-(1-N-dimethylphenylsilylmethyl-triazoline)-C60 (2b)
Yield: 36% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 0.82 (6H, s), 3.82 (2H, s), 7.41–7.44 (5H, m);
13C NMR (125 MHz, CS2:CDCl3 = 3:2)
d
ꢀ2.87, 38.14, 83.09,
104.03, 127.96, 129.56, 130.28, 132.60, 133.75, 135.71, 136.24,
136.47, 139.98, 140.25, 140.41, 141.62, 141.80, 141.92, 141.94,
142.20, 142.25, 142.40, 142.56, 142.70, 143.63, 144.13, 144.71,
144.81, 144.88, 145.11, 145.45, 145.60, 145.61, 145.77, 145.81,
145.90, 145.94, 147.11, 147.28; MS (MALDI-TOF mass) calcd. for
C69H12N3Si ([MꢀN2ꢀH]ꢀ), 883, found, 883; UV–Vis (toluene)
kmax/nm (e) 427 (3200).
3.3.3. [6,6]-(1-N-triphenylsilylmethyl-triazoline)-C60 (2c)
Yield: 31% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 4.44 (2H, s), 7.45–7.78 (15H, m); 13C NMR
(125 MHz, CS2:CDCl3 = 3:2)
d 35.89, 82.85, 104.33, 128.00,
132.60, 135.58, 135.73, 136.50, 139.98, 140.02, 140.35, 141.60,
141.75, 141.88, 142.16, 142.23, 142.35, 142.50, 142.65, 143.57,
144.10, 144.63, 144.75, 144.83, 145.04, 145.37, 145.55, 145.57,
145.68, 145.79, 145.84, 145.90, 147.04, 147.23; MS (MALDI-TOF
mass) calcd. for C79H16N3Si ([MꢀN2ꢀH]ꢀ), 1007, found, 1007;
3.4.3. [5,6]-(1-N-triphenylsilylmethyl-azafulleroid)-C60 (3c) and [6,6]-
(1-N-triphenylsilylmethyl-fulleroaziridine)-C60 (4c)
3c: yield: 41% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 4.23 (2H, s), 7.41–7.78 (15H, m); 13C NMR
(125 MHz, CS2:CDCl3 = 3:2)
d 41.31, 125.17, 128.06, 129.97,
UV–Vis (toluene) kmax/nm (e) 427 (3300).
132.80, 133.60, 135.41, 136.06, 136.80, 137.28, 137.50, 137.86,
138.23, 138.98, 140.49, 141.03, 142.32, 142.50, 142.54, 142.64,
142.89, 142.95, 143.14, 143.33, 143.37, 143.52, 143.80, 143.85,
143.99, 144.04, 144.14, 144.17, 144.49, 144.75, 147.55, 148.32;
MS (MALDI-TOF mass) calcd. for C79H16NSi ([MꢀH]ꢀ), 1007, found,
1007.
3.3.4. [6,6]-(1-N-triphenylgermylmethyl-triazoline)-C60 (2d)
Yield: 26% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 4.47 (2H, s), 7.39–7.66 (15H, m); 13C NMR
(125 MHz, CS2:CDCl3 = 3:2) d 36.28, 82.83, 104.78, 128.41, 129.38,
134.95, 134.97, 135.72, 136.59, 140.03, 140.43, 141.68, 141.83,
141.91, 141.95, 142.23, 142.28, 142.43, 142.58, 142.72, 143.65,
144.17,144.66, 144.74, 144.84, 144.91, 145.12, 145.45, 145.63,
145.65, 145.72, 145.85, 145.94, 145.98, 147.14, 147.32; MS (MAL-
DI-TOFmass)calcd. forC79H17N3Ge([MꢀN2+S]ꢀ), 1085, found, 1085.
4c: yield: 33%: when obtained as the major product (black so-
lid). m.p. >300 °C; 1H NMR (500 MHz, CS2:CDCl3 = 3:2) d 4.03
(2H, s), 7.40–7.85 (15H, m); 13C NMR (125 MHz, CS2:CDCl3 = 3:2)
d 39.72, 86.15, 128.12, 130.00, 132.62, 136.17, 140.12, 141.87,
142.04, 142.53, 142.78, 143.53, 144.26, 144.87; MS (MALDI-TOF
mass) calcd. for C79H16NSi ([MꢀH]ꢀ), 1007, found, 1007; UV–Vis
3.4. Azafulleroid 3a–d and aziridinofullerene 4a–d
(toluene) kmax/nm (e) 428 (2600), 498 (1800).
3.4.1. Typical procedure: [5,6]-(1-N-trimethylsilylmethyl-
azafulleroid)-C60 (3a) and [6,6]-(1-N-trimethylsilylmethyl-
fulleroaziridine)-C60 (4a)
Solid Me3SiCH2N3C60 (2a) (0.019 mmol) was heated at 100 °C
for 33 h under argon atmosphere. The crude product was purified
3.4.4. [5,6]-(1-N-triphenylgermylmethyl-azafulleroid)-C60 (3d) and
[6,6]-(1-N-triphenylgermylmethyl-fulleroaziridine)-C60 (4d)
3d: yield: 41% (black solid). m.p. >300 °C; 1H NMR (500 MHz,
CS2:CDCl3 = 3:2) d 4.35 (2H, s), 7.42–7.78 (15H, m); 13C NMR
(125 MHz, CS2:CDCl3 = 3:2)
d 41.91, 128.35, 129.29, 134.81,

H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
635
Table 4
135.11, 135.92, 136.75, 137.05, 137.34, 138.17, 138.94, 140.11,
Crystal data and data collection parameters.
140.43, 140.96, 142.32, 142.43, 142.49, 142.61, 142.76, 142.84,
142.90, 143.09, 143.33, 143.47, 143.77, 143.80, 143.94, 144.01,
144.13, 144.26, 144.42, 144.71, 144.85, 147.50, 148.21; MS (MAL-
DI-TOF mass) calcd. for C79H17NGe ([M+S]ꢀ), 1085, found, 1085.
4d: yield: 9%: when obtained as the major product (black solid).
m.p. >300 °C; 1H NMR (500 MHz, CS2:CDCl3 = 3:2) d 4.17 (2H, s),
7.40–7.78 (15H, m); 13C NMR (125 MHz, CS2:CDCl3 = 3:2) d 40.78,
86.36, 128.47, 129.41, 134.88, 135.36, 140.15, 141.89, 142.03,
142.57, 142.80, 142.90, 143.57, 144.30, 144.32, 144.90; MS (MAL-
DI-TOF mass) calcd. for C79H17NGe ([M+S]ꢀ), 1085, found, 1085.
3d ꢁ toluene
C86H25NGe
1144.66
150 (2)
4c ꢁ benzene
C85H23NSi
1086.13
150 (2)
Empirical formula
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
a (Å)
0.71073
Triclinic
0.71073
Triclinic
ꢀ
ꢀ
P1
P1
9.993 (2)
13.433(2)
18.848(4)
101.149 (11)
96.146 (8)
106.582 (8)
2343.6 (8)
2
10.040 (5)
13.292 (9)
18.748 (9)
100.53 (19)
97.75 (24)
106.11 (18)
2317.1 (23)
2
b (Å)
c (Å)
a
(°)
b (°)
3.5. X-ray crystallography
c
(°)
Volume (Å3)
Z
Single crystals of 3c, 3d and 4c suitable for X-ray diffraction
study were mounted on a Rigaku RAXIS RAPID S Imaging Plate dif-
Density (calculated) (g/cm3)
Absorption coefficient (mmꢀ1
F(000)
1.622
0.717
1160
1.557
0.114
1108
)
fractometer with Mo K
a (graphite monochromated, k = 0.71073)
radiation. Crystal data and statistics are summarized in Tables 3
and 4. The structures were solved by direct methods (SHELXS-97
[8] and SIR 2004 [9]) using the WinGX v1.70.01 interface [10]. The
non-hydrogen atoms were refined anisotropically by full-matrix
least-square methods (SHELXL-97) [8]. The hydrogen atoms were
placed at calculated positions and kept fixed. In subsequent refine-
Crystal size (mm)
Theta range for data collection 3.01–27.48
(°)
0.75 ꢃ 0.38 ꢃ 0.30
0.75 ꢃ 0.18 ꢃ 0.10
3.00–27.48
Index ranges
ꢀ12 6 h 6 10
ꢀ17 6 k 6 17
ꢀ24 6 l 6 24
22862
10646 (0.0338)
99.0
ꢀ13 6 h 6 12
ꢀ17 6 k 6 17
ꢀ24 6 l 6 24
22379
10400 (0.0886)
97.9
Reflections collected
P
2
ment, the function
x
ðF2o ꢀ F2c Þ was minimized, where |Fo| and
Independent reflections [R(int)
Completeness to theta (%)
Absorption correction
Refinement method
]
|Fc| are the observed and calculated structure factor amplitudes,
None
None
respectively.
The
agreement
|Fo| and wR2 ¼ ½
indices
x
are
defined
as
Full-matrix least-
squares on F2
10646/0/793
1.013
Full-matrix least-
squares on F2
10400/0/784
1.033
P
P
2
1=2
R1 =
R
(||Fo| ꢀ |Fc||)/
R
ðF2o ꢀ F2c Þ =
ð
x
F4oÞꢂ
.
Data/restraints/parameters
Goodness-of-fit (GOF)
indicator
3.5.1. Crystallographic data for 3c ꢁ toluene and 3c
See Table 3.
Final R indices [I > 2
r
(I)]
R1 = 0.0461,
R1 = 0.0857,
wR2 = 0.1109
R1 = 0.0600,
wR2 = 0.1174
0.606 and ꢀ0.624
wR2 = 0.1345
R1 = 0.1715,
wR2 = 0.1585
0.349 and ꢀ0.490
Table 3
R indices (all data)
Crystal data and data collection parameters.
Largest difference peak and
hole (e Åꢀ3
3c ꢁ toluene
C86H25NSi
1100.16
150 (2)
3c
)
Empirical formula
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
a (Å)
C79H17NSi
1008.03
150 (2)
3.5.2. Crystallographic data for 3d ꢁ toluene and 4c ꢁ benzene
0.71073
Triclinic
0.71073
Triclinic
See Table 4.
ꢀ
ꢀ
P1
P1
9.9609 (15)
13.423 (3)
18.859 (4)
101.006 (7)
96.025 (7)
106.643 (9)
2337.1 (8)
2
10.140 (6)
13.348 (7)
16.682(11)
76.47 (2)
86.077 (17)
74.259 (19)
2113 (2)
2
3.6. Computational studies
b (Å)
c (Å)
Calculations were carried out on HPC-P4/GLW and HPC3000-
XC104T workstations provided by HPC Inc. in Japan. All geometric
optimizations were optimized by DFT calculations at the B3LYP/6-
31G level using Gaussian 03 programs with no symmetry restric-
tions [11]. The POAV/3D-HMO analyses were performed using the
POAV3 program [7c].
a
(°)
b (°)
c
(°)
Volume (Å3)
**
Z
Density (calculated) (g/cm3)
Absorption coefficient (mmꢀ1
F(000)
1.563
0.114
1124
1.584
0.118
1024
)
Crystal size (mm)
Theta range for data collection 3.02–27.48
0.50 ꢃ 0.50 ꢃ 0.20
0.75 ꢃ 0.38 ꢃ 0.30
Acknowledgments
3.08–27.47
(°)
This work was supported by Grant-in Aid for a High-Tech Re-
search Center Project from the Ministry of Education, Culture,
Sports, Science and Technology, Japan. The authors are grateful to
the Shin-Etsu Chemical Co. Ltd. and the Asai Germanium Co. Ltd.
for providing the chlorosilanes and tetrachlorogermane.
Index ranges
ꢀ12 6 h 6 11
ꢀ17 6 k 6 17
ꢀ23 6 l 6 24
22685
10568 (0.0356)
98.5
ꢀ12 6 h 6 13
ꢀ16 6 k 6 17
ꢀ21 6 l 6 21
22379
8823 (0.0911)
91.2
Reflections collected
Independent reflections [R(int)
Completeness to theta (%)
Absorption correction
Refinement method
]
None
None
Full-matrix least-
squares on F2
10568/0/893
1.035
Full-matrix least-
squares on F2
8823/0/730
1.048
References
Data/restraints/parameters
Goodness-of-fit (GOF)
indicator
[1] (a) Cocrystalization of fullerenes with porphyrins, see: M.M. Olmstead, D.A.
Costa, K. Maitra, B.C. Noll, S.L. Phillips, P.M. Van Calcar, A.L. Balch, J. Am. Chem.
Soc. 121 (1999) 7090;
(b) P.D.W. Boyd, C.A. Reed, Acc. Chem. Res. 38 (2005) 235;
(c) . Benzenes:M.F. Meidine, P.B. Hitchcock, H.W. Kroto, R. Taylor, D.R.M.
Walton, J. Chem. Soc., Chem. Commun. (1992) 1534;
(d) A.L. Balch, J.W. Lee, B.C. Noll, M.M. Olmstead, J. Chem. Soc., Chem.
Commun. (1993) 56;
Final R indices [I > 2
r
(I)]
R1 = 0.0535,
wR2 = 0.1224
R1 = 0.0711,
wR2 = 0.1310
0.402 and ꢀ0.451
R1 = 0.1258,
wR2 = 0.3092
R1 = 0.2338,
wR2 = 0.3740
0.672 and ꢀ0.325
R indices (all data)
Largest difference peak and
hole (e Åꢀ3
(e) H.B. Bürgi, R. Restori, D. Schwarzenbach, A.L. Balch, J.W. Lee, B.C. Noll, M.M.
Olmstead, Chem. Mater. 6 (1994) 1325;
)

636
H. Hachiya et al. / Journal of Organometallic Chemistry 694 (2009) 630–636
(f) . Others cited in:D.V. Konarev, R.N. Lyubovskaya, N.V. Drichko, E.I.
Yudanova, Y.M. Shul‘ga, A.L. Litvinov, V.N. Semkin, B.P. Tarasov, J. Mater.
Chem. 10 (2000) 803.
(o) N. Wang, J. Li, D. Zhu, T.H. Chan, Tetrahedron Lett. 36 (1995) 431;
(p) A.B. Smith III, H. Tokuyama, Tetrahedron 52 (1996) 5257;
(q) G. Schick, A. Hirsch, H. Mauser, T. Clark, Eur. Chem. J. 2 (1996) 935;
(r) C.K.-F. Shen, K.-M. Chien, C.-G. Juo, G.-R. Her, T.-Y. Luh, J. Org. Chem. 61
(1996) 9242;
(s) B. Nuber, F. Hampel, A. Hirsch, Chem. Commun. (1996) 1799;
(t) A. Ikeda, C. Fukuhara, S. Shinkai, Chem. Lett. 26 (1997) 407;
(u) C. Bellavia-Lund, F. Wudl, J. Am. Chem. Soc. 119 (1997) 943;
(v) A. Ikeda, C. Fukuhara, S. Shinkai, Chem. Lett. 27 (1998) 915;
(w) P.P. Kanakamma, S.-L. Huang, C.-G. Juo, G.-R. Her, T.-Y. Luh, Chem. Eur. J. 4
(1998) 2037;
[2] (a) Review of transition metal complexes and supramolecular complexes with
fullerenes, see: A.L. Balch, M.M. Olmstead, Chem. Rev. 98 (1998) 2123;
(b) . Ir-complexs involving brnzylether of fullerenes:A.L. Balch, V.J. Catalano,
J.W. Lee, M.M. Olmstead, J. Am. Chem. Soc. 114 (1992) 5455;
(c) V.J. Catalano, N. Parodi, Inorg. Chem. 36 (1997) 537;
(d) F. Diederich, M. Gómez-López, Chem. Soc. Rev. 28 (1999) 263;
(e) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 98 (1998) 2527;
(f) E.C. Constable, Angew. Chem., Int. Ed. 33 (1994) 2269.
[3] (a) S.I. Khan, A.M. Oliver, M.N. Paddon-Row, Y. Rubin, J. Am. Chem. Soc. 115
(1993) 4919;
(x) C.-F. Chen, J.-S. Li, G.-J. Ji, Q.-Y. Zheng, D.-B. Zhu, Synth. Commun. 28 (1998)
3097;
(b) F. Diederich, U. Jonas, V. Gramlich, A. Hermann, H. Ringsdorf, C. Thilgen,
Helv. Chim. Acta 76 (1993) 2445;
(c) P. Seiler, A. Hermann, F. Diederich, Helv. Chim. Acta 78 (1995) 344;
(d) T. Ishida, K. Shinozuka, T. Nogami, S. Sasaki, M. Iyoda, Chem. Lett. 24 (1995)
317;
(y) M. Iglesias, B. Gómez-Lor, A. Santos, J. Organomet. Chem. 599 (2000) 8;
(z) A. Ouchi, R. Hatsuda, B.Z.S. Awen, M. Sakurai, R. Ogura, T. Ishii, T. Araki, O.
Ito, J. Am. Chem. Soc. 124 (2002) 13364;
(a’) L. Ulmer, J. Mattay, Eur. J. Org. Chem. (2003) 2933;
(b’) G.-S. Tang, X.-L. Chen, S.-Y. Zhang, J. Wang, Org. Lett. 6 (2004) 3925;
(c’) A. Ouchi, B.Z.S. Awen, H. Luo, Y. Araki, O. Ito, Tetrahedron Lett. 46 (2005)
6713;
(e) H. Imgartinger, C.-M. Köhler, G. Baum, D. Fenske, Liebigs Ann. Chem. (1996)
1609;
(f) H. Irngartinger, A. Weber, T. Oeser, Angew. Chem., Int. Ed. 38 (1999) 1279;
(g) J. Osterodt, M. Nieger, F. Vögtle, J. Chem. Soc., Chem. Commun. (1994)
1607;
(h) F. Djojo, A. Herzog, I. Lamparth, F. Hampel, A. Hirsch, Chem. Eur. J. 2 (1996)
1537;
(d’) S. Minakata, R. Tsuruoka, T. Nagamachi, Mitsuo Komatsu, Chem. Commun.
(2008) 323.
[6] (a) X-ray structures of fulleroid and bisfulleroid: A.F. Kiely, R.C. Haddon, M.S.
Meier, J.P. Selegue, C.P. Brock, B.O. Patrick, G.-W. Wang, Y. Chen, J. Am. Chem.
Soc. 121 (1999) 7971;
(i) H.M. Lee, M.M. Olmstead, E. Iezzi, J.C. Duchamp, H.C. Dorn, A.L. Balch, J. Am.
Chem. Soc. 124 (2002) 3494;
(j) E. Iezzi, J.C. Duchamp, K. Harich, T.E. Glass, H.M. Lee, M.M. Olmstead, A.L.
Balch, H.C. Dorn, J. Am. Chem. Soc. 124 (2002) 524.
(b) Y. Murata, M. Murata, K. Komatsu, Chem. Eur. J. 9 (2003) 1600.
[7] (a) POAV/3D-HMO analyses: R.C. Haddon, Acc. Chem. Res. 21 (1988) 243;
(b) R.C. Haddon, Science 261 (1993) 1545;
(c) R.C. Haddon, K. Raghavachari, Tetrahedron 52 (1996) 5207. POAV3
program is available from QCPE.
[4] Simulaneously but independently Prof. Akasaka was also able to characterize a
[5,6]-azafulleroid and [6,6]-azamethanofullerene by X-ray crystallography
using N-tosylsulfilimine with C60
: T. Nakahodo, M. Okada, H. Morita, T.
[8] G.M. Sheldrick, Program for the Solution of Crystal Structures, University of
Göttingen, Germany.
Yoshimura, M.O. Ishitsuka, T. Tsuchiya, Y. Maeda, H. Fujihara, T. Akasaka, X.
Gao, S. Nagase, Angew. Chem., Int. Ed. 47 (2008) 1298.
[5] (a) M. Prato, Q.C. Li, F. Wudl, V. Lucchini, J. Am. Chem. Soc. 115 (1993) 1148;
(b) M. Yan, S.X. Cai, J.F.W. Keana, J. Org. Chem. 59 (1994) 5951;
(c) L.-L. Shiu, K.-M. Chien, T.-Y. Liu, T.-I. Lin, G.-R. Her, S.-L. Huang, T.-Y. Luh, J.
Chem. Soc., Perkin Trans. 1 (1994) 3355;
[9] M.C. Burla, R. Caliandro, M. Camalli, B. Carrozzini, G.L. Cascarano, L. De Caro, C.
Giacovazzo, G. Polidori, R. Spagna, J. Appl. Cryst. 38 (2005) 381.
[10] L.J. Farrugia, J. Appl. Cryst. 32 (1999) 837.
[11] GAUSSIAN 03 (Revision C.02): M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria,
M.A. Robb, J.R. Cheeseman, J.A. Montgomery Jr., T. Vreven, K.N. Kudin, J.C.
Burant, J.M. Millam, S.S. Iyengar, J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G.
Scalmani, N. Rega, G.A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R.
Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, M.
Klene, X. Li, J.E. Knox, H.P. Hratchian, J.B. Cross, C. Adamo, J. Jaramillo, R.
Gomperts, R.E. Stratmann, O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W.
Ochterski, P.Y. Ayala, K. Morokuma, G.A. Voth, P. Salvador, J.J. Dannenberg, V.G.
Zakrzewski, S. Dapprich, A.D. Daniels, M.C. Strain, O. Farkas, D.K. Malick, A.D.
Rabuck, K. Raghavachari, J.B. Foresman, J.V. Ortiz, Q. Cui, A.G. Baboul, S.
Clifford, J. Cioslowski, B.B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I.
Komaromi, R.L. Martin, D.J. Fox, T. Keith, M.A. Al-Laham, C.Y. Peng, A.
Nanayakkar, M. Challacombe, P.M.W. Gill, B. Johnson, W. Chen, M.W. Wong,
C. Gonzalez, J.A. Pople, GAUSSIAN, Inc., Wallingford CT, 2004.
(d) M.R. Banks, J.I.G. Cadogan, I. Gosney, P.K.G. Hodgson, P.R.R. Langridge-
Smith, D.W.H. Rankin, J. Chem. Soc., Chem. Commun. (1994) 1365;
(e) M. Takeshita, T. Suzuki, S. Shinkai, J. Chem. Soc., Chem. Commun. (1994)
2587;
(f) M.R. Banks, J.I.G. Cadogan, I. Gosney, P.K.G. Hodgson, P.R.R. Langridge-
Smith, J.R.A. Millar, A.T. Taylor, Tetrahedron Lett. 35 (1994) 9067;
(g) T. Ishida, K. Tanaka, T. Nogami, Chem. Lett. (1994) 561;
(h) C.J. Hawker, P.M. Saville, J.W. White, J. Org. Chem. 59 (1994) 3503;
(i) M.R. Banks, J.I.G. Cadogan, I. Gosney, P.K.G. Hodgson, P.R.R. Langridge-
Smith, J.R.A. Millar, A.T. Taylor, J. Chem. Soc., Chem. Commun. (1995) 885;
(j) M.R. Banks, J.I.G. Cadogan, I. Gosney, P.K.G. Hodgson, P.R.R. Langridge-
Smith, J.R.A. Millar, John A. Parkinson, D.W.H. Rankin, A.T. Taylor, J. Chem. Soc.,
Chem. Commun. (1995) 887;
[12] One of reviewers recommended
a carbon analog (E = C in Scheme 1) as
comparison with silyl and germylphenyl groups. However, the corresponding
Ph3CCH2N3 is unknown compound. The reaction of triphenylmethyl
derivatives such as Ph3CCH2X (X = halogen, MgX, etc.) as starting compound
seems to undergo an appreciable amount of a phenyl migration to afford
Ph2C@C(Cl)Ph or Ph2CXCHPh [J.C. Charlton, I. Dostrovsky, E.D. Hughes, Nature
167 (1951) 986; E.Grovenstein, A.B. Cottingham, L.T. Gelbaum, J. Org. Chem. 43
(1978) 3332]. So in the synthetic point of view, triphenylsilyl or germyl groups
are more easily accessible.
(k) L.-L. Shiu, K.-M. Chien, T.-Y. Liu, T.-I. Lin, G.-R. Her, T.-Y. Luh, J. Chem. Soc.,
Chem. Commun. (1995) 1159;
(l) G.-X. Dong, J.-S. Li, T.-H. Chan, J. Chem. Soc., Chem. Commun. (1995) 1725;
(m) G. Schick, T. Grösser, A. Hirsch, J. Chem. Soc., Chem. Commun. (1995)
2289;
(n) T. Grösser, M. Prato, V. Lucchini, A. Hirsch, F. Wudl, Angew. Chem., Int. Ed.
34 (1995) 1343;