Ruthenium(II) complexes of pentamethylated [60]fullerene, alkyl, alkynyl, chloro, isocyanide, and phosphine complexes

Article abstract of DOI:10.1021/om0302387

A ruthenium chloro dicarbonyl complex bearing a pentamethylated [60]fullerene ligand, Ru(η⁵-C₆₀Me₅) Cl(CO)₂ (1), was prepared by the reaction of [RuCl₂(CO)₃]₂ with C₆₀ Me₅K in THF. A variety of ligand exchange reactions involving the carbonyl and chloro ligands took place on the ruthenium metal attached directly to the exterior of the fullerene framework. Treatment of 1 with a phosphine ligand afforded phosphine complexes, Ru(η⁵-C₆₀ Me₅)Cl(PEt₃)(CO) (2) and Ru(η⁵-C₆₀Me₅)Cl(PPh₃)(CO) (3). Isocyanide complexes, Ru(η⁵-C₆₀Me₅) Cl(^tBuNC)(CO) (4), Ru(η⁵-C₆₀Me₅) Cl(MeNC)(CO) (5), and Ru(η⁵-C₆₀Me₅) Cl(XylNC)(CO) (6; Xyl = 2,6-dimethylphenyl), were also prepared by reaction with an appropriate isocyanide ligand, while the use of a large excess of the same isocyanides gave bis(isocyanide)complexes, Ru(η⁵-C₆₀ Me₅)Cl(^tBuNC)₂ (7) and Ru(η⁵-C₆₀Me₅)Cl(XylNC)₂. (8) Metathetic replacement of the halogen atom on the transition-metal fullerene complexes was achieved: methyl and (trimethylsilyl)methyl Grignard reagents reacted with 1 to give a methyl complex, Ru(η⁵-C₆₀Me₅)Me(CO)₂ (9), and a (trimethylsilyl)methyl complex, Ru(η⁵-C₆₀ Me₅)(CH₂SiMe₃)(CO)₂ (10), respectively. Alkynylation reactions gave various alkynyl complexes, Ru(η⁵-C₆₀Me₅)(C≡CPh)(CO)₂ (12), Ru(η⁵-C₆₀Me₅) (C≡CⁿBu)(CO)₂ (13), Ru(η⁵-C₆₀Me₅)(C≡CSiMe₃) (CO)₂ (14), and Ru(η⁵-C₆₀Me₅) (C≡CH)(CO)₂ (15). X-ray single-crystal structure analyses and electrochemical studies of a series of new ruthenium fullerene complexes were performed.

Full text of DOI:10.1021/om0302387

2554
Organometallics 2003, 22, 2554-2563
Articles
Ru th en iu m (II) Com p lexes of P en ta m eth yla ted
[60]F u ller en e. Alk yl, Alk yn yl, Ch lor o, Isocya n id e, a n d
P h osp h in e Com p lexes
Yutaka Matsuo and Eiichi Nakamura*
Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, J apan
Received April 1, 2003
A ruthenium chloro dicarbonyl complex bearing a pentamethylated [60]fullerene ligand,
Ru(η5-C60Me5)Cl(CO)2 (1), was prepared by the reaction of [RuCl2(CO)3]2 with C60Me5K in
THF. A variety of ligand exchange reactions involving the carbonyl and chloro ligands took
place on the ruthenium metal attached directly to the exterior of the fullerene framework.
Treatment of 1 with a phosphine ligand afforded phosphine complexes, Ru(η5-C60Me5)Cl-
(PEt3)(CO) (2) and Ru(η5-C60Me5)Cl(PPh3)(CO) (3). Isocyanide complexes, Ru(η5-C60Me5)Cl(t-
BuNC)(CO) (4), Ru(η5-C60Me5)Cl(MeNC)(CO) (5), and Ru(η5-C60Me5)Cl(XylNC)(CO) (6; Xyl
) 2,6-dimethylphenyl), were also prepared by reaction with an appropriate isocyanide ligand,
while the use of a large excess of the same isocyanides gave bis(isocyanide)complexes, Ru-
(η5-C60Me5)Cl(tBuNC)2 (7) and Ru(η5-C60Me5)Cl(XylNC)2 (8). Metathetic replacement of the
halogen atom on the transition-metal fullerene complexes was achieved: methyl and
(trimethylsilyl)methyl Grignard reagents reacted with 1 to give a methyl complex, Ru(η5-
C60Me5)Me(CO)2 (9), and a (trimethylsilyl)methyl complex, Ru(η5-C60Me5)(CH2SiMe3)(CO)2
(10), respectively. Alkynylation reactions gave various alkynyl complexes, Ru(η5-C60Me5)-
(CtCPh)(CO)2 (12), Ru(η5-C60Me5)(CtCnBu)(CO)2 (13), Ru(η5-C60Me5)(CtCSiMe3)(CO)2 (14),
and Ru(η5-C60Me5)(CtCH)(CO)2 (15). X-ray single-crystal structure analyses and electro-
chemical studies of a series of new ruthenium fullerene complexes were performed.
In tr od u ction
their high-temperature superconductivity,1 the current
attention of chemists is focused more on the transition-
metal fullerene complexes. The most readily available
metal complexes are η2-[60]fullerene complexes, in
which an electron-rich transition metal coordinates to
a fullerene core that serves as an electron-deficient
olefinic η2 ligand.8-10 A major problem of such transi-
tion-metal fullerene complexes has thus far been the
inflexibility of molecular design, owing to their instabil-
ity toward various transformations that are mandatory
for derivatization. For instance, while some polymetallic
η2:η2- and η2:η2:η2-fullerene complexes are quite stable,11
the mononuclear metal η2-fullerene complexes easily
release the fullerene ligand upon addition of a donor/
π-acidic ligand such as a triorganophosphine.8,12
Metal fullerene complexes and related compounds
have attracted much interest, owing to their potential
applications to catalysis, to electrochemical1 and pho-
tochemical2 reactions, to materials of nonlinear optical3
and electron transfer4 properties, and to the construc-
tion of nanoscale molecular and supramolecular archi-
tectures.5 These compounds may be classified into three
classes, alkali-metal fulleride salts,1,6 endohedral metal
fullerene compounds,7 and exohedral transition-metal
fullerene complexes.8 While alkali-metal fulleride salts
have surprised scientists for quite some time due to
* To whom correspondence should be addressed. E-mail: nakamura@
chem.s.u-tokyo.ac.jp.
(1) The Physics of Fullerene-based and Fullerene-Related Materials;
Andreoni, W., Ed.; Kluwer Academic: Dordrecht, The Netherlands,
2000.
(2) Kunieda, R.; Fujitsuka, M.; Ito, O.; Ito, M.; Murata, Y.; Komatsu,
K. J . Phys. Chem. B 2002, 106, 7193.
(3) Brusatin, G.; Signorini, R. J . Mater. Chem. 2002, 12, 1964.
(4) Fukuzumi, S.; Guldi, D. M. Electron-Transfer Chemistry of
Fullerenes. In Electron Transfer in Chemistry; Balzani, V., Ed.; Wiley-
VCH: Weinheim, Germany, 2000; Vol. 2, pp 270-337.
(5) (a) Diederich, F.; Go´mez-Lo´pez, M. Chem. Soc. Rev. 1999, 28,
263. (b) Georgakilas, V.; Pellarini, F.; Prato, M.; Guldi, D. M.; Melle-
Franco, M.; Zerbetto, F. Proc. Natl. Acad. Sci. 2002, 99, 5075. (c)
Chuard, T.; Deschenaux, R. J . Mater. Chem. 2002, 12, 1944.
(6) (a) Rosseinsky, M. J . Chem. Mater. 1998, 10, 2665. (b) Reed, C.
A.; Bolskar, R. D. Chem. Rev. 2000, 100, 1075.
We recently reported the syntheses of transition-
metal η5 complexes, Rh(η5-C60Me5)(CO)213 and Fe(η5-C60-
Me5)Cp,14 which bear an η5-pentamethylated [60]-
fullerene ligand, η5-C60Me5 (to be abbreviated as
MeFCp).15 These η5-cyclopentadienide complexes were
(8) (a) Stephens, A. H. H.; Green, M. L. H. Adv. Inorg. Chem. 1997,
44, 1. (b) Balch, A. L.; Olmstead, M. M. Chem. Rev. 1998, 98, 2123.
(9) (a) Fagan, P. J .; Calabrese, J . C.; Malone, B. Science 1991, 252,
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1992, 25, 134.
(10) (a) Balch, A. L.; Catalano, V. J .; Lee, J . W. Inorg. Chem. 1991,
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M.; Parkin, S. R. J . Am. Chem. Soc. 1991, 113, 8953.
(7) Shinohara, H. Rep. Prog. Phys. 2000, 63, 843.
10.1021/om0302387 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 05/17/2003

Ru(II) Complexes of Pentamethylated [60]Fullerene
Organometallics, Vol. 22, No. 13, 2003 2555
Sch em e 1
found to be stable compounds. In these complexes, there
is electronic communication between the metal and the
bottom 50-π-electron system through the cyclopentadi-
enide moiety.16 We therefore considered it necessary as
the second stage of our studies to examine whether one
can perform synthetically useful transformations on a
transition-metal fullerene η5-complex. To this end, we
focused on Ru(II)-MeFCp complexes bearing a metal-
halogen bond and on their transformations. We report,
in this article, the synthesis and the characterization
of a ruthenium chloro complex bearing the FCp ligand,
Ru(η5-C60Me5)Cl(CO)2 (1), as well as substitution reac-
tions of the carbonyl and the chloro ligands on the
ruthenium center with phosphine, isocyanide, alkyl, and
alkynyl ligands. The alkylation and alkynylation reac-
tions represent the first example of metathesis reactions
of a halide atom on transition metal fullerene complexes.
The present results also provide the first example of a
successful ligand exchange reaction of the carbonyl
ligand on the metal center of mononuclear fullerene
complexes.17 We anticipate that the new half-sandwich
Ru-MeFCp complexes will expand the platform for the
organometallic extension of fullerene chemistry and that
for catalysis and materials science in general.18
(11) (a) Nagashima, H.; Yamaguchi, H.; Kato, Y.; Saito, Y.; Haga,
M.; Itoh, K. Chem. Lett. 1993, 2153. (b) Ishii, Y.; Hoshi, H.; Hamada,
Y.; Hidai, M. Chem. Lett. 1994, 801. (c) Nagashima, H.; Kato, Y.;
Yamaguchi, H.; Kimura, E.; Kawanishi, T.; Kato, M.; Saito, Y.; Haga,
M.; Itoh, K. Chem. Lett. 1994, 1207. (d) Park, J . T.; Cho, J .-J .; Song,
H. J . Chem. Soc., Chem. Commun. 1995, 15. (e) Mavunkal, I. J .; Chi,
Y.; Peng, S.-M.; Lee, G.-H. Organometallics 1995, 14, 4454. (f) Hsu,
H.-F.; Shapley, J . R. J . Am. Chem. Soc. 1996, 118, 9192. (g) Lee, K.;
Hsu, H.-F.; Shapley, J . R. Organometallics 1997, 16, 3876. (h) Lee,
K.; Choi, Z.-H.; Cho, Y.-J .; Song, H.; Park, J . T. Organometallics 2001,
20, 5564.
Resu lts a n d Discu ssion
Syn th esis a n d Ch a r a cter iza tion of Ch lor o Di-
ca r bon yl Com p lexes of Ru th en iu m . The reaction of
[RuCl2(CO)3]2 with a potassium salt of the MeFCp
ligand in THF led to the formation of a half-sandwich
complex of ruthenium, Ru(η5-C60Me5)Cl(CO)2 (1), in 80%
yield on a gram scale (Scheme 1). Other ruthenium
complexes were examined as the starting material
without success: e.g., RuCl3‚nH2O, Ru3(CO)12, [RuCl2-
(p-cymene)]2, [RuCl2(cod)]n (cod ) 1,5-cyclooctadiene),
RuCl2(PPh3)2, RuCl2(MeCN)2(PPh3)2, and RuCl2(nbd)-
(PPh3)2 (nbd ) norbornadiene). For the successful
complexation of 1, therefore, we must avoid the presence
(12) Rasinkangas, M.; Pakkanen, T. T.; Pakkanen, T. A. J . Orga-
nomet. Chem. 1994, 476, C6.
(13) Sawamura, M.; Kuninobu, Y.; Nakamura, E. J . Am. Chem. Soc.
2000, 122, 12407.
(14) Sawamura, M.; Kuninobu, Y.; Toganoh, M.; Matsuo, Y.; Ya-
manaka, M.; Nakamura, E. J . Am. Chem. Soc. 2002, 124, 9354.
(15) (a) Sawamura, M.; Iikura, H.; Nakamura, E. J . Am. Chem. Soc.
1996, 118, 12850. (b) Sawamura, M.; Iikura, H.; Hirai, A.; Nakamura,
E. J . Am. Chem. Soc. 1998, 120, 8285. (c) Sawamura, M.; Toganoh,
M.; Kuninobu, Y.; Kato, S.; Nakamura, E. Chem. Lett. 2000, 270. (d)
Sawamura, M.; Iikura, H.; Ohama, T.; Hackler, U. E.; Nakamura, E.
J . Organomet. Chem. 2000, 599, 32. (e) Sawamura, M.; Toganoh, M.;
Suzuki, K.; Hirai, A.; Iikura, H.; Nakamura, E. Org. Lett. 2000, 2, 1919.
(f) Nakamura, E.; Sawamura, M. Pure Appl. Chem. 2001, 73, 355. (g)
Sawamura, M.; Toganoh, M.; Iikura, H.; Matsuo, Y.; Hirai, A.;
Nakamura, E. J . Mater. Chem. 2002, 12, 2109.
(17) A few monometallic ruthenium [60]fullerene complexes have
been reported; see ref 9a and 12 and: Green, M. L. H.; Stephens, A.
H. H. Chem. Commun. 1997, 793.
(16) Iikura, H.; Mori, S.; Sawamura, M.; Nakamura, E. J . Org.
Chem. 1997, 62, 7912.
(18) Trost, B. M.; Toste, F. D.; Pinkerton, A. B. Chem. Rev. 2001,
101, 2067.

2556 Organometallics, Vol. 22, No. 13, 2003
Matsuo and Nakamura
of a strongly coordinating ligand such as phosphine and
arene ligands. Complex 1, which is reasonably soluble
in toluene, was easily separated from byproducts, the
salt KCl and a small amount of oxidation products
derived from the MeFCp ligand, with the aid of a short
silica gel column (toluene eluent). Orange crystals of 1
are stable in air and also in solution (hydrocarbon and
halogenated solvents).
Identification of 1 was achieved first by spectroscopic
1
and combustion analyses. The H NMR spectrum of 1
displayed a singlet signal at δ 2.18 due to five magneti-
cally equivalent methyl groups, suggesting that the C60-
Me5 ligand is coordinated to the ruthenium metal in an
η5 fashion. The 13C NMR spectrum displayed only a
small number of signals due to the C5v-symmetric
fullerene skeleton: the cyclopentadienyl moiety (δ
111.69), the sp3 fullerene carbon atom (C(R); δ 51.19),
the sp2 carbon atom next to C(R) (C(â); δ 152.28), and
five other types of fullerene sp2 carbon atoms (δ 143.83,
144.17, 147.42, 148.60, and 148.98), together with a
methyl group signal (δ 30.82) and a carbonyl signal on
the metal (δ 196.93). The asymmetric and symmetric
stretching vibrations of the carbonyl groups, ν(CO), in
the IR spectrum of 1 were observed at 2052 and 2006
cm-1. These wavenumbers are similar to those found
for a ruthenium η5-Cp chloro carbonyl complex, RuCpCl-
(CO)2 (2059 and 2008 cm-1),19 and are larger than those
of the Cp* ()pentamethylcyclopentadienyl) analogue
RuCp*Cl(CO)2 (2030 and 1988 cm-1).20 The fact that the
CO stretching frequencies of 1 are higher than those of
the Cp* analogue may suggest that the MeFCp ligand
is a more electron deficient ligand. The UV/visible
spectrum (λ 370 (sh), 395 nm) is similar to those of [60]-
fullerene and related organic derivatives.15a,21
F igu r e 1. Molecular structure of 1 with 30% probability
level ellipsoids. The toluene molecule found in the unit cell
is omitted for clarity.
Ta ble 1. Selected Bon d Dista n ces a n d An gles for 1
Bond Distances (Å)
Ru-C1
Ru-C2
Ru-C3
Ru-C4
Ru-C5
2.285(9)
2.304(10)
2.247(9)
2.246(10)
2.284(10)
Ru-Cl
Ru-C6
Ru-C7
O1-C6
O2-C7
2.387(9)
1.97(2)
1.92(4)
0.955(19)
0.93(4)
Ru-C(Cp) (av)
2.273
1.919
1.433
1.502
1.542
1.366
Ru-(centroid of Cp)
C(Cp)-C(Cp) (av)
C(Cp)-C(R) (av)
C(R)-C(â) (av)
C(â)-C(â) (av)
To conclusively determine the structure of the half-
sandwich complex 1, a single-crystal X-ray diffraction
study was performed. Recrystallization of 1 from a
toluene/ethanol mixture gave single crystals composed
of a 1:1 mixture of 1 and toluene. Figure 1 shows the
molecular structure of 1, and selected metrical param-
eters are summarized in Table 1. A feature of interest
in the structure of 1 is the “fold-back angle” of the
fullerene carbon atoms (C(R)) out of the Cp mean plane.
This angle (average 17.5°) is much larger than that in
a cyclopentadienyl ruthenium complex such as Ru(η5-
C5Me4CH2Cl)Cl(CO)2 (average <4.8°).22 Nonetheless, an
averaged interatomic distance between the ruthenium
atom and the η5-Cp carbon atoms (average 2.27 Å) in 1
is comparable to that found for Ru(η5-C5Me4CH2Cl)Cl-
(CO)2 (average 2.23 Å) and other related complexes (ca.
2.2s2.3 Å).22,23 The sum of the three angles around C(R)
Bond Angles (deg)
Cl-Ru-C6
Cl-Ru -C7
84.6(6)
83.7(14)
C6-Ru-C7
86.3(13)
hold-back angle
17.47
356.22
312.64
353.69
sum of three angles around C(Cp) (av)a
sum of three angles around C(R) (av)a
sum of three angles around C(â) (av)
a
Within the fullerene core.
(included in the fullerene core, excluding those related
to the methyl group) (average 312.6°) is smaller than
the 316° value for a usual sp3 carbon atom and the 324°
value of [60]fullerene, indicating that the C(R) atoms
protrude out of the mean sphere of the fullerene core.
Intercarbon distances in the Cp moiety (C(Cp)-C(Cp))
are normal for a Cp ligand (average 1.43 Å; 1.40-1.45
Å for RuCp2)24 and are shorter than those of the
corresponding 5:6 ring junction found in [60]fullerene
(1.467 Å).25
Liga n d Exch a n ge Rea ction of 1. The carbonyl
ligands in 1 can be replaced with phosphine and
isocyanide ligands. Treatment of 1 with a slight excess
of PEt3 in toluene at 70 °C resulted in quantitative
formation of the desired phosphine complex, Ru(η5-C60-
Me5)Cl(PEt3)(CO) (2) (Scheme 1). This finding stands
(19) (a) Brown, D. A.; Lyons, H. J .; Sane, R. T. Inorg. Chim. Acta
1970, 4, 621. (b) Haines, R. J .; du Preez, A. L. J . Chem. Soc., Dalton
Trans. 1972, 944.
(20) Stasunik, A.; Malisch, W. J . Organomet. Chem. 1984, 270,
C56.
(21) (a) Kra¨tschmer, W.; Lamb, L. D.; Fostiropoulos, K.; Huffman,
D. R. Nature 1990, 347, 354. (b) Ajie, H.; Alvarez, M. M.; Anz, S. J .;
Beck, R. D.; Diederich, F.; Fostiropoulos, K.; Huffman, D. R.; Kra¨tschmer,
W.; Rubin, Y.; Schriver, K. E.; Sensharma, D.; Whetten, R. L. J . Phys.
Chem. 1990, 94, 8630.
(22) The crystal structure of RuCp*Cl(CO)2 has not been reported.
We therefore compared the structure of the closest chloromethyl
analogue with that of 1. Fan, L.; Turner, M. L.; Adams, H.; Bailey, N.
A.; Maitlis, P. M. Organometallics 1995, 14, 676.
(24) (a) Hardgrove, G. L.; Templeton, D. H. Acta Crystallogr. 1959,
12, 28. (b) Seiler, P.; Dunitz, J . D. Acta Crystallogr., Sect. B 1980, 36,
(23) (a) Adams, H.; Bailey, N. A.; White, C. Inorg. Chem. 1983, 22,
1155. (b) Knowles, D. R. T.; Adams, H.; Maitlis, P. M. Organometallics
1998, 17, 1741.
2946.
(25) Liu, S.; Lu, Y.-J .; Kappes, M. M.; Ibers, J . A. Science 1991, 254,
408.

Ru(II) Complexes of Pentamethylated [60]Fullerene
Organometallics, Vol. 22, No. 13, 2003 2557
in sharp contrast to the reported observation that the
C60 ligand on an η2 complex, Ru(C60)(CO)4, is lost upon
addition of a phosphine ligand.12 In the MeFCp complex,
a basic alkylphosphine ligand is expected to stabilize
coordination of the MeFCp ligand to the ruthenium
center, because the latter may act as an acceptor of
electron donation by the phosphine ligand. Complex 2
was air- and moisture-stable in toluene at ambient and
boiling temperatures. When the arylphosphine PPh3
was allowed to react with 1, the triphenylphosphine
complex Ru(η5-C60Me5)Cl(PPh3)(CO) (3) was obtained
only in moderate (51%) yield, even in the presence of
10 equiv of PPh3 at reflux temperature.26 This unfavor-
able exchange is consistent with the relatively low
basicity and steric bulk of the triarylphosphine ligand.
Complexes 2 and 3 were found to be inert to further
ligand exchange with a phosphine ligand, even at reflux
1
temperature. The H NMR spectra of 2 and 3 showed
singlet signals at δ 2.47 and 2.22, respectively, due to
the C5v symmetry of the MeFCp ligand. The 31P{1H}
NMR spectra exhibited a singlet signal due to the
phosphine ligands at δ 32.28 and 37.23 for 2 and 3,
respectively. The presence of a carbonyl group in 2 and
3 was confirmed by the 13C NMR spectra (δ 204.84 for
2 and δ 201.93 for 3), the signal possessing a coupling
constant J P-C of 25 Hz for 2 and 24 Hz for 3, and also
by the IR spectra (ν(CO) 1937 cm-1 for 2 and ν(CO) 1950
cm-1 for 3).
F igu r e 2. Molecular structure of 2 with 30% probability
level ellipsoids. The toluene molecule found in the unit cell
is omitted for clarity.
A similar exchange reaction with isocyanides gave the
corresponding ruthenium isocyanide complexes Ru(η5-
C60Me5)Cl(tBuNC)(CO) (4), Ru(η5-C60Me5)Cl(MeNC)(CO)
(5), and Ru(η5-C60Me5)Cl(XylNC)(CO) (6; Xyl ) 2,6-
dimethylphenyl). Isocyanide ligands are expected to
form stable complexes, owing to their large σ-donor
properties27 and their small steric bulk. In fact, com-
plexes 4 and 5 formed much more smoothly than the
phosphine complexes. Heating 1 in toluene with 1.5
equiv of tert-butyl and methyl isocyanide ligands gave
orange microcrystals of 4 and 5 in 94% and 93% yields,
respectively. Xylyl isocyanide was less reactive, and
hence, the maximum yield (90%) was obtained by the
use of 4.5 equiv of XylNC. These isocyanide carbonyl
1
mixed ligand complexes were identified by the H and
13C NMR spectra as well as IR spectra. In particular,
the IR spectra of 4-6 showed strong absorptions due
to both the CO groups (ν 1976, 1978, and 1978 cm-1
,
respectively) and the NC groups (ν 2159, 2178, and 2140
cm-1, respectively). In contrast to the phosphine ligands,
an excess amount of isocyanide ligands afforded bis-
(isocyanide) complexes, Ru(η5-C60Me5)Cl(tBuNC)2 (7)
and Ru(η5-C60Me5)Cl(XylNC)2 (8). When a toluene solu-
tion of 1 was treated with 10 equiv of tBuNC and XylNC
at 100 °C for 24 h, the bis(isocyanide) complexes 7 and
8 formed as predominant products in two steps via the
mono(isocyanide) complex. These bis(isocyanide) com-
plexes decomposed gradually during isolation and,
hence, were characterized in solution with NMR spec-
troscopy; the 1H NMR spectra of these complexes
exhibited one set of signals due to both MeFCp and
isocyanide ligands in an exactly 1:2 integral ratio.
F igu r e 3. Molecular structure of 4 with 30% probability
level ellipsoids. The toluene molecule found in the unit cell
is omitted for clarity.
Molecular structures of the phosphine complex 2 and
the isocyanide complex 4 were determined by X-ray
crystallographic analysis (Figures 2 and 3). The selected
bond distances and angles are listed in Tables 2 and 3,
respectively. The structural features of 2 and 4 are
similar to those of the dicarbonyl complex 1. The chloro
ligands of both 2 and 4 are set in the space between
two methyl groups of the MeFCp ligand, while the
carbonyl and the phosphine/isocyanide ligands sit above
the methyl groups. The ruthenium-Cp carbon (C(Cp))
bond distances of 2 (Ru-C(Cp) ) 2.296 Å (average),
Ru-(centroid of Cp) ) 1.947 Å) are longer than those
of 4 (Ru-C(Cp) ) 2.273 Å (average), Ru-(centroid of
(26) For the corresponding Cp analogue of 3, RuCpCl(PPh3)(CO),
see: Davies, S. G.; Simpson, S. J . J . Chem. Soc., Dalton Trans. 1984,
993.
(27) Cotton, F. A.; Wilkinson, G.; Murillo, C. A.; Bochmann, M.
Advanced Inorganic Chemistry, 5th ed.; Wiley: New York, 1999.

2558 Organometallics, Vol. 22, No. 13, 2003
Matsuo and Nakamura
Ta ble 2. Selected Bon d Dista n ces a n d An gles for 2
Bond Distances (Å)
Ru-C1
Ru-C2
Ru-C3
Ru-C4
Ru-C5
2.334(6)
2.312(6)
2.267(6)
2.269(6)
2.275(7)
Ru-P
2.3417(19)
2.425(3)
1.965(11)
0.879(10)
Ru-Cl
Ru-C6
C6-O
Ru-C(Cp) (av)
2.291
1.943
1.429
1.520
1.542
1.370
Ru-(centroid of Cp)
C(Cp)-C(Cp) (av)
C(Cp)-C(R) (av)
C(R)-C(â) (av)
C(â)-C(â) (av)
Bond Angles (deg)
82.53(8) Cl-Ru-C6
84.4(2)
P-Ru-Cl
P-Ru-C6
95.4(3)
hold-back angle
18.38
355.78
313.08
353.87
sum of three angles around C(Cp) (av)a
sum of three angles around C(R) (av)a
sum of three angles around C(â) (av)
F igu r e 4. Molecular structure of 9 with 30% probability
level ellipsoids. The chlorobenzene molecule found in the
unit cell is omitted for clarity.
a
Within the fullerene core.
Ta ble 3. Selected Bon d Dista n ces a n d An gles for 4
Bond Distances (Å)
°C) gave the alkylated complexes in lower yield (ca.
50%). The metal-carbon bond was characterized by the
1H and 13C NMR spectra: the signals due to the CH3-
Ru group in 9 and the CH2-Ru group in 10 appear at
high field (δ 1.17 and 1.03) as singlet signals, and the
carbon signals of the CH3-Ru and the CH2-Ru groups
appear also at high field (δ -28.23 and -28.50, respec-
tively). The CO stretching frequencies of the MeFCp
compound 9 (νasym 2014 and νsym 1955 cm-1) are similar
to those of a Cp analogue, RuCp(CH3)(CO)2 (νasym 2019
and νsym 1958 cm-1),29 and larger than those of a Cp*
analogue, RuCp*(CH3)(CO)2 (νasym 1998 and νsym 1935
cm-1).30 The phosphine complex 2 was similarly con-
verted to a methyl complex. The reaction of Ru(η5-C60-
Me5)Cl(PEt3)(CO) (2) with 1.5 equiv of MeMgBr in
toluene afforded the methyl complex Ru(η5-C60Me5)-
(CH3)(PEt3)(CO) (11) in 93% yield. The methyl complex
11 is thermally stable both in solution and as a solid.
The 1H NMR spectrum of 11 in CDCl3 exhibits a doublet
signal (δ 0.77, 3J P-H ) 5.2 Hz) due to the CH3-Ru group
and one set of signals due to the phosphine and C60Me5
ligand. The 13C NMR spectrum exhibited a doublet of
Ru-C1
Ru-C2
Ru-C3
Ru-C4
Ru-C5
2.243(6)
2.267(6)
2.298(5)
2.279(5)
2.236(5)
Ru-Cl
Ru-C6
Ru-C7
N-C6
O-C7
2.409(2)
1.953(7)
2.004(6)
1.164(8)
0.946(8)
Ru-C(Cp) (av)
2.265
1.909
1.432
1.505
1.542
1.373
Ru-(centroid of Cp)
C(Cp)-C(Cp) (av)
C(Cp)-C(R) (av)
C(R)-C(â) (av)
C(â)-C(â) (av)
Bond Angles (deg)
Cl-Ru-C6
Cl-Ru-C7
87.0(2)
86.7(2)
C6-Ru-C7
85.2(2)
hold-back angle
17.52
356.18
313.38
353.47
sum of three angles around C(Cp) (av)a
sum of three angles around C(R) (av)a
sum of three angles around C(â) (av)
a
Within the fullerene core.
Cp) ) 1.919 Å), because of steric repulsion between the
phosphine ligands and the methyl group on the [60]-
fullerene. The methyl group near the phosphine group
is pushed down due to steric effects. Consistent with
the higher reactivity of 4 relative to 2, the ruthenium-
C(CO) bond length in 4 is elongated to 2.004 Å, which
is longer than those of 1 (1.92(4) and 1.97(2) Å), 2 (1.965-
(11) Å), and the usual terminal carbonyl-ruthenium
bond (ca. 1.85-1.90 Å).28
Alkylation an d Alkyn ylation of Ru th en iu m Ch lo-
r o Com p lexes. The chloro ligand on the ruthenium
center can also be exchanged readily with an alkyl or
an alkynyl ligand with the aid of a nucleophilic alkyl-
ation or alkynylation reagent. The reaction of 1 with
1.2 equiv of alkyl Grignard reagents such as MeMgBr
and Me3SiCH2MgCl in toluene at 0 °C afforded the alkyl
complexes Ru(η5-C60Me5)(CH3)(CO)2 (9) and Ru(η5-C60-
Me5)(CH2SiMe3)(CO)2 (10) as orange microcrystals in
90% and 78% yields, respectively (Scheme 1). The
reactions performed in THF at low temperature (-78
1
2
quartets signal (δ -28.03, J C-H ) 131.0 Hz, J P-C
12.9 Hz) due to the methyl carbon.
)
X-ray crystallographic analysis (Figure 4) was per-
formed for the methyl complex 9 recrystallized from
chlorobenzene/ethanol as a 1:1 mixture of 9 and chlo-
robenzene. The selected bond distances and angles of 9
are shown in Table 4. The methyl group on the ruthe-
nium center is located above one of the five methyl
groups on the fullerene sphere, despite apparent steric
problems. Coordination of the MeFCp ligand is therefore
slightly disturbed (Ru-C(Cp) ) 2.272(4)-2.331(4) Å).
The Ru-CH3 distance (2.168(5) Å) is comparable to that
of a cyclopentadienyl methyl complex such as Ru[C5-
Me4(neomenthyl)](CH3)(CO)(PPh3) (Ru-CH3 ) 2.166
Å).31
(29) Robertson, A. H. J .; McQuillan, G. P.; McKean, D. C. J . Chem.
Soc., Dalton Trans. 1995, 3955.
(30) Stasunik, A.; Wilson, D. R.; Malisch, W. J . Organomet. Chem.
1984, 270, C18.
(28) (a) Mills, O. S.; Nice, J . P. J . Organomet. Chem. 1967, 9, 339.
(b) Mague, J . T. Acta Crystallogr., Sect. C 1995, 51, 831.
(31) Lindsay, C.; Cesarotti, E.; Adams, H.; Bailey, N. A.; White, C.
Organometallics 1990, 9, 2594.

Ru(II) Complexes of Pentamethylated [60]Fullerene
Organometallics, Vol. 22, No. 13, 2003 2559
Ta ble 4. Selected Bon d Dista n ces a n d An gles for 9
Bond Distances (Å)
Ru-C1
Ru-C2
Ru-C
Ru-C4
Ru-C5
2.331(4)
2.287(4)
2.272(4)
2.286(4)
2.302(4)
Ru-C6
Ru-C7
Ru-C8
O1-C7
O2-C8
2.168(5)
1.867(5)
1.878(5)
1.149(6)
1.136(6)
Ru-C(Cp) (av)
2.296
1.947
1.429
1.512
1.542
1.374
Ru-(centroid of Cp)
C(Cp)-C(Cp) (av)
C(Cp)-C(R) (av)
C(R)-C(â) (av)
C(â)-C(â) (av)
Bond Angles (deg)
C6-Ru-C7
C6-Ru-C8
83.1(2)
84.6(2)
C7-Ru-C8
90.5(2)
hold-back angle
17.63
356.14
312.86
353.66
sum of three angles around C(Cp) (av)a
sum of three angles around C(R) (av)a
sum of three angles around C(â) (av)
a
Within the fullerene core.
Alkynylation of 1 also took place smoothly by treat-
ment with an alkynyl Grignard reagent or an alkynyl-
lithium reagent; the reaction of 1 with 1.2 equiv of
(phenylethynyl)magnesium bromide in toluene at 0 °C
afforded a ruthenium alkynyl dicarbonyl complex, Ru-
(η5-C60Me5)(CtCPh)(CO)2 (12) (Scheme 1). Similarly,
the reactions using 1-hexynylmagnesium bromide, ((tri-
methylsilyl)ethynyl)magnesium bromide, and ethynyl-
magnesium bromide afforded Ru(η5-C60Me5)(CtCnBu)-
(CO)2 (13), Ru(η5-C60Me5)(CtCSiMe3)(CO)2 (14), and
Ru(η5-C60Me5)(CtCH)(CO)2 (15), respectively, as orange
microcrystals, all in good yield (87-93%).32 These alky-
F igu r e 5. Molecular structure of 12 with 30% probability
level ellipsoids. The chlorobenzene molecule found in the
unit cell is omitted for clarity.
Ta ble 5. Selected Bon d Dista n ces a n d An gles
for 12
Bond Distances (Å)
Ru-C1
Ru-C2
Ru-C3
Ru-C4
Ru-C5
C6-C7
2.314(9)
2.258(9)
2.265(9)
2.282(9)
2.293(8)
1.17(1)
Ru-C6
Ru-C8
Ru-C9
O1-C8
O2-C9
2.05(1)
1.875(9)
1.913(9)
1.15(1)
1
nyl complexes were characterized by H and 13C NMR
1.107(9)
and APCI-mass spectroscopic analyses as well as by
combustion analysis. The NMR spectroscopic analyses
Ru-C(Cp) (av)
2.282
1.929
1.432
1.502
1.544
1.368
1
of these complexes are straightforward; their H NMR
Ru-(centroid of Cp)
C(Cp)-C(Cp) (av)
C(Cp)-C(R) (av)
C(R)-C(â) (av)
spectra exhibited one set of signals due to both the η5-
C60Me5 ligand and the substituted or unsubstituted
alkynyl ligand in a 1:1 integral ratio. The 13C NMR
spectra show the alkyne carbons at δ 113.05 (Ru-Ct
CPh), 100.89 (Ru-CtCPh), 110.86 (Ru-CtCnBu), 99.51
(Ru-CtCnBu), 120.00 (Ru-CtCSiMe3), 99.60 (Ru-Ct
CSiMe3), 113.23 (Ru-CtCH), and 99.37 (Ru-CtCH,
1J C-H ) 231.4 Hz). The IR spectra of the alkynyl
complexes showed the expected stretching absorptions
CtC (ν/cm-1: 2132 for 12, 2163 for 13, and 2163 for
14) and CO absorptions (ν/cm-1: 2038 and 1991 for 12,
2041 and 1989 for 13, 2036 and 1995 for 14, and 2046
and 1994 for 15).
C(â)-C(â) (av)
Bond Angles (deg)
C6-Ru-C8
C6-Ru-C9
82.0(3)
85.7(4)
C8-Ru-C9
92.6(4)
hold-back angle
17.28
356.22
312.72
353.16
sum of three angles around C(Cp) (av)a
sum of three angles around C(R) (av)a
sum of three angles around C(â) (av)
a
Within the fullerene core.
donation from the d orbital of the metal fragment to the
sp-hybridized orbital of the CtCPh fragment. The metal
center thus can be regarded as being electron deficient,
owing to an electron-withdrawing effect of the C60Me5
ligands.
Electr och em ical Stu dies of th e Ru -MeFCp Com -
p lexes a n d Rela ted Com p ou n d s. The redox behavior
of the Ru-MeFCp complexes was examined. The cyclic
voltammogram of 1 in THF or in dichloromethane
The molecular structure of the phenylalkynyl complex
12 was determined by X-ray analysis. Single crystals
of 12 suitable for X-ray crystallographic analysis were
obtained from a mixture of chlorobenzene and methanol.
The molecular structure of 12 is shown in Figure 5, and
selected bond lengths and angles are listed in Table 5.
A longer Ru-C(alkyne) bond length (2.05(1) Å) and a
shorter CtC triple bond (1.165(12) Å) compared to those
of reported phenylethynyl complexes (Ru-C ) 2.00-
2.03 Å; CtC ) 1.20-1.22 Å)33 are best interpreted in
terms of a great deal of inefficient π electron back-
(33) (a) Wisner, J . M.; Bartczak, T. J .; Ibers, J . A. Inorg. Chim. Acta
1985, 100, 115. (b) Bruce, M. I.; Humphrey, M. G.; Snow, M. R.;
Tiekink, E. R. T. J . Organomet. Chem. 1986 314, 213. (c) Yi, C. S.;
Liu, N.; Rheingold, A. L.; Liable-Sands, L. M.; Guzei, I. A. Organome-
tallics 1997, 16, 3729. (d) Bruce, M. I.; Hall, B. C.; Zaitseva, N. N.;
Skelton, B. W.; White, A. H. J . Chem. Soc., Dalton Trans. 1998, 1793.
(e) Hartbaum, C.; Roth, G.; Fischer, H. Chem. Ber. 1997, 130, 479.
(32) For the corresponding Cp analogue of 15, RuCp(CCH)(CO)2,
see: Viola, E.; Lo Sterzo, C.; Crescenzi, R.; Frachey. G. J . Organomet.
Chem. 1995, 493, 55.

2560 Organometallics, Vol. 22, No. 13, 2003
Matsuo and Nakamura
parable to those of Rh(η5-C60Me5)(CO)2 (E1/2 ) -1.94
V),13 C60Me5H (E1/2 ) -2.07 V), and the third reduction
potential of the parent [60]fullerene (-2.00 V in THF
and -1.87 V in toluene/MeCN vs Fc/Fc+).6b,35,36 Since
the Ru-MeFCp complexes bearing suitable ligands
retain the inherent reduction property of fullerene, as
indicated by the above data, we therefore expect that
the present Ru-MeFCp complexes can be applied to
catalytic reactions both under neutral and under reduc-
tive conditions.
Con clu sion
We have demonstrated that the ruthenium chloro
dicarbonyl complex 1, bearing the MeFCp ligand, can
be synthesized in high yield on a large scale and be
derivatized with retention of metal-FCp bonding. While
the ligand exchange reaction of the carbonyl ligand in
the previous mononuclear transition-metal fullerene
complex was not successful, owing to loss of the fullerene
ligand,8,12 the carbonyl ligands in the present complexes
can be cleanly replaced to obtain the phosphine and
isonitrile complexes without cleavage of the fullerene-
metal bond. Moreover, the metal-halogen bonds in the
present complexes can be exploited for further reac-
tion: alkylation and alkynylation reactions of 1 take
place smoothly to afford various alkyl and alkynyl
complexes. In light of the high stability of the metal-
fullerene bond under redox conditions, we expect that
the present Ru-MeFCp complexes as well as their
congeners will serve as key compounds in catalysis18 and
in materials science.37-40
F igu r e 6. Reduction potentials of 1, 2, 4, 9 and related
compounds in THF. Legend: (a) ref 13; (b) ref 34; (c) ref
16; (d) ref 13; (e) ref 14; (f) ref 36.
F igu r e 7. Cyclic voltammograms of 9 in THF at 25 °C
showing successive reversible reductions to 92-
.
showed an irreversible reduction behavior with an Ep
value of -1.30 V (vs Fc/Fc+, in THF), while no oxidation
wave was observed for the window of THF. However,
the phosphine complex 2 and the isonitrile complex 4
exhibited reversible one-electron reduction, the values
of which are E1/2 ) -1.45 and -1.53 V, respectively.
Note that, usually, ruthenium(II) cyclopentadienyl com-
plexes are not reduced under the same conditions. These
reduction potentials are comparable to those of the Rh-
MeFCp complex Rh(η5-C60Me5)(CO)2 (E1/2 ) -1.35 V),13
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations involving air- and
moisture-sensitive compounds were carried out using standard
Schlenk techniques under nitrogen or argon. Hexane, toluene,
THF, benzene-d6, and THF-d8 were distilled from Na/K alloy
and thoroughly degassed by trap-to-trap distillation before use.
Pentamethyl-hydro-[60]fullerene, C60Me5H, was prepared ac-
cording to the literature.15c t-BuOK in THF was purchased
from Sigma-Aldrich and used as received.
The 1H (500, 400 MHz), 13C (125, 100 MHz), and 31P (200,
160 MHz) NMR spectra were measured on a Bruker DRX500
or J EOL EX 400 spectrometer. When benzene-d6, toluene-d8,
and THF-d8 were used as solvents, the spectra were referenced
the Fe-MeFCp complex Fe(η5-C60Me5)(η5-Cp) (E1/2
-1.46 V),14 and the parent molecule C60Me5H (E1/2
)
)
-1.45 V), indicating the one-electron reductions found
in 2 and 4 are due to reductions of the fullerene moieties
(Figure 6). This observation of the metal-dependent
change of the reduction potential allows us to consider
that the redox behavior in the fullerene moiety can be
controlled by the changing the ligands on the metal
center.16 We can rationalize the irreversible reduction
of 1 by assuming irreversible loss of chloride anion or
carbonyl ligand from the metal center, which is trig-
gered by initial reduction of the fullerene moiety fol-
lowed by electron transfer to the metal center. The lack
of a reduction wave due to the MeFCp- anion (-1.84
and -2.38 V)34 indicates that the metal-MeFCp bond
is not cleaved in this process.
1
to residual solvent protons in the H NMR spectra and to the
solvent signal in the 13C NMR spectra. Other spectra were
recorded on the following instruments: IR spectra, J ASCO IR-
420 and Applied Systems Inc. ReactIR 1000; UV/vis spectra,
HITACHI U3500; mass spectra, Shimadzu LCMS-QP8000,
Waters ZQ2000, and J EOL J MS T100LC. Elemental analyses
were performed at the organic elemental analysis laboratory
in this department.
(35) Xie, Q.; Perez-Cordero, E.; Echegoyen, L. J . Am. Chem. Soc.
1992, 114, 3978.
(36) Lerke, S. A.; Parkinson, B. A.; Evans, D. H.; Fagan, P. J . J .
Am. Chem. Soc. 1992, 114, 7807.
(37) Paul, F.; Lapinte, C. Coord. Chem. Rev. 1998, 180, 431.
(38) Stahl, J .; Bohling, J . C.; Bauer, E. B.; Peters, T. B.; Mohr, W.;
Mart´ın-Alvarez, J . M.; Hampel, F.; Gladysz, J . A. Angew. Chem., Int.
Ed. 2002, 41, 1872.
(39) Zhou, S.; Burger, C.; Chu, B.; Sawamura, M.; Nagahama, N.;
Toganoh, M.; Hackler, U. E.; Isobe, H.; Nakamura, E. Science 2001,
291, 1944.
The methyl complex 9 showed reversible two-electron
reductions (-1.34 and -1.94 V; Figure 7), whereas the
alkynyl complexes 12-15 do not show reversible redox
behavior. The second reduction potential of 9 is com-
(40) (a) Sawamura, M.; Kawai, K.; Matsuo, Y.; Kanie, K.; Kato, T.;
Nakamura, E. Nature 2002, 419, 702. (b) Nakamura, E.; Tahara, K.;
Matsuo, Y.; Sawamura, M. J . Am. Chem. Soc. 2003, 125, 2834.
(34) Determined for K(MeFCp).

Ru(II) Complexes of Pentamethylated [60]Fullerene
Organometallics, Vol. 22, No. 13, 2003 2561
P r ep a r a tion of Ru (η5-C60Me5)Cl(CO)2 (1). To a solution
of C60Me5H (1.00 g, 1.25 mmol) in THF (200 mL) was added a
solution of t-BuOK (2.50 mmol) in THF (2.50 mL) at 25 °C.
After the mixture was stirred for 15 min, [RuCl2(CO)3]2 (1.28
g, 2.50 mmol) was added to the resulting dark brown solution
at 25 °C, and this reaction mixture was stirred for 30 min at
25 °C. Insoluble products were separated through a pad of
silica gel, and purification of the soluble products through
HPLC (Nacalai Tesque, Buckyprep, 250 mm, 7/3 toluene/2-
propanol) afforded orange microcrystals of 1 (990 mg, 1.00
mmol, 80% yield). 1H NMR (C6D6, 25 °C): δ 2.18 (s, 15H,
Me3C), 108.01 (s, 5C, C60(CCp)), 143.69 (s, 10C, C60), 143.81 (s,
10C, C60), 147.06 (s, 5C, C60), 148.19 (s, 10C, C60), 148.49 (s,
5C, C60), 152.79 (s, 10C, C60(Câ)), 200.38 (s, 1C, CO), 211.65
(s, 1C, NC). IR (diamond probe): ν(NC)/cm-1 2159 (s), ν(CO)/
cm-1 1976 (s). APCI-MS (+): m/z 1044 (M+). Complex 4
exhibited reversible one-electron reduction at -1.53 V (vs Fc/
Fc+) in THF. Anal. Calcd for C71H24ClNORu: C, 81.72; H, 2.32;
N, 1.34. Found: C, 81.50; H, 2.30; N, 1.27.
P r ep a r a tion of Ru (η5-C60Me5)Cl(MeNC)(CO) (5). The
procedure described for 4 was performed to obtain 5. Complex
5 was prepared from 1 (20 mg, 0.020 mmol) and methyl
isocyanide (0.050 mmol) in toluene (0.5 mL). Yield: 18 mg
C
60Me5). 13C NMR (C6D6, 25 °C): δ 30.82 (5C, C60Me5), 51.19
1
(5C, C60(CR)), 111.69 (5C, C60(CCp)), 143.83 (10C, C60), 144.17
(10C, C60), 147.42 (5C, C60), 148.60 (10C, C60), 148.98 (5C, C60),
152.28 (10C, C60(Câ)), 196.93 (2C, CO). UV-vis (7/3 toluene/
iPrOH): λmax 370 (sh), 395 nm. IR (diamond probe): ν(CO)/
cm-1 2052 (s), 2006 (s). APCI-MS (+): m/z 988 (M+). The cyclic
voltammogram of 1 in THF or in dichloromethane showed
irreversible reduction behavior with an Ep value of -1.30 V
(vs Fc/Fc+, in THF), while no oxidation wave was observed.
(0.019 mmol, 93%). H NMR (CDCl3, 25 °C): δ 2.43 (s, 15H,
C
60Me5), 2.45 (s, 3H, MeNC). 13C NMR (CDCl3, 25 °C): δ 29.47
(5C, C60Me5), 29.73 (1C, MeNC), 51.09 (5C, C60(CR)), 108.06
(5C, C60(CCp)), 143.62 (10C, C60), 143.69 (10C, C60), 146.98 (5C,
C
60), 148.10 (10C, C60), 148.42 (5C, C60), 152.59 (10C, C60(Câ)),
199.99 (2C, CO), 220.78 (1C, MeNC). IR (diamond probe): ν-
(NC)/cm-1 2188 (s), ν(CO)/cm-1 1976 (s). APCI-MS (+): m/z
1002 (M+). Anal. Calcd for C68H18ClNORu: C, 81.55; H, 1.81;
N, 1.40. Found: C, 81.22; H, 2.02; N, 1.35.
Anal. Calcd for
Found: C, 81.78; H, 2.52.
C74H23ClO2Ru‚C7H8: C, 82.25; H, 2.15.
P r ep a r a tion of Ru (η5-C60Me5)Cl(XylNC)(CO) (6). The
procedure described for 4 was performed to obtain 6. Complex
6 was prepared from 1 (70 mg, 0.071 mmol) and 2,6-dimeth-
ylphenyl isocyanide (20 mg, 0.15 mmol) in toluene (0.5 mL).
Yield: 70 mg (0.064 mmol, 90%). 1H NMR (C6D6, 25 °C): δ
2.35 (s, 15H, C60Me5), 2.44 (s, 6H, Me2C6H3), 6.74 (d, 2H,
m-C6H3), 6.84 (t, 1H, p-C6H3). 13C NMR (C6D6, 25 °C): δ 29.63
(2C, Me2C6H3), 29.74 (5C, C60Me5), 51.41 (5C, C60(CR)), 109.32
(5C, C60(CCp)), 125.64 (1C, p-C6H3), 128.88 (2C, m-C6H3), 135.71
(2C, o-C6H3), 144.14 (10C, C60), 144.21 (10C, C60), 147.50 (5C,
P r ep a r a tion of Ru (η5-C60Me5)Cl(P Et3)(CO) (2). To a
solution of 1 (100 mg, 0.101 mmol) in toluene (20 mL) was
added a solution of PEt3 (0.152 mmol) in toluene (0.15 mL).
The mixture was stirred and heated at 70 °C for 12 h, and the
progress of the reaction was monitored by HPLC. Insoluble
products were separated through a pad of silica gel, and
purification by HPLC afforded orange microcrystals of 2 (105
mg, 0.0971 mmol, 96% yield). 1H NMR (CDCl3): δ 1.19 (qd,
3J H-H ) 7.7 Hz, 2J P-H ) 23.8 Hz, 6H, CH2CH3), 1.42 (td, 3J H-H
) 7.6 Hz, 3J P-H ) 15.1 Hz, 9H, CH2CH3), 2.47 (s, 15H, C60Me5).
C
60), 148.63 (10C, C60), 148.98 (5C, C60), 152.25 (ipso-C6H3),
1
2
13C NMR (CDCl3): δ 8.71 (qd, J C-H ) 128.0 Hz, J P-C ) 4.8
153.08 (10C, C60(Câ)), 201.13 (1C, CO), 203.98 (1C, NC). IR
1
1
(diamond probe): ν(NC)/cm-1 2140 (s), ν(CO)/cm-1 1978 (s).
Hz, CH2CH3), 21.84 (td, J C-H ) 127.7 Hz, J P-C ) 28.4 Hz,
1
APCI-MS (+): m/z 1092 (M+). Anal. Calcd for C75H24
-
CH2CH3), 29.19 (q, J C-H ) 130.7 Hz, 5C, C60Me5), 51.44 (s,
5C, C60(CR)), 109.98 (s, 5C, C60(CCp)), 143.66 (s, 10C, C60),
ClNORu: C, 82.52; H, 2.22; N, 1.28. Found: C, 82.21; H, 2.34;
N, 1.26.
143.68 (s, 10C, C60), 147.08 (s, 5C, C60), 148.21 (s, 10C, C60),
2
P r ep a r a tion of Ru (η5-C60Me5)Cl(tBu NC)2 (7). To a solu-
tion of 1 (50 mg, 0.050 mmol) in toluene (10 mL) was added a
solution of tert-butyl isocyanide (0.50 mmol) in toluene (5.0
mL). The mixture was stirred and heated at 100 °C for 24 h,
and the progress of the reaction was monitored by HPLC.
Insoluble products were separated through a pad of silica gel,
and purification by HPLC afforded orange microcrystals of 7
(30 mg, 0.027 mmol, 54% yield). 1H NMR (CDCl3, 25 °C): δ
1.70 (s, 18H, Me3C), 2.43 (s, 15H, C60Me5). 13C NMR (CDCl3,
148.41 (s, 5C, C60), 152.72 (s, 10C, C60(Câ)), 204.84 (d, J P-C
)
24.7 Hz, 2C, CO). 31P{1H} NMR (CDCl3): δ 32.28 (PEt3). IR
(diamond probe): ν(CO)/cm-1 1937 (s). APCI-MS (+): m/z 1079
(M+). Complex 2 exhibited reversible one-electron reduction
at -1.45 V (vs Fc/Fc+) in THF. Anal. Calcd for C72H30ClOPRu‚
C7H8: C, 81.05; H, 3.27. Found: C, 80.54; H, 3.50.
P r ep a r a tion of Ru (η5-C60Me5)Cl(P P h 3)(CO) (3). To a
solution of 1 (40 mg, 0.041 mmol) in toluene (10 mL) was added
a solution of PPh3 (0.41 mmol) in toluene (0.41 mL). The mix-
ture was stirred and heated at 70 °C for 12 h, and the progress
of the reaction was monitored by HPLC. Insoluble products
were separated through a pad of silica gel, and purification
by HPLC afforded orange microcrystals of 3 (26 mg, 0.021
mmol, 51% yield). 1H NMR (CDCl3, 25 °C): δ 2.22 (s, 15H,
1
25 °C): δ 29.29 (q, J C-H ) 130.7 Hz, 5C, C60Me5), 31.26 (q,
1J C-H ) 129.0 Hz, 1C, Me3C), 51.25 (s, 5C, C60(CR)), 64.62 (s,
1C, Me3C), 103.79 (s, 5C, C60(CCp)), 143.50 (s, 10C, C60), 144.11
(s, 10C, C60), 147.07 (s, 5C, C60), 148.11 (s, 10C, C60), 148.37
(s, 5C, C60), 153.69 (s, 10C, C60(Câ)), 206.09 (s, 2C, NC). APCI-
MS (+): m/z 1099 (M+).
C
60Me5), 7.10 (t, 1H, p-Ph), 7.24 (s, 2H, m-Ph), 7.76 (s, 2H,
o-Ph). 13C NMR (CDCl3, 25 °C): δ 28.27 (5C, C60Me5), 51.75
(5C, C60(CR)), 109.75 (5C, C60(CCp)), 128-135 (Ph), 143.50 (10C,
P r ep a r a tion of Ru (η5-C60Me5)Cl(XylNC)2 (8). The pro-
cedure described for 7 was performed to obtain 8. Complex 8
(18 mg, 0.015 mmol, 51% yield) was synthesized from 1 (30
mg, 0.030 mmol) and 2,6-dimethylphenyl isocyanide (39 mg,
C
60), 143.66 (10C, C60), 147.10 (5C, C60), 148.23 (10C, C60),
148.23 (5C, C60), 152.43 (10C, C60(Câ)), 201.93 (d, 2J P-C ) 24.2
Hz, 2C, CO). 31P{1H} NMR (CDCl3): δ 37.23 (PPh3). IR
(diamond probe): ν(CO)/cm-1 1950 (s). APCI-MS (+): m/z 1223
(M+). Anal. Calcd for C84H30ClOPRu: C, 82.51; H, 2.47.
Found: C, 82.24; H, 2.50.
1
0.30 mmol). H NMR (CDCl3, 25 °C): δ 2.50 (s, 15H, C60Me5),
2.67 (s, 12H, Me2C6H3), 7.18 (s, 6H, m- and p-C6H3). 13C NMR
(CDCl3, 25 °C): δ 19.33 (4C, Me2C6H3), 29.68 (5C, C60Me5),
51.29 (5C, C60(CR)), 106.03 (5C, C60(CCp)), 128.04 (6C, m- and
p-C6H3), 135.16 (4C, o-C6H3), 143.60 (10C, C60), 144.00 (10C,
C60), 147.07 (5C, C60), 148.17 (10C, C60), 148.43 (5C, C60), 152.32
(ipso-C6H3), 153.33 (10C, C60(Câ)), 180.33 (2C, NC). APCI-MS
(+): m/z 1195 (M+).
P r ep a r a tion of Ru (η5-C60Me5)Cl(tBu NC)(CO) (4). To a
solution of 1 (50 mg, 0.050 mmol) in toluene (10 mL) was added
a solution of tert-butyl isocyanide (0.075 mmol) in toluene (0.75
mL). The mixture was stirred and heated at 70 °C for 12 h,
and the progress of the reaction was monitored by HPLC.
Insoluble products were separated through a pad of silica gel,
and purification by HPLC afforded orange microcrystals of 4
(50 mg, 0.048 mmol, 94% yield). 1H NMR (CDCl3, 25 °C): δ
1.74 (s, 9H, Me3C), 2.44 (s, 15H, C60Me5). 13C NMR (CDCl3, 25
°C): δ 29.42 (q, 1J C-H ) 130.8 Hz, 5C, C60Me5), 30.84 (q, 1J C-H
) 129.1 Hz, 1C, Me3C), 51.12 (s, 5C, C60(CR)), 59.20 (s, 1C,
P r ep a r a tion of Ru (η5-C60Me5)(CH3)(CO)2 (9). To a solu-
tion of 1 (33 mg, 0.033 mmol) in THF (8.0 mL) was added a
solution of MeMgBr (1.5 equiv, 0.050 mmol) in THF (0.050
mL) at 25 °C. The reaction mixture was stirred for 10 min at
25 °C. After removal of the solvent, the resulting solid was
extracted with toluene (30 mL). Purification by HPLC afforded
1
orange microcrystals of 9 (29 mg, 0.030 mmol, 90% yield). H

2562 Organometallics, Vol. 22, No. 13, 2003
Matsuo and Nakamura
Ta ble 6. Cr ysta l Da ta a n d Da ta Collection P a r a m eter s for 1, 2, 4, 9, a n d 12
1‚C7H8
2‚C7H8
4‚C7H8
9‚C6H5Cl
12‚C6H5Cl
formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
C
77H23ClO2Ru
C79H38ClOPRu
1170.58
triclinic
C78H24ClNORu
1127.50
monoclinic
P21/n (No. 14)
15.967(2)
9.9800(16)
30.543(4)
90
105.269(9)
90
4695.2(11)
4
C74H23ClO2Ru
1080.44
monoclinic
P21/n (No. 14)
11.6440(4)
17.0040(9)
21.7500(10)
90
96.644(3)
90
4277.5(3)
4
C81H25ClO2Ru
1166.61
monoclinic
P21/c (No. 14)
9.910(3)
17.204(5)
27.875(9)
90
99.98(2)
90
4680.6(2)
4
1080.618
monoclinic
P21/n (No. 14)
11.7640(6)
16.9730(9)
21.9850(12)
90
97.444(3)
90
4352.8(4)
4
P1h (No. 2)
9.989(2)
15.136(4)
17.686(5)
70.886(12)
75.406(17)
85.650(17)
2445.0(11)
2
Z
D
calcd, g cm-3
1.649
1.590
1.649
1.678
1.655
T, K
193(2)
120(2)
120(2)
153(2)
93(2)
cryst size, mm
2θmin, 2θmax, deg
no. of rflns measd (unique)
0.50 × 0.22 × 0.12 0.45 × 0.22 × 0.18 0.40 × 0.22 × 0.05 0.25 × 0.10 × 0.05 0.25 × 0.10 × 0.05
4.44, 51.16
7506
4.22, 51.66
6501
4.30, 51.52
8469
4.82, 51.74
8131
6.00, 60.20
13 588
no. of rflns measd (I > 2.0σ(I)) 6148
5202
749
0.099, 0.253
0.084, 0.224
1.9
6032
767
0.106, 0.245
0.080, 0.215
1.07
6814
704
0.074, 0.195
0.062, 0.171
1.07
5523
521
-, 0.243
0.148, -
1.027
no. of params
R1, wR2 (all data)
R, Rw (I > 2.0σ(I))
GOF on F2
721
0.155, 0.471
0.144, 0.464
2.22
∆, e Å-3
2.79, -1.37
1.64, -1.31
1.34, -1.13
2.35, -1.88
0.171, -0.105
NMR (C6D6, 25 °C): δ 1.17 (s, 3H, Ru-CH3), 2.01 (s, 15H,
60Me5). 13C NMR (C6D6, 25 °C): δ -28.23 (1C, Ru-CH3),
mL) at 25 °C. The reaction mixture was stirred for 10 min at
25 °C. After removal of the solvent, the resulting solid was
extracted with toluene (40 mL). Purification by HPLC (Nacalai
Tesque, Buckyprep, 250 mm, 7/3 toluene/2-propanol) afforded
orange microcrystals of 12 (50 mg, 0.047 mmol, 93% yield).
1H NMR (C6D6, 25 °C): δ 2.22 (s, 15H, C60Me5), 7.10 (t, 1H,
p-Ph), 7.24 (s, 2H, m-Ph), 7.76 (s, 2H, o-Ph). 13C NMR (C6D6,
25 °C): δ 30.67 (5C, C60Me5), 50.97 (5C, C60(CR)), 100.89 (1C,
CCPh), 112.61 (5C, C60(CCp)), 113.05 (1C, Ru-CCPh), 144.15
(10C, C60), 144.15 (10C, C60), 147.35 (5C, C60), 148.53 (10C,
C
30.197 (5C, C60Me5), 51.18 (5C, C60(CR)), 112.18 (5C, C60(CCp)),
144.08 (10C, C60), 144.39 (10C, C60), 147.34 (5C, C60), 148.48
(10C, C60), 148.99 (5C, C60), 153.09 (10C, C60(Câ)), 195.26 (2C,
CO). IR (diamond probe): ν(CO)/cm-1 2014 (s), 1955 (s). APCI-
MS (+): m/z 968 (M+). Complex 9 showed reversible two-
electron reductions (-1.34 and -1.94 V (vs Fc/Fc+)) in THF.
Anal. Calcd for C68H18O2Ru‚C7H8: C, 84.97; H, 2.47. Found:
C, 84.88; H, 2.71.
P r ep a r a tion of Ru (η5-C60Me5)(CH2SiMe3)(CO)2 (10). The
procedure described for 9 was performed to obtain 10. Complex
10 (6.2 mg, 0.0060 mmol, 78% yield) was derived from 1 (8.0
mg, 0.0081 mmol) and Me3SiCH2MgCl (0.0122 mmol). 1H NMR
(C6D6, 25 °C): δ 0.55 (s, 9H, Si-CH3), 1.03 (s, 2H, Ru-CH2),
2.15 (s, 15H, C60Me5). 13C NMR (C6D6, 25 °C): δ -28.50 (2C,
C60), 149.00 (5C, C60), 152.60 (10C, C60(Câ)), 197.42 (2C, CO).
IR (diamond probe): ν(CC)/cm-1 2132 (s), ν(CO)/cm-1 2038 (s),
1989 (s). APCI-MS (+): m/z 1054 (M+). Anal. Calcd for
C
75H20O2Ru: C, 85.45; H, 1.91. Found: C, 85.31; H, 2.20.
P r ep a r a t ion of R u (η5-C60Me5)(CCn Bu )(CO)2 (13). The
procedure described for 12 was performed to obtain 13.
Complex 13 (19 mg, 0.018 mmol, 91% yield) was derived from
1 (20 mg, 0.020 mmol) and nBuCCMgBr (0.030 mmol). 1H NMR
(C6D6, 25 °C): δ 1.05 (t, 3H, CH2CH3), 1.67 (qt, 2H, CH2CH3),
1.75 (tt, 2H, CCCH2CH2), 2.23 (s, 15H, C60Me5), 2.66 (t, 2H,
CCCH2). 13C NMR (C6D6, 25 °C): δ 14.05 (3C, CH2CH3), 22.10
(2C, CH2CH3), 22.57 (2C, CCCH2), 30.67 (5C, C60Me5), 33.00
(2C, CCCH2CH2), 50.97 (5C, C60(CR)), 99.51 (1C, CCnBu),
110.86 (1C, Ru-CCnBu), 112.28 (5C, C60(CCp)), 144.14 (10C,
Ru-CH2), 2.16 (3C, SiMe3), 30.00 (5C, C60Me5), 51.32 (5C, C60
-
(CR)), 112.66 (5C, C60(CCp)), 144.09 (10C, C60), 144.27 (10C, C60),
147.35 (5C, C60), 148.50 (10C, C60), 149.00 (5C, C60), 152.94
(10C, C60(Câ)), 202.96 (2C, CO). IR (diamond probe): ν(CO)/
cm-1 2013 (s), 1954 (s). APCI-MS (+): m/z 1040 (M+). Anal.
Calcd for C70H24O2RuSi: C, 81.93; H, 2.36. Found: C, 81.79;
H, 2.42.
P r ep a r a tion of Ru (η5-C60Me5)Me(P Et3)(CO) (11). To a
solution of 2 (15 mg, 0.014 mmol) in THF (4.0 mL) was added
a solution of MeMgBr (1.5 equiv, 0.021 mmol) in THF (0.021
mL) at 25 °C. The reaction mixture was stirred for 30 min at
25 °C. After removal of the solvent, the resulting solid was
extracted with toluene (20 mL). Purification by HPLC afforded
orange microcrystals of 11 (13.8 mg, 0.013 mmol, 93% yield).
C
60), 144.24 (10C, C60), 147.35 (5C, C60), 148.52 (10C, C60),
149.00 (5C, C60), 152.78 (10C, C60(Câ)), 197.93 (2C, CO). IR
(diamond probe): ν(CC)/cm-1 2163 (s), ν(CO)/cm-1 2041 (s),
1991 (s). APCI-MS (+): m/z 1034 (M+). Anal. Calcd for
C
73H24O2Ru: C, 84.78; H, 2.34. Found: C, 84.52; H, 2.60.
P r ep a r a tion of Ru (η5-C60Me5)(CCSiMe3)(CO)2 (14). The
3
1H NMR (CDCl3): δ 0.77 (d, J P-H ) 5.2 Hz, 3H, Ru-CH3),
procedure described for 12 was performed to obtain 14.
Complex 14 (29 mg, 0.027 mmol, 92% yield) was derived from
1 (30 mg, 0.030 mmol) and Me3SiCCMgBr (0.045 mmol). 1H
3
3
1.33 (td, J H-H ) 7.6 Hz, J P-H ) 14.8 Hz, 9H, CH2CH3), 2.15
3
2
(qd, J H-H ) 7.5 Hz, J P-H ) 22.2 Hz, 6H, CH2CH3), 2.41 (s,
15H, C60Me5). 13C NMR (CDCl3): δ -28.03 (qd, J C-H ) 131.0
NMR (C6D6, 25 °C): δ 0.47 (s, 9H, SiCH3), 2.20 (s, 15H,
1
2
1
1
Hz, J P-C ) 12.9 Hz, Ru-CH3), 8.43 (qd, J C-H ) 127.7 Hz,
C
60Me5). 13C NMR (C6D6, 25 °C): δ 1.47 (q, J C-H ) 117.5 Hz,
2J P-C ) 3.2 Hz, CH2CH3), 21.95 (td, 1J C-H ) 128.8 Hz, 1J P-C
)
3C, SiCH3), 30.71 (q, 1J C-H ) 131.0 Hz, 5C, C60Me5), 50.95 (5C,
60(CR)), 99.60 (s, 1C, CCSi), 112.53 (s, 5C, C60(CCp)), 120.00
(s, 1C, Ru-CC), 144.14 (10C, C60), 144.16 (10C, C60), 147.34
1
27.4 Hz, CH2CH3), 30.11 (q, J C-H ) 130.0 Hz, 5C, C60Me5),
C
2
51.45 (s, 5C, C60(CR)), 110.32 (d, 5C, J P-C ) 1.9 Hz, C60(CCp)),
143.48 (s, 10C, C60), 144.18 (s, 10C, C60), 146.95 (s, 5C, C60),
(5C, C60), 148.52 (10C, C60), 149.00 (5C, C60), 152.61 (10C, C60-
148.01 (s, 10C, C60), 148.35 (s, 5C, C60), 153.61 (s, 10C, C60
-
(Câ)), 197.35 (2C, CO). IR (diamond probe): ν(CC)/cm-1 2163
(s), ν(CO)/cm-1 2036 (s), 1999 (s). APCI-MS (+): m/z 1050 (M+).
Anal. Calcd for C72H24O2RuSi: C, 82.34; H, 2.30. Found: C,
82.45; H, 2.51.
2
(Câ)), 208.33 (d, J P-C ) 23.4 Hz, 2C, CO). 31P{1H} NMR
(CDCl3): δ 37.82 (PEt3). APCI-MS (-): m/z 1058 (M-). Anal.
Calcd for C73H33OPRu: C, 82.86; H, 3.14. Found: C, 82.54; H,
3.40.
P r ep a r a t ion of R u (η5-C60Me5)(CCH)(CO)2 (15). The
procedure described for 12 was performed to obtain 15.
Complex 15 (21 mg, 0.022 mmol, 87% yield) was derived from
1 (25 mg, 0.025 mmol) and HCCMgBr (0.038 mmol). 1H NMR
P r ep a r a tion of Ru (η5-C60Me5)(CCP h )(CO)2 (12). To a
solution of 1 (50 mg, 0.051 mmol) in THF (8.0 mL) was added
a solution of PhCCMgBr (1.5 equiv, 0.075 mmol) in THF (0.075

Ru(II) Complexes of Pentamethylated [60]Fullerene
Organometallics, Vol. 22, No. 13, 2003 2563
(C6D6, 25 °C): δ 1.42 (s, 1H, CCH), 2.20 (s, 15H, C60Me5). 13C
NMR (C6D6, 25 °C): δ 30.70 (q, 1J C-H ) 131.1 Hz, 5C, C60Me5),
50.94 (s, 5C, C60(CR)), 99.37 (d, 1J C-H ) 231.4 Hz, CCH), 112.38
(s, 5C, C60(CCp)), 113.23 (s, Ru-CCH), 144.13 (s, 10C, C60),
144.14 (s, 10C, C60), 147.34 (s, 5C, C60), 148.53 (s, 10C, C60),
148.98 (s, 5C, C60), 152.61 (s, 10C, C60(Câ)), 197.42 (s, 2C, CO).
IR (diamond probe): ν(CO)/cm-1 2047 (s), 2003 (s). APCI-MS
(-): m/z 978 (M-). Anal. Calcd for C69H16O2Ru: C, 84.74; H,
1.65. Found: C, 84.53; H, 1.69.
9 were anisotropically refined. The ruthenium atom, oxygen
atoms, and carbon atoms of the phenylethynyl group and
carbonyl group of 12 were anisotropically refined, while the
carbon atoms in the C60 skeleton of 12 were refined isotropi-
cally. In the subsequent refinement, the function ∑w(Fo2 - Fc )2
2
was minimized, where |Fo| and |Fc| are the observed and
calculated structure factor amplitudes, respectively. The agree-
ment indices are defined as R1 ) ∑(||Fo| - |Fc||)/Σ|Fo| and wR2
) [∑w(Fo - Fc2)2/∑(wFo4)]1/2. Due to the Cl/CO disorder in 1,
2
the Ru-Cl, Ru-C(O), and C-O distances have less certainty
than those of 2, 4, 9, and 12.
Cr ysta llogr a p h ic Da ta Collection a n d Str u ctu r e De-
ter m in a tion of 1, 2, 4, 9, a n d 12. Crystals of 1, 2, 4, and 9
suitable for X-ray diffraction study were mounted on a Mac-
Science DIP2030 imaging plate diffractometer for data collec-
tion using Mo KR (graphite monochromated, λ ) 0.710 69 Å)
radiation. Crystal structural analysis of 12 was performed by
using a Rigaku RAXIS-RAPID imaging plate diffractometer
for data collection using Mo KR (graphite monochromated, λ
) 0.710 69 Å, fine focused) radiation. Crystal data and data
statistics are summarized in Table 6.
The structure of the complexes 1, 2, 4, 9, and 12 were solved
by direct methods (SHELXS-97)41 and expanded using Fourier
techniques (DIRDIF-94).42 The positional parameters and
thermal parameters of non-hydrogen atoms of 1, 2, 4, 9, and
12 were refined using a full-matrix least-squares method.
Hydrogen atoms were placed at calculated positions (C-H )
0.95 Å) and kept fixed. All non-hydrogen atoms of 1, 2, 4, and
Electr och em ica l Mea su r em en ts. Electrochemical mea-
surements were performed using a BAS CV-50W voltammetric
analyzer. A glassy-carbon electrode was used as the working
electrode. The counter electrode was a platinum coil, and the
reference electrode was an Ag/Ag+ electrode. Cyclic voltam-
metry (CV) was performed at a scan rate of 100 mV s-1. All
half-wave potentials are given as E1/2 ) (Ep,c + Ep,a)/2, where
Ep,c and Ep,a are the cathodic and anodic peak potentials,
respectively.
Ack n ow led gm en t. The present research was sup-
ported by a Grant-in-Aid for Scientific Research (Spe-
cially Promoted Research) and The 21st Century COE
Programs in Fundamental Chemistry. We thank Fron-
tier Carbon Corp. for a generous supply of [60]fullerene.
(41) Sheldrick, G. M. Program for the Solution of Crystal Structures;
University of Go¨ttingen, Germany, 1997. Sheldrick, G. M. Program
for the Solution of Crystal Structures; University of Go¨ttingen,
Germany, 1997.
(42) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.;
de Gelder, R.; Israel, R.; Smits, J . M. M. The DIRDIF-94 Program
System; Technical Report of the Crystallography Laboratory; Univer-
sity of Nijmegen, Nijmegen, The Netherlands, 1994.
Su p p or tin g In for m a tion Ava ila ble: Lists of positional
parameters, thermal displacement parameters, bond lengths,
and bond angles for 1, 2, 4, 9, and 12; these data are also
available as CIF files. This material is available free of charge
via the Internet at http://pubs.acs.org.
OM0302387