Synthesis of metal fullerene complexes by the use of fullerene halides

Article abstract of DOI:10.1021/om8001262

K(C₆₀R₅) (1, R = Me, Ph) was generated by deprotonation of C₆₀R₅H (2) and allowed to react with N-fluoropyridinium triflate and N-chloro- and N-bromosuccinimide in benzene at 25°C for 10 min to obtain halogenated fullerenes C₆₀R ₅X (3a: R = Me, X = F; 3b: R = Me, X = Cl; 3c: R = Me, X = Br; 4a: R = Ph, X = F; 4b: R = Ph, X = Cl, 4c: R = Ph, X = Br) in good yield. The pentamethyl[60]fullerene halides are useful for the synthesis of a variety of η⁵-fullerene metal complexes. The reaction of the fullerene bromide 3c with the low-valent transition metal complexes Na[Re(CO) ₄], Fe(CO)₅, Ru₃(CO)₁₂, and Na[Co(CO)₄] gave Re(η⁵-C₆₀Me ₅)(CO)₃ (5), Fe(η⁵-C₆₀Me ₅)Br(CO)₂ (6), Ru(η⁵-C₆₀Me ₅)Br(CO)₂ (7), and Co(η⁵-C ₆₀Me₅)(CO)₂ (8), respectively. The structures of halide 3c and rhenium complex 5 were determined by X-ray crystallography. Electrochemical measurements on 3b and 3c were also performed. The iron complex 6 was converted into Fe(η⁵-C₆₀Me₅)Cp (9), Fe(η⁵-C₆₀Me₅)Me(CO)₂ (10), Fe(η⁵-C₆₀Me₅)(CO)₂(CCH) (11), and Fe(η⁵-C₆₀Me₅)(CO)₂(CCPh) (12), by ligand exchange reactions.

Full text of DOI:10.1021/om8001262

Organometallics 2008, 27, 3403–3409
3403
Synthesis of Metal Fullerene Complexes by the Use of Fullerene
Halides
Yutaka Matsuo,† Yoichiro Kuninobu,# Ayako Muramatsu,‡ Masaya Sawamura,§ and
Eiichi Nakamura*,†,‡
Nakamura Functional Carbon Cluster Project, ERATO, Japan Science and Technology Agency,
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Chemistry, The UniVersity of Tokyo,
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
ReceiVed February 13, 2008
K(C60R5) (1, R ) Me, Ph) was generated by deprotonation of C60R5H (2) and allowed to react with
N-fluoropyridinium triflate and N-chloro- and N-bromosuccinimide in benzene at 25 °C for 10 min to
obtain halogenated fullerenes C60R5X (3a: R ) Me, X ) F; 3b: R ) Me, X ) Cl; 3c: R ) Me, X ) Br;
4a: R ) Ph, X ) F; 4b: R ) Ph, X ) Cl, 4c: R ) Ph, X ) Br) in good yield. The pentamethyl[60]fullerene
halides are useful for the synthesis of a variety of η5-fullerene metal complexes. The reaction of the
fullerene bromide 3c with the low-valent transition metal complexes Na[Re(CO)4], Fe(CO)5, Ru3(CO)12,
and Na[Co(CO)4] gave Re(η5-C60Me5)(CO)3 (5), Fe(η5-C60Me5)Br(CO)2 (6), Ru(η5-C60Me5)Br(CO)2 (7),
and Co(η5-C60Me5)(CO)2 (8), respectively. The structures of halide 3c and rhenium complex 5 were
determined by X-ray crystallography. Electrochemical measurements on 3b and 3c were also performed.
The iron complex 6 was converted into Fe(η5-C60Me5)Cp (9), Fe(η5-C60Me5)Me(CO)2 (10), Fe(η5-
C60Me5)(CO)2(CCH) (11), and Fe(η5-C60Me5)(CO)2(CCPh) (12), by ligand exchange reactions.
crystalline materials,5d to form a photoinduced charge separation
state,6 and to effect asymmetric organic transformations.2f,g The
synthesis of these complexes has been achieved by the reaction
of a C60R5 anion (1)1,7 with appropriate transition metal halides
(Scheme 1a),2 by metal-mediated C-H bond activation of
C60R5H (2 in Scheme 1b),3 and by hydrometalation of
[60]fullerene (Scheme 1c).4 In this article, we report a fourth
approach that relies on the reaction of a fullerene halide (3 or
4) either with a metal anion or with a low-valent metal complex
(Scheme 1d,e).
The synthesis of penta(organo)fullerene halides C60R5X (X
) halides) was first described by R. Taylor et al. in 1994. They
synthesized C60Cl68 and allowed it to react with methyllithium
to obtain C60Me5Cl (3b)9 in 4.5% yield among other products,
or with benzene in the presence of FeCl3 to obtain C60Ph5Cl
(4b) in 68% yield.10 The synthesis of C60Me5X (3a: X ) F;
3b: X ) Cl; 3c: X ) Br) and C60Ph5X (4a: X ) F; 4b: X )
Introduction
The transition metal η5-fullerene complexes of type M(η5-
C60R5)Ln (M ) metal atoms, R ) organic groups, L )
ligands)1–5 belong to a new class of organometallic compounds
that exhibit unique functions, such as an ability to form liquid
* Corresponding author. E-mail: nakamura@chem.s.u-tokyo.ac.jp.
† Japan Science and Technology Agency.
# Present address: Graduate School of Natural Science and Technology,
Okayama University.
‡ The University of Tokyo.
§ Present address: Department of Chemistry, School of Science, Hokkaido
University.
(1) (a) Sawamura, M.; Iikura, H.; Nakamura, E. J. Am. Chem. Soc. 1996,
118, 12850. (b) Iikura, H.; Mori, S.; Sawamura, M.; Nakamura, E. J. Org.
Chem. 1997, 62, 7912. (c) Sawamura, M.; Iikura, H.; Ohama, T.; Hackler,
U. E.; Nakamura, E. J. Organomet. Chem. 2000, 599, 32. (d) Sawamura,
M.; Toganoh, M.; Kuninobu, Y.; Kato, S.; Nakamura, E. Chem. Lett. 2000,
270. (e) Nakamura, E.; Sawamura, M. Pure Appl. Chem. 2001, 73, 355. (f)
Hamasaki, R.; Matsuo, Y.; Nakamura, E. Chem. Lett. 2004, 33, 328. (g)
Zhong, Y.-W.; Matsuo, Y.; Nakamura, E. Org. Lett. 2006, 8, 1463. (h)
Matsuo, Y.; Iwashita, A.; Nakamura, E. Chem. Lett. 2006, 35, 858. (i)
Matsuo, Y.; Muramatsu, A.; Tahara, K.; Koide, M.; Nakamura, E. Org.
Synth. 2006, 83, 80.
(2) (a) Sawamura, M.; Kuninobu, Y.; Nakamura, E. J. Am. Chem. Soc.
2000, 122, 12407. (b) Matsuo, Y.; Nakamura, E. Organometallics 2003,
22, 2554. (c) Matsuo, Y.; Kuninobu, Y.; Ito, S.; Nakamura, E. Chem. Lett.
2004, 33, 328. (d) Kuninobu, Y.; Matsuo, Y.; Toganoh, M.; Sawamura,
M.; Nakamura, E. Organometallics 2004, 23, 3259. (e) Matsuo, Y.; Iwashita,
A.; Nakamura, E. Organometallics 2005, 24, 89. (f) Matsuo, Y.; Nakamura,
E. Inorg. Chim. Acta 2006, 359, 1979. (g) Matsuo, Y.; Mitani, Y.; Zhong,
Y.-W.; Nakamura, E. Organometallics 2006, 25, 2826. (h) Zhong, Y.-W.;
Matsuo, Y.; Nakamura, E. Chem. Asian J. 2007, 2, 358.
(3) (a) Sawamura, M.; Kuninobu, Y.; Toganoh, M.; Matsuo, Y.;
Yamanaka, M.; Nakamura, E. J. Am. Chem. Soc. 2002, 124, 9354. (b)
Nakamura, E. Pure Appl. Chem. 2003, 75, 427. (c) Nakamura, E. J.
Organomet. Chem. 2004, 689, 4630. (d) Herber, R. H.; Nowik, I.; Matsuo,
Y.; Toganoh, M.; Kuninobu, Y.; Nakamura, E. Inorg. Chem. 2005, 44, 5629.
(e) Matsuo, Y.; Isobe, H.; Tanaka, T.; Murata, Y.; Murata, M.; Komatsu,
K.; Nakamura, E. J. Am. Chem. Soc. 2005, 127, 17148. (f) Matsuo, Y.;
Tahara, K.; Nakamura, E. J. Am. Chem. Soc. 2006, 128, 7154.
(4) (a) Toganoh, M.; Matsuo, Y.; Nakamura, E. Angew. Chem., Int. Ed.
2003, 42, 3530. (b) Toganoh, M.; Matsuo, Y.; Nakamura, E. J. Am. Chem.
Soc. 2003, 125, 13974.
(5) (a) Sawamura, M.; Kawai, K.; Matsuo, Y.; Kanie, K.; Kato, T.;
Nakamura, E. Nature 2002, 419, 702. (b) Matsuo, Y.; Muramatsu, A.;
Hamasaki, R.; Mizoshita, N.; Kato, T.; Nakamura, E. J. Am. Chem. Soc.
2004, 126, 432. (c) Okada, S.; Arita, R.; Matsuo, Y.; Nakamura, E.;
Oshiyama, A.; Aoki, H. Chem. Phys. Lett. 2004, 399, 157. (d) Matsuo, Y.;
Muramatsu, A.; Kamikawa, Y.; Kato, T.; Nakamura, E. J. Am. Chem. Soc.
2006, 128, 9586. (e) Zhong, Y.-W.; Matsuo, Y.; Nakamura, E. J. Am. Chem.
Soc. 2007, 129, 3052.
(6) Guldi, D. M.; Rahman, G. M. A.; Marczak, R.; Matsuo, Y.;
Yamanaka, M.; Nakamura, E. J. Am. Chem. Soc. 2006, 128, 9420.
(7) Matsuo, Y.; Tahara, K.; Nakamura, E. Chem. Lett. 2005, 34, 1078.
(8) Birkett, P. R.; Avent, A. G.; Darwish, A. D.; Kroto, H. W.; Taylor,
R.; Walton, D. R. M. J. Chem. Soc., Chem. Commun. 1993, 1230.
(9) Al-Matar, H.; Abdul-Sada, A. K.; Avent, A. G.; Fowler, P. W.;
Hitchcock, P. B.; Rogers, K. M.; Taylor, R. J. Chem. Soc., Perkin Trans.
2 2002, 53.
(10) (a) Avent, A. G.; Birkett, P. R.; Crane, J. D.; Darwish, A. D.;
Langley, G. J.; Kroto, H. W.; Taylor, R.; Walton, D. R. M. J. Chem. Soc.,
Chem. Commun. 1994, 1463. (b) Birkett, P. R.; Taylor, R.; Wachter, N. K.;
Carano, M.; Paolucci, F.; Roffia, S.; Zerbetto, F. J. Am. Chem. Soc. 2000,
122, 4209. (c) Birkett, P. R.; Avent, A. G.; Darwish, A. D.; Hahn, I.; Kroto,
H. W.; Langley, G. J.; O’Loughlin, J.; Taylor, R.; Walton, D. R. M. J. Chem.
Soc., Perkin Trans. 2 1997, 1211.
10.1021/om8001262 CCC: $40.75
2008 American Chemical Society
Publication on Web 06/21/2008

3404 Organometallics, Vol. 27, No. 14, 2008
Matsuo et al.
Scheme 1
Figure 1. Cyclic voltammogram of 3b at a scan rate of 100 mV/s
at 25 °C in a 1.0 mM THF solution containing [Bu4N][ClO4] (100
mM) as supporting electrolyte.
Scheme 3
Scheme 2
adduct, C60Me5(2-pyridyl) (3d, 15% yield). The halides thus
obtained are air- and moisture-stable reddish-orange solids.
APCI-MS spectra of the products exhibited the parent ion
1
signals for all halides. In the H and 13C NMR spectra of the
pentamethylated fullerene halides 3a, 3b, and 3c, three signals
due to the methyl groups were observed in the ratio 2:2:1, in
1
Cl; 4c: X ) Br) is much more straightforward and high yielding.
Herein the fullerene bromide 3c was found to be useful for the
synthesis of the corresponding transition metal-penta(organo)-
fullerene complexes Re(η5-C60Me5)(CO)3 (5), Fe(η5-C60Me5)-
Br(CO)2 (6), Ru(η5-C60Me5)Br(CO)2 (7), and Co(η5-C60Me5)-
(CO)2 (8), which will find uses in materials applications.11,12
agreement with the expected Cs symmetry of 1a-c. The H
and 13C NMR spectra of the pentaphenylated fullerene halides
4a, 4b, and 4c also showed Cs symmetry, suggesting fast rotation
of the phenyl group on the NMR time scale.
Electrochemical Studies of Penta(organo)[60]fullerene
Halides. The redox properties of pentamethylated fullerene
halides 3b and 3c were examined. The electrochemistry of
C60Ph5Cl (4b) was previously reported by Birkett et al.10b Figure
1 shows the cyclic voltammogram of 3b in THF. The halide
3b showed no oxidation wave within the THF window, but
showed irreversible reduction waves on the reduction side. In
Results and Discussion
Synthesis and Characterization of Penta(organo)[60]-
fullerene Halides. Penta(organo)fullerene halides C60R5X 3a-c
and 4a-c were synthesized by reaction of the corresponding
potassium complex [K(thf)n][C60R5] (R ) Me, Ph, 1)1,7 with
N-fluoropyridinium triflate and N-chloro- and N-bromosuccin-
imide in benzene at room temperature in up to 92% yield
(Scheme 2). We could synthesize the halides also by the reaction
of the protio compound 2 with these halogenating reagents in
benzene at 50 °C, but the yield remained low (about 20%). The
synthesis of fluoride 3a accompanied the formation of a pyridine
-
the course of the reduction, C60Me5 and its oxidized species
•
C60Me5 were observed. The result indicated that the C-Cl bond
of 3b was cleaved by the reduction process. The first step of
the reduction at Epc ) -1.35 V vs Fc/Fc+ is ascribed to the
two-electron reduction, where the first electron is used for the
formation of the radical C60Me5• (A) and a chloride anion (Cl-)
•
and, in the second reduction, C60Me5 is reduced to form the
-
anion C60Me5 (A-) (Scheme 3). The anion subsequently
undergoes a quasi-reversible two-electron reduction process to
(11) (a) Nakamura, E.; Tahara, K.; Matsuo, Y.; Sawamura, M. J. Am.
Chem. Soc. 2003, 125, 2834. (b) Matsuo, Y.; Tahara, K.; Sawamura, M.;
Nakamura, E. J. Am. Chem. Soc. 2004, 126, 8725.
(12) (a) Sawamura, M.; Nagahama, N.; Toganoh, M.; Hackler, U. E.;
Isobe, H.; Nakamura, E.; Zhou, S.-Q.; Chu, B. Chem. Lett. 2000, 1098. (b)
Zhou, S.; Burger, C.; Chu, B.; Sawamura, M.; Nagahama, N.; Toganoh,
M.; Hackler, U. E.; Isobe, H.; Nakamura, E. Science 2001, 291, 1944. (c)
Nakamura, E.; Isobe, H. Acc. Chem. Res. 2003, 36, 807. (d) Isobe, H.;
Homma, T.; Nakamura, E. Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 14895.
give a dianion C60Me52- (A2-) and a trianion C60Me53- (A3-
)
at E1/2 ) -1.88 and -2.44 V vs Fc/Fc+, respectively. These
reduction potentials show good agreement with the values
reported previously for the dianion and trianion formation by
electrochemical reduction of C60Ph5- (E1/2 ) -1.84 and -2.52
V vs Fc/Fc+) and C60(biphenyl)5- (E1/2 ) -1.69 and -2.26 V

Synthesis of Metal Fullerene Complexes
Organometallics, Vol. 27, No. 14, 2008 3405
Scheme 4
similar to those found for the cyclopentadienyl rhenium tricar-
bonyl complex ReCp(CO)3 (2019, 1897 cm-1 14
and our
)
previously reported rhenium tri(organo)dihydrofullerene com-
plex Re(η5-C60Bn2PhH2)(CO)3 (2024, 1939 cm-1).4
The cobalt-penta(methyl)[60]fullerene dicarbonyl complex
Co(η5-C60Me5)(CO)2 (8) was synthesized by the reaction of 1c
with Na[Co(CO)4] in THF at 25 °C in 46% yield. Characteriza-
tion of 8 was performed with NMR and MS analyses. In the
1H and 13C NMR spectra, compound 8 exhibited a C5V
symmetric spectral pattern with chemical shift values similar
to those of the corresponding rhodium complex Rh(η5-
C60Me5)(CO)2.2a In the FAB-MS spectrum, the molecular ion
signal (m/z ) 910) of cobalt complex 8 was observed. In the
IR spectrum, symmetric and asymmetric stretching vibrations
due to the two carbonyl groups were observed at 2019 and 1965
cm-1, respectively. The cobalt complex 8 was very sensitive
to light in air, and we could not perform any further investiga-
tions of 8. The ordinary cyclopentadienyl complex CoCp(CO)2
in solution is also light sensitive and readily forms a dimer,
Co2Cp2(CO)3.15 We suspect that a similar decomposition process
may be occurring because of the strong light absorption property
of the fullerene ligand in 8.
Syntheses of Iron and Ruthenium Complexes via
Oxidative Addition to 3c. Next, we examined the oxidative
addition route (Scheme 1e) by the use of low-valent transition
metal complexes. Treatment of 3c with Fe(CO)5 in 1,2-
dichlorobenzene at 25 °C afforded the iron bromo dicarbonyl
complex Fe(η5-C60Me5)Br(CO)2 (6) in 95% yield (Scheme 4).
The iron carbonyl complex 6 in solution was sensitive to air
and light and decomposed to give C60Me5H and its oxidation
products. Complex 6 was identified by its spectral properties,
vs Fc/Fc+).13 In the anodic process, oxidation of the anion A-
to the radical A• was observed at 0.61 V vs Fc/Fc+. A
comparable observation was also reported for C60Ph5Cl.10b The
bromide 3c showed an electrochemical behavior similar to 3b
except for the first reduction, i.e., the C-X bond cleavage
process, whose reduction potential was -1.14 V vs Fc/Fc+. Note
that the first reduction potentials of 3b and 3c were positively
shifted compared with that of C60Me5H (E1/2 ) -1.48 V vs
Fc/Fc+),1d which must reflect the electron-withdrawing property
of the halogen atoms. Such a low potential in the first reduction
is the reason that the organometallic syntheses reported below
were successful.
Synthesis of Rhenium and Cobalt Complexes via Trans-
metalation with 3c. We next investigated the synthesis of
organometallic complexes via the (formal) nucleophilic substitu-
tion route by the use of the pentamethyl[60]fullerene halides 3
(Scheme 4). First, we examined route d shown in Scheme 1,
which involves the reaction of the penta(organo)fullerene
bromide 3c with alkali metal salts of the transition metal
complexes. Treatment of 3c with the anionic rhenium complex
Na[Re(CO)5] gave the desired rhenium tricarbonyl complex
Re(η5-C60Me5)(CO)3 (5) in only 10% yield (Scheme 4) through
a nucleophilic substitution pathway. The major products were
C60Me5H (and its oxidation products due to air oxidation of
intermediates and/or the product during and after the reaction).
The result is consistent with the assumption that the reaction
involves fast electron transfer from the low-valent rhenate
Na[Re(CO)5] to 3c, which generates the radical C60Me5• or the
anion C60Me5-, which, however, do not react further with the
rhenate. In the reaction of the pentaphenyl[60]fullerene halides
4 under various conditions, such a nonproductive pathway was
dominant and gave none of the desired products.
which were similar to those of the ruthenium halo dicarbonyl
2b
complexes Ru(η5-C60Me5)Cl(CO)2
and Ru(η5-C60Me5)-
Br(CO)2 (7).2c The IR spectrum exhibited symmetric and
asymmetric stretching vibrations of the carbonyl groups at 2037
and 1996 cm-1, which are comparable to those of FeCpBr(CO)2
(2048 and 2002 cm-1).16
Ruthenium complex 7 was also obtained with the oxidative
addition method. As compared with the previously reported
route,2b,c the new route has the advantage of having a readily
available starting rhenium complex, because commonly available
Ru3(CO)12 can be used in this reaction instead of the more
expensive [RuCl2(CO)3]2 that was used in the previous synthesis.
Heating 3c with Ru3(CO)12 in 1,2-dichlorobenzene at 100 °C
afforded the bromo dicarbonyl complex 72c in moderate yield.
The same procedure was applied to 3b to obtain Ru(η5-
C60Me5)Cl(CO)2 in 38% yield. These complexes can be de-
rivatized to various ruthenium-pentamethyl[60]fullerene
complexes2b and used in asymmetric transformation reactions.2f,g
A similar reaction of C5Ph5Br with [Ru3(CO)12] has been
reported by Connelly and Manners.17
X-ray Crystallographic Study of the Rhenium-
Penta(methyl)[60]fullerene Complex. Red single crystals of
5 suitable for X-ray diffraction were obtained by recrystallization
from CS2/ethanol (Figure 2). The C60Me5 ligand coordinates to
the rhenium atom in an η5-fashion with an average Re-C(C60)
Characterization of 5 was achieved with APCI-MS, NMR,
and IR measurements, as well as X-ray crystallography. The
1H and 13C NMR spectra showed C5V symmetry for the C60Me5
ligand. The carbonyl ligand on the rhenium metal was charac-
terized by the 13C NMR spectrum and IR spectrum. The
stretching vibrations of the three carbonyl groups, ν(CO), were
observed at 2022 and 1932 cm-1. These wavenumbers are
(14) (a) Barrientos-Penna, C. F.; Einstein, F. W. B.; Jones, T.; Sutton,
D. Inorg. Chem. 1982, 21, 2578. (b) Tellers, D. M.; Skoog, S. J.; Bergman,
R. G.; Gunnoe, T. B.; Harman, W. D. Organometallics 2000, 19, 2428.
(15) (a) Vollhardt, K. P. C.; Bercaw, J. E.; Bergman, R. G. J. Am. Chem.
Soc. 1974, 96, 4998. (b) Campbell, J. M.; Martel, A. A.; Chen, S.-P.; Waller,
I. M. J. Am. Chem. Soc. 1997, 119, 4678.
(16) Pankowski, M.; Bigorgne, M. J. Organomet. Chem. 1976, 110, 331.
(17) Connelly, N. G.; Manners, I. J. Chem. Soc., Dalton Trans. 1989,
283.
(13) (a) Matsuo, Y.; Nakamura, E. J. Am. Chem. Soc. 2005, 127, 8457.
(b) Aprahamian, I.; Eisenberg, D.; Hoffman, R. E.; Sternfeld, T.; Matsuo,
Y.; Jackson, E. A.; Nakamura, E.; Scott, L. T.; Sheradsky, T.; Rabinovitz,
M. J. Am. Chem. Soc. 2005, 127, 9581.

3406 Organometallics, Vol. 27, No. 14, 2008
Matsuo et al.
(CO)2(CCPh)20 (ν(CO) ) 2045, 2000 cm-1) as well as the
corresponding ruthenium-penta(methyl)[60]fullerene complexes
Ru(η5-C60Me5)Me(CO)2Me, Ru(η5-C60Me5)(CCH)(CO)2, and
Ru(η5-C60Me5)(CCPh)(CO)2.2b
Conclusion
We have developed a new and convenient synthetic entry to
the pentamethyl- and pentaphenyl[60]fullerene halides and new
routes to the rhenium, iron, ruthenium, and cobalt complexes
of pentamethyl[60]fullerene. The substitution reactions between
fullerene halides with anionic metal complexes are comple-
mentary to the previously reported substitution approaches using
fullerene anions and metal halides. The described oxidative
addition approach represents a powerful method for the synthesis
of useful metal-halo complexes, which does not produce any
alkali metal halide side-products. These new synthetic methods
willsignificantlybroadentherepertoireofthemetal-penta(organo)-
[60]fullerene complexes and will contribute to the development
of materials science and catalysis applications of metal fullerene
complexes.
Figure 2. Molecular structure of the rhenium tricarbonyl complex
Re(η5-C60Me5)(CO)3 (5) with 30% probability level ellipsoids. A
CS2 molecule in the unit cell is omitted for clarity. (a) ORTEP
drawing. (b) CPK model, top view. (c) CPK model, side view.
Experimental Section
Scheme 5
General Procedures. All manipulations were carried out under
a nitrogen or argon atmosphere using standard Schlenk techniques.
THF was distilled from Na/K alloy and thoroughly degassed by
trap-to-trap distillation. Benzene was distilled from calcium hydride.
C60Me5H and C60Ph5H were prepared according to the literature.1
A THF solution of t-BuOK was purchased from Sigma-Aldrich
Co. and used as received. N-Fluoropyridinium triflate, N-chloro-
succinimide, and N-bromosuccinimide were purchased from Tokyo
Kasei Co. and were recrystallized from benzene. MeLi was
purchased from Kanto Chemical Co., Inc. HCCMgBr was purchased
from Sigma-Aldrich Co. PhCCMgBr was prepared from the reaction
of phenylacetylene and ethylmagnesium bromide.
HPLC analyses were performed on a Shimadzu LC-10A system
equipped with a SPD-M10A diode array detector and a Cosmosil-
Buckyprep column (4.6 × 250 mm, Nacalai Tesque Inc.). Prepara-
tive HPLC separations were performed by the use of a Buckyprep
column (20 mm × 250 mm) using toluene/2-propanol (7:3 or 1:1)
as eluent. All 1H (400 MHz) and 13C{1H} (100 MHz) spectra were
recorded on a JEOL ECX400 spectrometer. Spectra were reported
in parts per million from internal tetramethylsilane (δ 0.00 ppm)
or residual protons of the deuterated solvent for the 1H NMR.
Carbon chemical shifts are reported relative to CDCl3 at δ 77.00
or THF-d8 at δ 25.20 and 67.40 ppm. Other spectra were recorded
on the following instruments: IR, JASCO IR-420 and ReactIR 1000;
UV/vis spectra, Hitachi U3500 and Shimadzu SPD-6A; mass
spectra, Shimadzu LCMS-QP8000 and JEOL JMS-T100LC APCI/
ESI-TOF mass spectrometers. High-resolution MS data for the iron
complexes were not obtained because of instability, in particular,
light sensitivity of these compounds.
Preparation of C60Me5F (3a). To a suspension of C60Me5H (202
mg, 0.251 mmol) in THF (10 mL) was added a solution of t-BuOK
(1.0 M, 0.28 mL, 0.028 mmol) in THF. After stirring for 1.5 h,
N-fluoropyridinium triflate (93.1 mg, 0.377 mmol) was added. The
mixture was stirred for 0.5 h. After dilution with toluene, the mixture
was washed with water. The organic phase was concentrated in
vacuo. Preparative HPLC separation (toluene/2-propanol ) 7:3,
flow rate ) 18 mL/min, retention time ) 7.5-9.0 min) afforded
3a (37.9 mg, 19% yield) and a side-product, C60Me5(2-pyridyl) (3d)
(32.2 mg, 15%), as air-stable reddish-orange solids.
bond length of 2.327(11) Å. The average bond lengths of
Re-C(CO) (1.911(18) Å) and C(CO)-O(CO) (1.159(19) Å)
are almost the same as those of Re(η5-C60Bn2PhH2)(CO)3
(1.909(12) and 1.165(15) Å).4
Derivatization of Iron Bromo Dicarbonyl Complex. Com-
plex 6, having the bromo ligand, is useful as a starting material
for the synthesis of other iron-pentamethyl[60]fullerene com-
plexes. A transmetalation reaction of the bromo ligand afforded
the buckyferrocene Fe(η5-C60Me5)Cp (9),3 the methyl complex
Fe(η5-C60Me5)(CO)2Me (10; ν(CO) ) 2004, 1953 cm-1; δMe
(1H)
)
-20.8 ppm), alkynyl complexes Fe(η5-
C60Me5)(CCH)(CO)2 (11; ν(CO) ) 2035, 1991 cm-1) and
Fe(η5-C60Me5)(CCPh)(CO)2 (12; ν(CO) ) 2035, 1990 cm-1
)
(Scheme 5), which were characterized by comparison of spectral
data for ordinary cyclopentadienyl complexes, FeCp(CO)2Me18
(ν(CO) ) 2010, 1955 cm-1; δMe (1H) ) -23.5 ppm),
FeCp(CO)2(CCH)19 (ν(CO) ) 2050, 1998 cm-1), and FeCp-
(18) Piper, T. S.; Wilkinson, G. J. Inorg. Nucl. Chem. 1956, 3, 104.
(19) Kim, P. J.; Masai, H.; Sonogashira, K.; Hagihara, N. Inorg. Nucl.
Chem. Lett. 1970, 6, 181.
(20) (a) Bruce, M. I.; Harbourne, D. A.; Waugh, F.; Stone, F. G. A.
J. Chem. Soc. (A) 1968, 356. (b) Green, M. L. H.; Mole, T. J. Organomet.
Chem. 1968, 12, 404.

Synthesis of Metal Fullerene Complexes
Organometallics, Vol. 27, No. 14, 2008 3407
1
3a. H NMR (400 MHz, CDCl3): δ 2.24 (s, 6H, Me), 2.34 (s,
(m), 2920 (m), 2859 (m), 1444 (s), 1417 (w), 1373 (w), 1287 (w),
1265 (w), 1238 (w), 1201 (w), 1129 (w), 815 (m), 797 (m), 686
(m), 656 (w), 576 (w), 553 (m), 543 (m), 526 (m). UV-vis (1.0 ×
10-5 mol · L-1 in CH2Cl2): λmax/nm (ꢀ), 258 (110 000), 272
(105 000), 338 (33 900), 354 (30 600), 394 (17 400), 475 (5020,
shoulder). APCI-MS (+): m/z 830. HR-APCI-MS (+): m/z found
830.0864; calcd for 3b 830.0862.
1
6H, Me), 2.36 (s, 3H, Me). H NMR (400 MHz, CDCl3/CS2): δ
2.21 (s, 6H, Me), 2.29 (s, 3H, Me), 2.32 (s, 6H, Me). 13C{1H}
NMR (100 MHz, CDCl3/CS2): δ 24.97 (d, JF-C ) 1.7 Hz, 2C, Me),
26.37 (d, JF-C ) 1.7 Hz, 2C, Me), 26.57 (d, 3JF-C ) 19.0 Hz, 1C,
Me), 50.27 (d, JF-C ) 1.7 Hz, 2C, sp3-C60), 51.61 (2C, sp3-C60),
3
53.49 (d, JF-C ) 27.3 Hz, 1C, sp3-C60), 82.18 (d, JF-C ) 338
Hz, 1C, C(sp3-C60)-F), 142.47 (2C), 142.72 (2C), 143.43 (2C),
143.63 (2C), 143.66 (2C), 143.74 (2C), 144.04 (2C), 144.19 (2C),
144.51 (2C), 145.24 (2C), 146.35 (1C), 146.37 (2C), 146.43 (2C),
146.44 (2C), 147.12 (2C), 147.44 (2C), 147.50 (2C), 147.55 (1C),
147.88 (2C), 147.96 (2C), 147.99 (2C), 148.16 (2C), 148.18 (2C),
148.35 (1C), 151.15 (2C), 151.17 (2C), 152.78 (2C), 156.12 (2C).
2
1
Preparation of C60Me5Br (3c). Bromide 3c was synthesized as
for 3b, using the following reagents: C60Me5H (1.00 g, 1.26 mmol),
t-BuOK (1.0 M, 1.50 mL, 1.50 mmol) in THF, N-bromosuccinimide
(289 mg, 1.62 mmol), benzene (40 mL). Yield: 848 mg (77% yield).
1H NMR (400 MHz, CDCl3): δ 2.31 (s, 6H, Me), 2.43 (s, 6H, Me),
2.67 (s, 3H, Me). 1H NMR (400 MHz, CDCl3/CS2): δ 2.29 (s, 6H,
Me), 2.41 (s, 6H, Me), 2.65 (s, 3H, Me). 13C{1H} NMR (100 MHz,
CDCl3): δ 24.68 (2C, Me), 26.37 (2C, Me), 37.73 (1C, Me), 50.60
(2C, sp3-C60), 52.73 (2C, sp3-C60), 54.10 (1C, sp3-C60), 69.54 (1C,
C(sp3-C60)-Br), 141.91 (2C), 142.76 (2C), 143.05 (2C), 143.52 (2C),
143.82 (2C), 143.87 (2C), 144.19 (5C), 144.35 (2C), 144.42 (2C),
145.16 (4C), 146.71 (2C), 146.76 (2C), 147.64 (2C), 147.87 (2C),
147.95 (1C), 148.06 (2C), 148.28 (6C), 148.51 (2C), 148.58 (2C),
152.00 (2C), 153.34 (2C), 155.18 (2C), 157.15 (2C). 13C{1H} NMR
(100 MHz, CDCl3/CS2): δ 24.52 (2C, Me), 26.22 (2C, Me), 37.52
(1C, Me), 50.26 (2C, sp3-C60), 52.39 (2C, sp3-C60), 53.83 (1C, sp3-
C60), 69.43 (1C, C(sp3-C60)-Br), 141.57 (2C), 142.63 (2C), 142.75
(2C), 143.20 (2C), 143.68 (2C), 143.73 (2C), 143.89 (2C), 144.04
(2C), 144.12 (2C), 144.20 (2C), 144.35 (1C), 144.77 (2C), 144.86
(2C), 146.44 (2C), 146.48 (2C), 147.39 (2C), 147.62 (2C), 147.72
(1C), 147.83 (2C), 148.05 (6C), 148.19 (2C), 148.25 (2C), 151.64
19F NMR (376.4 MHz, CDCl3/CS2): δ 47.05 (q, JF-H ) 9.0 Hz,
4
1F). IR (KBr) ν/cm-1, 2962 (m), 2920 (m), 2859 (w), 1513 (s),
1445 (s), 1417 (w), 1373 (w), 1288 (w), 1266 (w), 1239 (w), 1201
(w), 1179 (w), 1127 (w), 1104 (w), 1063 (w), 1028 (w), 1010 (w),
998 (w), 982 (m), 955 (w), 685 (m), 660 (w), 656 (w), 576 (w),
569 (w), 555 (m), 545 (m), 528 (m), 521 (m), 509 (w), 499 (m),
461 (w). UV-vis (1.0 × 10-5 mol · L-1 in CH2Cl2): λmax/nm (ꢀ),
258 (76 600), 271 (74 900), 355 (21 600, shoulder), 393 (12 500),
470 (3830, shoulder). APCI-MS (+): m/z 814 (M+), (-) m/z 795
([M - F]-). HR-APCI-MS (+): m/z found 814.1100; calcd for 3a
814.1158.
1
3d. H NMR (400 MHz, CDCl3): δ 2.08 (s, 3H, Me), 2.21 (s,
6H, Me), 2.52 (s, 6H, Me), 7.37 (dd, 3JC-H ) 7.6 Hz, 3JC-H ) 4.4
3
4
Hz, 1H, pyridyl), 7.82 (td, JC-H ) 7.6 Hz, JC-H ) 2.0 Hz, 1H,
pyridyl), 7.91 (d, 3JC-H ) 7.6 Hz, 1H, pyridyl), 8.81 (dt, 3JC-H
)
4
4.4 Hz, JC-H ) 2.0 Hz, 1H, pyridyl). 13C{1H} NMR (100 MHz,
CDCl3): δ 26.57 (2C, Me), 27.23 (2C, Me), 32.36 (1C, Me), 50.68
(2C, sp3-C60), 53.56 (2C, sp3-C60), 54.71 (1C, sp3-C60), 71.71 (1C,
sp3-C60), 119.73 (1C, pyridyl), 121.88 (1C, pyridyl), 136.67 (1C,
pyridyl), 142.70 (2C), 143.22 (2C), 143.78 (2C), 143.87 (2C),
143.92 (1C), 143.99 (2C), 144.09 (2C), 144.49 (2C), 144.90 (2C),
145.19 (2C), 145.53 (2C), 146.24 (2C), 146.62 (2C), 146.80 (2C),
146.90 (2C), 147.29 (1C, pyridyl), 147.61 (1C), 147.78 (2C), 147.82
(2C), 147.95 (2C), 148.21 (2C), 148.26 (2C), 148.28 (2C), 148 51
(2C), 149.24 (2C), 152.12 (2C), 153.57 (2C), 155.70 (1C, pyridyl),
156.98 (2C), 158.69 (2C). IR (KBr): ν/cm-1 2960 (m), 2919 (m),
2859 (w), 1581 (m), 1515 (m), 1458 (m), 1447 (m), 1428 (m),
1417 (w), 1370 (w), 1287 (w), 1266 (w), 1239 (w), 1200 (w), 1127
(w), 1093 (w), 1051 (w), 997 (w), 924 (w), 879 (w), 795 (w), 782
(w), 747 (w), 729 (w), 694 (w), 686 (m), 655 (w), 577 (w), 569
(w), 561 (w), 552 (m), 541 (m), 527 (m), 519 (m). UV-vis (1.0 ×
10-5 mol · L-1 in CH2Cl2): λmax/nm, (ꢀ) 260 (72 000), 270 (71 500),
347 (21 500), 355 (20 700, shoulder), 393 (12 200), 470 (3860,
shoulder). APCI-MS (+): m/z 874 ([M + H]+), (-) m/z 873 ([M]-).
HR-APCI-MS (+): m/z found 873.1509; calcd for 3d 873.1518.
Preparation of C60Me5Cl (3b). To a suspension of C60Me5H
(501 mg, 0.628 mmol) in benzene (20 mL) was added a solution
of t-BuOK (1.0 M, 0.75 mL, 0.075 mmol) in THF. After stirring
for 5.5 h, N-chlorosuccinimide (109 mg, 0.816 mmol) was added.
The mixture was stirred for 10 min. After the mixture was diluted
with toluene, the mixture was washed with water. The organic phase
was concentrated in vacuo. After preparative HPLC separation
(toluene/2-propanol ) 7:3, flow rate ) 18 mL/min, retentions time
) 7.0-8.0 min), 3b (285 mg, 55% yield) was obtained as air-
stable reddish-orange solids. 1H NMR (400 MHz, CDCl3): δ 2.33
(s, 6H, Me), 2.35 (s, 6H, Me), 2.55 (s, 3H, Me). 13C{1H} NMR
(100 MHz, CDCl3): δ 24.55 (2C, Me), 26.53 (2C, Me), 33.58 (1C,
Me), 50.65 (2C, sp3-C60), 52.49 (2C, sp3-C60), 54.25 (1C, sp3-C60),
77.64 (1C, C(sp3-C60)-Cl), 142.79 (2C), 142.99 (2C), 143.20 (2C),
143.58 (2C), 143.87 (2C), 144.15 (2C), 144.24 (2C), 144.37 (2C),
144.41 (2C), 145.12 (2C), 145.13 (2C), 146.74 (2C), 146.80 (2C),
147.70 (2C), 147.86 (2C), 147.94 (2C), 148.13 (2C), 148.27 (2C),
148.28 (2C), 148.30 (2C), 148.31 (2C), 148.52 (2C), 152.40 (2C),
153.41 (2C), 154.63 (2C), 156.92 (2C). IR (KBr): ν/cm-1, 2963
(2C), 152.96 (2C), 154.84 (2C), 156.78 (2C). IR (KBr): ν/cm-1
,
2963 (m), 2920 (m), 2859 (m), 1443 (s), 1417 (w), 1372 (w), 1287
(w), 1264 (w), 1238 (w), 1200 (w), 1129 (w), 806 (w), 782 (m),
756 (w), 685 (m), 656 (w), 576 (w), 552 (m), 541 (m), 526 (m).
UV-vis (1.0 × 10-5 mol · L-1 in CH2Cl2): λmax/nm (ꢀ), 259
(104 000), 271 (100 000), 340 (32 500), 354 (29 600), 393 (17 300),
475 (4880, shoulder). FAB-MS (+): m/z 874 (M+). APCI-MS (+):
m/z 874 (M+). HR-APCI-MS (+): m/z found 874.0371; calcd for
3c 874.0357.
Preparation of C60Ph5F (4a). Fluoride 4a was synthesized with
a similar procedure for the synthesis of 3a, using the following
reagents: C60Ph5H (100 mg, 90.3 µmol), t-BuOK (1.0 M, 99.3 µL,
99.3 µmol) in THF, N-fluoropyridinium triflate (26.8 mg, 108
µmol), THF (5.0 mL). Yield: 93.1 mg (92%). 1H NMR (400 MHz,
CDCl3/CS2 ) 1:3): δ 7.01-7.19 (m, 11H, Ph), 7.31-7.38 (m, 6H,
Ph), 7.49-7.51 (m, 4H, Ph), 7.84-7.87 (m, 4H, Ph). 13C{1H} NMR
(100 MHz, CDCl3/CS2 ) 1:3): δ 58.21 (2C, sp3-C60), 60.28 (2C,
sp3-C60), 61.93 (1C, sp3-C60), 67.75 (1C, C(sp3-C60)-F), 127.16 (1C,
Ph), 127.59 (2C, Ph), 127.73 (2C, Ph), 127.84 (4C, Ph), 127.90
(2C, Ph), 127.96 (2C, Ph), 127.99 (4C, Ph), 128.65 (4C, Ph), 128.90
(4C, Ph), 130.10 (2C, Ph), 137.73 (2C, Ph), 137.92 (1C, Ph), 142.72
(2C), 143.10 (2C), 144.01 (1C), 144.10 (2C), 144.11 (2C), 144.16
(2C), 144.40 (2C), 144.58 (2C), 144.64 (2C), 145.07 (2C), 145.15
(2C), 145.58 (2C), 147.09 (2C), 147.11 (2C), 147.22 (2C), 147.36
(2C), 147.39 (2C), 147.58 (2C), 147.82 (2C), 147.98 (1C), 148.06
(2C), 148.46 (2C), 148.49 (2C), 148.53 (2C), 148.57 (2C), 148.61
(2C), 151.45 (2C), 155.62 (2C). IR (KBr): ν/cm-1, 1598 (w), 1492
(m), 1463 (w), 1447 (m), 1419 (w), 1261 (m), 1237 (w), 1158 (w),
1069 (w), 1031 (m), 1012 (m), 964 (w), 943 (w), 910 (w), 889
(w), 735 (m), 692 (s), 668 (m), 656 (m). UV-vis (in toluene/2-
propanol ) 7:3): λmax/nm, 287, 340, 354 (shoulder), 394, 470.
APCI-MS ((): m/z 1124 (M ().
Preparation of C60Ph5Cl (4b). Chloride 4b was synthesized with
a similar procedure for the synthesis of 3b, using the following
reagents: C60Ph5H (201 mg, 0.181 mmol), t-BuOK (1.0 M, 0.22
mmol, 0.22 mL) in THF, N-chlorosuccinimide (31.4 mg, 0.235
1
mmol), benzene (8.0 mL). Yield: 114 mg (55%). H NMR (400
MHz, CDCl3): δ 7.10-7.40 (m, 17H, Ph), 7.64-7.69 (m, 4H, Ph),
1
7.93-7.98 (m, 4H, Ph). H NMR (400 MHz, CDCl3/CS2 ) 1:1):

3408 Organometallics, Vol. 27, No. 14, 2008
Matsuo et al.
δ 7.04-7.30 (m, 17H, Ph), 7.59-7.61 (m, 4H, Ph), 7.89-7.90 (m,
4H, Ph). 13C{1H} NMR (100 MHz, CDCl3): δ 58.25 (2C, sp3-
C60), 60.89 (2C, sp3-C60), 63.47 (1C, sp3-C60), 127.19 (1C, Ph),
127.72 (4C, Ph), 127.82 (2C, Ph), 128.45 (4C, Ph), 128.49 (4C,
Ph), 128.68 (4C, Ph), 128.69 (4C, Ph), 130.03 (2C, Ph), 137.10
(2C, Ph), 138.60 (2C, Ph), 143.47 (1C, Ph), 142.78, 143.28, 143.53,
143.62, 143.74, 143.89, 144.07, 144.18, 144.29, 144.43, 145.21,
145.25, 146.66, 147.18, 147.30, 147.75, 148.06, 148.18, 148.40,
148.56, 148.62, 148.69, 150.22, 151.09, 153.61, 156.63 (signals
due to sp2 carbon atoms of C60). 13C{1H} NMR (100 MHz, CDCl3/
CS2 ) 1:1): δ 57.95 (2C, sp3-C60), 60.63 (2C, sp3-C60), 63.21 (1C,
sp3-C60), 76.13 (1C, C(sp3-C60)-Cl), 127.00 (1C, Ph), 127.57(4C,
Ph), 127.62 (2C, Ph), 128.25 (4C, Ph), 128.33 (4C, Ph), 128.49
(4C, Ph), 128.55 (4C, Ph), 129.83 (2C, Ph), 136.75 (2C, Ph), 138.26
(2C, Ph), 142.65 (2C), 143.03 (1C, Ph), 143.03 (2C), 143.23 (2C),
143.37 (2C), 143.44 (2C), 143.66 (2C), 143.94 (2C), 144.04 (2C),
144.11 (2C), 144.30 (2C), 144.94 (2C), 145.01 (2C), 146.37 (2C),
146.94 (2C+1C), 147.07 (2C), 147.54 (2C), 147.83 (1C), 147.97
(2C), 148.16 (2C), 148.35 (6C), 148.46 (2C), 149.96 (2C), 150.77
(2C), 153.29 (2C), 156.33 (2C). IR (KBr): ν/cm-1, 3058 (w), 3028
(w), 2924 (w), 1599 (m), 1493 (s), 1462 (w), 1446 (m), 1418 (w),
1288 (w), 1263 (w), 1236 (w), 1204 (w), 1185 (w), 1157 (w), 1109
(w), 1070 (w), 1032 (m), 1003 (w), 911 (w), 837 (w), 788 (w),
735 (m), 694 (s), 666 (w), 584 (m), 565 (m), 543 (s), 479 (w).
UV-vis (1.0 × 10-5 mol · L-1 in CH2Cl2): λmax/nm (ꢀ), 260
(106 000), 273 (96 300, shoulder), 339 (32 300), 356 (28 300,
shoulder), 390 (14 600), 475 (4850, shoulder). APCI-MS (+): m/z
1140 (M+). HR-APCI-MS (+): m/z found 1140.1745; calcd for
4b 1140.1645.
1932. UV-vis (in toluene/2-propanol ) 7:3) λmax/nm, 285, 355,
395, 468. APCI-MS (() m/z ) 1064 (M (). HR-APCI-MS (+):
m/z found 1064.0602; calcd for 5 1064.0551.
Synthesis of Fe(η5-C60Me5)Br(CO)2 (6). To a suspension of
C60Me5Br (3c) (660 mg, 0.754 mmol) in 1,2-dichlorobenzene (11
mL) was added Fe(CO)5 (500 mL, 3.80 mmol). After stirring for
17 h at 25 °C, a dark orange precipitate was formed. Degassed
hexane (40 mL) was added to the reaction mixture, and then the
precipitate was filtered and washed with hexane. After the solid
was dried under reduced pressure, compound 6 (707 mg, 95%) was
obtained as a reddish-orange powder. 1H NMR (400 MHz, C6D6):
δ 2.23 (s, 15H, Me). 13C{1H} NMR (100 MHz, C6D6): δ 28.70
(5C, Me), 51.11 (5C, sp3-C60), 105.89 (5C, C(Cp)), 143.62 (10C),
144.10 (10C), 147.38 (5C), 148.59 (10C), 148.86 (5C), 152.33
(10C), 214.06 (2C, CO). IR (KBr): ν/cm-1, 2037, 1996. UV-vis
(in toluene/2-propanol ) 7:3): λmax/nm, 288, 336 (shoulder), 356
(shoulder), 394, 466 (shoulder).
Synthesis of Ru(η5-C60Me5)Br(CO)2 (7). A solution of 3c (87.9
mg, 100 µmol) in 1,2-dichlorobenzene (9 mL) was degassed under
reduced pressure over 30 min at 0 °C. Then Ru3(CO)12 (26.8 mg,
41.9 µmol) was added to the solution, which was stirred at 100 °C
for 12 h. The solution was concentrated to dryness under reduced
pressure. The residue was dissolved in toluene, and insoluble
products were removed by filtration through a pad of silica gel.
The crude material was purified with silica gel column chroma-
tography (eluent: CS2 then toluene), and the solution was concen-
trated under reduced pressure to give 7 (53.8 mg, 52% yield) as
reddish-orange microcrystals. The product was identical with an
1
authentic sample by HPLC and H NMR.2c
Preparation of C60Ph5Br (4c). Bromide 4c was synthesized with
a similar procedure for the synthesis of 3b, using the following
reagents: C60Ph5H (100 mg, 90.3 µmol), t-BuOK (1.0 M, 99.3 µL,
99.3 µmol) in THF, N-bromosuccinimide (19.2 mg, 108 µmol),
benzene (5.0 mL). Yield: 91.8 mg (86%). 1H NMR (400 MHz,
CDCl3): δ 7.10-7.42 (m, 17H, Ph), 7.66-7.73 (m, 4H, Ph),
Synthesis of Ru(η5-C60Me5)Cl(CO)2. A solution of 3b (32.8
mg, 39.5 µmol) in 1,2-dichlorobenzene (3 mL) was degassed under
reduced pressure over 30 min at 0 °C. Then Ru3(CO)12 (9.7 mg,
15.2 µmol) was added to the solution, which was stirred at 100 °C
for 13 h. The solution was concentrated to dryness under reduced
pressure. The residue was dissolved in toluene, and insoluble
products were removed by filtration through a pad of silica gel.
The crude material was purified with silica gel column chroma-
tography (eluent: CS2 then toluene), and the solution was concen-
trated under reduced pressure to give the title compound (15 mg,
38% yield) as reddish-orange microcrystals. The product was
1
7.94-8.03 (m, 4H, Ph). H NMR (500 MHz, CDCl3/CS2 ) 1:3):
δ 7.03-7.27 (m, 17H, Ph), 7.57-7.58 (m, 4H, Ph), 7.88 (s, 4H,
Ph). 13C{1H} NMR (125 MHz, CDCl3/CS2 ) 1:3): δ 57.69 (2C,
sp3-C60), 60.60 (2C, sp3-C60), 67.62 (1C, sp3-C60), 69.45 (1C, sp3-
C60), 127.51 (1C, Ph), 127.60 (2C, Ph), 128.35 (4C, Ph), 128.67
(12C, Ph), 128.29 (2C, Ph), 129.49 (2C, Ph), 136.83 (1C, Ph),
138.48 (2C, Ph), 141.90 (2C), 142.64 (2C), 142.99(2C), 143.21
(2C), 143.33 (2C), 143.64 (2C), 144.06 (4C), 144.33 (2C), 145.04
(2C), 145.78 (1C), 146.75 (2C), 146.95 (6C), 147.08 (2C), 147.54
(2C), 147.89 (1C), 148.04 (2C), 148.10 (2C), 148.18 (2C), 148.45
(6C), 149.94 (2C), 150.68 (2C), 153.93 (2C), 156.60 (2C). IR (KBr):
ν/cm-1, 3058 (w), 3028 (w), 2960 (m), 2924 (w), 1599 (m), 1493
(s), 1462 (m), 1446 (m), 1418 (w), 1288 (w), 1260 (s), 1236 (w),
1204 (w), 1185 (w), 1156 (w), 1094 (brs), 1030 (brs), 910 (w),
863 (w), 804 (s), 735 (m), 695 (s), 666 (w), 584 (m), 565 (w), 554
(w), 541 (m), 478 (w). UV-vis (1.0 × 10-5 mol · L-1 in CH2Cl2):
1
identical with an authentic sample by HPLC and H NMR.2b
Synthesis of Co(η5-C60Me5)(CO)2 (8). To a solution of
C60Me5Br (3c) (20.1 mg, 23.0 µmol) in THF (5.0 mL) was added
a solution of Na[Co(CO)4] (4.45 mg, 22.9 µmol) in THF (0.97 mL).
After the mixture was stirred for 1 h, the mixture was diluted with
toluene and passed through a pad of silica gel. The solution was
concentrated under reduced pressure (ca. 2 mL), and methanol was
added to obtain precipitates. The title compound was obtained as
1
orange solids (46% yield). H NMR (400 MHz, THF-d8): δ 2.43
(s, 15H, Me). 13C{1H} NMR (C6D6/CS2): δ 30.0 (5C, Me), 50.1
(5C, sp3-C60), 108.0 (5C, C(Cp)), 144.1 (5C), 144.5 (10C), 147.1
(10C), 148.3 (10C), 148.8 (10C), 153.2 (5C). One signal due to
the carbonyl ligand was not observed because of low solubility of
this compound. IR (KBr): ν/cm-1, 2019, 1965. FAB-MS (+): m/z
910 (M+).
λmax/nm (ꢀ), 260 (122 000), 350 (35 500), 395 (18 300), 475 (6230,
shoulder). APCI-MS (+): m/z 1184.
Synthesis of Re(η5-C60Me5)(CO)3 (5). To a solution of
C60Me5Br (3c) (10.0 mg, 11.4 µmol) in THF (4.0 mL) was added
a solution of Na[Re(CO)5] (3.98 mg, 11.4 µmol) in THF (46.6 µL).
After the mixture was stirred for 13 h, the reaction mixture was
quenched with saturated aqueous NH4Cl (0.50 mL). The mixture
was diluted with toluene and washed with water. The organic layer
was dried with anhydrous MgSO4 and concentrated under reduced
pressure. Preparative HPLC separations (toluene/2-propanol ) 7:3,
flow rate ) 14 mL/min, retention time ) 11.5-12.5 min) afforded
5 (1.2 mg, 10%) as dark reddish-orange microcrystals. 5: 1H NMR
(400 MHz, CDCl3): δ 2.41 (s, 15H, Me). 13C{1H} NMR (100 MHz,
CDCl3): δ 32.11 (5C, Me), 50.96 (5C, sp3-C60), 110.80 (5C, C(Cp)),
143.65 (10C), 143.87 (10C), 146.72 (5C), 147.86 (10C), 148.47
(5C), 152.39 (10C), 193.40 (3C, CO). IR (KBr): ν/cm-1, 2022,
Synthesis of Fe(η5-C60Me5)Me(CO)2 (10). To a solution of 6
(47.6 mg, 48.1 µmol) in benzene (8.4 mL) was added a 1.14 M
solution of MeLi in ether (84.5 µL, 96.2 µmol) at 25 °C. After
stirring for 10 min, the reaction mixture was passed through a pad
of silica gel. The solution was concentrated under reduced pressure
(ca. 5 mL), and methanol was added to obtain precipitates. The
title compound was obtained as orange solids (22.3 mg, 50%).
1
MeMgBr in THF could be also used in this synthesis. H NMR
(400 MHz, C6D6): δ 0.99 (s, 3H, Fe-Me), 2.10 (s, 15H, Me).
13C{1H} NMR (100 MHz, C6D6): δ -20.83 (1C, Fe-Me), 28.18
(5C, Me), 50.95 (5C, sp3-C60), 106.59 (5C, C(Cp)), 144.04 (10C),

Synthesis of Metal Fullerene Complexes
Organometallics, Vol. 27, No. 14, 2008 3409
Table 1. Crystal Data and Structure Analysis Results for Complex 5
144.22 (10C), 147.39 (5C), 148.55 (10C), 148.93 (5C), 153.11
(10C), 218.13 (2C, CO). IR (KBr): ν/cm-1, 2004, 1953.
5 · CS2
Synthesis of Fe(η5-C60Me5)(CCH)(CO)2 (11). To a solution of
6 (108 mg, 110 µmol) in benzene (19.2 mL) was added a 0.95 M
solution of HCCMgBr in THF (217 µL, 206 µmol) at 25 °C. After
stirring for 10 min, the reaction mixture was passed through a pad
of silica gel. The solution was concentrated under reduced pressure
(ca. 10 mL), and methanol was added to obtain precipitates. The
title compound was obtained as orange solids (74.3 mg, 71%). 1H
NMR (400 MHz, C6D6): δ 1.72 (s, 1H, CCH), 2.34 (s, 15H, Me).
1H NMR (400 MHz, THF-d8/CS2 ) 1:1): δ 1.80 (s, 1H, CCH),
2.57 (s, 15H, Me). 13C{1H} NMR (100 MHz, THF-d8/CS2 ) 1:1):
δ 29.26 (5C, Me), 51.45 (5C, sp3-C60), 107.36 (5C, C(Cp)), 108.24
(1C, CCH), 144.35 (10C), 144.40 (10C), 147.58 (5C), 148.76 (10C),
149.07 (5C), 153.36 (10C), 213.52 (2C, CO). One of two signals
due to the alkynyl group was not observed because of low solubility
of this compound. IR (KBr): ν/cm-1, 2038, 1992.
formula
C69H15O3Re1S2
monoclinic
C2/c (No. 15)
0.0863, 0.0900
0.2523, 0.2565
1.067
32.909(1)
14.7480(7)
19.4810(6)
90
122.842(2)
90
7943.8(5)
8
153(2)
0.70, 0.20, 0.10
1.91
cryst syst
space group
R, Rw (I > 2s(I))
R1, wR2 (all data)
GOF on F2
a, Å
b, Å
c, Å
R, deg
ꢀ, deg
γ, deg
V, Å3
Z
T, K
cryst size, mm
Dcalcd, g/cm-3
2θmin, 2θmax, deg
no. reflns measd (I > 2σ(I))
no. params
Synthesis of Fe(η5-C60Me5)(CCPh)(CO)2 (12). To a solution
of 6 (102 mg, 103 µmol) in benzene (18.0 mL) was added a 0.95
M solution of PhCCMgBr in THF (217 µL, 206 µmol) at 25 °C.
After stirring for 10 min, the reaction mixture was passed through
a pad of silica gel. The solution was concentrated under reduced
pressure (ca. 10 mL), and methanol was added to obtain precipitates.
The title compound was obtained as orange solids (55.8 mg, 54%).
1H NMR (400 MHz, C6D6): δ 2.25 (s, 15H, Me), 7.34-7.67 (m,
5H, Ph). 1H NMR (400 MHz, THF-d8/CS2 ) 1:1): δ 2.60 (s, 15H,
Me), 7.10 (m, 1H, Ph), 7.21 (m, 2H, Ph), 7.33 (m, 2H, Ph). 13C{1H}
NMR (100 MHz, C6D6): δ 28.73 (5C, Me), 50.74 (5C, sp3-C60),
107.24 (5C, C(Cp)), 126.15, 128.58, 131.64, 143.62 (10C), 144.10
(10C), 147.38 (5C), 148.59 (10C), 148.94 (5C), 152.33 (10C),
213.62 (2C, CO). Two signals due to the alkynyl group were not
observed because of low solubility of this compound. IR (KBr):
ν/cm-1, 2035, 1991.
Electrochemical Studies. Electrochemical measurements were
performed using a BAS CV-50W voltammetric analyzer. A glassy
carbon electrode, a platinum coil, and an Ag/Ag+ electrode were
used as the working electrode, the counter electrode, and the
reference electrode, respectively. Cyclic voltammetry (CV) was
performed at a scan rate of 100 mV/s. All half-wave potentials
E1/2 ) (Epc + Epa)/2, where Epc and Epa are the cathodic and anodic
peak potentials, respectively. The potential was corrected against
Fc/Fc+.
4.46, 51.12
6790
677
direct method (SHELXS-97).21 The positional and thermal param-
eters of non-hydrogen atoms were refined anisotropically on F2 by
the full-matrix least-squares method, using SHELXL-97.22 Hydro-
gen atoms were placed at calculated positions and refined with
riding mode on their corresponding carbon atoms. In the subsequent
refinement, the function ∑w(Fo2 - Fc2)2 was minimized, where Fo
and Fc are the observed and calculated structure factor amplitudes,
respectively. The agreement indices are defined as R1 ) ∑(|Fo| -
|Fc|)/∑|Fo| and wR2 ) [∑w(Fo - Fc2)2/∑(wFo )]1/2
.
2
4
Acknowledgment. This study was partially supported by
the 21st Century COE Program for Frontiers in Fundamental
Chemistry from the Ministry of Education, Culture, Sports,
Science and Technology, Japan.
Supporting Information Available: Crystallographic data of 5
(CIF file) and NMR spectra of new compounds (PDF file). This
material is available free of charge via the Internet at http://pubs.acs.
org.
OM8001262
X-ray Crystallographic Analysis. Single crystals 5 suitable for
X-ray diffraction studies were grown and subjected to data
collection. The data set was collected on a MacScience DIP2030
imaging plate diffractometer using Mo KR (graphite-monochro-
mated, λ ) 0.71069 Å) radiation. Crystal data and data statistics
are summarized in Table 1. The structure of 5 was solved by the
(21) Sheldrick, G. M. SHELXS-97, Program for the Solution of Crystal
Structures; University of Go¨ttingen: Germany, 1997.
(22) Sheldrick, G. M. SHELXL-97, Programs for Crystal Structure
Analysis (Release 97-2); Institut fu¨r Anorganische Chemie der Universita¨t
Go¨ttingen: Germany, 1998.