Nickel, palladium, and platinum complexes of η5- cyclopentadienide C60R5 ligands. Kinetic and thermodynamic stabilization effects of the C60Ph5 ligand

Article abstract of DOI:10.1021/om0499153

The nickel-, palladium-, and platinum-RFC_p complexes η⁵-RFC_p)(η³-allylic) (3b, RFC _p = C₆₀R₅, R = Me, allylic = methallyl; 4a, R = Ph, allylic = allyl; 4b, R = Ph, allylic = meth

Full text of DOI:10.1021/om0499153

Organometallics 2004, 23, 3259-3266
3259
Nick el, P a lla d iu m , a n d P la tin u m Com p lexes of
η5-Cyclop en ta d ien id e C60R5 Liga n d s. Kin etic a n d
Th er m od yn a m ic Sta biliza tion Effects of th e C60P h 5
Liga n d
Yoichiro Kuninobu,† Yutaka Matsuo, Motoki Toganoh,‡ Masaya Sawamura,§ and
Eiichi Nakamura*
Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, J apan
Received February 2, 2004
The nickel-, palladium-, and platinum-RFCp complexes Ni(η5-RFCp)(η3-allylic) (3b,
RFCp ) C60R5, R ) Me, allylic ) methallyl; 4a , R ) Ph, allylic ) allyl; 4b, R ) Ph, allylic
) methallyl), Pd(η5-RFCp)(η3-allylic) (7a , R ) Me, allylic ) allyl; 7b , R ) Me, allylic )
methallyl; 7c, R ) Me, allylic ) crotyl; 8a , R ) Ph, allylic ) allyl; 8b, R ) Ph, allylic )
methallyl; 8c, R ) Ph, allylic ) crotyl), and Pt(η5-RFCp)(η3-methallyl) (9, R ) Me; 10, R )
Ph), were synthesized by transmetalation between K(RFCp) (R ) Me, Ph) and [Ni(allylic)-
Br]2, [Pd(allylic)Cl]2, or [Pt(methallyl)Cl]2 in THF at 25 °C for 10 min. The nickel-PhFCp
complexes 4a ,b are unusually more stable toward molecular oxygen than the corresponding
simple nickel cyclopentadienides and survive in air for many hours at elevated temperature.
The crystal structures and the electrochemical properties of the palladium complexes suggest
that the unusual stability of the PhFCp complexes is due to the kinetic stabilization effect
of the five Ph groups surrounding the metal atom and the thermodynamic stabilization effect
of the electron-withdrawing fullerene moiety, hence suggesting new opportunities for the
synthesis of otherwise unstable organometallic compounds.
In tr od u ction
unsaturated metal complexes by shielding the space
around the metal atom. Isopropyl-substituted tris-
(pyrazolyl)borate is a recent example of such ligands.5,6
We previously reported the synthesis of a series of η5
metal compounds that bear a C60R5 cyclopentadienyl
ligand (generically denoted as FCp ligands):7 Re(η5-
C60R5)(CO)3,8 Fe(η5-C60Me5)(η5-C5H5),9 Ru(η5-C60Me5)-
Ln,10,11 and Rh(η5-C60Me5)(CO)212 (C60Me5 is abbreviated
as MeFCp). We have so far synthesized MeFCp com-
plexes or, in one case, FCp ligands bearing hydrogen
atoms.8,13 Though we reported the synthesis of the C60-
Ph5 ligand (PhFCp) and its thallium complex several
years ago,7a we have so far been unable to synthesize
The electronic structure of the ligand is the major
factor that controls the reactivity and stability of
transition-metal complexes: an illustrative example is
the 18-electron sandwich complex of iron(II), ferrocene,
where a pair of 6-π-electron cyclopentadienide ligands
endow the complex with extremely high stability.1 The
sandwich structure may not be enough for the stability,
since ferrocene’s immediate neighbor, 20-electron nick-
elocene, is relatively unstable and susceptible to oxida-
tion by molecular oxygen.2 The 18-electron nickel π-allyl
cyclopentadienyl complex Ni(η5-Cp)(η3-allyl) is even
more unstable to oxygen and immediately decomposes
upon exposure to air.3,4 The physical structure of the
ligand is another controlling factor. Suitably designed
bulky ligands are known to stabilize coordinatively
(4) (a) Fischer, E. O.; Bu¨rger, G. Chem. Ber. 1961, 94, 2409. (b)
McClellan, W. R.; Hoehn, H. H.; Cripps, H. N.; Muetterties, E. L.;
Howk, B. W. J . Am. Chem. Soc. 1961, 83, 1601.
(5) (a) Trofimenko, S. Chem. Rev. 1993, 93, 943. (b) Kitajima, N.;
Tolman, W. B. Prog. Inorg. Chem. 1995, 43, 419. (c) Trofimenko, S.
Scorpionates: The Coordination Chemistry of Polypyrazolylborate
Ligands; Imperial College Press: London, 1999.
(6) (a) Bruce, M. I.; Ostazewski, A. P. P. 1973, 2433. (b) Abu Salah,
O. M.; Bruce, M. I.; Hameister, C. Inorg. Synth. 1982, 21, 107.
(7) (a) Sawamura, M.; Iikura, H.; Nakamura, E. J . Am. Chem. Soc.
1996, 118, 12850. (b) Sawamura, M.; Iikura, H.; Ohama, T.; Hackler,
U. E.; Nakamura, E. J . Organomet. Chem. 2000, 599, 32. (c) Sawa-
mura, M.; Toganoh, M.; Kuninobu, Y.; Kato, S.; Nakamura, E. Chem.
Lett. 2000, 270.
(8) Toganoh, M.; Matsuo, Y.; Nakamura, E. Angew. Chem., Int. Ed.
2003, 42, 3530.
(9) Sawamura, M.; Kuninobu, Y.; Toganoh, M.; Matsuo, Y.; Ya-
manaka, M.; Nakamura, E. J . Am. Chem. Soc. 2002, 124, 9354.
(10) Matsuo, Y.; Nakamura, E. Organometallics 2003, 22, 2554.
(11) Matsuo, Y.; Kuninobu, Y.; Ito, S.; Nakamura, E. Chem. Lett.
2004, 33, 68.
* To whom correspondence should be addressed. E-mail:
nakamura@chem.s.u-tokyo.ac.jp.
† Present address: Department of Applied Chemistry, Faculty of
Engineering, Okayama University.
‡ Present address: Department of Applied Chemistry, Graduate
School of Engineering, Kyushu University.
§ Present address: Department of Chemistry, Graduate School of
Science, Hokkaido University.
(1) (a) Kealy, T. J .; Pauson, P. L. Nature 1951, 168, 1039. (b) Miller,
S. A.; Tebboth, J . A.; Tremaine, J . F. J . Chem. Soc. 1952, 632. (c)
Wilkinson, G.; Rosenblum, M.; Whiting, M. C.; Woodward, R. B. J .
Am. Chem. Soc. 1952, 74, 2125. (d) Fischer, E. O.; Pfab, W. Z. Z.
Naturforsch. 1952, 7B, 377.
(2) Wilke, G.; J olly, P. W. The Organic Chemistry of Nickel; Academic
Press: New York, London, 1974; Vol. 1 (Organonickel Complexes), p
422.
(3) (a) Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds. Comprehen-
sive Organometallic Chemistry; Pergamon: New York, 1982; Vol. 6.
(b) Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds. Comprehensive
Organometallic Chemistry II; Pergamon: New York, 1995; Vol. 9.
(12) Sawamura, M.; Kuninobu, Y.; Nakamura, E. J . Am. Chem. Soc.
2000, 122, 12407.
(13) Toganoh, M.; Matsuo, Y.; Nakamura, E. J . Am. Chem. Soc.
2003, 125, 13974.
10.1021/om0499153 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 05/18/2004

3260 Organometallics, Vol. 23, No. 13, 2004
Kuninobu et al.
PhFCp transition-metal complexes, very likely because
of steric congestion imposed by the five phenyl groups
surrounding the cyclopentadienide moiety. This obser-
vation in turn suggested us that the PhFCp ligand may
act to stabilize the otherwise unstable transition-metal
complex by steric protection. In this article, we report
the first synthesis of PhFCp transition-metal complexes
(as well as MeFCp complexes) for the group 10 triad
and show that the PhFCp ligand allows the preparation
of the first stable nickel π-allyl complex, which is stable
to heat, water, and molecular oxygen at high temper-
ature (80 °C). Palladium and platinum complexes, Pd-
(η5-C60R5)(η3-allylic) (allylic ) allyl, methallyl, crotyl; R
) Me, Ph) and Pt(η5-C60R5)(η3-methallyl) (R ) Me, Ph),
have also been synthesized and provide clues in under-
standing the origin of the stabilization effects of the C60-
Ph5 group.
of Ni(η5-MeFCp)(η3-allyl) resulted in exclusive formation
of the allylated product C60Me5(CH2CHdCH2) (5a ) in
22% yield. In the synthesis of 4a , the allyl compound
C60Ph5(CH2CHdCH2) (6a ) was also obtained as a side
product in 6% yield. The remainder of the material
balance was largely the starting material C60Ph5H (85%)
and its oxidation products17 (5%) that were formed
during workup. Once formed, 4a does not decompose
to give 6a upon heating. A plausible possibility is that
the allylic compounds 5a , 6a , and 5b were formed in
situ by the nucleophilic attack of anions MeFCp- and
PhFCp- at the allylic palladium or platinum species.18
Structure assignment was achieved by the standard
physical methods. High-resolution APCI-TOF-MS(+)
data were consistent with the assigned structures. The
1H and 13C NMR measurements of nickel complexes 3b
and 4a ,b indicated that the FCp moieties have C5v
symmetry. For instance, the 13C NMR spectrum dis-
played only eight signals due to the C5v-symmetric
fullerene skeleton: the cyclopentadienyl moiety (δ
111.88), the sp3 fullerene carbon atom (δ 51.01), the sp2
carbon atom next to the sp3 carbon (δ 154.19), and five
other types of fullerene sp2 carbon atoms (δ 143.30,
145.05, 146.39, 147.55, and 148.29), together with a
methyl group signal (δ 30.08) and signals due to the
methallyl ligand (δ 29.79 (CH3), 44.20 (CH2), and 100.51
(center carbon)). Therefore, the rotation of the FCp
moiety around the Ni-FCp axis and the five addends
on the fullerene sp3 carbon atoms is faster than the
NMR relaxation time.
All FCp nickel complexes 3b and 4a ,b were found to
be far more stable than the parent π-allyl complex Ni-
(η5-Cp)(η3-allyl), which decomposes in 1 min upon
exposure to air. For instance, the methallyl MeFCp
complex 3b in toluene decomposes very slowly in air at
25 °C, leaving 30% of the material even after 5 days.
The PhFCp complexes are far more stable: heating a
stirred toluene solution of the complexes 4a ,b in air at
80 °C for 15 h resulted in quantitative recovery.
Syn th esis of th e P a lla d iu m a n d P la tin u m Com -
p lexes. While the nickel complexes did not give crystals
suitable for crystallographic analysis, the corresponding
palladium complexes produced single crystals and hence
gave us information on their molecular structure and
the origin of the stabilization. Electrochemical measure-
ments also afforded data relevant to the properties of
the FCp ligands. Platinum complexes were also syn-
thesized, albeit in low yield.
Resu lts a n d Discu ssion
Syn th esis of th e Nick el-RF Cp Com p lexes. The
parent π-allyl nickel complex Ni(η5-Cp)(η3-allyl) is a
sensitive compound; it can be handled at ambient
temperature and is stable to water but instantly de-
composes upon exposure to air, as confirmed by our own
hand.14 We therefore synthesized the π-allyl nickel
complexes to see if the FCp ligand can stabilize them.
Because of the electronegative fullerene core, the FCp
anion is thermodynamically more stable than the C5H5
anion.15 Between MeFCp and PhFCp, the latter is
markedly more congested sterically (vide infra). We thus
synthesized the π-allyl nickel complexes of the MeFCp
and PhFCp ligands.
Metal exchange starting with potassium complexes
afforded the desired complexes. The reactions of K(η5-
RFCp) (1,7c R ) Me; 2,7a R ) Ph) with [Ni(allylic)Br]2
(allylic ) allyl, methallyl)16 provided the desired nickel
complexes Ni(η5-RFCp)(η3-allylic) (3b, allylic ) meth-
allyl, R ) Me; 4a , allylic ) allyl, R ) Ph; 4b, allylic )
methallyl, R ) Ph) (eq 1). After purification by prepara-
(14) In our reexamination of the synthesis and properties of Ni(η3-
allyl)(η5-Cp), this complex is stable to water but reacts rapidly with
air to give a pale yellow solid. Since the molecular ion peak corre-
sponding to the molecular weight of allylcyclopentadiene was detected
by GC-MS measurements, we speculate that Ni(η3-allyl)(η5-Cp) de-
composes via the oxidation of the nickel atom followed by reductive
elimination of allylcyclopentadiene.
(15) (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.-Q.; Burger, C.; Chu, B.; Sawamura, M.; Nagahama,
N.; Toganoh, M.; Hackler, U. E.; Isobe, H.; Nakamura, E. Science 2001,
291, 1944.
(16) π-Allyl nickel halide: (a) U. S. Patent 3 422 128, J an 14th, 1969.
(b) German Published Patent Application 1 194 417, Aug 10th, 1963
(Studiengesellschaft Kohle).
(17) (a) Avent, A. G.; Birkett, P. R.; Darwish, A. D.; Kroto, H. W.;
Taylor, R.; Walton, D. R. M. Chem. Commun. 1997, 1579. (b). Al-Matar,
M.; Hitchcock, P. B.; Avent, A. G.; Taylor, R. Chem. Commun. 2000,
1071.
(18) Davies, J . A. Palladium-Carbon π-Bonded Complexes. In
Comprehensive Organometallic Chemistry II; Abel, E. W., Stone, F. G
A., Wilkinson, G., Eds.; Pergamon: New York, 1995; Vol. 9, p 291.
tive HPLC separation, complexes 3b and 4a ,b were
obtained in 4-22% isolated yield. Attempted synthesis

Ni, Pd, and Pt Complexes of C60R5 Ligands
Organometallics, Vol. 23, No. 13, 2004 3261
1
Ta ble 1. Com p a r ison of H NMR Ch em ica l Sh ifts
The syntheses followed those of the nickel complexes.
The palladium and platinum allyl and methallyl com-
plexes Pd(η5-RFCp)(η3-allylic) (7a , allylic ) allyl, R )
Me; 7b, allylic ) methallyl, R ) Me; 7c, allylic ) crotyl,
R ) Me; 8a , allylic ) allyl, R ) Ph; 8b, allylic )
methallyl, R ) Ph; 8c, allylic ) crotyl, R ) Ph) and Pt-
(η5-RFCp)(η3-methallyl) (9, R ) Me; 10, R ) Ph) were
synthesized by transmetalation of the potassium salt 1
or 2 with [Pd(η3-allylic)Cl]2 (allylic ) allyl, methallyl,
(p p m ) betw een π-Allylic Liga n d s of P a lla d iu m
Com p lexes 7a -c a n d 8a -c
Ha Hb Hc
Hd
He
Mec Med
crotyl)19 or [Pt(η3-methallyl)Cl]2 (eqs 2 and 3). After
20
7a
7b
7c
8a
8b
8c
2.99 4.32 5.51 ()Hb) ()Ha)
2.94 4.25
2.81 4.10 5.41
2.09 3.08 4.70 ()Hb) ()Ha)
1.95 2.99
1.73 2.67 4.66
()Hb) ()Ha) 2.36
4.06
2.02
0.51
()Hb) ()Ha) 1.63
3.08
Pd(η3-allyl)(η5-C5Me5) 1.91 2.96 4.75
Pd(η3-allyl)(η5-C5Ph5) 2.66 3.65 5.30
protons in the Pd-PhFCp complexes 8a -c were ob-
served at higher magnetic field (δ 2.09, 3.08, and 4.70)
than were the Pd-C5Ph5 protons (δ 2.66, 3.65, and 5.30
ppm) (Table 1).19d The upfield shift is caused by the
proximity of the five phenyl groups surrounding the
π-allylic palladium moiety, which will be discussed later
regarding the crystal structures of 8a -c (Figure 2). This
upfield shift stands in contrast to the downfield shift
upon going from the C5Me5 to the C5Ph5 compound in a
simple Cp series; namely, the proton signals of the
π-allyl moiety of the C5Ph5 palladium complex Pd(η5-
C5Ph5)(η3-allyl)19d appears at lower magnetic field
(δ 1.91, 2.96, and 4.75) than those of the C5Me5 pal-
ladium complex Pd(η5-C5Me5)(η3-allyl)19c (Table 1).
X-r a y Cr ysta l Str u ctu r a l An a lysis. Dark red single
crystals of palladium complexes 7a ,b and 8a -c suitable
for X-ray crystallographic analysis were obtained by
recrystallization from CS2/EtOH, and the structures are
shown in Figures 1 and 2. The FCp ligands coordinate
to the palladium atom in an η5 fashion to make a
sandwich structure. The hydrogen atoms on the π-allylic
ligand in the palladium-PhFCp complexes 8a -c are
located in the space surrounded by five phenyl groups.
This spatial arrangement accounts for the upfield shift
of the allylic protons of the palladium-PhFCp com-
plexes 8a -c discussed above. The average bond lengths
of the five Pd-C(FCp) bonds in the palladium-MeFCp
(7a ,b) and -PhFCp complexes (8a -c) (2.34 Å for 7a ,
2.36 Å for 7b, 2.37 Å for 8a , 2.37 Å for 8b, and 2.40 Å
for 8c) are slightly longer than that of the simple Cp
complex Pd(η5-Cp)(η3-allyl)22 (2.26 Å) (Table 2). The
bond lengths of the three Pd-C(π-allylic) bonds in
complexes 7a ,b and 8a -c (2.15, 2.09, 2.18 Å for 7a ; 2.13,
2.11, 2.13 Å for 7b; 2.13, 2.08, 2.15 Å for 8a ; 2.13, 2.13,
2.14 Å for 8b; 2.18, 2.10, 2.16 Å for 8c) are also slightly
longer than those of Pd(η5-Cp)(η3-allyl)22 (2.10, 2.04, 2.07
Å) (Table 2). All bond lengths in the palladium-MeFCp
and -PhFCp series are identical with each other within
the standard deviation, indicating that there is little
steric hindrance between the allyl moiety and the RFCp
ligand. In agreement with this conclusion, the closest
C-H and H-H bond distances in the Pd-PhFCp
complexes are 2.89-3.28 Å (between carbon atoms of
the five phenyl groups and the hydrogen atoms of the
methallyl ligand, in 8b) and 2.43-3.04 Å (between
purification by preparative HPLC, the palladium com-
plexes 7a -c and 8a -c and the platinum complexes 9
and 10 were obtained in 21-71% (palladium complexes)
and 6.5-14% (platinum complexes) isolated yield, re-
spectively.
As in the synthesis of the nickel complexes, the
synthesis of the palladium and platinum complexes also
produced allylated and methallylated side products, C60-
Me5(CH2CHdCH2) (5a ), C60Ph5(CH2CHdCH2) (6a ), and
C60Me5(CH2C(Me)dCH2) (5b), in 8-10% yield. Like the
nickel complexes 3 and 4, the palladium complexes 7a
and 8a and platinum complex 9 did not decompose into
allylic compounds 5a , 6a , and C60Me5(CH2C(Me)dCH2)
(5b) upon heating.
Identification of these palladium and platinum com-
plexes was achieved by high-resolution APCI-TOF-MS-
1
1
(+) and H and 13C NMR measurements. The H NMR
spectra of the platinum complexes 9 and 10 exhibited
platinum-hydrogen spin-spin coupling (9, J Pt-H(Me)
)
27.2, J Pt-H(syn) ) 111.6, J Pt-H(anti) ) 63.6 Hz; 10, J Pt-H(Me)
) 32.1, J Pt-H(syn) ) 117.8, J Pt-H(anti) ) 64.6 Hz). The
magnitude of the coupling agrees well with that in Pt-
(η5-Cp)(η3-methallyl)21 (J ) 34, 111, 61 Hz). The allylic
(19) (a) Shaw, B. L. Proc. Chem. Soc. 1960, 247. (b) Parker, G.;
Werner, H. Helv. Chim. Acta 1973, 56, 2819. (c) Werner, H.; Crisp, G.
T.; J olly, P. W.; Kraus, H,-J .; Kruger, C. Organometallics 1983, 2, 1369.
(d) Powell, J .; Dowling, N. I. Organometallics 1983, 2, 1742.
(20) Mabbott, D. J .; Mann, B. E.; Maitlis, P. M. J . Chem. Soc., Dalton
Trans. 1977, 294.
(22) Minasyants M. K.; Struchkov, Y. T. Zh. Strukt. Khim. 1968, 9,
(21) Mann, B. E.; Shaw, B. L.; Shaw, G. J . Chem. Soc. A 1971, 3536.
481.

3262 Organometallics, Vol. 23, No. 13, 2004
Kuninobu et al.
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles (d eg) of P a lla d iu m Com p lexes 7a ,b a n d 8a -c
7a
7b
8a
8b
8c
Pd(π-allyl)Cp
Pd-C(FCp) (av)
Pd-C1
2.337(9)
2.357(3)
2.131(4)
2.105(4)
2.131(5)
2.370(3)
2.134(5)
2.076(5)
2.148(5)
2.367(5)
2.126(6)
2.130(7)
2.143(8)
2.398(6)
2.18(2)
2.10(2)
2.16(2)
2.26
2.10
2.04
2.07
2.153(12)
2.090(12)
2.179(12)
Pd-C2
Pd-C3
fullerene angle suma
313.38
312.98
312.66
313.68
312.56
a
Sum of three angles around the fullerene sp3 carbon atoms, within the fullerene skeleton.
F igu r e 1. Molecular structures of the Pd-MeFCp com-
plexes with 30% probability level ellipsoids: (a) 7a ‚CS2;
(b) 7b‚1.5CS2. The solvent molecules in the unit cell are
omitted for clarity.
hydrogen atoms of the five phenyl groups and those of
the methallyl ligand, in 8b), respectively, and these
distances are longer than the van der Waals contacts
(H-C ) 2.90 Å; H-H ) 2.40 Å).23
Electr och em ica l In vestiga tion s. Cyclic voltamme-
try (CV) gives useful information on the electronic
properties of metal complexes and provided insights into
the properties of the PhFCp metal complexes. The redox
behavior of the π-allyl palladium complexes 7a and 8a
is shown in Figure 3 and Table 3, and the data are
compared with those of Fe(η5-Cp)(η5-MeFCp),9 Ru(η5-
MeFCp)(CH3)(CO)2,10 and Rh(η5-MeFCp)(CO)2.12
Scanning between 0.82 and -2.87 V (vs Fc/Fc+, scan
rate 100 mV/s) showed that the MeFCp complex 7a is
stable upon one-electron reduction (Figure 3a) but the
PhFCp complex 8a partially decomposes upon one-
electron reduction (Figure 3b). The reduction potentials
of 7a and 8a are comparable to those of Fe(η5-MeFCp)-
(η5-Cp),9 Ru(η5-MeFCp)(CH3)(CO)2,10 Rh(η5-MeFCp)-
(CO)2,12 and C60Ph5H.24 We therefore consider that the
reduction puts the electron into the fullerene moiety.
F igu r e 2. Molecular structures of the Pd-PhFCp com-
plexes with 30% probability level ellipsoids: (a) 8a ‚2.5CS2;
(b) 8b‚0.25CS2; (c) 8c‚2CHCl3. The solvent molecules in the
unit cell are omitted for clarity.
The electron-withdrawing effect of the five phenyl
groups makes the reduction of the PhFCp complex 8a
red1
(E1/2
) -1.40 V) easier than that of the MeFCp
red1
complex 7a (E1/2
) -1.47 V). This electron-deficient
nature of the PhFCp complex accounts for the higher
stability of the PhFCp nickel complex toward oxidation
as compared to the MeFCp complex and also as com-
pared to the simple Cp complexes.
The analysis of the CV data led us to speculate on
the reactions taking place during the reduction/oxida-
tion process (Figure 3b). In the course of the one-electron
reductions of 8a , new species formed together with the
reduced complex 8a •-. In view of our previous work,24
we consider the new species to be the anion PhFCp-;
hence, the Pd-PhFCp bond was cleaved in the reduction
processes. The result per se is nonproductive; nonethe-
(23) Pauling, L. The Nature of the Chemical Bond, 3rd ed.; Cornell
University Press: New York, 1960.
(24) Iikura, H.; Mori, S.; Sawamura, M.; Nakamura, E. J . Org.
Chem. 1997, 62, 7912.

Ni, Pd, and Pt Complexes of C60R5 Ligands
Organometallics, Vol. 23, No. 13, 2004 3263
thus, the electron-deficient PhFCp complex is more
stable toward molecular oxygen than the MeFCp com-
plex and is much more stable than the simplex Cp
complexes.
One may recall that a highly substituted version of
the hydrotris(pyrazolyl)borate (Tp) ligand5,26-28 can
significantly enhance the stability of transition-metal
complexes29,30 and that the RFCp ligand can be modified
in various ways: the R group can be either electron-
withdrawing or donating, can be bulky or relatively less
sterically hindering,31 may bear water-soluble groups
such as sugar,32 and may be a part of a mesogenic
structure.25 We therefore expect that a variety of new
possibilities for the control of the reactivities of metal
centers will become available on the basis of the RFCp
ligand systems.
Exp er im en ta l Section
Gen er a l P r oced u r es. 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. C60Me5H and C60Ph5H
were prepared according to the literature.7 A THF solution of
tBuOK was purchased from Sigma-Aldrich Co. and used as
received. The complexes [Ni(η3-allyl)Br]2,16a [Ni(η3-methallyl)-
Br]2,16b [Pd(η3-allyl)Cl]2,19 [Pd(η3-methallyl)Cl]2,19 [Pd(η3-crotyl)-
Cl]2,19 and [Pt(η3-methallyl)Cl]2 were prepared as reported
20
F igu r e 3. Cyclic voltammograms of the palladium-RFCp
π-allyl complexes: (a) reversible one-electron reduction of
7a ; (b) irreversible one-electron reduction of 8a . Both
measurements were carried out in a 1.0 mM THF solution
containing 100 mM [nBu4N][ClO4] as a supporting electro-
lyte.
in the literature. Preparative HPLC separations were per-
formed by use of a Buckyprep column (Nacalai Tesque Co., 20
1
mm × 250 mm). The H (400 MHz) and 13C (100 MHz) NMR
spectra were recorded using a J EOL EX-400 spectrometer.
Proton chemical shifts are reported relative to Me4Si (CDCl3)
at δ 0.00 ppm or residual solvent signals (CDCl3 at δ 7.26 ppm;
THF-d8 at δ 1.73 and 3.58 ppm). Carbon chemical shifts are
reported relative to CDCl3 at δ 77.00 ppm or THF-d8 at δ 25.20
and 67.40 ppm. Other spectra were recorded on the following
instruments: IR, J ASCO IR-420 and ReactIR 1000; UV/vis
spectra, Hitachi U3500 and Shimadzu SPD-6A; mass spectra,
Shimadzu LCMS-QP8000, J EOL J MS-T100LC, and J EOL
J MS-GCMATE II. Elemental analyses were performed at the
organic elemental analysis laboratory in this department.
P r ep a r a tion of Ni(η5-MeF Cp )(η3-m eth a llyl) (3b). To a
suspension of C60Me5H (50.0 mg, 62.7 µmol) in THF (5.0 mL)
was added a solution of tBuOK (1.0 M, 69.0 µL, 69.0 µmol) in
THF. To the resulting dark reddish orange solution was added
[Ni(η3-methallyl)Br]2 (13.4 mg, 34.5 µmol). The reaction mix-
ture was stirred at 25 °C for 10 min before being quenched by
addition of saturated aqueous NH4Cl (1.0 mL). The mixture
was diluted with toluene and washed with water. The organic
layer was dried over MgSO4 and was concentrated under
reduced pressure. Preparative HPLC separations (eluent 7/3
toluene/2-propanol) afforded 3b (4.0 mg, 7.0% yield) as dark
Ta ble 3. Red u ction P oten tia ls for P a lla d iu m
Com p lexes a n d F u ller en e Der iva tivesa
E1/2red(1) (V)
E1/2red(2) (V)
Pd(η5-MeFCp)(η3-allyl) (7a )
Pd(η5-PhFCp)(η3-allyl) (8a )
Fe(η5-MeFCp)(η5-Cp)c
-1.47
-1.40
-1.46
-1.43
-1.34
-1.35
-1.48
-1.38
-2.06b
-1.99b
-2.06d
-2.01
-1.94
-1.94
-2.07
-1.98
Ru(η5-MeFCp)(η5-Cp)e
Ru(η5-MeFCp)(CH3)(CO)2
f
Rh(η5-MeFCp)(CO)2
g
C
C
60Me5He
60Ph5Hh
a
b
In V vs ferrocene/ferrocenium couple. 25 °C. Irreversible
reduction. c Reference 9. Peak top potential. e Reference 11. f Ref-
erence 10. Reference 12. Reference 24.
d
g
h
less, it indicates that the electron, once supplied to the
fullerene core, moves to the metal center through the
cyclopentadienide moiety, suggesting the possibility of
controlling the reactivity of the metal by manipulation
of the fullerene moiety.
Con clu sion : Kin etic a n d Th er m od yn a m ic Sta -
biliza tion by th e P h F Cp Liga n d . The PhFCp allyl
nickel complexes Ni(η5-PhFCp)(η3-allyl) (4a ) and Ni(η5-
PhFCp)(η3-methallyl) (4b) are stable upon exposure to
air, even at 80 °C for 12 h, while the parent nickel Cp
allyl complexes instantly decompose in air at room
temperature. We ascribe the high stability of the PhFCp
complexes first to the steric shielding effect of the phenyl
groups. To enhance such “kinetic” stability, a bulkier
aryl group such as a biphenyl group25 would be useful.
“Thermodynamic” stabilization may also play a role:
1
red fine crystals. H NMR (400 MHz, CDCl3): δ 2.29 (s, 3H),
2.30 (s, 15H), 2.54 (s, 2H), 3.61 (s, 2H). 13C{1H} NMR (100
MHz, CDCl3): δ 29.79 (1C), 30.08 (5C), 44.20 (2C), 51.01 (5C),
100.51 (1C), 111.88 (5C), 143.30 (10C), 145.05 (10C), 146.39
(26) (a) Akita, M.; Shirasawa, N.; Hikichi, S.; Moro-oka, Y. Chem.
Commun. 1998, 973. (b) Shirasawa, N.; Nguyet, T. T.; Hikichi, S.;
Moro-oka, Y.; Akita M. Organometallics 2001, 20, 3582.
(27) Kisko, J . L.; Hascall, T.; Parkin, G. J . Am. Chem. Soc. 1998,
120, 10561.
(28) J ewson, J . D.; Liable-Sands, L. M.; Yap, G. P. A.; Rheingold,
A. L.; Theopold, K. H. Organometallics 1999, 18, 300.
(29) Trofimenko, S. Prog. Inorg. Chem. 1986, 34, 115.
(30) Akita, M.; Hikichi, S.; Moro-oka, Y. J . Synth. Org. Chem., J pn.
1999, 57, 67.
(31) Matsuo, Y.; Muramatsu, A.; Hamasaki, R.; Mizoshita, N.; Kato,
T.; Nakamura, E. J . Am. Chem. Soc. 2004, 126, 432.
(32) Isobe, H.; Mashima, H.; Yorimitsu, H.; Nakamura, E. Org. Lett.
2003, 5, 4461.
(25) Sawamura, M.; Kawai, K.; Matsuo, Y.; Kanie, K.; Kato, T.;
Nakamura, E. Nature 2002, 419, 702.

3264 Organometallics, Vol. 23, No. 13, 2004
Kuninobu et al.
(5C), 147.55 (10C), 148.29 (5C), 154.19 (10C). IR (powder,
cm-1): ν 2959 (m), 2918 (m), 2854 (m), 1723 (m), 1441 (s), 1368
(m), 1286 (m), 1264 (m), 1236 (w), 1213 (w), 1200 (w), 1156
(w), 1115 (w), 1071 (w), 1018 (w), 902 (m), 802 (m), 752 (s),
728 (s), 685 (s), 666 (m), 658 (m). UV-vis (7/3 toluene/2-
propanol, nm): λmax 286, 348 (shoulder), 395, 480 (shoulder).
HR-APCI-MS(-) (m/z): found, 908.1081; calcd for 3b, 908.1075.
der). HR-APCI-MS(-) (m/z): found, 1218.1968; calcd for 4b,
1218.1858.
P r ep a r a tion of P d (η5-MeF Cp )(η3-a llyl) (7a ). Complex 7a
was synthesized as for 3b, using the following compounds: C60-
t
Me5H (100 mg, 125 µmol), BuOK (1.0 M, 138 µL, 138 µmol)
in THF, [Pd(η3-allyl)Cl]2 (25.2 mg, 68.9 µmol), and THF (10.0
1
mL). Yield: 25 mg (21%). H NMR (400 MHz, CDCl3): δ 2.32
3
3
P r ep a r a tion of Ni(η5-P h F Cp )(η3-a llyl) (4a ). Complex 4a
was synthesized as for 3b, using the following compounds: C60-
Ph5H (50.0 mg, 45.2 µmol), tBuOK (1.0 M, 49.7 µL, 49.7 µmol)
in THF, [Ni(η3-methallyl)Br]2 (8.93 mg, 24.8 µmol), and THF
(1.0 mL). Yield: 2.2 mg (4.0%). 1H NMR (400 MHz, CDCl3): δ
(s, 15H), 2.99 (d, J ) 11.2 Hz, 2H), 4.32 (d, J ) 6.4 Hz, 2H),
5.51 (tt, 3J ) 11.2 Hz, 3J ) 6.4 Hz, 1H). 13C{1H} NMR (100
MHz, CDCl3): δ 32.13 (5C), 47.90 (2C), 51.02 (5C), 95.89 (1C),
119.13 (5C), 143.32 (10C), 145.19 (10C), 146.30 (5C), 147.47
(10C), 148.30 (5C), 154.03 (10C). IR (powder, cm-1): ν 2957
(m), 2913 (m), 2853 (w), 1603 (w), 1579 (w), 1548 (w), 1514
(w), 1494 (m), 1454 (m), 1439 (s), 1416 (m), 1366 (m), 1286
(w), 1265 (m), 1236 (m), 1219 (w), 1200 (m), 1178 (w), 1155
(m), 1136 (m), 1111 (m), 1080 (w), 1009 (m), 951 (w), 904 (m),
728 (s), 695 (m), 684 (s), 657 (m). UV-vis (1.0 × 10-5 mol L-1
in CH2Cl2; λmax, nm (ꢀ, M-1 cm-1)): 273 (78 700), 339 (35 300),
356 (30 400, shoulder), 395 (13 100, shoulder), 472 (3430,
shoulder). APCI-MS(+) (m/z): 942 (M+), Anal. Calcd for 7a ‚
0.5CS2: C, 83.83; H, 2.05. Found: C, 83.35; H, 2.23.
3
3
1.18 (d, J ) 11.8 Hz, 2H), 2.27 (d, J ) 6.4 Hz, 2H), 4.99 (tt,
3J ) 11.8 Hz, J ) 6.4 Hz, 1H), 7.19-7.23 (m, 15H), 7.71 (d,
3
3J ) 7.4 Hz, 10H). 13C{1H} NMR (100 MHz, CDCl3): δ 51.00
(2C), 58.74 (5C), 98.46 (1C), 112.71 (5C), 127.48 (5C), 127.96
(10C), 128.40 (10C), 142.69 (5C), 143.55 (10C), 145.27 (10C),
146.95 (5C), 147.89 (10C), 148.74 (5C), 152.30 (10C). UV-vis
(7/3 toluene/2-propanol, nm): λmax 287, 355 (shoulder), 396,
470 (shoulder). HR-APCI-MS(-) (m/z): found, 1204.1628; calcd
for 4a , 1204.1701.
The reaction also gave the allylated pentamethyl[60]-
The reaction also gave the allylated pentaphenyl[60]-
1
fullerene 5a (8.6 mg, 8.2% yield) as a side product. H NMR
1
fullerene 6a (2.2 mg, 6.0% yield) as a side product. H NMR
(400 MHz, CDCl3): δ 2.24 (s, 6H), 2.27 (s, 6H), 2.40 (s, 3H),
3
3
(400 MHz, CDCl3): δ 2.24 (d, J ) 6.8 Hz, 2H), 4.64 (dd, J )
3
3
3
3.27 (d, J ) 7.2 Hz, 2H), 5.27 (dd, J ) 16.0 Hz, J ) 2.0 Hz,
19.2 Hz, 3J ) 2.0 Hz, 1H), 5.10 (dd, 3J ) 12.4 Hz, 3J ) 2.0 Hz,
3
3
3
1H), 5.41 (dd, J ) 10.0 Hz, J ) 2.0 Hz, 1H), 6.19 (ddt, J )
16.0 Hz, J ) 10.0 Hz, J ) 7.2 Hz, 1H). H NMR (400 MHz,
1/3 CDCl3/CS2): δ 2.28 (s, 6H), 2.30 (s, 6H), 2.43 (s, 3H), 3.29
(d, J ) 7.2 Hz, 2H), 5.30 (dd, J ) 16.0 Hz, J ) 2.0 Hz, 1H),
5.41 (dd, J ) 10.0 Hz, J ) 2.0 Hz, 1H), 6.21 (ddt, J ) 16.0
3
3
3
1H), 5.96 (ddt, J ) 19.2 Hz, J ) 12.4 Hz, J ) 6.8 Hz, 1H),
7.16-7.19 (m, 4H), 7.30-7.43 (m, 13H), 7.75-7.78 (m, 4H),
7.87-7.90 (m, 4H). 1H NMR (400 MHz, 1/3 CDCl3/CS2): δ 2.18
3
3
1
3
3
3
3
3
3
(d, J ) 6.8 Hz, 2H), 4.58 (d, J ) 17.2 Hz, 2H), 5.02 (d, J )
3
3
3
3
3
3
10.0 Hz, 2H), 5.89 (ddt, J ) 17.2 Hz, J ) 10.0 Hz, J ) 6.8
Hz, 1H), 7.09-7.11 (m, 4H), 7.22-7.32 (m, 13H), 7.67-7.69
(m, 4H), 7.77-7.79 (m, 4H). 13C{1H} NMR (100 MHz, 1/3
CDCl3/CS2): δ 43.81 (1C), 58.26 (2C), 60.80 (1C), 62.86 (1C),
64.81 (2C), 118.91 (1C), 126.77 (1C), 127.34 (2C), 127.47 (2C),
127.73 (2C), 127.85 (4C), 128.05 (4C), 128.41 (4C), 128.52 (4C),
130.23 (2C), 133.56 (2C), 137.97 (2C), 139.40 (1C), 142.01 (1C),
142.36 (2C), 143.13 (2C), 143.30 (2C), 143.50 (2C), 143.68 (2C),
143.76 (2C), 143.83 (2C), 143.95 (2C), 144.08 (2C), 144.19 (2C),
144.89 (2C), 145.01 (2C), 146.68 (1C), 146.87 (2C), 146.92 (2C),
147.06 (2C), 147.43 (1C), 147.66 (2C), 147.80 (2C), 147.89 (2C),
148.05 (2C), 148.19 (2C), 148.32 (2C), 148.39 (2C), 150.85 (2C),
152.48 (2C), 155.85 (2C), 156.25 (2C). IR (powder, cm-1): ν
3056 (w), 3023 (w), 2956 (w), 2920 (m), 2851 (m), 1961 (w),
1943 (w), 1724 (brm), 1597 (m), 1491 (m), 1462 (m), 1445 (m),
1419 (w), 1376 (w), 1288 (w), 1260 (m), 1237 (w), 1203 (w),
1183 (w), 1156 (w), 1069 (m), 1029 (s), 1003 (m), 910 (m), 896
(w), 837 (w), 799 (m), 758 (m), 742 (m), 733 (m), 693 (s), 683
(m), 671 (m). UV-vis (1.0 × 10-5 mol L-1 in CH2Cl2; λmax, nm
(ꢀ, M-1 cm-1)): 260 (81 800, shoulder), 272 (75 100, shoulder),
354 (22 300, shoulder), 395 (11 800, shoulder), 474 (4310,
shoulder). APCI-MS(() (m/z): ) 1147 ([M + H]+), 1146 (M-).
Anal. Calcd for 6a ‚0.5CS2: C, 94.74; H, 2.55. Found: C, 94.60;
H, 3.02.
3
3
Hz, J ) 10.0 Hz, J ) 7.2 Hz, 1H). 13C{1H} NMR (100 MHz,
1/3 CDCl3/CS2): δ 24.31 (2C), 27.16 (2C), 28.92 (1C), 40.02 (1C),
50.31 (2C), 52.40 (2C), 53.40 (1C), 61.80 (1C), 118.66 (1C),
131.48 (1C), 142.49 (2C), 142.98 (2C), 143.59 (2C), 143.61 (2C),
144.00 (2C), 144.04 (2C), 144.08 (2C), 144.39 (2C), 144.42 (2C),
145.05 (2C), 145.54 (2C), 146.25 (2C), 146.44 (2C), 146.46 (2C),
147.37 (2C), 147.49 (2C), 147.56 (1C), 147.65 (2C), 147.86 (2C),
147.97 (2C), 147.99 (1C), 148.06 (2C), 148.20 (2C), 148.91 (2C),
153.23 (2C), 154.34 (2C), 155.21 (2C), 157.30 (2C). IR (powder,
cm-1): ν 2957 (m), 2915 (m), 2855 (w), 1636 (w), 1603 (w), 1573
(w), 1545 (w), 1521 (w), 1494 (w), 1458 (m), 1439 (s), 1416 (m),
1370 (m), 1286 (m), 1266 (m), 1238 (m), 1200 (m), 1174 (w),
1160 (w), 1153 (w), 1142 (w), 1129 (m), 1105 (m), 1041 (w),
984 (m), 952 (w), 912 (s), 803 (m), 790 (m), 778 (w), 771 (m),
725 (s), 713 (m), 695 (m), 688 (s), 667 (m). UV-vis (1.0 × 10-5
mol L-1 in CH2Cl2; λmax, nm (ꢀ, M-1 cm-1)): 255 (66 800,
shoulder), 348 (21 900), 356 (20 600, shoulder), 396 (12 500),
476 (3450, shoulder). APCI-MS(+) (m/z): 837 ([M + H]+). Anal.
Calcd for 5a ‚0.5CS2: C, 94.03; H, 2.30. Found: C, 94.31; H,
2.75.
P r ep a r a tion of P d (η5-MeF Cp )(η3-m eth a llyl) (7b). Com-
plex 7b was synthesized as for 3b, using the following
t
compounds: C60Me5H (100 mg, 125 µmol), BuOK (1.0 M, 138
µL, 138 µmol) in THF, [Pd(η3-methallyl)Cl]2 (27.2 mg, 68.9
µmol), and THF (10.0 mL). Yield: 66.0 mg (55%). 1H NMR
(400 MHz, CDCl3): δ 2.33 (s, 15H), 2.36 (s, 3H), 2.94 (s, 2H),
4.25 (s, 2H). 1H NMR (400 MHz, THF-d8): δ 2.38 (s, 15H),
2.46 (s, 3H), 3,05 (s, 2H), 4.39 (s, 2H). 13C{1H} NMR (100 MHz,
CDCl3): δ 24.52 (1C), 31.90 (5C), 49.17 (5C), 51.08 (2C), 113.41
(1C), 118.94 (5C), 143.31 (10C), 145.24 (10C), 146.29 (5C),
147.46 (10C), 148.31 (5C), 154.14 (10C). 13C{1H} NMR (100
MHz, THF-d8): δ 24.47 (1C), 32.11 (5C), 50.35 (2C), 52.24 (5C),
115.19 (1C), 119.89 (5C), 144.10 (10C), 146.31 (10C), 147.15
(5C), 148.28 (10C), 149.12 (5C), 155.51 (10C). IR (powder,
cm-1): ν 2956 (m), 2912 (m), 2852 (w), 1571 (w), 1547 (w), 1514
(w), 1494 (w), 1454 (m), 1440 (s), 1410 (m), 1378 (w), 1365 (m),
1285 (w), 1265 (m), 1230 (m), 1199 (m), 1155 (m), 1136 (m),
1111 (m), 1030 (w), 1020 (m), 986 (w), 951 (w), 923 (w), 830
(s), 806 (w), 789 (w), 767 (w), 726 (s), 692 (m), 685 (s), 669 (m),
657 (m). UV-vis (1.0 × 10-5 mol L-1 in CH2Cl2; λmax, nm (ꢀ,
M-1 cm-1)): 272 (97 300), 338 (44 500), 358 (34 700, shoulder),
P r ep a r a tion of Ni(η5-P h F Cp )(η3-m eth a llyl) (4b). Com-
plex 4b was synthesized as for 3b, using the following
compounds: C60Ph5H (10.0 mg, 9.03 µmol), tBuOK (1.0 M, 10.0
µL, 10.0 µmol) in THF, [Ni(η3-methallyl)Br]2 (1.92 mg, 4.97
1
µmol), and THF (1.0 mL). Yield: 2.4 mg (22%). H NMR (400
MHz, CDCl3): δ 1.12 (s, 2H), 1.59 (s, 3H), 2.17 (s, 2H), 7.25 (t,
3
3
3J ) 7.6 Hz, 10H), 7.29 (d, J ) 7.6 Hz, 5H), 7.73 (d, J ) 7.6
Hz, 10H). 13C{1H} NMR (100 MHz, CDCl3): δ 29.79 (1C), 50.62
(2C), 58.96 (5C), 100.87 (1C), 112.69 (5C), 127.34 (5C), 127.91
(10C), 128.53 (10C), 142.69 (5C), 143.40 (10C), 145.09 (10C),
146.82 (5C), 147.76 (10C), 148.58 (5C), 152.12 (10C). IR
(powder, cm-1): ν 2960 (m), 2922 (s), 2851 (m), 1720 (m), 1599
(m), 1492 (m), 1459 (m), 1445 (m), 1418 (w), 1285 (m), 1261
(s), 1238 (m), 1201 (m), 1155 (m), 1105 (m), 1091 (m), 1072
(m), 1030 (s), 1018 (s), 959 (m), 832 (m), 798 (s), 761 (m), 734
(s), 711 (m), 697 (s), 668 (m). UV-vis (7/3 toluene/2-propanol,
nm) λmax 285, 334 (shoulder), 356 (shoulder), 393, 475 (shoul-

Ni, Pd, and Pt Complexes of C60R5 Ligands
Organometallics, Vol. 23, No. 13, 2004 3265
t
391 (15 900), 473 (4220, shoulder). APCI-MS(+) (m/z): 956
(M+). Anal. Calcd for 7b: C, 86.57; H, 2.32. Found: C, 86.80;
H, 2.60.
C60Ph5H (100 mg, 90.3 mmol), BuOK (1.0 M, 99.3 mL, 99.3
mmol) in THF, [Pd(η3-crotyl)Cl]2 (19.6 mg, 49.7 mmol), and
THF (10.0 mL). Yield: 60.0 mg (52%). 1H NMR (400 MHz,
CDCl3): δ 0.51 (d, 3J ) 6.4 Hz, 3H), 1.73 (d, 3J ) 10.8 Hz,
1H), 2.67 (d, 3J ) 6.4 Hz, 1H), 3.08 (dq, 3J ) 10.8 Hz, 3J ) 6.4
P r ep a r a tion of P d (η5-MeF Cp )(η3-cr otyl) (7c). Complex
7c was synthesized as for 3b, using the following compounds:
3
3
C
60Me5H (100 mg, 125 µmol), tBuOK (1.0 M, 138 µL, 138 µmol)
Hz, 1H), 4.66 (td, J ) 10.8 Hz, J ) 6.4 Hz, 1H), 7.20-7.25
(m, 15H), 7.88-7.90 (m, 10H). 13C{1H} NMR (100 MHz,
CDCl3): δ 18.31 (1C), 54.31 (1C), 59.13 (5C), 78.36 (1C), 101.32
(1C), 120.20 (5C), 127.14 (5C), 127.82 (10C), 128.30 (10C),
143.35 (10C), 145.30 (10C), 145.50 (5C), 146.68 (5C), 147.62
(10C), 148.59 (5C), 152.10 (10C). IR (powder, cm-1): ν 3055
(m), 3022 (m), 2999 (w), 1949 (m), 1875 (m), 1795 (m), 1596
(m), 1583 (m), 1575 (m), 1491 (s), 1456 (s), 1444 (s), 1417 (m),
1376 (m), 1284 (m), 1264 (m), 1234 (m), 1202 (m), 1179 (m),
1155 (m), 1108 (m), 1070 (w), 1052 (w), 1030 (m), 1002 (w),
980 (w), 959 (m), 910 (m), 893 (m), 836 (m), 821 (w), 741 (m),
727 (s), 710 (m), 692 (s), 685 (s), 664 (s). UV-vis (1.0 × 10-5
mol L-1 in CH2Cl2; λmax, nm (ꢀ, M-1 cm-1)): 258 (72 600), 278
(77 900, shoulder), 338 (34 500), 356 (31 900, shoulder), 394
(16 300, shoulder), 472 (4150, shoulder). HR-APCI-MS(-) (m/
z): found, 1266.1564; calcd for 8c, 1266.1567.
in THF, [Pd(η3-crotyl)Cl]2 (27.2 mg, 68.9 µmol), and THF (10.0
mL). Yield: 25.6 mg (21%). 1H NMR (400 MHz, CDCl3): δ 2.02
3
3
(d, J ) 6.0 Hz, 3H), 2.34 (s, 15H), 2.81 (d, J ) 10.8 Hz, 1H),
4.06 (dq, 3J ) 10.8 Hz, 1H), 4.10 (d, 3J ) 6.4 Hz, 1H), 5.41
(ddd, 3J ) 10.8 Hz, 3J ) 10.8 Hz, 3J ) 6.4 Hz, 1H). 13C{1H}
NMR (100 MHz, CDCl3): δ 22.60 (1C), 31.75 (5C), 44.18 (1C),
51.26 (5C), 71.47 (1C), 97.39 (1C), 119.17 (5C), 143.28 (10C),
145.22 (10C), 146.28 (5C), 147.44 (10C), 148.29 (5C), 154.19
(10C). IR (powder, cm-1): ν 2957 (m), 2914 (m), 2854 (w), 1454
(w), 1440 (s), 1417 (w), 1366 (m), 1285 (w), 1265 (m), 1236 (m),
1199 (m), 1156 (m), 1136 (m), 1111 (m), 1019 (m), 984 (w),
962 (w), 877 (w), 831 (w), 727 (m), 694 (w), 685 (s), 657 (m).
UV-vis (1.0 × 10-5 mol L-1 in CH2Cl2; λmax, nm (ꢀ, M-1 cm-1)):
258 (78 000, shoulder), 273 (71 800, shoulder), 348 (23 100,
shoulder), 390 (13 800, shoulder), 471 (4590, shoulder). HR-
APCI-MS(+) (m/z): found, 956.0753; calcd for 7c, 956.0756.
P r ep a r a tion of P d (η5-P h F Cp )(η3-a llyl) (8a ). Complex 8a
was synthesized as for 3b, using the following compounds: C60-
P r ep a r a tion of P t(η5-MeF Cp )(η3-m eth a llyl) (9). Complex
9 was synthesized as for 3b, using the following compounds:
t
C
60Me5H (50.4 mg, 63.2 µmol), BuOK (1.0 M, 69.6 µL, 69.6
µmol) in THF, [Pt(η3-methallyl)Cl]2 (19.9 mg, 34.8 µmol), and
THF (5.0 mL). Yield: 9, 4.3 mg (6.5%); 5b, 5.2 mg (9.7%). Data
for 9 are as follows. 1H NMR (400 MHz, CDCl3): δ 2.38 (s,
15H), 2.66 (s with satellite, J Pt-H ) 27.2 Hz, 3H), 3.06 (s with
t
Me5H (100 mg, 90.3 µmol), BuOK (1.0 M, 99.3 µL, 99.3 µmol)
in THF, [Pd(η3-crotyl)Cl]2 (18.2 mg, 49.7 µmol), and THF (10.0
mL). Yield: 8a , 54.3 mg (48%); 6a , 9.5 mg (9.2%). Data for 8a
are as follows. 1H NMR (400 MHz, CDCl3): δ 2.09 (d, 3J )
3
3
satellite, J Pt-H ) 111.6 Hz, 2H), 4.40 (s with satellite, J Pt-H
)
11.2 Hz, 2H), 3.08 (d, J ) 6.4 Hz, 2H), 4.70 (tt, J ) 11.2 Hz,
3J ) 6.4 Hz, 1H), 7.16-7.20 (m, 15H), 7.77-7.79 (m, 10H).
13C{1H} NMR (100 MHz, CDCl3): δ 57.64 (2C), 59.07 (5C),
100.13 (1C), 120.73 (5C), 127.26 (5C), 127.73 (10C), 128.19
(10C), 143.43 (10C), 143.96 (10C), 145.40 (10C), 146.71 (5C),
147.66 (5C), 148.62 (5C), 152.22 (10C). IR (powder, cm-1): ν
3055 (m), 3027 (m), 2999 (w), 2921 (m), 2855 (m), 2350 (w),
2336 (w), 2216 (w), 2191 (w), 1959 (m), 1942 (m), 1887 (m),
1872 (m), 1798 (m), 1596 (s), 1589 (m), 1575 (m), 1491 (s), 1457
(s), 1444 (s), 1419 (m), 1378 (w), 1346 (w), 1332 (w), 1326 (w),
1284 (m), 1267 (m), 1237 (m), 1218 (m), 1200 (m), 1180 (m),
1156 (m), 1107 (m), 1071 (m), 1053 (m), 1030 (s), 1012 (m),
960 (s), 950 (w), 928 (w), 910 (m), 893 (m), 836 (m), 761 (m),
743 (m), 733 (m), 711 (m), 691 (s), 685 (s), 664 (m). UV-vis
(1.0 × 10-5 mol L-1 in CH2Cl2; λmax, nm (ꢀ, M-1 cm-1)): 260
(115 000), 280 (94 600, shoulder), 340 (43 400, shoulder), 356
(39 000, shoulder), 396 (18 200). APCI-MS(+) (m/z): 1252 (M+).
Anal. Calcd for 8a ‚0.5C7H8: C, 89.18; H, 2.64. Found: C, 89.28;
H, 2.90.
63.6 Hz, 2H). 13C{1H} NMR (100 MHz, CDCl3): δ 23.52 (1C),
31.35 (satellite, J Pt-C ) 20.7 Hz, 5C), 33.22 (2C), 52.05 (5C),
92.60 (1C), 118.23 (5C), 144.34 (10C), 146.21 (10C), 147.40
(5C), 148.47 (10C), 149.28 (5C), 155.26 (10C). IR (powder,
cm-1): ν 2959 (m), 2916 (m), 2852 (m), 1729 (m), 1454 (m),
1439 (s), 1417 (m), 1378 (w), 1367 (m), 1264 (m), 1237 (m),
1213 (m), 1199 (m), 1156 (m), 1136 (m), 1111 (w), 1074 (w),
1036 (w), 1021 (m), 967 (w), 950 (w), 942 (w), 904 (m), 835
(m), 806 (m), 752 (s), 729 (s), 685 (s), 670 (m), 658 (s). UV-vis
(7/3 toluene/2-propanol; nm): λmax 285, 356 (shoulder), 393,
460 (shoulder). APCI-MS(+) (m/z): 1045 (M+). HR-APCI-MS-
(-) (m/z): found, 1045.1314; calcd for 9, 1045.1375.
1
Data for 5b are as follows. H NMR (400 MHz, CDCl3): δ
2.24 (s, 3H), 2.26 (s, 6H), 2.30 (s. 6H), 2.41 (s, 3H), 3.34 (2,
2H), 4.94 (s, 1H), 5.44 (s, 1H). 13C{1H} NMR (100 MHz, 1/1
CDCl3/CS2): δ 25.03 (2C), 26.79 (2C), 26.99 (1C), 29.04 (1C),
44.72 (1C), 50.29 (2C), 52.50 (2C), 53.94 (1C), 62.29 (1C),
118.99 (1C), 139.23 (1C), 142.70 (2C), 143.18 (2C), 143.37 (1C),
143.75 (2C), 143.79 (2C), 144.10 (2C), 144.13 (2C), 144.20 (2C),
144.27 (2C), 144.47 (2C), 145.19 (2C), 145.19 (2C), 145.23 (2C),
145.96 (2C), 146.69 (2C), 147.41 (1C), 147.61 (2C), 147.70 (2C),
147.73 (2C), 147.84 (2C), 148.08 (2C), 148.18 (2C), 148.24 (2C),
148.44 (2C), 149.27 (2C), 153.31 (2C), 154.57 (2C), 155.35 (2C),
157.59 (2C). IR (powder, cm-1): ν 2960 (m), 2918 (m), 2855
(m), 1727 (m), 1444 (s), 1417 (w), 1371 (w), 1286 (w), 1265 (w),
1238 (w), 1200 (w), 1172 (w), 1156 (w), 1130 (w), 1112 (w),
1104 (w), 1036 (w), 889 (m), 727 (s), 690 (m), 684 (s), 671 (m),
660 (m). UV-vis (7/3 toluene/2-propanol; nm): λmax 286, 348,
360 (shoulder), 394, 470 (shoulder). HR-APCI-MS(-) (m/z):
found, 850.1714; calcd for 5b, 850.1722.
P r ep a r a tion of P d (η5-P h F Cp )(η3-m eth a llyl) (8b). Com-
plex 8b was synthesized as for 3b, using the following
compounds: C60Ph5H (100 mg, 90.3 µmol), tBuOK (1.0 M, 99.3
µL, 99.3 µmol) in THF, [Pd(η3-methallyl)Cl]2 (19.6 mg, 49.7
µmol), and THF (10.0 mL). Yield: 81.6 mg (71%). 1H NMR
(400 MHz, CDCl3): δ 1.63 (s, 3H), 1.95 (s, 2H), 2.99 (s, 2H),
7.15-7.21 (m, 15H), 7.79-7.81 (m, 10H). 13C{1H} NMR (100
MHz, CDCl3): δ 21.62 (1C), 57.82 (2C), 59.18 (5C), 116.07 (1C),
120.66 (5C), 127.19 (5C), 127,79 (10C), 128.26 (10C), 143.41
(10C), 144.10 (5C), 145.40 (10C), 146.70 (5C), 147.65 (10C),
148,60 (5C), 152.25 (10C). IR (powder, cm-1): ν 3055 (m), 3023
(m), 3002 (w), 2916 (m), 2855 (m), 1958 (m), 1866 (m), 1805
(m), 1596 (m), 1493 (s), 1456 (m), 1445 (m), 1417 (m), 1377
(m), 1284 (m), 1265 (w), 1235 (m), 1202 (m), 1155 (m), 1108
(m), 1081 (w), 1072 (w), 1053 (w), 1031 (m), 1021 (m), 1003
(w), 983 (w), 959 (m), 911 (m), 894 (m), 831 (m), 822 (w), 788
(w), 781 (w), 760 (m), 751 (m), 742 (s), 711 (m), 693 (s), 684
(s), 664 (s). UV-vis (1.0 × 10-5 mol L-1 in CH2Cl2; λmax, nm (ꢀ,
M-1 cm-1)): 260 (83 400), 276 (73 400, shoulder), 340 (30 900),
358 (27 200, shoulder), 395 (12 800, shoulder). APCI-MS(+)
(m/z): 1266 (M+). Anal. Calcd for 8b‚0.25CS2: C, 87.98; H,
2.51. Found: C, 87.85; H, 2.72.
P r ep a r a tion of P t(η5-P h F Cp )(η3-m eth a llyl) (10). Com-
plex 10 was synthesized as for 3b, using the following
compounds: C60Ph5H (50.0 mg, 45.2 µmol), tBuOK (1.0 M, 49.7
µL, 49.7 µmol) in THF, [Pt(η3-methallyl)Cl]2 (14.2 mg, 24.8
1
µmol), and THF (5.0 mL). Yield: 8.6 mg (14%). H NMR (400
MHz, CDCl3): δ 1.97 (s with satellite, J Pt-H ) 32.1 Hz, 3H),
2.02 (s with satellite, J Pt-H ) 117.8 Hz, 2H), 3.29 (s with
satellite, J Pt-H ) 64.6 Hz, 2H), 7.19 (m, 15H), 7.79 (d, 3J ) 6.9
Hz, 10H). 13C{1H} NMR (100 MHz, CDCl3): δ 29.83 (1C), 41.55
(2C), 58.88 (5C), 101.62 (1C), 120.30 (5C), 127.19 (5C), 127.66
(10C), 128.43 (10C), 142.96 (5C), 143.49 (10C), 145.01 (10C),
146.75 (5C), 147.65 (10C), 148.54 (5C), 151.67 (10C). IR
P r ep a r a tion of P d (η5-P h F Cp )(η3-cr otyl) (8c). Complex
8c was synthesized as for 3b, using the following compounds:

3266 Organometallics, Vol. 23, No. 13, 2004
Kuninobu et al.
Ta ble 4. Cr ysta l Da ta a n d Str u ctu r e An a lysis Resu lts for Com p lexes 7a ,b a n d 8a -c
7a ‚CS2
7b‚1.5CS2
8a ‚2.5CS2
8b‚0.25CS2
8c‚2CHCl3
formula
cryst syst
space group
R, Rw (I > 2σ(I))
R1, wR2 (all data)
GOF on F2
a, Å
C
69H20Pd1S2
C
70.50H22Pd1S3
C
95.50H30Pd1S5
C
94.25H32Pd1S0.5
C
96H34Cl6Pd1
orthorhombic
Pca21 (No. 29)
0.0683, 0.0693
0.1905, 0.1924
1.071
17.775(5)
12.451(5)
17.726(5)
90
90
90
3923(2)
4
monoclinic
P21/n (No. 14)
0.0690, 0.0751
0.1735, 0.1827
1.111
12.2190(5)
19.4580(8)
18.0680(6)
90
101.240(3)
90
4213.4(3)
4
triclinic
triclinic
triclinic
P1h (No. 2)
0.0609, 0.0661
0.1691, 0.1752
1.025
13.5850(7)
13.5910(5)
19.2570(9)
103.033(3)
95.960(2)
117.024(2)
2997(6)
P1h (No. 2)
0.0811, 0.2118
0.1114, 0.2541
1.063
13.4150(11)
21.3700(12)
21.1590(16)
65.206(3)
80.338(3)
78.855(4)
5377.1(7)
4
P1h (No. 2)
0.076,a
-
-, 0.115
2.543
13.742(2)
13.943(2)
18.661(3)
96.250(5)
94.407(5)
116.421(6)
3151.4(5)
2
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
2
T, K
153(2)
120(2)
120(2)
153(2)
298(2)
cryst size, mm
D
0.88 × 0.52 × 0.12 0.80 × 0.42 × 0.05 0.32 × 0.20 × 0.12 0.45 × 0.18 × 0.12 0.40 × 0.20 × 0.10
calcd, g cm-3
1.726
1.689
1.600
1.589
1.588
2θmin, 2θmax, deg
4.58, 51.22
3322
4.18, 51.14
7787
7008
674
1.29, -1.58
4.32, 51.56
10 232
9162
925
1.80, -1.00
4.26, 51.64
18 245
12 391
1727
1.78, -1.79
4.0, 55.0
10 742
9366
926
2.14, -1.49
no. of rflns measd (unique)
no. of rflns measd (I > 2σ(I)) 3225
no. of params
650
1.23, -1.75
∆, e Å-3
a
A final R index is calculated with I > 3σ(I).
(powder, cm-1): ν 2954 (m), 2922 (s), 2852 (m), 1733 (m), 1596
(m), 1492 (s), 1459 (s), 1445 (s), 1418 (w), 1378 (w), 1285 (w),
1263 (w), 1236 (w), 1202 (w), 1186 (w), 1156 (w), 1107 (w),
1071 (w), 1031 (m), 1021 (w), 1003 (w), 959 (m), 908 (m), 894
(w), 836 (w), 821 (w), 761 (m), 751 (m), 742 (m), 733 (s), 712
(m), 692 (s), 687 (m), 665 (m). UV-vis (7/3 toluene/2-propanol;
nm): λmax 285, 320 (shoulder), 357 (shoulder), 390, 460
(shoulder). HR-APCI-MS(-) (m/z): found, 1355.2092; calcd for
10, 1355.2158.
using the maXus software package. The crotyl ligand of 8c is
disordered, assuming two orientations with site occupation
parameters 0.70 and 0.30. Due to the disorder in the crotyl
ligand, Pd-C1, Pd-C2, and Pd-C3 distances in 8c have less
certainty than those of 7a ,b and 8a ,b.
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 a Ag/Ag+ electrode. Cyclic voltammetry
(CV) was performed at a scan rate of 100 mV/s. All half-wave
potentials E1/2 ) (Ep,c + Ep,a)/2, where Ep,c and Ep,a are the
cathodic and anodic peak potentials, respectively. The potential
was corrected against Fc/Fc+.
X-r a y Diffr a ction Stu d ies. Crystals of 7a ,b and 8a -c
suitable for the X-ray diffraction study were mounted on a
MacScience DIP2030 imaging plate diffractometer for data
collection using Mo KR (graphite monochromated, λ ) 0.710 69
Å) radiation. Crystal data and data statistics are summarized
in Table 4. The atomic parameters of most of the atoms for
7a ,b and 8a ,b were solved by the direct methods of SIR-97.33
The positional parameters and thermal parameters of non-
hydrogen atoms were refined anisotropically on F2 by the full-
matrix least-squares method, using SHELXL-97.34 Hydrogen
atoms were placed at calculated positions and refined “riding”
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
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 for Frontiers in Fundamental Chemistry. We
thank Frontier Carbon Corp. for a generous supply of
[60]fullerene.
as R1 ) ∑(||Fo| - |Fc||)/∑|Fo| and wR2 ) [∑w(Fo - Fc2)2/
2
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
details, including lists of positional parameters, thermal
displacement parameters, bond lengths, and bond angles for
7a ,b and 8a -c; data are also available as CIF files. This
material is available free of charge via the Internet at
http://pubs.acs.org.
∑(wFo4)]1/2. The structure of 8c was solved by direct methods
and refined on F2 by full-matrix least-squares calculations
(33) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G. L.;
Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna,
R. J . Appl. Crystallogr. 1999, 32, 115.
(34) Sheldrick, G. M. Program for the Solution of Crystal Structures;
University of Go¨ttingen, Go¨ttingen, Germany, 1997.
OM0499153