Synthesis and reactivities of cationic diruthenium complexes with terminal vinylidene ligands. Hydration and novel cyclization of acetylenes on the diruthenium center

Article abstract of DOI:10.1021/om970307f

The cationic diruthenium complexes with a terminal vinylidene ligand [Cp*RuCl(μ₂-SPrⁱ) ₂-Ru(=C=CHR)Cp*][OTf] (3a, R = COOMe; 3b, R = COMe; 3c, R = H; Cp* = η-C₅Me₅, OTf = OSO₂CF₃) were obtained in high yields by the reaction of [Cp*RuCl(μ2-SPrⁱ)₂Ru(OH ₂)-Cp*][OTfJ with HC≡CR. Hydration of 3a and 3b gave the carbonyl complex [Cp*RuCl(μ2-SPrⁱ)₂Ru(CO)Cp*]tOTf] and CH₃R in almost quantitative yields, while the reaction of 3c with water gave the μ₂-acetyl complex [Cp*RuCl(μ₂-SPrⁱ)₂{μ ₂-C(=O)Me}RuCp*][OTf] (5). A reaction mechanism for the former reactions is proposed, which includes hydration of the vinylidene ligands to form the μ₂-β-ketoacetyl complexes with a six-membered dimetallacyclic structure [Cp*Ru(μ₂-SPrⁱ)₂(η ¹:η¹-μ₂-COCH ₂COR′)RuCp*]+ (R′ = OMe, Me) and the following decarbonylation reaction of the μ₂-COCH₂COR′ ligand on the bimetallic center to produce the carbonyl complex and CH₃COR′ via the enolato-carbonyl complexes [Cp*Ru(CO)(μ₂-SPrⁱ) ₂Ru(OCR′=CH2)Cp*]+. In accordance with this mechanism, the reaction of 3a with MeOH afforded [Cp*Ru(μ₂-SPrⁱ)₂{η ¹:ηη¹-μ ₂-C(OMe)=CHCOOMe}RuCp*][OTf] (7). Complexes 3a and 3b reacted with p-tolylacetylene to form the dinuclear metallacyclic complexes 9a and 9b [Cp*Ru(μ₂-SPrⁱ)₂{η ¹:η¹-μ2-C(Tol)=CCCH=C(R′)O}RuCp*][OTf] (9a, R′ = OMe; 9b, R′= Me), respectively. The structures of 3b, 5, 7, and 9a have been determined by X-ray crystallography.

Full text of DOI:10.1021/om970307f

Organometallics 1997, 16, 4445-4452
4445
Syn th esis a n d Rea ctivities of Ca tion ic Dir u th en iu m
Com p lexes w ith Ter m in a l Vin ylid en e Liga n d s.
Hyd r a tion a n d Novel Cycliza tion of Acetylen es on th e
Dir u th en iu m Cen ter
Yukihiro Takagi, Hiroyuki Matsuzaka,† Youichi Ishii, and Masanobu Hidai*
Department of Chemistry and Biotechnology, Graduate School of Engineering,
The University of Tokyo, Hongo, Tokyo 113, J apan
Received April 14, 1997X
The cationic diruthenium complexes with a terminal vinylidene ligand [Cp*RuCl(µ2-SPri)2-
Ru(dCdCHR)Cp*][OTf] (3a , R ) COOMe; 3b, R ) COMe; 3c, R ) H; Cp* ) η5-C5Me5, OTf
) OSO2CF3) were obtained in high yields by the reaction of [Cp*RuCl(µ2-SPri)2Ru(OH2)-
Cp*][OTf] with HCtCR. Hydration of 3a and 3b gave the carbonyl complex [Cp*RuCl(µ2-
SPri)2Ru(CO)Cp*][OTf] and CH3R in almost quantitative yields, while the reaction of 3c
with water gave the µ2-acetyl complex [Cp*RuCl(µ2-SPri)2{µ2-C(dO)Me}RuCp*][OTf] (5). A
reaction mechanism for the former reactions is proposed, which includes hydration of the
vinylidene ligands to form the µ2-â-ketoacetyl complexes with a six-membered dimetallacyclic
structure [Cp*Ru(µ2-SPri)2(η1:η1-µ2-COCH2COR′)RuCp*]+ (R′ ) OMe, Me) and the following
decarbonylation reaction of the µ2-COCH2COR′ ligand on the bimetallic center to produce
the carbonyl complex and CH3COR′ via the enolato-carbonyl complexes [Cp*Ru(CO)(µ2-
SPri)2Ru(OCR′dCH2)Cp*]+. In accordance with this mechanism, the reaction of 3a with
MeOH afforded [Cp*Ru(µ2-SPri)2{η1:η1-µ2-C(OMe)dCHCOOMe}RuCp*][OTf] (7). Complexes
3a and 3b reacted with p-tolylacetylene to form the dinuclear metallacyclic complexes 9a
and 9b [Cp*Ru(µ2-SPri)2{η1:η1-µ2-C(Tol)dCCCHdC(R′)O}RuCp*][OTf] (9a , R′ ) OMe; 9b,
R′ ) Me), respectively. The structures of 3b, 5, 7, and 9a have been determined by X-ray
crystallography.
In tr od u ction
alkynes, organic halides, and hydrazines.6 Of special
interest are the facile couplings of HCCR (R ) Ph, Tol,
cyclohexenyl) at the bimetallic center of the cationic
diruthenium complex 1 to form complexes with an
indan-type framework4a (2) (eq 1), and the linear di- and
trimerization of ferrocenylacetylene catalyzed by 1.4b In
these reactions, dinuclear species with a terminal
vinylidene ligand are considered to play a critical role.
However, such species have not yet been prepared from
complex 1, although a diruthenium complex with a
terminal allenylidene ligand was obtained from 1 and
1,1-diaryl-2-propyn-1-ol.4a
Intensive efforts have recently been devoted to inves-
tigations into the syntheses and reactivities of multi-
nuclear transition metal complexes, because novel
chemical transformations are expected to occur at the
multimetallic centers.1 In our precedent studies on
thiolato- or sulfido-bridged multinuclear complexes, we
have synthesized a series of dinuclear Cp*Ru-thiolato
complexes, such as [Cp*Ru(µ2-SPri)2RuCp*],2 [Cp*Ru-
(µ2-SPri)3RuCp*],3 and [Cp*RuCl(µ2-SPri)2Ru(OH2)Cp*]-
[OTf]4,5 (1), and revealed that these complexes provide
unique bimetallic reaction sites for various stoichiomet-
ric and catalytic transformations of substrates such as
On the other hand, it has been well-documented that
the hydration of terminal alkynes promoted by certain
transition metal complexes affords acyl or alkyl-car-
bonyl complexes.7 Such reactions have been considered
† Present address: Department of Chemistry, Tokyo Metropolitan
University, Minami-osawa, Hachioji, Tokyo 192-03, J apan.
X Abstract published in Advance ACS Abstracts, September 15, 1997.
(1) (a) Adams, R. D.; Horvath, I. T. Prog. Inorg. Chem. 1985, 33,
127. (b) Braunstein, P.; Rose, J . In Stereochemistry of Organometallic
and Inorganic Compounds; Bernal, I., Ed.; Elsevier: Amsterdam, 1989;
Vol. 3, Chapter 1. (c) Su¨ss-Fink, G.; Meister, G. Adv. Organomet. Chem.
1993, 35, 41.
(2) (a) Takahashi, A.; Mizobe, Y.; Matsuzaka, H.; Dev, S.; Hidai, M.
J . Organomet. Chem. 1993, 456, 243. (b) Nishio, M.; Matsuzaka, H.;
Mizobe, Y.; Tanase, T.; Hidai, M. Organometallics 1994, 13, 4214. (c)
Takahashi, A.; Mizobe, Y.; Tanase, T.; Hidai, M. J . Organomet. Chem.
1995, 496, 109. (d) Nishio, M.; Matsuzaka, H.; Mizobe, Y.; Hidai, M.
Organometallics 1996, 15, 965 and references therein.
(3) (a) Matsuzaka, H.; Hirayama, Y.; Nishio, M.; Mizobe, Y.; Hidai,
M. Organometallics 1993, 12, 36. (b) Matsuzaka, H.; Koizumi, H.;
Takagi, Y.; Nishio, M.; Hidai, M. J . Am. Chem. Soc. 1993, 115, 10396.
(4) (a) Matsuzaka, H.; Takagi, Y.; Hidai, M. Organometallics 1994,
13, 13. (b) Matsuzaka, H.; Takagi, Y.; Ishii, Y.; Nishio, M.; Hidai, M.
Organometallics 1995, 14, 2153. (c) Shimada, H.; Qu¨, J .-P.; Matsuzaka,
H.; Ishii, Y.; Hidai, M. Chem. Lett. 1995, 671. (d) Nishibayashi, Y.;
Yamanashi, M.; Takagi, Y.; Hidai, M. J . Chem. Soc., Chem. Commun.
1997, 859.
(5) In a previous paper4a we reported that complex 1 had a formula
of [Cp*Ru(µ2-Cl)(µ2-SPri)2RuCp*][OTf]. However, on the basis of more
detailed studies by variable temperature 1H NMR spectroscopy,
preliminary X-ray crystallography, and carefully repeated elemental
analyses, we have finally concluded that complex 1 is formulated as
[Cp*RuCl(µ2-SPri)2Ru(OH2)Cp*][OTf] in the solid state, and in solution,
a rapid exchange between Cl and H2O ligands on the two ruthenium
atoms takes place to make the Cp* protons virtually equivalent in 1H
NMR at room temperature. 1H NMR (CDCl3): δ 4.05 (sep, 2 H, J )
6.8 Hz, SCHMe2), 2.97 (br, 2 H, Ru(OH2)), 1.64 (s, 30 H, Cp*), 1.52 (d,
12 H, J ) 6.8 Hz, SCHMe2). At -50 °C, the Me signals at δ 1.64 and
1.52 split into two singlets (δ 1.63, 1.59 (15 H each)) and two doublets
(δ 1.52, 1.44 (6 H each)), respectively, and the signal at δ 2.97 due to
the H2O ligand shifted to δ 3.13. Anal. Calcd for C27H46ClF3O4Ru2S3:
C, 39.29; H, 5.62; Cl, 4.29; S, 11.66. Found: C, 38.83; H, 5.59; Cl, 4.67;
S, 11.81.
(6) (a) Hidai, M.; Mizobe, Y. In Transition Metal Sulfur Chemistry:
Biological and Industrial Significance; Stiefel, E. I.; Matsumoto, K.,
Eds; ACS Symposium Series 653; American Chemical Society: Wash-
ington, DC, 1996; p 310. (b) Hidai, M.; Mizobe, Y.; Matsuzaka, H. J .
Organomet. Chem. 1994, 473, 1.
S0276-7333(97)00307-5 CCC: $14.00 © 1997 American Chemical Society

4446 Organometallics, Vol. 16, No. 20, 1997
Takagi et al.
to include the hydrolysis of vinylidene ligands derived
from terminal alkynes, although only a limited number
of studies have provided direct information about the
details of this reaction mechanism.7a This background
prompted us to investigate the reactivities of the isolable
diruthenium vinylidene complexes derived from termi-
nal alkynes and complex 1.
In this article, we describe the synthesis and reac-
tivities of the cationic diruthenium complexes with a
terminal vinylidene ligand [Cp*RuCl(µ2-SPri)2Ru-
(dCdCHR)Cp*][OTf] (3a R ) COOMe; 3b, R ) COMe;
3c, R ) H). Interestingly, the hydration of 3a and 3b
results in the very facile decarbonylation of the initially
formed acyl ligand on the dinuclear center through a
diruthenacyclic intermediate. The reactions of com-
plexes 3a and 3b with p-tolylacetylene produce novel
diruthenacycles fused with a furan ring.
F igu r e 1. ORTEP drawing for the cationic part of 3b.
Hydrogen atoms are omitted for clarity.
Ta ble 1. Selected Bon d Dista n ces a n d An gles
for 3b
Distances (Å)
Ru(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-C(1)
Ru(2)-Cl(1)
Ru(2)-S(1)
2.806(1)
2.321(2)
2.338(3)
1.785(9)
2.413(3)
2.295(2)
Ru(2)-S(2)
O(1)-C(3)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
2.288(3)
1.25(1)
1.30(1)
1.52(1)
1.50(1)
Resu lts a n d Discu ssion
Angles (deg)
99.3(3) Ru(1)-C(1)-C(2) 173.3(9)
Ru(2)-Ru(1)-C(1)
S(1)-Ru(1)-S(2)
Ru(1)-Ru(2)-Cl(1)
S(1)-Ru(2)-S(2)
Ru(1)-S(1)-Ru(2)
Ru(1)-S(2)-Ru(2)
P r ep a r a tion a n d Ch a r a cter iza tion of th e Ca t-
ion ic Dir u th en iu m Vin ylid en e Com p lexes. Treat-
ment of complex 1 with methyl propiolate, in dry CH2Cl2
at room temperature for 10 min, resulted in the almost
quantitative formation of the dinuclear vinylidene com-
plex [Cp*RuCl(µ2-SPri)2Ru(dCdCHCOOMe)Cp*][OTf]
(3a ) (eq 2). Similar reactions of 1 with 3-butyn-2-one
and acetylene gas also afforded the corresponding
vinylidene complexes [Cp*RuCl(µ2-SPri)2Ru(dCdCH-
COMe)Cp*][OTf] (3b ) and [Cp*RuCl(µ2-SPri)2Ru-
(dCdCH2)Cp*][OTf] (3c), respectively.
103.79(9) C(1)-C(2)-C(3)
95.58(7) O(1)-C(3)-C(2)
106.27(9) O(1)-C(3)-C(4)
74.87(7) C(2)-C(3)-C(4)
74.68(8)
126(1)
122(1)
117(1)
119(1)
respectively.8 The vinyl proton signals observed in the
1H NMR (3a , δ 4.77; 3b, δ 5.22; 3c, δ 3.87) also
confirmed the formation of the vinylidene ligands from
the starting alkynes. The IR spectra of 3 showed strong
ν(CdC) absorptions (3a , 1601 cm-1; 3b, 1549 cm-1; 3c,
1601 cm-1) which are characteristic of the vinylidene
ligands. These spectroscopic features clearly indicate
that one molecule of each alkyne is incorporated onto
the diruthenium center to form the terminal vinylidene
complexes 3a -c, as formulated in eq 2.
The molecular structure of 3b was unambiguously
determined by X-ray crystallography. An ORTEP draw-
ing of 3b is shown in Figure 1, with selected bond
lengths and angles summarized in Table 1. The ORTEP
view displays an unsymmetrically substituted dinuclear
structure, in which the terminal vinylidene and chloro
ligands are coordinated to the respective ruthenium
centers in mutual cis configuration, and is in full
accordance with the NMR and IR observations. The
Ru(1)dC(1)dC(2) moiety is almost linear (173.3(9)°),
and the Ru(1)dC(1) and C(1)dC(2) bond distances
(1.785(9) and 1.30(1) Å, respectively) fall within the
range of the reported values for vinylidene complexes.8
The intramolecular distance between the two ruthenium
atoms (2.806(1) Å) corresponds to a Ru-Ru single bond
(2.6-2.9 Å).2-4
1
The H NMR spectra of 3a -c exhibited two singlets
attributable to nonequivalent Cp* ligands and two
doublets due to the diastereotopic methyl protons of the
SPri ligands, suggesting that complex 3 has an unsym-
metrically substituted diruthenium core bridged by two
SPri ligands. The 13C{1H} NMR spectra of 3a -c
showed typical low-field resonances at δ 361.6-365.8,
as well as signals at δ 93.3-113.8, which are diagnostic
of the R- and â-carbon atoms of the vinylidene ligands,
(7) (a) Bianchini, C.; Casares, J . A.; Peruzzini, M.; Romerosa, A.;
Zanobini, F. J . Am. Chem. Soc. 1996, 118, 4585. (b) Mountassir, C.;
Ben Hadda, T.; Le Bozec, H. J . Organomet. Chem. 1990, 388, C13. (c)
Knaup, W.; Werner, H. J . Organomet. Chem. 1991, 411, 471. (d) Davies,
S. G.; McNally, J . P.; Smallridge, A. J . Adv. Organomet. Chem. 1990,
30, 1.
(8) (a) Bruce, M. I. Chem. Rev. 1991, 91, 197. (b) Bruce, M. I.;
Swincer, A. G. Adv. Organomet. Chem. 1983, 22, 59. (c) Koelle, U.;
Rietmann, C.; Tjoe, J .; Wagner, T.; Englert, U. Organometallics 1995,
14, 703.

Cationic Diruthenium Complexes
Organometallics, Vol. 16, No. 20, 1997 4447
Ch a r t 1
Ch a r t 2
F igu r e 2. ORTEP drawing for the cationic part of 5.
Hydrogen atoms are omitted for clarity.
We have previously reported that the reaction of
complex 1 with HCCC(OH)Ar2 (Ar ) Ph, Tol) affords
the terminal allenylidene complexes [Cp*RuCl(µ2-SPri)2-
Ru()CdC)CAr2)Cp*][OTf]4a (Chart 1, 4), while the
reaction with arylacetylene or cyclohexenylacetylene
does not lead to isolation of vinylidene complexes but
results in the coupling of the initially formed vinylidene
ligand with a second alkyne molecule (eq 1). The lower
reactivity of methyl propiolate, 3-butyn-2-one, and
acetylene gas, compared with either arylacetylene or
cyclohexenylacetylene, enabled the high-yield synthesis
of the vinylidene complexes 3. The isolation of com-
plexes 3 also suggests that the first step of the alkyne
coupling reaction depicted in eq 1 is the formation of
the corresponding terminal vinylidene complexes.
Rea ction s of th e Vin ylid en e Com p lexes 3 w ith
H2O a n d Meth a n ol. Although the previously reported
diruthenium allenylidene complex 4 failed to react with
nucleophiles such as H2O and alcohol, the vinylidene
complexes 3 reacted with H2O smoothly. Thus, hydra-
tion of 3c, performed on an alumina column, gave the
stable µ2-acetyl complex [Cp*Ru(µ2-SPri)2{µ2-C()O)Me}-
RuCp*][OTf] (5) in high yield (eq 3). The IR spectrum
of 5 shows a significantly low ν(CdO) absorption (1395
cm-1), indicating that the acetyl ligand derived from the
vinylidene ligand is coordinated to the two metals in a
µ2-fashion with a considerable contribution of the oxy-
carbene structure (Chart 2, 5B).
Ta ble 2. Selected Bon d Dista n ces a n d An gles for 5
Distances (Å)
Ru(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-C(1)
Ru(2)-S(1)
2.6950(8)
2.295(2)
2.303(2)
2.005(6)
2.317(2)
Ru(2)-S(2)
Ru(2)-O(1)
O(1)-C(1)
C(1)-C(2)
2.319(2)
2.189(4)
1.264(7)
1.490(8)
Angles (deg)
Ru(2)-Ru(1)-C(1)
S(1)-Ru(1)-S(2)
Ru(1)-Ru(2)-O(1)
S(1)-Ru(2)-S(2)
Ru(1)-S(1)-Ru(2)
71.1(2)
Ru(1)-S(2)-Ru(2)
71.33(5)
104.7(4)
115.4(4)
127.7(5)
116.9(6)
108.96(6) Ru(2)-O(1)-C(1)
68.8(1)
107.66(6) Ru(1)-C(1)-C(2)
71.52(5) O(1)-C(1)-C(2)
Ru(1)-C(1)-O(1)
[OTf] (Fc ) ferrocenyl) (2.091(10) Å),4b and [Cp*-
(Bu t N C)Ru (µ2-SP r i)[µ2-C(Tol)dCH C{C(Tol)dCH -
SPri}dCH(Tol)]RuCp*] (2.166(7) Å).2d The Ru(1)-C(1)
bond is considerably inclined toward the Ru(2) atom
(Ru(2)-Ru(1)-C(1), 71.1(2)°), suggesting a strong in-
teraction between the Ru(2) and O(1) atoms. The C(1)-
O(1) bond distance (1.264(7) Å) falls between the values
expected for acyl and oxycarbene ligands.9 These metri-
cal features also support the large contribution of the
oxycarbene structure in complex 5.
In contrast, the reaction of 3a with H2O in CH2ClCH2-
Cl at room temperature resulted in the quantitative
formation of methyl acetate and the cationic carbonyl
complex [Cp*RuCl(µ2-SPri)2Ru(CO)Cp*][OTf] (6), the
latter of which was characterized spectroscopically. Gas
chromatographic analysis of the reaction solution over
a period of 64 h confirmed the clean formation of methyl
acetate as the only volatile organic product (eq 4).
Similarly, 3b reacted with H2O to give acetone and
complex 6 in high yields. Interestingly, this type of
decarbonylation was not observed in the hydration of
3c, although the initial step of the hydration-de-
carbonylation of 3a and 3b is also considered to proceed
via the acyl complexes formed by the nucleophilic
addition of H2O to the vinylidene ligands. We presume
that the two adjacent ruthenium centers cooperatively
promote the decarbonylation (deinsertion of CO) of the
The molecular structure of 5 was further determined
by X-ray crystallography. Selected bond distances and
angles are summarized in Table 2. The ORTEP view
of 5 given in Figure 2 clearly shows that the acetyl
ligand is bound to the diruthenium core in a η1:η1-µ2-
fashion, forming a diruthenacyclic structure. The
Ru(1)-C(1) bond (2.005(6) Å) is considerably longer than
the RudC(vinylidene) bond (1.785(9) Å) found in 3b, but
significantly shorter than the Ru-C single bond lengths
found in [Cp*RuBr(µ2-SPri)2Ru(CH2CH2Ph)Cp*] (2.152-
(8) Å),2a [Cp*Ru{µ2-C(dCHFc)CCFc}(µ2-SPri)2RuCp*]-
acyl ligands formed from complexes 3a and 3b.
A
plausible mechanism for this hydration-decarbonylation
(9) (a) Longato, B.; Norton, J . R.; Huffman, J . C.; Marsella, J . A.;
Caulton, K. G. J . Am. Chem. Soc. 1981, 103, 209. (b) Yu, Y.-F.; Gallucci,
J .; Wojcicki, A. J . Am. Chem. Soc. 1983, 105, 4826. (c) Rosen, R. P.;
Hoke, J . B.; Whittle, R. R.; Geoffroy, G. L.; Hutchinson, J . P.; Zubieta,
J . A. Organometallics 1984, 3, 846.

4448 Organometallics, Vol. 16, No. 20, 1997
Takagi et al.
Sch em e 1
Sch em e 2
reaction is shown in Scheme 1.
At first, the R-carbon of the vinylidene ligand in 3 is
attacked by H2O to give the hydroxycarbene complex
A, whose deprotonation generates the acyl intermediate
B. In the reaction of 3c, substitution of the chloro ligand
by the acetyl oxygen results in the formation of the µ2-
acetyl complex 5, which was isolated as a stable product.
However, in the case of 3a and 3b, coordination of the
other remote carbonyl group in the acyl moiety to the
adjacent ruthenium center gives rise to the µ2-acyl
intermediate C, and the succeeding C-C bond cleavage
in the bridging acyl ligand leads to the enolato-carbonyl
complex D. Finally, acidolysis of complex D affords the
final product 6 with either methyl acetate or acetone.
In principle, the decarbonylation of an acyl ligand
demands an additional vacant site on the metal center
to accommodate both the generated CO and alkyl
ligands. However, the conversion of C to D demands
no further vacant site to realize the decarbonylation of
the acyl ligand, and the reaction is considered to be a
facile process compared with the decarbonylation of 5.
We are inclined to believe that the two adjacent
ruthenium atoms participate cooperatively in the de-
carbonylation process and the six-membered dimetal-
lacyclic structure of C is responsible for the facile
decarbonylation observed during the hydration of 3a
and 3b, although none of the intermediates A-D were
vinyl complex [Cp*Ru(µ2-SPri)2{η1:η1-µ2-C(OMe)dCH-
COOMe}RuCp*][OTf] (7) in good yield (Scheme 2), and
its molecular structure was determined by X-ray analy-
sis. An ORTEP drawing for 7 is shown in Figure 3, and
selected bond lengths and angles are summarized in
Table 3. The ORTEP view clearly shows the µ2-
coordination of the -C(OMe)dCHCOOMe ligand by way
of both the σ-bond at the vinylic carbon C(1) and the
σ-donation of the lone pair on the carbonyl oxygen O(3).
1
The H NMR signal at δ 4.97, assignable to the vinyl
proton, and the IR absorption at 1495 cm-1, attributable
to the coordinated ester group, are both compatible with
the crystal structure. The Ru(2)-O(3) distance
(2.120(7) Å) is somewhat shorter than that of the
bridging acetyl ligand of 5 (2.189(4) Å), but falls within
the range of Ru-O distances found for metallacyclic
complexes containing a coordinated ester functionality
such as [Cp*Ru(CHMeCH2COOMe)(NO)][B{3,5-C6H3-
(CF3)2}4] (2.146(8) Å)10 and [Ru{C(COOMe)dCH-
COOMe}(CO)2(PMe2Ph)2][HgCl3] (2.13(1) Å).11 The six-
1
observed by H NMR.
In order to obtain further information about the
mechanism, we have examined the reaction of 3a with
methanol. Treatment of 3a with excess methanol in
CH2ClCH2Cl at 90 °C led to the isolation of the cationic
(10) Hauptman, E.; Brookhart, M.; Fagan, P. J .; Calabrese, J . C.
Organometallics 1994, 13, 774.
(11) Crook, J . R.; Chamberlain, B.; Mawby, R. J .; Ko¨rber, C. F.; Reid,
A. J .; Reynolds, C. D. J . Chem. Soc., Dalton Trans. 1992, 843.

Cationic Diruthenium Complexes
Organometallics, Vol. 16, No. 20, 1997 4449
Sch em e 3
F igu r e 3. ORTEP drawing for the cationic part of 7.
Hydrogen atoms are omitted for clarity.
reaction is considered to proceed via the vinylidene-
acetylide coupling on the cationic diruthenium center
forming an intermediary butenynyl complex followed by
its intramolecular cyclization to give the fused metalla-
cycle.4a Although several vinylidene-acetylide coupling
reactions on monometallic centers have been reported
to afford butenynyl complexes,12 the subsequent cycliza-
tion of the butenynyl ligands occurring on the diruthe-
nium site is very unique and seems to be characteristic
of the cationic dinuclear core. In order to gain further
insight into the reactivity of diruthenium vinylidene
complexes, we have examined the reaction of complex
3 with tolylacetylene.
Treatment of complex 3a with p-tolylacetylene in CH2-
ClCH2Cl at reflux for 3 h afforded a new metallacyclic
complex 9a in 48% yield, along with complex 2 (R )
Me) (Scheme 3). Formation of 2 indicates that the
vinylidene ligand in 3a is partly dissociated to form
methyl propiolate and a coordinatively unsaturated
diruthenium complex under heating. Under similar
conditions, complex 3b reacted with p-tolylacetylene to
produce an analogous metallacycle 9b in 62% yield, but
complex 3c afforded complex 2 (R ) Me) as the only
identified product.
The molecular structure of 9a was fully determined
by X-ray analysis. An ORTEP drawing for 9a is shown
in Figure 4, and selected bond lengths and angles are
summarized in Table 4. The ORTEP view shows that
a diruthenacyclopentadiene unit fused with a furan ring
is formed on the cationic diruthenium core by the
coupling of the vinylidene ligand and tolylacetylene.
Therefore this reaction accomplishes the stepwise in-
corporation of two different acetylenes, i.e., methyl
propiolate and tolylacetylene, on the bimetallic center
of 1. The fused ring system (Ru(1), Ru(2), C(1), C(2),
Ta ble 3. Selected Bon d Dista n ces a n d An gles for 7
Distances (Å)
Ru(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-C(1)
Ru(2)-S(1)
Ru(2)-S(2)
2.774(1)
2.286(3)
2.293(3)
2.08(1)
2.322(3)
2.316(3)
Ru(2)-O(3)
O(1)-C(1)
O(2)-C(3)
O(3)-C(3)
C(1)-C(2)
C(2)-C(3)
2.120(7)
1.35(1)
1.34(1)
1.26(1)
1.35(1)
1.39(1)
Angles (deg)
Ru(2)-Ru(1)-C(1)
S(1)-Ru(1)-S(2)
Ru(1)-Ru(2)-O(3)
S(1)-Ru(2)-S(2)
Ru(1)-S(1)-Ru(2)
Ru(1)-S(2)-Ru(2)
Ru(2)-O(3)-C(3)
94.7(3)
106.8(1)
93.2(2)
104.9(1)
74.01(9)
73.99(9)
136.8(8)
Ru(1)-C(1)-O(1)
Ru(1)-C(1)-C(2)
O(1)-C(1)-C(2)
C(1)-C(2)-C(3)
O(2)-C(3)-O(3)
O(2)-C(3)-C(2)
O(3)-C(3)-C(2)
107.1(8)
135.8(9)
117(1)
128(1)
116(1)
113(1)
131(1)
membered diruthenacycle is essentially planar and
perpendicular to the Ru2S2 core.
Complex 7 is obviously formed through the nucleo-
philic attack of a methanol molecule at the R-carbon of
the vinylidene ligand in 3a , followed by the substitution
of the chloride ligand by the carbonyl oxygen (Scheme
2). The 1-methoxyvinyl ligand in 7 thus formed corre-
sponds to the enol ether form of the µ-acyl ligand in the
intermediate C depicted in Scheme 1. Therefore, the
ready formation of 7 strongly supports that the dimet-
allacyclic µ-acyl complex C is involved in the hydration-
decarbonylation reaction of 3a as a key intermediate.
On the other hand, the reaction of 3c with methanol
resulted in the formation of the methoxycarbene com-
plex [Cp*RuCl(µ2-SPri)2Ru{dCMe(OMe)}Cp*][OTf] (8)
(eq 5), which corresponds to the ether form of the
hydroxycarbene intermediate A in Scheme 1.
(12) (a) Gotzig, J .; Otto, H.; Werner, H. J . Organomet. Chem. 1985,
287, 247. (b) Field, L. D.; George, A. V.; Hambley, T. W. Inorg. Chem.
1990, 29, 4565. (c) Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.; Satoh,
T.; Satoh, J . Y. J . Am. Chem. Soc. 1991, 113, 9604. (d) J ia, G.; Meek,
D. W. Organometallics 1991, 10, 1444. (e) Field, L. D.; George, A. V.;
Malouf, E. Y.; Slip, I. H. M.; Hambley, T. W. Organometallics 1991,
10, 3842. (f) Field, L. D.; George, A. V.; Purches, G. R.; Slip, I. H. M.
Organometallics 1992, 11, 3019. (g) Bianchini, C.; Bohanna, C.;
Esteruelas, M. A.; Frediani, P.; Meli, A.; Oro, L. A.; Peruzzini, M.
Organometallics 1992, 11, 3837. (h) Scha¨fer, V. M.; Mahr, N.; Wolf,
J .; Werner, H. Angew. Chem. 1993, 105, 1377. (i) Bianchini, C.;
Innocenti, P.; Peruzzini, M.; Romerosa, A.; Zanobini, F. Organometal-
lics 1996, 15, 272.
Rea ction s of th e Vin ylid en e Com p lexes 3 w ith
p-Tolyla cetylen e. As depicted in eq 1, the diruthe-
nium core of complex 1 provides an effective reaction
site for the intriguing coupling of arylacetylenes. This

4450 Organometallics, Vol. 16, No. 20, 1997
Takagi et al.
intramolecular nucleophilic attack of the carbonyl oxy-
gen atom on the acetylenic carbon coordinated to the
cationic ruthenium center results in the formation of
complex 9 (Scheme 3). This type of transformation of a
butenynyl ligand to a dimetallacycle-furan fused cyclic
system is unprecedented and is probably realized only
on the adjacent bimetallic centers. Studies aimed at
developing further reactivities of sulfur-bridged multi-
nuclear complexes are actively in progress in our group.
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All reactions were carried out
under a nitrogen atmosphere using standard Schlenk tech-
niques. All solvents were dried by standard methods and
distilled before use. NMR spectra were recorded on a J EOL
EX-270 spectrometer, and IR spectra were recorded on a
Shimadzu FTIR-8100M spectrometer. Elemental analyses
were carried out with a Perkin-Elmer 2400II CHN analyzer.
A Shimadzu GC-14A instrument equipped with
a flame
ionization detector was employed for quantitative analyses of
organic products. Alumina for column chromatography was
purchased from Nakarai Tesque, Inc. (Alumina Activated 200).
The starting material [Cp*RuCl(µ2-SPri)2Ru(OH2)Cp*] (1) was
prepared by a published method.4a Other reagents were
obtained from commercial sources and used without further
purification.
F igu r e 4. ORTEP drawing for the cationic part of 9a .
Hydrogen atoms are omitted for clarity.
Ta ble 4. Selected Bon d Dista n ces a n d An gles
for 9a
Distances (Å)
Ru(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(2)
Ru(1)-C(1)
Ru(2)-S(1)
Ru(2)-S(2)
Ru(2)-C(6)
2.7942(6)
2.297(1)
2.303(1)
2.009(4)
2.308(1)
2.304(1)
2.063(4)
O(1)-C(3)
O(1)-C(5)
C(1)-C(2)
C(1)-C(5)
C(2)-C(3)
C(5)-C(6)
1.329(4)
1.443(4)
1.392(5)
1.435(5)
1.374(5)
1.344(5)
P r epar ation of [Cp*Ru Cl(µ2-SP r i)2Ru (dCdCHCOOMe)-
Cp *][OTf] (3a ). To a CH2Cl2 (10 mL) solution of 1 (397 mg,
0.481 mmol) was added methyl propiolate (41 µL, 0.49 mmol),
and the mixture was stirred at room temperature for 10 min.
After removal of the solvent under reduced pressure, the
resulting solid was recrystallized from CH2Cl2-ether to give
3a as brown crystals (401 mg, 94%). IR (KBr): ν(CdO) 1703
Angles (deg)
cm-1; ν(CdC) 1601 cm-1
.
1H NMR (CDCl3): δ 4.77 (s, 1 H,
Ru(2)-Ru(1)-C(1)
S(1)-Ru(1)-S(2)
Ru(1)-Ru(2)-C(6)
S(1)-Ru(2)-S(2)
Ru(1)-S(1)-Ru(2)
Ru(1)-S(2)-Ru(2)
C(3)-O(1)-C(5)
Ru(1)-C(1)-C(2)
Ru(1)-C(1)-C(5)
C(2)-C(1)-C(5)
85.1(1)
105.50(4)
87.2(1)
105.09(4)
74.72(3)
74.69(4)
104.8(3)
134.3(3)
119.8(3)
105.8(3)
C(1)-C(2)-C(3)
O(1)-C(3)-O(2)
O(1)-C(3)-C(2)
O(2)-C(3)-C(2)
O(1)-C(5)-C(1)
O(1)-C(5)-C(6)
C(1)-C(5)-C(6)
Ru(2)-C(6)-C(5)
Ru(2)-C(6)-C(7)
C(5)-C(6)-C(7)
107.5(4)
113.0(4)
113.7(4)
133.3(4)
108.1(3)
121.0(3)
130.8(4)
116.8(3)
125.6(3)
117.6(4)
vinyl), 4.72 (sep, 2 H, J ) 6.6 Hz, SCHMe2), 3.63 (s, 3 H, OMe),
1.97, 1.68 (s, 15 H each, Cp*), 1.63, 1.43 (d, 6 H each, J ) 6.6
Hz, SCHMe2). 13C{1H} NMR (CDCl3): δ 361.6 (CR), 163.1
(CdO), 105.3 (Câ), 110.0, 101.0 (Cp*), 51.3 (OMe), 42.8
(SCHMe2), 23.4, 23.2 (SCHMe2), 10.6, 10.1 (Cp*). Anal. Calcd
for C31H48ClF3O5Ru2S3: C, 41.77; H, 5.43, Found: C, 41.58;
H, 5.41.
P r ep a r a tion of [Cp *Ru Cl(µ2-SP r i)2Ru (dCdCHCOMe)-
Cp *][OTf] (3b). To a CH2Cl2 (5 mL) solution of 1 (457 mg,
0.554 mmol) was added 3-butyn-2-one (44 µL, 0.56 mmol), and
the mixture was stirred at 0 °C for 1 min. After removal of
the solvent under reduced pressure, the resulting solid was
recrystallized from CH2Cl2-ether to give 3b as brown crystals
(370 mg, 76%). IR (KBr): ν(CdO) 1686 cm-1; ν(CdC) 1549
Ch a r t 3
cm-1 1H NMR (CDCl3): δ 5.22 (s, 1 H, vinyl), 4.70 (sep, 2 H,
.
J ) 6.6 Hz, SCHMe2), 1.94 (s, 3 H, COMe), 1.98, 1.69 (s, 15 H
each, Cp*), 1.64, 1.44 (d, 6 H each, J ) 6.6 Hz, SCHMe2). 13C-
{1H} NMR (CDCl3): δ 362.0 (CR), 193.5 (CdO), 113.8 (Câ),
110.6, 101.4 (Cp*), 43.5 (SCHMe2), 31.3 (COMe), 24.0, 23.9
(SCHMe2), 11.2, 10.7 (Cp*). Anal. Calcd for C31H48ClF3O4-
Ru2S3: C, 42.53; H, 5.53. Found: C, 42.15; H, 5.51.
C(3), C(5), C(6), and O(1)) is almost planar. The
Ru(1)-C(1) (2.009(4) Å) and C(5)-C(6) (1.344(5) Å)
distances are clearly shorter than the Ru(2)-C(6)
(2.063(4) Å) and C(1)-C(5) (1.435(5) Å) distances,
respectively. These data indicate that contribution of
the resonance structure 9B is small in 9a , which is in
contrast to the delocalized diruthenacyclopentadiene
structure found in 2.3a On the other hand, the O(1)-
C(3) bond (1.329(4) Å) is significantly shorter than the
O(1)-C(5) bond (1.443(4) Å), suggesting the important
contribution of the resonance structure 9C (Chart 3).
The above metallacycle formation is considered to
proceed via a mechanism similar to that proposed for
the formation of complex 2.3a Thus, p-tolylacetylene is
at first incorporated onto the diruthenium center of 3
as an acetylide ligand, and the following vinylidene-
acetylide coupling affords a butenynyl complex. Further
P r ep a r a t ion
of
[Cp *R u Cl(µ2-SP r i)2R u (dCdCH2)-
Cp *][OTf] (3c). Acetylene gas was bubbled through a CH2-
Cl2 (10 mL) solution of 1 (251 mg, 0.311 mmol) at room
temperature for 5 min. After removal of the solvent under
reduced pressure, the residual solid was recrystallized from
CH2Cl2-ether to give 3c as brown crystals (248 mg, 96%). IR
(KBr): ν(CdC) 1622 cm-1
.
1H NMR (CDCl3): δ 4.68 (sep, 2
H, J ) 6.7 Hz, SCHMe2), 3.87 (s, 2 H, vinyl), 1.90, 1.67 (s, 15
H each, Cp*), 1.56, 1.42 (d, 6 H each, J ) 6.7 Hz, SCHMe2).
13C{1H} NMR (CDCl3): δ 365.8 (CR), 107.3, 100.1 (Cp*), 93.3
(Câ), 41.6 (SCHMe2), 23.5 (SCHMe2), 10.7, 10.3 (Cp*). Anal.
Calcd for C29H46ClF3O3Ru2S3: C, 41.79; H, 5.56. Found: C,
41.66; H, 5.56.
Rea ction of 3a w ith Wa ter . To a CH2ClCH2Cl (4 mL)
solution of 3a (117 mg, 0.131 mmol) was added a drop of water,

Cationic Diruthenium Complexes
Organometallics, Vol. 16, No. 20, 1997 4451
Ta ble 5. X-r a y Cr ysta llogr a p h ic Da ta for 3b, 5, 7, a n d 9a
3b
5
7
9a
formula
fw
C31H48ClF3O4S3Ru2
875.49
C29H47F3O4S3Ru2
815.00
C32H51F3O6S3Ru2
887.07
C40H55F3O5S3Ru2
971.19
space group
cryst syst
cryst color
cryst dimens, mm
a, Å
Pbca
P21/n
P1h
P1h
orthorhombic
dark brown
0.50 × 0.40 × 0.30
31.373(4)
16.337(2)
14.167(3)
monoclinic
dark brown
0.20 × 0.20 × 0.30
15.807(3)
14.236(3)
16.590(2)
triclinic
dark brown
0.20 × 0.40 × 0.70
12.424(1)
15.187(1)
10.3468(9)
94.98(1)
92.270(10)
100.396(7)
1909.8(3)
2
triclinic
dark brown
0.20 × 0.40 × 0.70
13.441(2)
15.205(2)
11.288(1)
96.210(9)
101.133(9)
69.987(9)
2124.5(5)
2
b, Å
c, Å
R, deg
â, deg
114.949(9)
γ, deg
V, Å3
7260(1)
8
1.602
3384.9(7)
4
1.599
Z
D
calcd, g cm-1
1.542
1.518
F(000), e
3568
11.27
5 < 2θ < 55
16
+h,+k,+l
9129
0.93-1.00
3251 [I > 3σ(I)]
398
0.054
0.030
1.92
1.16
1664
11.26
4 < 2θ < 55
16
+h,+k,(l
8103
0.85-1.00
4374 [I > 3σ(I)]
371
0.045
0.039
1.66
0.76
908
10.08
6 < 2θ < 55
16
+h,(k,(l
8787
0.79-1.00
4810 [I > 3σ(I)]
381
0.059
0.051
4.13
1.38
996
9.12
5 < 2θ < 50
16
+h,(k,(l
7462
0.81-1.00
5276 [I > 3σ(I)]
479
0.034
0.024
2.21
0.60
µ(Mo KR), cm-1
2θ range, deg
scan rate, deg min-1
rflns measd
no. of unique rflns
trans factors
no. of rflns used
no. of variables
Ra
b
Rw
GOFc
max resd dens, e Å-3
a
b
2
R ) ∑||Fo| - |Fc||/∑|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑w|Fo| ]1/2, w ) 1/σ2(Fo). c GOF ) [∑w(|Fo| - |Fc|)2/(Nobs - Nparms)]1/2
.
and the mixture was stirred for 64 h at room temperature.
GC analysis of the resulting solution indicated the formation
of methyl acetate in 95% yield. Removal of the solvent in
vacuo gave 6 as a brown powder (107 mg, 96%). IR (KBr):
(CDCl3): δ 4.13 (s, 3 H, OMe), 4.00 (sep, 2 H, J ) 6.7 Hz,
SCHMe2), 2.69 (s, 3 H, Me), 1.70, 1.59 (s, 15 H each, Cp*),
1.70, 1.43 (d, 6 H each, J ) 6.7 Hz, SCHMe2). Anal. Calcd
for C30H50ClF3O4Ru2S3: C, 41.63; H, 5.82. Found: C, 41.59;
H, 5.89.
ν(CO) 2000 cm-1 1H NMR (CDCl3): δ 4.46 (sep, 2 H, J ) 6.6
.
Hz, SCHMe2), 1.94, 1.68 (s, 15 H each, Cp*), 1.57, 1.42 (d, 6 H
each, J ) 6.6 Hz, SCHMe2). Anal. Calcd for C28H44ClF3O4-
Ru2S3: C, 40.26; H, 5.31. Found: C, 39.87; H, 5.40.
Rea ction of 3b w ith Wa ter . To a CH2ClCH2Cl (5 mL)
solution of 3b (141 mg, 0.161 mmol) was added a drop of water,
and the mixture was stirred for 78 h at room temperature.
GC analysis of the resulting solution indicated the formation
of acetone in 78% yield. Removal of the solvent in vacuo gave
6 as a brown powder (136 mg, 99%).
Rea ction of 3a w ith Tolyla cetylen e. A CH2ClCH2Cl (5
mL) solution of 3a (120 mg, 0.135 mmol) and tolylacetylene
(20 µL, 0.16 mmol) was heated at reflux for 3 h. The solvent
was removed under reduced pressure, and the residual solid
was dissolved in CH2Cl2 and loaded on an activated alumina
column. Elution with CH2Cl2 gave two bands. The first, green
fraction, which contained complex 2 (R ) Me), was discarded.
The second, brown fraction was collected and evaporated to
give 9a (63 mg, 48%). 1H NMR (CDCl3): δ 7.10, 6.40 (d, 2 H
each, J ) 7.9 Hz, C6H4Me), 6.23 (s, 1 H, vinyl), 3.94 (s, 3 H,
OMe), 3.06 (sep, 2 H, J ) 6.6 Hz, SCHMe2), 2.33 (s, 3 H,
C6H4Me), 1.86, 1.47 (s, 15 H each, Cp*), 1.46, 1.09 (d, 6 H each,
J ) 6.6 Hz, SCHMe2). Anal. Calcd for C40H55F3O5Ru2S3: C,
49.47; H, 5.71. Found: C, 49.58; H, 5.66.
Rea ction of 3c w ith Wa ter . A CH2Cl2 (3 mL) solution of
3c (66 mg, 0.079 mmol) was passed through a column packed
with activated alumina. Slow elution with CH2Cl2 gave a
brown band, which was collected and evaporated to give 5 (52
mg, 81%). IR (KBr): ν(CdO) 1395 cm-1
.
1H NMR (CDCl3):
δ 2.82 (sep, 2 H, J ) 6.6 Hz, SCHMe2), 1.87 (s, 3 H, COMe),
1.86, 1.80 (s, 15 H each, Cp*), 1.57, 1.49 (d, 6 H each, J ) 6.6
Hz, SCHMe2). 13C{1H} NMR (CDCl3): δ 291.0 (RuCOMe), 93.7
(Cp*), 43.7 (SCHMe2), 39.5 (RuCOMe), 27.6, 26.0 (SCHMe2),
11.7, 11.1 (Cp*). Anal. Calcd for C29H47F3O4Ru2S3: C, 42.74;
H, 5.81. Found: C, 42.61; H, 5.74.
Rea ction of 3b w ith Tolyla cetylen e. A CH2ClCH2Cl (5
mL) solution of 3b (158 mg, 0.180 mmol) and tolylacetylene
(25 µL, 0.20 mmol) was heated at reflux for 4 h. After removal
of the solvent, the resulting solid was dissolved in CH2Cl2 and
loaded on an activated alumina column. Elution with CH2-
Cl2 gave two green bands. The first fraction, which contained
complex 2 (R ) Me), was discarded, and the second fraction
was collected and evaporated to give 9b (107 mg, 62%). 1H
NMR (CDCl3): δ 7.12, 6.38 (d, 2 H each, J ) 7.9 Hz, C6H4Me),
6.59 (s, 1 H, vinyl), 2.88 (sep, 2 H, J ) 6.9 Hz, SCHMe2), 2.33
(s, 3 H, C6H4Me), 2.05 (s, 3 H, Me), 1.83, 1.46 (s, 15 H each,
Cp*), 1.42, 1.00 (d, 6 H each, J ) 6.9 Hz, SCHMe2). Anal.
Calcd for C40H55F3O4Ru2S3: C, 50.30; H, 5.80. Found: C,
50.42; H, 6.02.
Rea ction of 3a w ith Meth a n ol. To a CH2ClCH2Cl (5 mL)
solution of 3a (87 mg, 0.098 mmol) was added excess methanol
(1 mL), and the mixture was stirred at 90 °C for 3 h. After
removal of the solvent under reduced pressure, the resulting
solid was dissolved in CH2Cl2 and loaded on an activated
alumina column. Elution with CH2Cl2 gave a brown band,
which was collected and evaporated to give 7 (58 mg, 66%).
IR (KBr): ν(CdO) 1495 cm-1 1H NMR (CDCl3): δ 4.97 (s, 1
.
H, vinyl), 3.56 (s, 3 H, OMe), 3.32 (s, 3 H, OMe), 3.20 (sep, 2
H, J ) 6.8 Hz, SCHMe2), 1.66, 1.65 (s, 15 H each, Cp*), 1.44,
1.21 (d, 6 H each, J ) 6.8 Hz, SCHMe2). Anal. Calcd for
X-r a y Diffr a ction Stu d ies. Single crystals of 3b, 5, 7, and
9a were sealed in glass capillaries under an argon atmosphere
and used for data collection. Diffraction data were collected
on a Rigaku AFC7R four-circle automated diffractometer with
graphite-monochromatized Mo KR radiation (λ ) 0.710 69 Å)
at 20 °C using the ω scan technique for 3b and the ω-2θ scan
technique for 5, 7, and 9a . The orientation matrices and unit
cell parameters were determined by least-squares refinement
of 25 machine-centered reflections with 29° < 2θ < 39° for 3b,
C
32H51F3O6Ru2S3: C, 43.33; H, 5.79. Found: C, 43.51; H, 5.75.
Rea ction of 3c w ith Meth a n ol. A methanol solution (10
mL) of 3c (48 mg, 0.058 mmol) was stirred at room tempera-
ture for 24 h. The solvent was removed under reduced
pressure, and the resulting solid was recrystallized form CH2-
Cl2-hexane to give 8 as brown crystals (36 mg, 72%). 1H NMR

4452 Organometallics, Vol. 16, No. 20, 1997
Takagi et al.
28° < 2θ < 34° for 5, 35° < 2θ < 40° for 7, and 39° < 2θ < 40°
for 9a . Intensity data were corrected for Lorentz and polariza-
tion effects and for absorption (empirical, Ψ scans). For all
crystals, no significant decay was observed for three standard
reflections monitored every 150 reflections during the data
collection. Details of the X-ray diffraction study are sum-
marized in Table 5.
The structure solution and refinement were carried out by
using the teXsan program package.13 The positions of the non-
hydrogen atoms were determined by Patterson methods
(DIRDIF PATTY) and subsequent Fourier syntheses. All non-
hydrogen atoms were refined by full-matrix least-squares
techniques with anisotropic thermal parameters except for the
carbon, oxygen, and fluorine atoms of the OTf anion in 7. The
OTf anion in 7 was found to be disordered to a minor extent,
and the atoms of this anion except for the sulfur atom were
refined isotropically. Hydrogen atoms were placed at the
calculated positions and were included in the final stage of
refinement with fixed isotropic parameters.
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Science, and Culture of J apan.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and equivalent isotropic thermal parameters,
anisotropic thermal parameters, and full bond lengths and
angles for 3b, 5, 7, and 9a (47 pages). Ordering information
is given on any current masthead page.
(13) teXsan: Crystal Structure Analysis Package, Molecular Struc-
ture Corp. (1985 and 1992).
OM970307F