Synthesis and redox behavior of ruthenium(II) 2,3,4,5-tetramethylruthenocenylacetylide and related complexes. Formation of μ-η6:η 1-[(cyclopentadienylidene)ethylidene]diruthenium complexes containing a strong metal-metal interaction

Article abstract of DOI:10.1021/om990138u

1-Ethynyl-2,3,4,5-tetramethylruthenocene was prepared by the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with trimethylsilyldiazomethyllithium and also by the reaction of 1-(2′,2′-dichlorovinyl)-2,3,4,5-tetramethylruthenocene, which was obtained from the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with lithium dichloromethyldiethylphosphonate and tert-butyluthium in good yield. 1-Ethynyl-2,3,4,5-tetramethylruthenocene reacted with RuClP₂L (P₂ = 2 PPh₃ or dppe; L = η-C₆H₆, η-C₅Me₆, or η⁵-C₉H₇) in the presence Of NH₄PF₆ or AgBF₄, followed by the column chromatography on deactivated Al₂O₃, to give Ru(C≡ CRc′)P₂L in moderate or good yield. Ru(C≡CRc)P₂(η⁵-C₉H₇) and Ru(C≡CRc*)P₂(η⁵-C₉H ₇) were similarly prepared (Rc, Rc′, and Rc* are ruthenocenyl, 2,3,4,5-tetramethylruthenocenyl, and l′,2′,3′,4′,5′-pentamethyhruthenocenyl, respectively). The structures of Ru(C≡CRc′)(dppe)-(PPh₃)₂(η-C ₅H₅), Ru(C=CRc)(dppe)(η⁵-C₉H₇), and Ru(C≡CRc′)(dppe)(η⁵-C₉H₇) were determined by X-ray analysis. Cyclic voltammetry of the acetylide complexes showed two well-separated quasi-reversible waves. Chemical oxidation of ruthenium(II) 2,3,4,5-tetramethylruthenocenylacetylide complexes gave products whose stability was dependent on the ligand on the Ru(II) moiety. The ¹³C NMR spectrum of the oxidized species isolated as stable crystals confirmed the structural rearrangement of the bridging acetylide ligand to a iμ-η-η⁶:η ¹-[(cyclopentadienylidene)ethylidene] ligand. The structure of [(η-C₅H₅)Ru(η-η⁶:η ¹-C₅Me₄=C=C)Ru-(dppe)(η⁵-C ₅Me₅)](BF₄)₂ was determined by X-ray analysis.

Full text of DOI:10.1021/om990138u

3208
Organometallics 1999, 18, 3208-3219
Syn th esis a n d Red ox Beh a vior of Ru th en iu m (II)
2,3,4,5-Tetr a m eth ylr u th en ocen yla cetylid e a n d Rela ted
Com p lexes. F or m a tion of
µ-η6:η1-[(Cyclop en ta d ien ylid en e)eth ylid en e]d ir u th en iu m
Com p lexes Con ta in in g a Str on g Meta l-Meta l In ter a ction
Masaru Sato,* Ayako Iwai, and Masanobu Watanabe
Chemical Analysis Center, Saitama University, Urawa, Saitama 338-8570, J apan
Received February 26, 1999
1-Ethynyl-2,3,4,5-tetramethylruthenocene was prepared by the reaction of 1-formyl-2,3,4,5-
tetramethylruthenocene with trimethylsilyldiazomethyllithium and also by the reaction of
1-(2′,2′-dichlorovinyl)-2,3,4,5-tetramethylruthenocene, which was obtained from the reaction
of 1-formyl-2,3,4,5-tetramethylruthenocene with lithium dichloromethyldiethylphosphonate
and tert-butyllithium in good yield. 1-Ethynyl-2,3,4,5-tetramethylruthenocene reacted with
RuClP 2L (P 2 ) 2 PPh3 or dppe; L ) η-C5H5, η-C5Me5, or η5-C9H7) in the presence of NH4PF6
or AgBF4, followed by the column chromatography on deactivated Al2O3, to give Ru(Ct
CRc′)P 2L in moderate or good yield. Ru(CtCRc)P 2(η5-C9H7) and Ru(CtCRc*)P 2(η5-C9H7)
were similarly prepared (Rc, Rc′, and Rc* are ruthenocenyl, 2,3,4,5-tetramethylruthenocenyl,
and 1′,2′,3′,4′,5′-pentamethylruthenocenyl, respectively). The structures of Ru(CtCRc′)(dppe)-
(PPh3)2(η-C5H5), Ru(CtCRc)(dppe)(η5-C9H7), and Ru(CtCRc′)(dppe)(η5-C9H7) were deter-
mined by X-ray analysis. Cyclic voltammetry of the acetylide complexes showed two well-
separated quasi-reversible waves. Chemical oxidation of ruthenium(II) 2,3,4,5-tetrameth-
ylruthenocenylacetylide complexes gave products whose stability was dependent on the ligand
on the Ru(II) moiety. The 13C NMR spectrum of the oxidized species isolated as stable crystals
confirmed the structural rearrangement of the bridging acetylide ligand to a µ-η6:η1-[(cyclo-
pentadienylidene)ethylidene] ligand. The structure of [(η-C5H5)Ru(µ-η6:η1-C5Me4dCdC)Ru-
(dppe)(η5-C5Me5)](BF4)2 was determined by X-ray analysis.
In tr od u ction
intensively as mixed-valence complexes,7 since ferrocene
is stable in both the neutral and oxidized forms.8
However, there have been relatively few reports about
the oxidation of ruthenocene derivatives,9-14 because
ruthenocene shows an irreversible two-electron oxida-
tion process which hinders understanding.
Investigation of binuclear complexes bridged by an
unsaturated hydrocarbon is a burgeoning field of orga-
nometallic chemistry, and complexes with two different
redox sites in close proximity or at a moderate distance
are of current interest to basic and applied study.1 These
complexes potentially possess unique physical proper-
ties as one particular compound rather than as the sum
of the properties of the individual redox sites. Binuclear
complexes with metallocene termini have been exten-
sively investigated because of their great stability. In
particular, ferrocene derivatives2-6 have been studied
(5) Amer, S. I.; Sadler, G.; Henry, P. M.; Ferguson, G.; Ruhl, B. L.
Inorg. Chem. 1985, 24, 1517.
(6) Lee, M.-T.; Foxman, B. M.; Rosenblum, M. Organometallics 1985,
4, 539.
(7) Brown, D. B., ed. Mixed-Valence Compounds; D. Reidel Publish-
ing Company: Dordrecht, The Netherlands, 1980.
(8) Togni, A.; Hayashi, T. Ferrocenes; VCH Publishers: New York,
1995.
(9) Ko¨lle, U.; Grub, J . J . Organomet. Chem. 1985, 289, 133.
(10) Rybinskaya, M. I.; Kreindlin, A. Z.; Fadeeva, S. S. J . Organomet.
Chem. 1988, 358, 363.
(11) (a) Watanabe, M.; Sano, H. Chem. Lett. 1991, 555. (b) Wa-
tanabe, M.; Iwamoto, T.; Kawata, S.; Kubo, A.; Sano, H.; Motoyama,
I. Inorg. Chem. 1992, 31, 177. (c) Watanabe, M.; Iwamoto, T.; Sano,
H.; Motoyama, I. J . Coord. Chem. 1992, 26, 223. (d) Watanabe, M.;
Iwamoto, T.; Sano, H.; Motoyama, I. Inorg. Chem. 1993, 32, 5223. (e)
Watanabe, M.; Motoyama, I.; Shimoi, M.; Iwamoto, T. Inorg. Chem.
1994, 33, 2518. (f) Watanabe, M.; Motoyama, I.; Sano, H. Inorg. Chim.
Acta 1994, 225, 103.
(12) (a) Mueller-Westerhoff, U. T. Angew. Chem., Int. Ed. Engl.
1986, 25, 711. (b) Diaz, A. F.; Mueller-Westerhoff, U. T.; Nazzal, A.;
Tanner, M. J . Organomet. Chem. 1982, 236, C45. (c) Mueller-Wester-
hoff, U. T.; Rheingold, A. L.; Swiegers, G. F. Angew. Chem., Int. Ed.
Engl. 1992, 31, 1352.
(1) (a) Beck, W.; Niemer, B.; Wieser, M. Angew. Chem., Int. Ed. Engl.
1993, 32. 923. (b) Ward, M. D. Chem. Soc. Rev. 1995, 121. (c) Astruc,
D. Electron Transfer and Radical Processes in Transition-metal
Chemistry; VCH Publishers: New York, 1995.
(2) (a) Cowan, D. O.; Kaufman, F. J . Am. Chem. Soc. 1970, 92, 219.
(b) Kaufman, F.; Cowan, D. O. J . Am. Chem. Soc. 1970, 92, 6198. (c)
Cowan, D. O.; LeVanda, C.; Park, J .; Kaufman, F. Acc. Chem. Res.
1973, 6, 1.
(3) (a) Cowan, D. O.; LeVanda, C. J . Am. Chem. Soc. 1972, 94, 9271.
(b) Mueller-Westerhoff, U. T.; Eilbracht, P. J . Am. Chem. Soc. 1972,
94, 9272. (c) LeVanda, C.; Bechgaard, K.; Cowan, D. O.; Mueller-
Westerhoff, U. T.; Eilbracht, P.; Candela, G. A.; Collins, R. L. J . Am.
Chem. Soc. 1976, 98, 3181. (d) Morrison, W. H., J r.; Krogsrud, S.;
Hendrickson, D. N. Inorg. Chem. 1973, 12, 1998.
(4) (a) LeVanda, C.; Bechgaard, K.; Cowan, D. O. J . Org. Chem.
1976, 41, 2700. (b) Motoyama, I.; Watanabe, M.; Sano, H. Chem. Lett.
1978, 513. (c) Kramer, J . A.; Hendrickson, D. N. Inorg. Chem. 1980,
19, 3330. (d) Powers, M. J .; Meyer, T. J . J . Am. Chem. Soc. 1978, 100,
4393.
(13) (a) Sato, M.; Kudo, A.; Kawata, Y.; Saitoh, H. J . Chem. Soc.,
Chem. Commun. 1996, 25. (b) Sato, M.; Kawata, Y.; Kudo, A.; Iwai,
A.; Saitoh, H.; Ochiai, S. J . Chem. Soc., Dalton Trans. 1998, 2215.
(14) Hashidzume, K.; Tobita, H.; Ogino, H. Organometallics 1995,
14, 1187.
10.1021/om990138u CCC: $18.00 © 1999 American Chemical Society
Publication on Web 07/17/1999

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Sch em e 1
Organometallics, Vol. 18, No. 16, 1999 3209
We have been interested in heterobinuclear mixed-
valence compounds containing ferrocene as part of a
redox center and have demonstrated new electron
delocalization systems15 and novel reactions of ferroce-
nylacetylide complexes of various transition metals.16
In these investigations, it was shown that the main
product of one-electron oxidation of ruthenium(II) ru-
thenocenyl- and 1′,2′,3′,4′,5′-pentamethylruthenocenyl-
acetylide complexes is the vinylidene analogues.17 Two-
electron (2 e) oxidation of ruthenium(II) 1′,2′,3′,4′,5′-
pentamethylruthenocenylacetylide gave the fulvene-
vinylidene complex, and that of ruthenium(II) rutheno-
cenylacetylide complex led to µ-η6:η1-[(cyclopentadien-
ylidene)ethylidene]diruthenium, which is sufficiently
interesting to warrant attempts at isolation. Stabiliza-
tion by means of steric protection was considered, name-
ly the introduction of methyl groups in the substituted
cyclopentadienyl ring of ruthenocenylacetylene or the
use of an indenyl ligand. It has been recently shown that
the preferred conformation of the indenyl ligand in
allenylidene complexes is such that the benzo ring is
oriented cis to the allenylidene group,18 while the pre-
ferred conformation is trans in acetylide complexes.19
We now report the synthesis, redox behavior, and chem-
ical oxidation of the acetylide complexes Ru(CtCRc′)-
P 2L, Ru(CtCRc)P 2(η5-C9H7), and Ru(CtCRc*)P 2(η5-
C9H7) (Rc, Rc′, and Rc* are the abbreviations for ruthe-
nocenyl, 2,3,4,5-tetramethylruthenocenyl, and 1′,2′,3′,4′,5′-
pentamethylruthenocenyl groups, respectively; P 2 ) 2
PPh3 or dppe; L ) η-C5H5, η-C5Me5, or η5-C9H7).
ing mono- and diformyl derivatives.21 The application
of the modified procedure22 of the Colvin rearrange-
ment23 to the aldehyde (2) afforded an excellent result.
Thus, the addition of 2 to a solution prepared from
trimethylsilyldiazomethane and LDA in THF at -78 °C,
with subsequent heating under reflux for 3 h, gave
1-ethynyl-2,3,4,5-tetra-methylruthenocene (Rc′CtCH,
4) in 71% yield. 1-Ethynyl-1′,2′,3′,4′,5′-pentamethylru-
thenocene (Rc*CtCH) was similarly obtained in moder-
ate yield from 1-formyl-1′,2′,3′,4′,5′-pentamethylru-
thenocene. As another route to the acetylene 4, the
aldehyde 2 was allowed to react with the solution
prepared from diethyl(trichloromethyl)phosphonate24
and n-BuLi in THF at -90 °C to give 1-(2′,2′-dichlo-
rovinyl)-2,3,4,5-tetramethylruthenocene (5) in 85% yield.
The reaction of dichloro derivative 5 with t-BuLi in THF
at -78 °C led to the mixture of acetylene 4 (70% yield)
and 1,4-(2′,3′,4′,5′-tetramethylruthenocenyl)-1,3-butadiyne
(6) (19% yield), which were separated by SiO2 chroma-
tography (Scheme 1).
Syn th esis of Acetylid e Com p lexes. Acetylene 4
reacted with RuCl(PPh3)2(η-C5H5) in the presence of
NH4PF6 in CH2Cl2/MeOH, with subsequent column
(15) (a) Sato, M.; Hayashi, Y.; Shintate, H.; Katada, M.; Kawata, S.
J . Organomet. Chem. 1994, 471, 179. (b) Sato, M.; Shintate, H.;
Kawata, Y.; Sekino, M.; Katada, M.; Kawata, S. Organometallics 1994,
13, 1956. (c) Sato, M.; Mogi, E. Organometallics 1995, 14, 4837. (d)
Sato, M.; Hayashi, Y.; Kumakura, S.; Shimizu, N.; Katada, M.; Kawata,
S. Organometallics 1996, 15, 721. (e) Sato, M.; Mogi, E. J . Organomet.
Chem. 1996, 517, 1.
(16) Sato, M.; Mogi, E.; Kumakura, S. Organometallics 1995, 14,
3157.
(17) Sato, M.; Kawata, Y.; Shintate, H.; Habata, Y.; Akabori, S.;
Unoura. K. Organometallics 1997, 16, 1693.
Resu lts a n d Discu ssion
(18) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Gonza´lez-Cueva,
M.; Lastra, E.; Borge, J .; Garc´ıa-Granda, S.; Pe´rez-Carren˜, O, E.
Organometallics 1996, 15, 2137. (b) Gamasa, M. P.; Gimeno, J .;
Gonzalez-Bernardo, C.; Borge, J .; Garc´ıa-Granda, S. Organometallics
1997, 16, 2483.
(19) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lo´pez-Gonza´lez, M.
C.; Borge, J .; Garc´ıa-Granda, S. Organometallics 1997, 16, 4453.
(20) Attenburrow, J .; Cameron, A. F. B.; Chapman, J . H.; Evans,
R. M.; Hems, B. A.; J ansen, A. B. A.; Walker, T. J . Chem. Soc. 1952,
1094.
(21) Kreindlin, A. Z.; Petrovskii, P. V.; Rybinskaya, M. I. Izv. Akad.
Nauk. SSSR, Ser. Khim. 1987, 1620.
(22) Miwa, K.; Aoyama, T.; Shioiri, T. Synlett 1994, 107.
(23) Colvin, E. W.; Hamill, B. J . J . Chem. Soc. Chem. Commun. 1973,
151. Colvin, E. W.; Hamill, B. J . J . Chem. Soc., Perkin Trans 1 1977,
869.
Syn t h esis of 1-E t h yn yl-2,3,4,5-t et r a m et h ylr u -
th en ocen e. Pentamethylruthenocene (1) was oxidized
with activated manganese oxide (available from Aldrich,
Inc.) in refluxing 1,2-dichloroethane for 4 h to give
1-formyl-2,3,4,5-tetramethylruthenocene (2) and 1,2-
diformyl-3,4,5-trimethylruthenocene (3) in 42% and 8%
yields, respectively, with the recovery of the starting
material (40%). The use of activated manganese oxide,
which was prepared according to Attenburrow’s proce-
dure,20 gave a rather low yield of the desired product.
A similar oxidative approach was reported in the
conversion of decamethylruthenocene to the correspond-
(24) Kosolapoff, G. M. J . Am. Chem. Soc. 1947, 69, 1002.

3210 Organometallics, Vol. 18, No. 16, 1999
Sato et al.
Sch em e 2
Sch em e 3
chromatography on deactivated alumina, to give the
acetylide complex, Ru(CtCRc′)(PPh3)2(η-C5H5) (7) in
97% yield (Scheme 2). In a similar manner, the acetylide
complexes Ru(CtCRc′)(PPh3)2(η-C5Me5) (8), Ru(Ct
CRc′)(PPh3)2(η5-C9H7) (9), and Ru(CtCRc′)(dppe)(η-C5-
Me5) (11) were obtained in good yields. The acetylide
complexes Ru(CtCRc′)(dppe)(η-C5H5) (10) and Ru(Ct
CRc′)(dppe)(η5-C9H7) (12) were prepared by using
AgBF4 in acetone instead of NH4PF6. To examine the
effect of an indenyl ligand, Ru(CtCRc)(PPh3)2(η5-C9H7)
(13), Ru(CtCRc*)(PPh3)2(η5-C9H7) (15), Ru(CtCRc)-
(dppe)(η5-C9H7) (14), and Ru(CtCRc*)(dppe)(η5-C9H7)
(16) were prepared (Scheme 3). The structure of these
acetylide complexes was determined on the base of
spectral data, some of which are summarized in Table
1. The formation of the acetylide chain is clearly
confirmed by the IR CtC stretching vibration in the
range 2062-2089 cm-1, which is somewhat lower in
bridge was observed in the narrow range (104-106
ppm), while the R-carbon signal attached directly to the
Ru(II) atom is influenced by the ligands on the Ru(II)
atom, especially the η-C5Me5 ligand, which caused a
considerably large high-field shift.
X-r a y An a lysis of th e Acetylid e Com p lexes. The
structure of complex 10 was determined by X-ray
diffraction. The crystallographical data are collected in
Table 2 , and the selected bond distances and angles
are summarized in Table 3. The ORTEP view of 10 is
shown in Figure 1. The Ru(II) center clearly adopts a
pseudooctahedral geometry, as generally observed for
the piano-stool complexes, with the η-C5H5 ring occupy-
ing three coordination sites and the carbon atom of the
acetylide ligand and the two P atoms of triphenylphos-
phines occupying the other three sites. The Ru-C(1)
distance is 2.018(4) Å, which is similar to those in Ru-
(CtCPh){Ph2PCH(CH3)CH(CH3)PPh2}(η-C5H5) (2.038-
(7) Å),25 [Ru(CtCPh)(NH3)(dppe)2]PF6 (2.014(5) Å),26
1
wavelength than that of Rc′CtCH (2103 cm-1). The H
NMR spectra exhibited signals in accordance with the
proposed structures. In the 13C NMR spectra, the signals
of the acetylene carbons were observed in the range
100-120 ppm. The â-carbon signal of the acetylide
(25) Consiglio, G.; Morandini, F.; Sironi, A. J . Organomet. Chem.
1986, 306, C45.
(26) Touchard, D.; Haquette, P.; Guesmi, S.; Pichon, L. L.; Daridor,
A.; Toupet, L.; Dixnerf, P. H. Organometallics 1997, 16, 3640.

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Organometallics, Vol. 18, No. 16, 1999 3211
Ta ble 1. IR a n d 13C a n d 31P NMR Da ta for th e Acetylid e Com p lexes 7-16a
complex
formula
13C NMR
no.
IR ν(CtC)
Ru-CtC
RuCtC
31P NMR
7
8
9
10
11
12
13
14
15
16
Rc′CtCRu(PPh3)2(η-Cp)
Rc′CtCRu(PPh3)2(η-Cp*)
Rc′CtCRu(PPh3)2(η5-Ind)
Rc′CtCRu(dppe)(η-Cp)
Rc′CtCRu(dppe)(η-Cp*)
Rc′CtCRu(dppe)(η5-Ind)
RcCtCRu(PPh3)2(η5-Ind)
RcCtCRu(dppe)(η5-Ind)
Rc*CtCRu(PPh3)2(η5-Ind)
Rc*CtCRu(dppe)(η5-Ind)
2081
2062
2075
2088
2073
2089
2086
2070
2088
2079
105.90 (25.1)
117.81 (24.3)
104.01 (28.3)
106.45 (24.4)
119.92 (25.9)
107.23 (25.0)
102.80 (25.6)
106.65 (26.0)
101.31 (25.7)
103.83 (25.5)
107.58
106.26
107.22
105.48
102.78
105.21
106.55
104.64
106.54
104.16
50.74
52.72
53.36
87.35
81.61
89.08
51.34
86.48
50.49
87.52
a
η-Cp ) η5-cyclopentadienyl, η-Cp* ) η5-pentamethylcyclopentadienyl, and η5-Ind ) η5-indenyl.
Ta ble 2. Cr ysta l a n d In ten sity Collection Da ta for 9, 10, 14, a n d 19
compound
9
10
14
19
chem formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
C
70H63P2Ru2
C47H46P2Ru2
874.97
monoclinic
P21/n
13.138(4)
15.190(3)
20.45(1)
C48H44OP2Ru2
900.97
monoclinic
P21/n
10.5230(5)
25.456(1)
14.6560(8)
C52H56B2F8Ru2
1118.72
triclinic
P1
12.556(2)
12.192(1)
18.405(2)
82.461(7)
93.184(3)
70.405(6)
2534.4(5)
2
1168.37
monoclinic
P21/a
24.489(6)
23.689(5)
9.751(3)
94.63(2)
104.99(2)
91.574(3)
5638.2(3)
4
1.376
1073.7
4
1.47
3924.5(2)
4
1.525
Z
D
calcd, g cm-3
1.466
cryst dimens, mm
linear abs coeff, cm-1
radiation (λ, Å)
0.35 × 0.3 × 0.2
0.26 × 0.16 × 0.15
0.25 × 0.10 × 0.10
0.24 × 0.06 × 0.04
6.141
8.624
8.622
7.082
Mo KR (0.710 73)
-31 e h e 31
-30 e k e 0
-1 e l e 12
15216
Mo KR (0.710 73)
0 e h e 16
0 e k e 21
-29 e l e 28
9937
Mo KR (0.710 73)
0 e h e 14
0 e k e 34
-20 e l e 20
10928
Mo KR (0.710 73)
0 e h e 17
-15 e k e 17
-24 e l e 25
12326
rfln (hkl) limits
total no. of rflns measd
no. of unique rflns
8471
9636
8415
10991
no. of rflns used in L.S.
7782
6870
8415
5840
L.S. params
766
640
626
604
R
0.073
0.034
0.048
0.078
Rw
0.082
0.96
-0.96
0.036
0.55
-1.05
0.050
1.86
-0.65
0.098
1.41
-1.51
max peak in final Fourier map, e Å-3
min peak in final Fourier map, e Å-3
Ta ble 3. Selected Bon d Dista n ces a n d An gles for 10, 14, a n d 9
14
10
9
Bond Distances (Å)
Ru(1)-C(1)
Ru(1)-P(1)
Ru(1)-P(2)
2.018(4)
2.247(2)
2.243(2)
Ru(1)-C(1)
Ru(1)-P(1)
Ru(1)-P(2)
2.022(5)
2.268(2)
2.230(2)
Ru(1)-C(1)
Ru(1)-P(1)
Ru(1)-P(2)
Ru(1)-C(17)
Ru(1)-C(18)
Ru(1)-C(19)
Ru(1)-C(20)
Ru(1)-C(21)
C(1)-C(2)
1.988(10)
2.314(3)
2.309(3)
2.238(12)
2.207(12)
2.241(11)
2.400(00)
2.398(11)
1.216(14)
1.426(14)
2.166(av)
1.424(av)
C(1)-C(2)
C(2)-C(3)
Ru(2)-C(Cp-ring)
C-C(Rc′ ring)
1.208(6)
1.425(6)
2.182(av)
1.416(av)
C(1)-C(2)
C(2)-C(3)
Ru(2)-C(Cp ring)
C-C(Rc ring)
1.210(7)
1.432(7)
2.170(av)
1.421(av)
C(2)-C(3)
Ru(2)-C(Cp ring)
C-C(Rc′ ring)
Bond Angles (deg)
C(1)-C(2)-C(3)
Ru(1)-C(1)-C(2)
C(1)-Ru(1)-P(1)
C(1)-Ru(1)-P(2)
P(1)-Ru(1)-P(2)
175.1(4)
C(1)-C(2)-C(3)
Ru(1)-C(1)-C(2)
C(1)-Ru(1)-P(1)
C(1)-Ru(1)-P(2)
P(1)-Ru(1)-P(2)
174.2(5)
C(1)-C(2)-C(3)
Ru(1)-C(1)-C(2)
C(1)-Ru(1)-P(1)
C(1)-Ru(1)-P(2)
P(1)-Ru(1)-P(2)
176.7(11)
172.9(9)
89.3(3)
90.2(3)
101.4(1)
179.2(4)
86.7(2)
82.7(2)
84.6(1)
174.0(4)
80.1(2)
87.8(2)
84.9(1)
and Ru{CtC(η1-C7H7)}(PPh3)2(η-C5H5) (2.03(1) Å).27
The structural features of the Rc′CtC- part in complex
10 [C(1)-C(2) 1.208(6) Å, Ru(1)-C(1)-C(2) 179.2(4)°,
C(1)-C(2)-C(3) 175.1(4)°] is very similar to those in Ru-
(CtCRc)(PPh3)2(η-C5Me5), [C(1)-C(2) 1.21(1) Å, Ru(1)-
C(1)-C(2) 176.3(8)°, C(1)-C(2)-C(11) 170(1)°].17 The
plane of the η-C5Me4 ring in the Rc′ group is inclined
by 50.3(2)° from the plane consisting of the Ru(1) atom,
the center of the η-C5H5 ring, and the C(1) atom. In
(27) Tamm, M.; J entzsch, T.; Werncke, W. Organometallics 1997,
16, 1418.

3212 Organometallics, Vol. 18, No. 16, 1999
Sato et al.
F igu r e 1. ORTEP view of complex 10.
F igu r e 3. ORTEP view of complex 9. (The solvent mol-
ecule is removed for clarity.)
atom, the center of the 5-membered ring of the indenyl
ligand, and the center of the six-membered ring of the
indenyl ligand is inclined away from the Rc group by
61.6(11)° from the plane containing the Ru(1) atom, the
center of the five-membered ring of the indenyl ligand,
and the C(1) atom. That is, the benzo ring of the indenyl
ligand takes an orientation cis to the Rc part, contrary
to the trans orientation in Ru(CtCPh)(PPh3)2(η-C9H7)
(161.9(1)°).19 In the allenylidene complex, the benzo ring
of the indenyl ligand was reported to have a cis
orientation for the phenylacetylide part (9.6(3)°).18 Such
a change in the indenyl ligand may allow for an
increased protecting effect around the ruthenocenyl-
acetylide moiety in the oxidized complex of 14 and
related complexes; a similar steric protection effect by
the indenyl ligand is indicated in the nucleophilic attack
to the allenylidene chain.19,28
F igu r e 2. ORTEP view of complex 14.
The molecular geometry of 9, which is the most
congested ruthenium(II) ruthenocenylacetylide com-
plexes reported herein, was determined by X-ray dif-
fraction. The unit cell contains 3/2 benzene molecules
with the center of one benzene molecule situated at a
center of symmetry. The crystallographic data are
collected in Table 2, and the selected bond distances and
angles are summarized in Table 3. An ORTEP view of
9 is shown in Figure 3. The stereochemistry of the
η-C9H7 and the acetylide ligands and two triphenylphos-
phines around the Ru(II) atom keeps a three-legged
piano-stool configuration, similar to 10 and 14. The
plane of η-C5H4 ring in the Rc group is inclined by 26.2-
(1)° from the plane consisting of the Ru(1) atom, the
center of the five-membered ring of the indenyl ligand,
and the C(1) atom. The angle is similar to that (26.4°)
of Ru(CtCRc)(PPh3)2(η-C5Me5)17 and is different from
those of 10 and 14 and seems to support the suggestion
that the magnitude of the inclination may be dependent
on the kind of phosphine ligand coordinated to the Ru-
(II) atom. The orientation of the benzo ring of the
indenyl ligand is nearly trans to the Rc′ group (161.2-
(5)°), which resembles with that observed in Ru(Ct
CCPh2CtCH)(PPh3)2(η5-C9H7) (161.9(1)°).19
contrast to this, the plane of η-C5H4 ring of the Rc group
in Ru(CtCRc)(PPh3)2(η-C5Me5) is inclined to less extent
(26.4°) from the plane described above. As the result,
the bridging acetylide moiety in 10 is protected by the
methyl substituents in 2,5-positions of the Rc′-group and
each phenyl group on the P atoms of the dppe ligand.
On the other hand, in the complex, Ru(CtCRc)(PPh3)2(η-
C5Me5), only two phenyl groups of the triphenylphos-
phine ligands take part in the protection of the bridging
acetylide moiety and therefore do not hinder attack of
a reagent. This may account for the increased stability
of the oxidized product of 10 (vide infra).
Crystallographic data for 14 are collected in Table 2,
and selected bond distances and angles are summarized
in Table 3. The ORTEP view of 14 is shown in Figure
2. The geometry around the Ru(II) atom in 14 is a
typical three-legged piano-stool, as seen in 10. The Ru-
C(1) and the C(1)-C(2) distances are nearly the same
with those in complex 10. The plane of the η-C5H4 ring
in the Rc group is inclined by 55.3(2)° from the plane
consisting of the Ru(1) atom, the center of the five-
membered ring of the indenyl ligand, and the C(1) atom.
The angle is similar to that (50.3°) in complex 10, rather
than that of Ru(CtCRc)(PPh3)2(η-C5Me5), suggesting
that the magnitude of the inclination may be due to the
common dppe ligand. The plane consisting of the Ru(1)
(28) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lastra, E. J . Orga-
nomet. Chem. 1994, 474, C27.

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Organometallics, Vol. 18, No. 16, 1999 3213
Ta ble 4. Red ox P oten tia ls of th e Acetylid e
Com p lexes
are shifted to lower potential compared with those of
corresponding reference compounds. In complex 7, for
example, the first (Epa ) -0.01 V) and second oxidation
potentials (Epa ) +0.22 V) are lower by 0.37 and 0.47 V
(∆Epa values) than those of the reference complexes, Ru-
(CtCPh)(PPh3)2(η-C5H5) (Epa ) +0.05 V) and Rc′CtCH
(Epa ) +0.69 V), respectively. The lower potential shift
of the first redox wave is probably due to the raised
HOMO level of the complexes by the electron-donating
effect of the ruthenocenyl group or more reasonably by
the filled/filled interaction between the nonbonding d
orbital of the Ru atoms and the bonding p orbital
(HOMO) of the bridging acetylide function. The latter
interaction was confirmed by photoelectron spectroscopy
in some transition-metal acetylide complexes.32 The
lower potential shift of the second redox wave is
unexpected, because the oxidized Ru(II) moiety in the
acetylide complexes should act as an electron-attracting
group and decrease the electron density of the rutheno-
cenyl moiety through the CtC bond electrostatically
and cause the second redox wave to shift to a higher
potential region, as seen in the case of biferrocene
derivatives.33 The similar large shift of the oxidation
potential to a lower potential region was also observed
in [1.1]ruthenocenophane, which led to the complex
containing a Ru-Ru bond on the oxidation,12c and 1,2-
bis(ruthenocenyl)ethylenes, which are oxidized to pen-
tafulvadiene diruthenium complexes.13 This character-
istic low-potential shift of the second redox wave observed
here suggests that the strong interaction acts between
the two metal sites in the 2 e oxidized species. Thus,
both Ru atoms in the Ru(II) ruthenocenylacetylide
complexes 7-16 are oxidized stepwise by a 1 e process
from Ru(II) to Ru(III) states and then the unpaired
electrons on the two Ru(III) atoms form a pair with
spins coupled through the CtC bond connecting the two
Ru atoms. Such interaction seems to be responsible for
the stabilization of the 2 e oxidized species and may also
cause the reversible 1 e oxidation of the ruthenocenyl
moiety observed in the cyclic voltammograms of the Ru-
(II) acetylide complexes 7-16, owing to the difficulty of
further oxidation of the stabilized 2 e oxidized species.
From Table 4, the following features are also found: (i)
The η-C5Me5 ligand makes the first redox wave shift to
a lower potential region and the second one to a higher
potential region compared with the η-C5H5 ligand, so
that the ∆E1/2 value is increased. (ii) The effect of the
η5-C9H7 ligand is similar to that of the η-C5H5 ligand.
(iii) The methyl substituent in the Rc moiety causes a
shift (∆ ∼ 0.08 V) of the first wave to lower potential.
(iv) The displacement of the PPh3 ligand by the dppe
ligand results in only a slight effect.
complex
E1/2(1)
E1/2(2)
∆E1/2
RcCtCRu(PPh3)2(η-Cp)a
-0.22
-0.34
-0.24
-0.32
-0.41
-0.32
-0.30
-0.40
-0.31
-0.23
-0.39
-0.11
-0.47
-0.39
-0.24
-0.31
-0.42
-0.33
+0.10
+0.16b
+0.09
-0.09
+0.06
-0.05
-0.02
+0.13b
-0.01
+0.05
-0.01
+0.10
-0.11
-0.18
-0.04
-0.10
+0.02b
-0.08
0.32
0.46c
0.33
0.23
0.47
0.27
0.28
0.48c
0.30
0.28
0.38
0.20
0.36
0.21
0.20
0.21
0.38c
0.25
RcCtCRu(PPh3)2(η-Cp*)a
RcCtCRu(PPh3)2(η5-C9H7) (13)
Rc′CtCRu(PPh3)2(η-Cp) (7)
Rc′CtCRu(PPh3)2(η-Cp*) (8)
Rc′CtCRu(PPh3)2(η5-C9H7) (9)
Rc*CtCRu(PPh3)2(η-Cp)a
Rc*CtCRu(PPh3)2(η-Cp*)a
Rc*CtCRu(PPh3)2(η5-C9H7) (14)
RcCtCRu(dppe)(η-Cp)a
RcCtCRu(dppe)(η-Cp*)a
RcCtCRu(dppe)(η5-C9H7) (15)
Rc′CtCRu(dppe)(η-Cp*) (11)
Rc′CtCRu(dppe)(η-Cp) (10)
Rc′CtCRu(dppe)(η5-C9H7) (12)
Rc*CtCRu(dppe)(η-Cp)a
Rc*CtCRu(dppe)(η-Cp*)a
Rc*CtCRu(dppe)(η5-C9H7) (16)
a
b
c
Reference 17. Irreversible, Epa value. Epa(2) - Epa(1). Cf.
PhCtCRu(PPh3)2(η-Cp), E1/2 ) +0.05 V; Rc′CtCH, E1/2 ) 0.59 V.
F igu r e 4. Cyclic voltammogram of complex 11 measured
at a scan rate of 0.10 V/s in the 10-3 M solution in CH2Cl2.
Red ox P r op er ties. The electrochemical properties
of the acetylide complexes prepared were measured by
cyclic voltammetry at the scan rates of 0.025-0.50 V/s.
The data obtained are summarized in Table 4, along
with those from previous work.17 The cyclic voltammo-
gram of complex 11 is given in Figure 4 as a typical
example. As seen clearly in Figure 4 and Table 4, the
Ru(II) ruthenocenylacetylide complexes show two 1 e
quasi-reversible waves, except for a few exceptions.
Each wave was confirmed to be a 1 e process by using
the Randles-Sevcik equation for complex 7 [n ) 0.74
for Epa(1) and n ) 0.71 for Epc(2) when the diffusion
coefficient of 7 was assumed to be similar to that in
ferrocene]. Ruthenocene itself shows a 2 e irreversible
wave at +0.55 V (vs FcH/FcH+) under ordinary condi-
tions,29 although a reversible 1 e redox wave was
observed for decamethylruthenocene30 and octamethyl-
[3]ruthenocenophane14 or when a large counteranion
was used.31 The first and second redox waves are
assigned to the Ru(II) and the ruthenocenyl moieties
by comparison with the redox potentials of Ru(CtCPh)-
Ch em ica l Oxid a tion . Chemical oxidation of the
ruthenium(II) 2,3,4,5-tetramethylruthenocenylacetylide
complexes 7-12 was carried out. In the oxidation of 7
and 11 with excess p-benzoquinone and BF3‚OEt2 in
CH2Cl2 below -80 °C, a deep green solution was
obtained, which changed immediately to a red brown
solution on standing or on warming to -70 °C. Com-
(PPh3)2(η-C5H5) (Epa ) +0.05 V) and RcCtCH (Epa
+0.58 V), respectively. Both the first and second waves
)
(29) (a) Kuwana, T.; Bublitz, D. E.; Hoh, G. J . Am. Chem. Soc. 1960,
82, 5811. (b) Kukharenko, S. V.; Bezrkova, A. A.; Rubezhov, A. Z.;
Strelets, A. Metalloorg. Khim. 1990, 3, 634. (c) Denisovich, L. I.;
Zakurin, N. V.; Bazurukova, A. A.; Gubin, S. P. J . Organomet. Chem.
1974, 81, 207. (d) Gubin, S. P.; Smirnova, L. I.; Denisovich, L. I.;
Lubovich, A. A. J . Organomet. Chem. 1971, 30, 243.
(32) (a) Louwen, J . N.; Hengelmolen, R.; Grove, D. M.; Oskam, A.
Organometallics 1984, 3, 908. (b) Lichtenberger, D. L.; Renshaw, S.
K.; Bullock, R. M. J . Am. Chem. Soc. 1993, 115, 3276.
(30) Ko¨lle, U.; Salzer, A. J . Organomet. Chem. 1983, 243, C27.
(31) Gale, R.; J ob, R. Inorg. Chem. 1981, 20, 42. (b) Hill, M. G.;
Lamanna, W. M.; Mann, K. R. Inorg. Chem. 1991, 30, 4688.
(33) (a) Levanda, C.; Bechgaard, K.; Cowan, D. O. J . Org. Chem.
1976, 41, 2700. (b) Levanda, C.; Bechgaard, K.; Cowan, D. O.; Rausch,
M. D. J . Am. Chem. Soc. 1977, 99, 2964.

3214 Organometallics, Vol. 18, No. 16, 1999
Sato et al.
Sch em e 4
Ta ble 5. 13C NMR Sp ectr a l Da ta for th e 2 e Oxid ized Com p lexes 17, 19, a n d 20
complex
C5Me5
C5Me4
CH2
C5H5
90.32
C5Me4
C5Me5
RuCCC
RuCCC
RuCCC
others
17
- - -
11.58
97.95
11.19
- - -
103.53
- - -
129.99
172.67
134.17,
167.01
315.41
135.04
313.45
132.21,
133.71
311.58
132.84
133.36
134.90
129.71, 132.24
112.08
28.27
94.89
19
20
- - -
11.31
89.50
110.98
103.43
102.73
- - -
116.55
116.48
130.16, 130.25
132.68
132.16,
169.57
132.58,
133.32,
134.33,
10.96
11.32
28.88
111.97
88.75
106.54
129.92, 130.34
plexes 7, 10, and 11 gave the 2 e oxidized complexes
17, 19, and 20 as stable crystalline compounds (Scheme
4) after workup (see Experimental Section). Complexes
containing the indenyl ligand (9) gave a stable but
inseparable mixture. No stable 2 e oxidized complex
could be isolated from the chemical oxidation of com-
315.4 ppm, which is in an intermediate region between
that (325.9-364.5 ppm) of the cationic vinylidene
complexes,34a and that (235.4-296.7 ppm) of the cationic
allenylidene complexes.18,27 The resonance of the phos-
phine ligand in the 31P NMR spectra of 17, 19, and 20
occurs at 42.34, 76.98, and 72.50 ppm, respectively. The
chemical shift in 17 is close to that (40.57 ppm) of
[(η5-C5H5)Ru(µ-η6:η1-C5H4CdCd)Ru(PPh3)2(η5-C5H5)]-
1
plexes 8 and 12. In the H NMR spectra of complexes
17, 19, and 20, the protons of the η-C5H5 ring of the
ruthenocenyl moiety appeared at δ 5.61, 4.90, and 4.92
as singlets, respectively, which are shifted by 1.2-1.5
ppm to lower field than those of the neutral complexes
(7, δ 4.42; 10, δ 3.70; 11, δ 4.40). Also, the proton signals
for the η-C5H5 ligand coordinated to the Ru atom in
complexes 17 and 19 were observed at δ 5.70 and 6.04,
respectively, which showed a low-field shift by ca. 1.3
ppm compared with those of the starting acetylide
complexes (7, δ 4.44; 10, δ 4.75). These results suggest
that the positive charge is localized in both Ru atoms
in these oxidized species. The CdC stretching vibration
in the IR spectra of the oxidized species was observed
at 1816, 1825, and 1803 cm-1 for 17, 19, and 20,
respectively, whose frequencies were intermediate be-
17
(BF4)2 and resembles that (42.75 ppm) of the vinyli-
dene complex [Ru(dCdCHPh)(PPh3)2(η-C5H5)](BF4)2.17
The chemical shifts of 19 and 20 are similar to those in
the cationic vinylidene complex [Ru(dCdCHPh)(dppe)-
(η-C5H5)]PF6 (76.4 ppm)35 and the related cationic
allenylidene complex[Ru(dCdCdCPh2)(dppe)(η5-C9H7)]-
PF6 (81.73 ppm).18a These IR and 13C and 31P NMR data
suggest that the vinylidene- or allenylidene-like struc-
ture occurs in the bridging unsaturated chain of the 2
e oxidized species 17, 19, and 20. In the 13C NMR
spectra of 17, 19, and 20, the signal of the C(γ) atom
appeared at 116.5-130.0 ppm, whose chemical shift is
similar to that of the corresponding C atom of the ful-
vene complexes [Ru(η6-C5Me4CH2)(η5-C5Me5)]PF6 (107.2
ppm)36 and [Ru(η6-C5Me4CH2)(η5-C5H5)]BF4 (108.44
ppm)17 but is much different from that of the cationic
allenylidene complex [Ru(dCdCdCPh2)(PPh3)2(η5-C9H7)]-
PF6 (156.59 ppm).18a The signal of the C(â) atom was
observed at 167.0-172.7 ppm, whose values are in much
higher field than that of the corresponding carbon of
the fulvene complexes [Ru(η6-C5Me4CH2)(η5-C5Me5)]PF6
(77.8 ppm)36 and [Ru(η6-C5Me4CH2)(η5-C5H5)]BF4 (69.4
ppm)17 and in much lower field than that of the cationic
allenylidene complex [Ru(dCdCdCPh2)(PPh3)2(η5-C9H7)]-
PF6 (208.44 ppm)18a and similar to that of the corre-
tween that of the vinylidene complexes (ca. 1650 cm-1 34b
)
and that of the allenylidene complexes (1908-1952
cm-1).18 The 13C NMR data of 17, 19, and 20 are
summarized in Table 5. The most noticeable points are
the chemical shift of the bridging unsaturated carbons.
The resonance of the C(R) atom is observed at 311.6-
(34) (a) Bruce, M. I. Chem. Rev. 1991, 91, 197. (b) Bruce, M. I.;
Wallis, R. C. Aust. J . Chem. 1979, 32, 1471. (c) Lomprey, J . P.; Selegue,
J . P. J . Am. Chem. Soc. 1992, 114, 5518. (d) Touchard, D.; Haquette,
P.; Pilio, N., Toupet, L.; Dixneuf, P. L. Organometallics 1993, 12, 3132.
(e) Le Lagadec, R.; Roman, E.; Toupet, L.; Mu¨ller, U.; Dixneuf, P. H.
Organometallics 1994, 13, 3, 5030. (f) Delos Pios, I.; Tenorio, M. J .;
Ruerta, M. C.; Valerga, P, J . Am. Chem. Soc. 1997, 119, 6529. (g)
Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Borge, J .; Garcia-Granda,
S., Organometallics 1997, 16, 3178. (h) Chang, C.-W.; Lin, Y.-C.; Lee,
G.-H.; Huang, S.-L.; Wang, Y. Organometallics 1998, 17, 2534.
(35) Consiglio, G.; Morandini, F. Inorg. Chimica Acta 1987, 127, 79.
(36) Kreindlin, A. Z.; Petrovskii, M. I.; Rybinskaya, M. I.; Yanovskii,
A. I.; Struchkov, Yu. T. J . Organomet. Chem. 1987, 319, 229.

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Organometallics, Vol. 18, No. 16, 1999 3215
allenylidene complexes (1.878-1.94 Å).18,27 The C(1)-
C(2) distance [1.246(12) Å] is somewhat longer than that
[1.208(6) Å] in the neutral acetylide complex 10, sug-
gesting somewhat loss of the triple bond character. A
similar elongation of the C-C bond was also reported
in the various vinylidene (1.22-1.34 Å)33 and allenyli-
dene complexes (1.23-1.267 Å).18,27 In the oxidation, the
ruthenocenyl part in 10 is transformed to the structure
of the ruthenium(II) fulvene complex in 19. That is, the
η6-C5Me4C moiety of 19 has a similar bond alternation
as can be seen in the cationic fulvene complex [Ru(η5-
C5Me5)(η6-C5Me4CH2)]BPh437 and the fulvene complexes
Ru(η6-C5Me4CH2)(η4-C8H12),38 [RuCl2(η6-C5Me4CH2)]2,39
RuCl(η2-ButNSPh)(η6-C5Me4CH2),40 and Cr(η6-C5H4-
CH2)(CO)3.41 Thus, the C(2)-C(3) distance [1.409(14) Å]
in 19 is shorter than the corresponding distances in 10
[1.425(6) Å]. The C(3)-C(4) [1.468(16) Å] and C(3)-C(7)
distances [1.448(18) Å] are long and the C(4)-C(5)
[1.412(19) Å] and C(6)-C(7) distances [1.401(17) Å] are
short. The Ru(2)-C(3) distance [2.081(10) Å ] proves the
presence of the Ru-C bond, being rather shorter than
that in [Ru(η5-C5Me5)(η6-C5Me4CH2)]BPh4 [2.270(3) Å],37
[RuCl2(η6-C5Me4CH2)]2 [2.268(4) and 2.271(4) Å],39 and
[Ru2(η5-C5Me5)2(µ-η6:η6-C5H4CHCHC5H4)](BF4)2 [aver-
age 2.410 Å].13 The C(1)-C(2)-C(3) angle is no longer
linear [154.0(9)°] because of the Ru(2)-C(3) bond. More-
over, only a slight distortion of the planarity of the C5-
Me4 ring is observed in 19 (the displacement of the C(3)
atom from the C(4)-C(7) plane is not greater than 0.066
Å, the dihedral angle between this and the C(4)C(3)-
C(7) plane being 4.4°), while the C(2)-C(3) bond is bent
by 40.4(10)° from the plane of the η-C5Me4 ring toward
the Ru(1) atom, whose angle is near that in the related
fulvene complexes (35-40°). The tilting angle between
the η-C5Me4 and η-C5H5 rings in the fulvene complex
part of 19 is 13.53(3)°, which is much larger than that
in 10 (1.54°). A similar large tilting angle was also
observed in [Ru2(η5-C5Me5)2(µ-η6:η6-C5H4CHCHC5H4)]-
(BF4)2 (11.29°)13 and the isomorphous Os analog (14°)42
of [Ru(η5-C5Me5)(η6-C5Me4CH2)]BPh4. The η-C5Me4 ring
plane in the fulvene complex part of 19 is inclined by
71.0(2)° from the plane consisting of the Ru(1) atom, the
center of the η-C5H5 ring, and the C(1) atom. This is
considerably larger than that in 10 [50.3(2)°], being
probably because of the steric hindrance due to the
increased tilting in the fulvene complex part.
Ta ble 6. Selected Bon d Dista n ces a n d An gles
for 19
Bond Distances (Å)
Ru(1)-P(1)
Ru(1)-C(1)
Ru(2)-C(3)
Ru(2)-C(5)
C(2)-C(3)
2.317(2)
1.886(8)
2.081(10)
2.240(12)
1.409(14)
2.179(10)
1.448(18)
1.38(2)
Ru(1)-P(2)
Ru(2)-C(2)
Ru(2)-C(4)
Ru(2)-C(6)
C(3)-C(4)
C(1)-C(2)
C(4)-C(5)
C(6)-C(7)
2.343(2)
2.281(9)
2.195(13)
2.246(10)
1.468(16)
1.246(12)
1.412(19)
1.401(17)
Ru(2)-C(7)
C(3)-C(7)
C(5)-C(6)
Ru(2)-C(Cp-ring)
2.188(av)
Bond Angles (deg)
C(1)-C(2)-C(3)
C(1)-Ru(1)-P(1)
P(1)-Ru(1)-P(2)
154.0(9)
86.4(3)
82.9(1)
Ru(1)-C(1)-C(2)
C(1)-Ru(1)-P(2)
173.8(7)
87.5(3)
F igu r e 5. ORTEP view of the cationic part in complex 19.
sponding carbon in the recently reported (cyclohepta-
trienylidene)ethenylidene complex [Ru(dCdCdC7H6)-
(PPh3)2(η-C5H5)]PF6 (168.2 ppm).27 The chemical shift
of the η6-C5Me4 ring carbon (102.8-103.5 ppm in the
3,4-positions and 110.0-112.1 ppm in the 2,5-positions)
in the 2 e oxidized species 17, 19, and 20 closely
resembles those of the fulvene complexes [Ru(η6-C5Me4-
CH2)(η5-C5H5)]BF4 (101.82 and 106.74 ppm).17 It is
evident from these spectral data that the 2 e oxidized
complexes 17, 19, and 20 are the complexes containing
a (cyclopentadienylidene)ethenylidene structure in the
bridging chain, that is, [(η5-C5H5)Ru(µ2-η6:η1-C5Me4Cd
C))RuP 2L](BF4)2 (P 2 ) 2 PPh3 or dppe; L ) η-C5H5 or
η-C5Me5). A similar structure was also proposed for the
2 e oxidized product of RcCtCRu(PPh3)2(η-C5H5), but
it was assigned on the basis of only IR and 1H NMR
spectral data.17
Crystallographic data for 19 are collected in Table 2,
and selected bond distances and angles are summarized
in Table 6. The ORTEP view of the cationic part of 19
is shown in Figure 5. The geometry around the Ru(II)
atom in 19 is a typical three-legged piano-stool config-
uration, as seen in the neutral complex 10. The most
remarkable feature in 19 is the presence of a (tetrameth-
ylcyclopentadienylidene)ethylidene structure in the bridg-
ing ligand. The Ru(1)-C(1) distance is 1.886(8) Å, which
is in the region of the double bond distance between the
Ru and C atoms, and a similar bond distance has been
observed in the various vinylidene (1.76-1.882 Å)33 and
The formation of 17, 19, and 20, having a µ-η6:η1-
[(cyclopentadienylidene)ethylidene]diruthenium struc-
ture, in the 2 e oxidation of the corresponding acetylide
derivatives may be elucidated as follows: In the oxida-
tion process, one electron is first removed from the Ru-
(II) atom of the RuP 2L moiety because of the higher
electron density and then the second electron is removed
from the Ru atom of the ruthenocene moiety. As a
result, a transient Ru(III)/Ru(III) species, which may
(37) Yanovskii, A. I.; Struchkov, Yu. T.; Kreindlin, A. Z.; Rybinskaya,
M. I. J . Organomet. Chem. 1989, 369, 125.
(38) Koelle, U.; Kang, B. S.; Thewalt, U. J . Organomet. Chem. 1990,
386, 267.
(39) Fan, L.; Wei, C.; Aigbirhio, F. I.; Turner, M. L, Gusev, O. V.;
Morozova, L. N.; Knowles, D. R. T.; Maitlis, P. M. Organometallics
1996, 15, 98.
(40) Hankin, D. M.; Danopoulos, A. A.; Wilkinson, G.; Sweet, T. K.
N.; Hursthouse, M. B. J . Chem. Soc., Dalton Trans. 1996, 4063.
(41) Koch O.; Erdmann, F.; Behrens, U. Chem. Ber. 1982, 115, 1313.
(42) Rybinskaya, M. I.; Kreindlin, A. Z.; Struchkov, Yu. T.; Yanovsky,
A. I. J . Organomet. Chem. 1989, 359, 233.

3216 Organometallics, Vol. 18, No. 16, 1999
Sato et al.
ruthenocene (1),48 ethynylruthenocene,49 1-ethynyl-1′,2′,3′,4′,5′-
pentamethylruthenocene,17 RuCl(PPh3)2(η-C5H5),50 RuCl(P-
Ph3)2(η-C5Me5),51 RuCl(PPh3)2(η5-C9H7),52 RuCl(dppe)(η-C5H5),53
RuCl(dppe)(η-C5Me5),54 and RuCl(dppe)(η5-C9H7)52 were pre-
pared according to the literature. 1-Ethynyl-1′,2′,3′,4′,5′-pen-
tamethylruthenocene was also prepared by the Colvin rear-
rangement23 modified by Shioiri22 (vide infra). Other reagents
were used as received from commercial suppliers.
be responsible for the deep green solution observed in
the oxidation at low temperature, results, and the
electronic communication between the two metal sites
accompanied by a chemical process immediately causes
structural rearrangement to the µ-η6:η1-[(cyclopentadi-
enylidene)ethylidene]diruthenium complex. On the other
hand, in the case of the 1′,2′,3′,4′,5′-pentamethylru-
thenocenyl derivative,17 the intramolecular hydrogen
transfer takes place in the transient Ru(III)/Ru(III)
species at first and then the rearrangement to the
fulvene-vinylidene complex follows. The difference
between the two processes seems to depend on the
stability of the µ-η6:η1-[(cyclopentadienylidene)ethylidene]-
diruthenium system. In the 2,3,4,5-tetramethylrutheno-
cenyl series, the two methyl groups next to the cumu-
lative bond of the five-membered ring would act as a
steric protection toward the cumulative bond of the
system. A similar stabilization effect due to the elec-
tronic interaction between two metal sites was observed
in the 2 e oxidation of bis(ruthenocenyl)ethylenes, which
gave (µ-η6:η6-pentafulvadiene)diruthenium complexes,13b
and [1.1]ruthenocenophane, which led to the dicationic
complex containing a Ru-Ru bond.12a Such an interac-
tion is very similar to that in the conversion of butadi-
enediyldiiron complex into a bis(carbene)-type complex
upon 2 e oxidation.43,44 A similar oxidative transforma-
tion accompanied by a structural rearrangement was
also reported in sp-carbon-bridged dirhenium com-
plexes45 and fulvalene-46 and cyclooctatetraene-bridged
dinuclear complexes.47
1-F or m yl-2,3,4,5-tetr a m eth ylr u th en ocen e (2). Activated
MnO2 (Aldrich Inc., 3 g) was added to a solution of 1,2,3,4,5-
pentamethylruthenocene (1) (0.60 g, 2 mmol) in ClCH2CH2Cl
(60 mL). The mixture was refluxed for 2 h. After cooling, the
mixture was filtered and the residue was washed with CH2-
Cl2. The filtrate and the washing were combined and con-
densed under reduced pressure. The residue was chromato-
graphed on alumina with hexane giving the recovered starting
material (1) (0.24 g, 40%). Elution with CH2Cl2 afforded the
title compound (2) which was recrystallized from hexane giving
yellow crystals (0.23 g, 37%). Mp: 151-152 °C. IR (KBr): 1673
1
cm-1. H NMR (CDCl3, 400 MHz): δ 2.01 (s, 6H, â-CH3), 2.18
(s, 6H, R-CH3), 4.35 (s, 5H, Cp), and 10.11 (s, 1H, CHO). 13C
NMR (CDCl3, 100 MHz): δ 11.6 (R-CH3), 12.1 (â-CH3), 73.5
(Cp), 80.0 (ipso-C), 87.3 (R-C), 90.3 (â-C), and 191.7 (CO). Anal.
Calcd for C15H18ORu: C, 57.13; H, 5.75. Found: C, 57.22; H,
5.79.
Elution with CH2Cl2-ethyl acetate (5%) gave 1,2-diformyl-
3,4,5-trimethylruthenocene (3) (23 mg, 7%) as yellow crystals
after recrystallization from CH2Cl2-hexane. Mp: 178.5-179.5
°C. IR (KBr): 1679 and 1730 cm-1 1H NMR (CDCl3, 400
.
MHz): δ 2.08 (s, 3H, â-CH3), 2.28 (s, 6H, R-CH3), 4.55 (s, 5H,
Cp), and 10.30 (s, 2H, CHO). 13C NMR (CDCl3, 100 MHz): δ
11.1 (R-CH3), 12.4 (â-CH3), 74.9 (Cp), 82.0 (ipso-C), 92.3 (R-
C), 94.5 (â-C), and 191.3 (CO). Anal. Calcd for C15H16O2Ru:
C, 54.70; H, 4.90. Found: C, 54.81; H, 4.88.
1-Eth yn yl-2,3,4,5-tetr a m eth ylr u th en ocen e (4) (P r oce-
d u r e A). To a solution of LDA, prepared from diisopropyl-
amine (0.2 mL, 1.3 mmol) and n-BuLi (0.75 mL of 1.5 M
solution in hexane, 1.2 mmol) in THF (8 mL) at 0 °C, was
added trimethylsilyldiazomethane (0.65 mL of 1.9 M solution,
1.2 mmol) at -78 °C under Ar. After the reaction mixture was
stirred for 10 min, a solution of 1 (0.32 g, 1.0 mmol) in THF (2
mL) was added. The solution was sirred for 1 h at the same
temperature and then gently refluxed for 3 h. The solution
was poured into a saturated aqueous solution of NH4Cl (30
mL). The mixture was extracted with diethyl ether. The extract
was washed with water and dried over MgSO4. After evapora-
tion, the residue was chromatographed on SiO2 with elution
of hexane-benzene (2:1) to give 1-ethynyl-2,3,4,5-tetrameth-
ylruthenocene (4) (0.22 g, 71%) as pale yellow crystals. Mp:
77.5-78.5 °C. IR (KBr): 2103 cm-1 (ν(CtC)). 1H NMR (CDCl3,
400 MHz): δ 1.95, (s, 6H, CH3), 2.06, (s, 6H, CH3), 2.87 (s,
1H, tCH), and 4.28 (s, 5H, Cp). 13C NMR (CDCl3, 100 MHz):
δ 12.2 (R-CH3), 12.8 (â-CH3), 68.4 (Ct) 73.3 (Cp), 76.4 (d, t
Exp er im en ta l Section
All reactions were carried out under an atmosphere of N2
and/or Ar, and workups were performed without precaution
to exclude air. NMR spectra were recorded on a Bruker AM400
or ARX400 spectrometer. IR (KBr disk) spectra were recorded
on a Perkin-Elmer System 2000 spectrometer. Cyclic voltam-
metry was carried out by using BAS CV27 in a 10-1 M solution
of n-Bu4NClO4 (polarography grade, Nacalai tesque) in CH2-
Cl2. CV cells were fitted with a glassy carbon (GC) working
electrode, a Pt wire counter electrode and a Ag/Ag+ pseudo
reference electrode. The cyclic voltammograms were obtained
at a scan rate of 0.1 V s-1 in a 10-3 M solution of complexes.
All potentials were represented vs FcH/FcH+, which were
obtained by the subsequent measurement of ferrocene at the
same conditions. Solvents were purified by distillation from
the drying agent prior to use as follows: CH2Cl2 (CaCl2);
ClCH2CH2Cl (CaCl2); CH3CN (CaH2); acetone (CaSO4); THF
(Na-benzophenone); ether (LiAlH4). 1,2,3,4,5-Pentamethyl-
1
CH, J CH ) 247 Hz), 81.9 (ipso-C), 86.3 (R-C), and 87.2 (â-C).
Anal. Calcd for C16H18Ru: C, 61.72; H, 5.83. Found: C, 61.84;
H, 5.83.
Similarly, 1-ethynyl-1′,2′,3′,4′,5′-pentamethylruthenocene17
was also prepared using the procedure described above.
Yield: 70%.
(43) (a) Le Narvor, N.; Lapinte, C. J . Chem. Soc., Chem. Commun.
1993, 357. (b) Le Narvor, N.; Toupet, L.; Lapinte, C. J . Am. Chem.
Soc. 1995, 117, 7, 7129. (c) Le Narvor, N.; Lapinte, C. Organometallics
1995, 14, 634. (d) Coat, F.; Lapinte, C. Organometallics 1996, 15, 477.
(e) Weyland, T.; Lapinte C.; Frapper, G.; Calhorda, M. J .; Halet, J .-F.;
Toupet, L. Organometallics 1997, 16, 2024.
(44) (a) Etzenhouser, B. A.; Cavanaugh, M. D.; Spurgeon, H. N.;
Sponsler, M. B. J . Am. Chem. Soc. 1994, 116, 2221. (b) Etzenhouser,
B. A.; Chen, Q.; Sponsler, M. B. Organometallics 1995, 14, 1920.
(45) (a) Seyler, J . W.; Weng, E.; Zhou, Y.; Gladysz, J . A. Organo-
metallics 1993, 12, 3802. (b) Zhou, Y.; Seyler, J . W.; Weng, E.; Arif, A.
M.; Gladysz, J . A. J . Am. Chem. Soc. 1993, 115, 8509. (c) Brady, M.;
Weng, E.; Gladysz, J . A. J . Chem. Soc., Chem. Commun. 1994, 2655.
(d) Bartik, T.; Bartik, B.; Brady, M.; Dembinski, R.; Gladysz, J . A.
Angew. Chem., Int. Ed. Engl. 1996, 35, 414.
(46) Delville, M.-H.; Lacoste, M.; Astruc, D. J . Am. Chem. Soc. 1992,
114, 8310.
(47) (a) Edwin, J .; Geiger, W. E. J . Am. Chem. Soc. 1990, 112, 7104.
(b) Geiger, W. E.; Salzer, A.; Edwin, J .; von Pillipsborn, W.; Pinatini,
U.; Rheingold, A. L. J . Am. Chem. Soc. 1990, 112, 7113. (c) Chin, T.
T.; Geiger, W. E.; Rheingold, A. L. J . Am. Chem. Soc. 1996, 118, 5002.
1-Eth yn yl-2,3,4,5-tetr a m eth ylr u th en ocen e (4) (P r oce-
d u r e B). A 1.5 M solution of t-BuLi in pentane (1.7 mL, 1.3
(48) Kudinov, A. R.; Rybinskaya, M. I.; Struchkov, Yu. T.; Yanovskii,
A. I.; Petrovskii, P. V. J . Organomet. Chem. 1987, 336, 187.
(49) Hofer, O.; Schlo¨gl, K. J . Organomet. Chem. 1968, 13, 443.
(50) Bruce, M. I.; Windsor, N. J . Aust. J . Chem. 1977, 30, 1601.
(51) Chinn, M. S.; Heinekey, D. M. J . Am. Chem. Soc. 1990, 112,
5166.
(52) Oro, L. A.; Ciriano, M. A.; Campo, M.; Foces-Foces, C.; Cano,
F. H. J . Organomet. Chem. 1985, 289, 117.
(53) Ashby, G. S.; Bruce, M. I.; Tomkins, I. B.; Wallis, R. C. Aust. J .
Chem. 1979, 32, 1003.
(54) Oshima M.; Suzuki, H.; Moro-oka, Y. Chem. Lett. 1984, 1161.

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Organometallics, Vol. 18, No. 16, 1999 3217
mmol) was added dropwise under Ar to a solution of 1,1-
dichloro-2-(2′,3′,4′,5′-tetramethylruthenocenyl)ethylene (5) (0.50
g, 1.3 mmol) cooled below -80 °C. The solution was stirred
for 10 min at that temperature and then warmed to ca. 5 °C
for a period of 1 h. After hydrolysis with a saturated aqueous
solution of NH4Cl, the solution was extracted with ether. The
extract was dried over MgSO4 and then evaporated under
reduced pressure. The residue was chromatographed on SiO2
by elution with hexane-benzene (10:1) to give the title
compound (4) (282 mg, 70%) and 1,4-bis(2′,3′,4′,5′-tetrameth-
ylruthenocenyl)-1,3-butadiyne (6) (86 mg, 19%). Mp: 253-254
°C. IR (KBr): 2137 cm-1 (ν(CtC)). 1H NMR (CDCl3, 400
MHz): δ 1.94, (s, 6H, CH3), 2.03, (s, 6H, CH3), and 4.29 (s,
5H, Cp). 13C NMR (CDCl3, 100 MHz): δ 12.20 (CH3), 12.88
(CH3), 65.26, 67.4, 68.79 (ipso-C, Rc′ CtC, or Rc′ CtC), 73.2
(Cp), 86.24 (R-C), and 87.25 (â-C). Anal. Calcd for C32H34Ru2:
C, 61.92; H, 5.52. Found: C, 61.80; H, 5.80.
was added. After evaporation under reduced pressure, the
residue was chromatographed on Al2O3 deactivated with 5%
H2O by elution with CH2Cl2. The title complex was obtained
as yellow crystals (38 mg, 39%). The product was purified by
SiO2 column chromatography (eluate: benzene) and then
recrystallization from benzene-MeOH to give orange crystals,
mp 141 °C. IR (KBr): 2062 cm-1 (ν(CtC)). 1H NMR (C6D6,
400 MHz): δ 1.40 (s, 15H, CH3), 2.15 (s, 6H, CH3), 2.52 (s,
6H, CH3), 4.60 (s, 5H, Rc), and 6.9-8.1 (bm, 30H, Ph). 13C NMR
(C6D6, 100 MHz): δ 10.00 (CH3 in Cp*), 12.93 (CH3), 14.70
(CH3), 72.61 (η-C5H5 in Rc), 81.48 (ipso-C5Me4), 84.26 (η-C5-
Me4), 86.46 (η-C5Me4), 93.67 (η-C5Me5), 106.26 (Ct), 117.81
2
(t, J CP ) 24.3 Hz, RuCt), 127.01 (p-Ph), 128.48 (bs, m-Ph),
135.38 (bs, o-Ph), and 138.31 (bs, ipso-Ph). 31P NMR (162 MHz,
C6D6): δ 52.72. Anal. Calcd for C62H62P2Ru2‚C6H6: C, 71.06;
H, 5.96. Found: C, 70.89; H, 5.96.
(η-C5H5)Ru (µ-η5,η1-C5Me4CtC)Ru (P P h 3)2(η5-C9H7) (9).
To a solution of 4 (28 mg, 0.09 mmol) and RuCl(PPh3)2(η5-C9H7)
(67.5 mg, 0.09 mmol) in CH2Cl2 (4 mL) and anhydrous MeOH
(2.5 mL) was added NH4PF6 (18 mg, 0.11 mmol) under an
atmosphere of Ar at room temperature. The solution was
stirred for 1 h. After evaporation of the solvent under reduced
pressure, the resulting deep brown residue was chromato-
graphed on Al2O3 deactivated with 5% H2O by elution with
hexane. The title complex was obtained as red crystals (76 mg,
80%), which are recrystallized from CH2Cl2-MeOH. Mp: ∼165
°C dec. IR (KBr): 2075 cm-1 (ν(CtC). 1H NMR (CDCl3, 400
MHz): δ 1.99 (s, 6H, CH3), 2.11 (s, 6H, CH3), 4.00 (s, 5H,
η-C5H5), 4.45 (d, J ) 2.5 Hz, 2H, 1-C9H7), 5.12 (t, J ) 2.5 Hz,
1H, 2-C9H7), 6.44 (dd, J ) 3.0 and 6.3 Hz, 2H, 5-C9H7), 6.74
(dd, J ) 3.0 and 6.3 Hz, 2H, 4-C9H7), and 7.03-7.41 (m, 30H,
Ph). 13C NMR (C6D6, 100 MHz): δ 12.89 (CH3), 14.38 (CH3),
72.69 (η-C5H5), 74.90 (1-C9H7), 80.36 (ipso-C5Me4), 84.11 (C5-
Me4), 86.28 (C5Me4), 95.47 (2-C9H7), 104.01 (t, 2J CP ) 28.3 Hz,
RuCt), 107.22 (Ct), 109.88 (ipso-C9H7), 123.45 (4 or 5-C9H7),
Sometimes, 1-acetyl-2,3,4,5-tetramethylruthenocene was
isolated from the reaction mixture, although in a tiny yield.
Mp: 122-122.5 °C. IR (KBr): 1656 cm-1 (ν CdO). 1H NMR
(CDCl3, 400 MHz): δ 1.99, (s, 6H, CH3), 2.18, (s, 6H, CH3),
2.48 (s, 3H, COCH3), and 4.29 (s, 5H, Cp). 13C NMR (CDCl3,
100 MHz): δ 11.3 (CH3), 13.2 (CH3), 73.0 (Cp), 83.2 (ipso-C),
85.4 (R-C), 88.8 (â-C), and 202.7 (CO). Anal.Calcd for C16H20
ORu: C, 58.34; H, 6.12. Found: C, 58.43; H, 6.07.
-
1,1-Dich lor o-2-(2′,3′,4′,5′-tetr a m eth ylr u th en ocen yl)eth -
ylen e (5). A solution of diethyl(trichloromethyl)phosphonate
(0.24 mL, 1.3 mmol) in anhydrous diethyl ether (1.2 mL) and
THF (1 mL) was chilled below -100 °C. To the solution was
added a solution of n-BuLi (0.45 mL of 1.5 M solution in
hexane, 0.72 mmol), and the resulting solution was stirred for
5 min. A solution of 2 (132 mg, 0.42 mmol) in THF (1 mL) was
added dropwise to the solution. After warming slowly to room
temperature, the solution was refluxed for 1 h and then chilled
at -50 °C, followed by hydrolysis with 2 N H2SO4. The solution
was extracted with diethyl ether. The extract was dried over
MgSO4 and evaporated under reduced pressure. The residue
was chromatographed on SiO2 by elution of hexane to give pale
yellow crystals which were recrystallized from hot hexane (136
3
126.13 (4 or 5-C9H7), 127.38 (t, J CP ) 4.6 Hz, m-Ph), 128.61
2
(p-Ph), 134.60 (t, J CP ) 4.6 Hz, o-Ph), and 138.83 (m, ipso-
Ph). 31P NMR (162 MHz, CD2Cl2): δ 53.36. Anal. Calcd for
C
61H54P2Ru2‚CH3OH: C, 68.75; H, 5.40. Found: C, 68.86; H,
5.19.
(η-C5H5)Ru (µ-η5:η1-C5Me4CtC)Ru (d p p e)(η-C5H5) (10).
mg, 85%). Mp: 68-69 °C. IR (KBr): 1634 cm-1 1H NMR
.
(CDCl3, 400 MHz): δ 1.97, 1.98, (2 × s, 12H, CH3), 4.24 (s,
5H, Cp), and 6.74 (s, 1H, CHd). 13C NMR (CDCl3, 100 MHz):
δ 12.2 (R-CH3), 13.5 (â-CH3), 72.8 (Cp), 82.9 (ipso-C), 84.7 (R-
C), 86.5 (â-C), 127.1 (CH)), and 83.4 (dCCl2). Anal. Calcd for
To a solution of AgBF4 (44 mg, 0.23 mmol) in anhydrous
acetone (10 mL) was added RuCl(dppe)(η-C5H5) (118 mg, 0.20
mmol) under nitrogen bubbling, and then the solution was
stirred for 1 h at room temperature. The resulting precipitate
of AgCl was removed by filtration. To the filtrate was added 4
(59.3 mg, 0.19 mmol) under an atmosphere of nitrogen at room
temperature. The solution was stirred for 1 h. After evapora-
tion of the solvent under reduced pressure, the resulting deep
brown residue was chromatographed on Al2O3 deactivated with
5% H2O by elution with hexane. The title complex was
obtained as deep yellow crystals (80 mg, 48%). Mp: 175 °C
dec. IR (KBr): 2088 cm-1 (ν(CtC)). 1H NMR (CDCl3, 400
MHz): δ 1.44 (s, 6H, CH3), 1.74 (s, 6H, CH3), 2.60 (m, 2H, CH2),
2.86 (m, 2H, CH2), 3.70 (s, 5H, Rc), 4.75 (s, 5H, η-C5H5) and
7.07-8.01 (m, 20H, Ph). 13C NMR (C6D6, 100 MHz): δ 12.74
(CH3), 13.19 (CH3), 28.64 (t, J ) 22.6 Hz), 72.29 (Cp in Rc),
80.27 (ipso-C), 82.98 (Cp), 83.76 (R-C), 85.99 (â-C), 105.48 (Ct
C
16H18Cl2Ru: C, 50.27; H, 4.75. Found: C, 50.39; H, 4.72.
(η-C5H 5)R u (µ-η5:η1-C5Me4CtC)R u (P P h 3)2(η-C5H 5) (7).
To a solution of 1-ethynyl-2,3,4,5-tetramethylruthenocene (4)
(23.3 mg, 0.07 mmol) and RuCl(PPh3)2(η-C5H5) (49.6 mg, 0.07
mmol) in CH2Cl2 (3 mL) and MeOH (1.8 mL) was added NH4-
PF6 (20 mg, 1.6 mmol) under an atmosphere of Ar at room
temperature. The solution was stirred for 1 h. After evapora-
tion of the solvent under reduced pressure, the resulting deep
brown residue was chromatographed on alumina deactivated
with 5% H2O by elution with hexane. The title complex was
obtained as yellow-orange crystals (68 mg, 97%). Mp: 135 °C.
1
IR (KBr): 2081 cm-1 (ν(CtC)). H NMR (C6D6, 400 MHz): δ
2.06 (s, 6H, CH3), 2.37 (s, 6H, CH3), 4.21 (s, 5H, η-C5H5 in Rc′),
4.44 (s, 5H, η-C5H5), and 6.93-7.76 (m, 30H, Ph). 13C NMR
(C6D6, 100 MHz): δ 12.92 (CH3), 14.29 (CH3), 72.60 (η-C5H5
in Rc), 80.67 (ipso-C5Me4), 84.07 (C5Me4), 86.02 (η-C5H5), 86.20
(C5Me4), 105.90 (t, 2J CP ) 25.1 Hz, RuCt), 107.59 (Ct), 127.47
2
3
), 106.45 (t, J CP ) 24.4 Hz, RuCt), 127.92 (t, J CP ) 3.9 Hz,
2
m-Ph), 128.44 (p-Ph), 129.73 (p-Ph), 131.39 (t, J CP ) 5.2 Hz,
o-Ph), 135.46 (t, 2J CP ) 5.4 Hz, o-Ph), 137.70 (m, ipso-Ph), and
134.23 (m, ipso-Ph). 31P NMR (162 MHz, CD2Cl2): δ 87.35.
3
2
(t, J CP ) 4.4 Hz, m-Ph), 128.60 (p-Ph), 134.42 (t, J CP ) 5.1
Hz), and 139.81 (m, ipso-Ph). 31P NMR (162 MHz, CD2Cl2): δ
50.74. Anal. Calcd for C57H52P2Ru2‚CH2Cl2: C, 64.14; H, 5.01.
Found: C, 64.29; H, 5.02.
Anal. Calcd for
Found: C, 63.29; H, 5.26.
C47H46P2Ru2‚CH3OH: C, 63.56; H, 5.56.
(η-C5H5)Ru (µ-η5:η1-C5Me4CtC)Ru (d p p e)(η-C5Me5) (11).
This complex was prepared according with the procedure used
in the preparation of 7, to give yellow crystals (86%). Mp: 195
°C. IR (KBr): 2073 cm-1 (ν(CtC)). 1H NMR (C6D6, 400 MHz):
δ 1.68 (s, 15H, η-C5Me5), 1.91 (s, 6H, Me), 1.95 (s, 6H, Me),
2.15 (m, 2H, CH2), 2.94 (m, 2H, CH2), 4.40 (s, 5H, Rc), and
6.98-7.96 (m, 20H, Ph). 13C NMR (C6D6, 100 MHz): δ 10.44
(η-C5H5)Ru (µ-η5:η1-C5Me4CtC)Ru (P P h 3)2(η-C5Me5) (8).
To a solution of 4 (28 mg, 0.09 mmol) and RuCl(PPh3)2(η5-C5-
Me5) (71.7 mg, 0.09 mmol) in CH2Cl2 (4 mL) and MeOH (2.5
mL) was added NH4PF6 (18 mg, 1.1 mmol) under bubbling of
nitrogen at room temperature. After the solution had been
stirred for 30 min, a 0.1 M solution of KOH in MeOH (1.2 mL)

3218 Organometallics, Vol. 18, No. 16, 1999
Sato et al.
(η-C5Me5), 12.79 (Me), 13.25 (Me), 29.64 (m, CH2), 72.41 (η-
C5H5 in Rc), 81.03 (ipso-C), 83.90 (R-C), 86.15 (â-C), 92.60 (η-
C5Me5), 102.78 (Ct), 119.92 (t, 2J CP ) 25.9 Hz, RuCt), 127.48
CDCl3): δ 86.48. Anal. Calcd for C47H40P2Ru2‚1/2CH3OH: C,
64.47; H, 4.78. Found: C, 64.32; H, 4.83.
(η-C5Me5)Ru (µ-η5,η1-C5H4CtC)Ru (P P h 3)2(η5-C9H7) (15).
This complex was prepared from 1-ethynyl-1′,2′,3′,4′,5′-pen-
tamethylruthenocene and RuCl(PPh3)2(η5-C9H7) according to
the procedure used in preparing 9 and purified by recrystal-
lization from CH2Cl2-MeOH, to give red-orange crystals (60%).
Mp ∼195 °C dec. IR (KBr): 2088 cm-1 (ν(CtC)). 1H NMR
(CDCl3, 400 MHz): δ 2.08 (s, 15H, CH3), 4.02 (s, 4H, η-C5H4),
4.51 (d, J ) 2.7 Hz, 2H, 1-C9H7), 5.41 (t, J ) 2.7 Hz, 1H,
2-C9H7), 6.67 (A2B2 type, 2H, 5-C9H7), 6.74 (A2B2 type, 2H,
4-C9H7), and 7.03-7.26 (m, 30H, Ph). 13C NMR (C6D6, 100
MHz): δ 12.30 (C5Me5), 71.12 (η-C5H4), 74.86 (η-C5H4), 74.78
(1-C9H7), 79.82 (ipso-C5H4), 84.53 (C5Me5), 95.40 (2-C9H7),
3
(t, J CP ) 4.5 Hz, m-Ph), 128.67 (p-Ph), 129.21 (p-Ph), 133.53
2
2
(t, J CP ) 5.1 Hz), 134.73 (t, J CP ) 4.6 Hz), 138.15 (dd, J )
44.0 and 3.0 Hz, ipso-Ph) and 139.75 (dd, J ) 36.4 and 3.0
Hz, ipso-Ph). 31P NMR (162 MHz, CD2Cl2): δ 81.61. Anal.Calcd
for C52H56P2Ru2: C, 66.09; H, 5.97. Found: C, 66.05; H, 5.97.
(η-C5H5)Ru (µ-η5:η1-C5Me4CtC)Ru (d p p e)(η5-C9H7) (12).
To a solution of AgBF4 (21 mg, 0.11 mmol) in anhydrous
acetone (10 mL) was added RuCl(dppe)(η5-C9H7) (59 mg, 0.09
mmol) under nitrogen bubbling, and then the solution was
stirred for 3 min at room temperature. To the resulting deep
green mixture was added 4 (28 mg, 0.09 mmol) under an
atmosphere of nitrogen at room temperature. The solution was
stirred for 10 min. After evaporation of the solvent under
reduced pressure, the resulting brown residue was chromato-
graphed on Al2O3 deactivated with 5% H2O by elution with
CH2Cl2. The title complex was obtained as orange-yellow
crystals (56 mg, 67%). Mp: 222 °C dec. IR (KBr): 2089 cm-1
(ν(CtC)). 1H NMR (C6D6, 400 MHz): δ 1.79,(s, 6H, CH3), 1.91
(s, 6H, CH3), 2.12 (m, 2H, CH2), 2.64 (m, 2H, CH2), 4.03 (s,
5H, η-C5H5), 4.88 (t, J ) 2.5 Hz, 1H, 2-C9H7), 4.88 (d, J ) 2.5
Hz, 1H, 1-C9H7), and 6.96-7.64 (m, 24H, Ph + 4,5-C9H7). 13C
NMR (C6D6, 100 MHz): δ 12.72 (CH3), 13.12 (CH3), 28.58 (t,
J ) 23.1 Hz, CH2), 70.18 (1-C9H7), 72.42 (Cp), 79.87 (ipso-C5-
Me4), 83.80 (C5Me4), 86.01 (C5Me4), 92.62 (2-C9H7), 105.21
2
101.31 (t, J CP ) 25.7 Hz, RuCt), 106.54 (Ct), 109.33 (ipso-
C9H7), 123.16 (4 or 5-C9H7), 125.69 (4 or 5-C9H7), 127.25 (t,
2
3J CP ) 4.5 Hz, m-Ph), 128.54 (p-Ph), 134.60 (t, J CP ) 4.9 Hz,
o-Ph), and 138.72 (m, ipso-Ph). 31P NMR (162 MHz, CDCl3):
δ 50.49. Anal. Calcd for C62H56P2Ru2: C, 69.91; H, 5.30.
Found: C, 69.84; H, 5.26.
(η-C5Me5)Ru (µ-η5:η1-C5H4CtC)Ru (d p p e)(η5-C9H7) (16).
This complex was prepared from 1-ethynyl-1′,2′,3′,4′,5′-pen-
tamethylruthenocene and RuCl(dppe)(η5-C9H7) according to
the procedure described for 12 and purified by recrystallization
from CH2Cl2-MeOH. The title complex was obtained as red-
orange crystals (48%). Mp: ∼170 °C dec. IR (KBr): 2079 cm-1
(ν(CtC)). 1H NMR (C6D6, 400 MHz): δ 1.82 (m, 2H, CH2), 2.00
(s, 15H, η-C5Me5), 2.40 (m, 2H, CH2), 3.82 (t, J ) 1.6 Hz,
â-C5H4), 4.02 (t, J ) 1.6 Hz, R-C5H4), 5.08 (d, J ) 2.6 Hz, 2H,
1-C9H7), 5.25 (t, J ) 2.6 Hz, 1H, 2-C9H7), 6.87 (A2B2 type, 2H,
4- or 5-C9H7), 7.10 (A2B2 type, 2H, 4- or 5-C9H7), and 7.00-
7.62 (m, 20H, Ph). 13C NMR (C6D6, 100 MHz): δ 12.08
(η-C5Me5), 28.21 (t, J ) 23.3 Hz, CH2), 70.16 (1-C9H7), 70.75
(η-C5H4), 75.10 (η-C5H4), 79.70 (ipso-C5H4), 84.30 (η-C5Me5),
2
(Ct), 107.23 (t, J CP ) 25.0 Hz, RuCt), 108.48 (ipso-C9H7),
3
123.91 (4 or 5-C9H7), 124.67 (4 or 5-C9H7), 127.90 (t, J CP
)
)
2
3.7 Hz, m-Ph), 128.71 (p-Ph), 129.71 (p-Ph), 131.75 (t, J CP
2
5.0 Hz, o-Ph), 135.18 (t, J CP ) 5.2 Hz, o-Ph), 136.33 (m, ipso-
Ph), and 143.04 (m, ipso-Ph). 31P NMR (162 MHz, CDCl3): δ
89.08. Anal. Calcd for C51H48P2Ru2‚CH3OH: C, 65.26; H, 5.48.
Found: C, 65.45; H, 5.18.
2
(η-C5H 5)R u (µ-η5,η1-C5H 4CtC)R u (P P h 3)2(η5-C9H 7) (13).
This complex was prepared from ethynylruthenocene and
RuCl(PPh3)2(η5-C9H7) according to the procedure described for
complex 7 and purified by recrystallization from benzene-
pentane, to give red crystals (82%). Mp; 165 °C dec. IR (KBr):
2086 cm-1 (ν(CtC)). 1H NMR (CDCl3, 400 MHz): δ 4.16 (s,
5H, Cp), 4.38 (t, J ) 1.6 Hz, 2H, C5H4), 4.49 (d, J ) 2.5 Hz,
2H, 1-C9H7), 4.57 (t, J ) 1.6 Hz, 2H, C5H4), 5.35 (t, J ) 2.5
Hz, 1H, 2-C9H7), 6.10 (dd, J ) 3.0 and 6.3 Hz, 2H, 5-C9H7),
6.68 (dd, J ) 3.0 and 6.3 Hz, 2H, 4-C9H7), and 7.00-7.35 (m,
30H, Ph). 13C NMR (C6D6, 100 MHz): δ 68.74 (C5H4), 71.02
(Cp), 73.10 (C5H4), 74.80 (1-C9H7), 80.7 (ipso-C5H4), 95.49 (2-
92.62 (2-C9H7), 104.16 (Ct), 103.83 (t, J CP ) 25.5 Hz, RuCt
), 107.89 (ipso-C9H7), 123.74 (4 or 5-C9H7), 124.24 (4 or 5-C9H7),
3
127.52 (t, J CP ) 5.0 Hz, m-Ph), 128.88 (p-Ph), 129.36 (p-Ph),
132.26 (t, 2J CP ) 5.0 Hz, o-Ph), 134.48 (t, 2J CP ) 5.0 Hz, o-Ph),
137.11 (m, ipso-Ph), and 141.85 (m, ipso-Ph). 31P NMR (162
MHz, CDCl3): δ 87.52. Anal. Calcd for C52H50P2Ru2: C, 66.51;
H, 5.37. Found: C, 66.12; H, 5.31.
[(η-C5H5)Ru(µ-η6:η1-C5Me4CdCd)Ru(P P h3)2(η-C5H5)](BF4)2
(17). A solution of complex 7 (30 mg, 0.03 mmol) and p-
benzoquinone (5.5 mg, 0.05 mmol) in CH2Cl2 (3 mL) was chilled
below -80 °C. To the solution was added BF3‚OEt2 (0.1 mL).
The color of the solution turned orange to deep green and then
to reddish brown as the reaction temperature rose. At -40
°C, anhydrous diethyl ether (4 mL) was added, and then the
mixture was allowed to warm to room temperature. The upper
solution was removed by syringe, and the oily crystals remain-
ing were washed with diethyl ether. The residues were
dissolved in dry CH2Cl2 (8 mL). The solution was diluted with
diethyl ether (8 mL) and then kept in a freezer. The title
complex was obtained as dark brown needles (28 mg, 79%).
2
C9H7), 102.80 (t, J CP ) 25.6 Hz, RuCt), 106.55 (Ct), 109.34
(ipso-C9H7), 122.99 (4 or 5-C9H7), 125.90 (4 or 5-C9H7), 127.36
3
2
(t, J CP ) 4.5 Hz, m-Ph), 128.60 (p-Ph), 134.61 (t, J CP ) 4.8
Hz, o-Ph), and 138.74 (m, ipso-Ph). 31P NMR (162 MHz, CD2-
Cl2): δ 51.34. Anal. Calcd for C57H46P2Ru2‚2C6H6: C, 71.98;
H, 5.08. Found: C, 71.64; H, 5.05.
(η-C5H5)Ru (µ-η5:η1-C5H4CtC)Ru (dppe)(η5-C9H7) (14). This
complex was prepared from ethynylruthenocene and RuCl-
(dppe)(η5-C9H7) according to the procedure described for
complex 12 and purified by recrystallization from CH2Cl2-
MeOH. The title complex was obtained as red-orange crystals
Mp: 169 °C dec. IR (KBr): 1816 cm-1 1H NMR (400 MHz,
.
acetone-d6): δ 2.10 (s, 6H, CH3), 2.28 (s, 6H, CH3), 5.61 (s,
5H, η-C5H5 in Rc), 5.70 (s, 5H, η-C5H5), and 7.18-7.52 (m, 30H,
Ph). 13C NMR (100 MHz, acetone-d6): δ 11.58 (CH3), 90.32 (η-
C5H5), 97.95 (η-C5H5), 103.53 (η-C5Me4), 112.08 (η-C5Me4),
129.71 (t, J ) 5.1 Hz, m-Ph), 129.99 (ipso-C5Me4), 132.24 (p-
Ph), 134.17 (t, J ) 5.4 Hz, o-Ph), 135.04 (m, ipso-Ph), 172.67
(RuCCC), and 315.41 (t, J ) 15.2 Hz, RuCCC). 31P NMR (162
MHz, acetone-d6): δ 42.34. Anal. Calcd for C57H52B2F8P2Ru2‚1/
2CH2Cl2: C, 56.74; H, 4.39. Found: C, 56.53; H, 4.51.
[(η-C5H5)Ru(µ-η6:η1-C5Me4CdCd)Ru(dppe)(η-C5H5)](BF4)2
(19). This complex was prepared from 10 according to the
above procedure, yielding dark brown needles (81%). Mp: 180
°C dec. IR (KBr): 1825 cm-1. 1H NMR (400 MHz, acetone-d6):
δ 1.71 (s, 6H, CH3), 2.07 (s, 6H, CH3), 3.31 (m, 4H, PCH2),
4.90 (s, 5H, η-C5H5 in Rc), 6.04 (s, 5H, η-C5H5), and 7.39-7.87
(m, 20H, Ph). 13C NMR (100 MHz, acetone-d6): δ 11.19 (CH3),
1
(52 mg, 66%). Mp 232 °C. IR (KBr): 2070 cm-1 (ν(CtC)). H
NMR (CDCl3, 400 MHz): δ 2.09 (m, 2H, CH2), 2.48 (m, 2H,
CH2), 3.99 (t, J ) 1.6 Hz, â-C5H4), 4.11 (s, 5H, η-C5H5), 4.14
(t, J ) 1.6 Hz, R-C5H4), 4.99 (d, J ) 2.6 Hz, 1H, 1-C9H7), 5.18
(t, J ) 2.6 Hz, 1H, 2-C9H7), 6.89 (A2B2 type, 2H, 4-or 5-C9H7),
6.98 (A2B2 type, 2H, 4-or 5-C9H7), and 7.07-7.52 (m, 20H, Ph).
13C NMR (C6D6, 100 MHz): δ 28.30 (t, J ) 23.4 Hz, CH2), 68.69
(η-C5H4), 69.64 (1-C9H7), 70.71 (η-C5H5), 73.00 (η-C5H4), 79.65
(ipso-C5H4), 92.43 (2-C9H7), 104.64 (Ct), 106.65 (t, 2J CP ) 26.0
Hz, RuCt), 107.91 (ipso-C9H7), 123.76 (4 or 5-C9H7), 124.31
3
3
(4 or 5-C9H7), 127.60 (t, J CP ) 5.0 Hz, m-Ph), 127.84 (t, J CP
2
) 4.3 Hz, m-Ph), 128.99 (p-Ph), 129.48 (p-Ph), 132.30 (t, J CP
2
) 5.2 Hz, o-Ph), 134.45 (t, J CP ) 5.0 Hz, o-Ph), 136.91 (m,
ipso-Ph) and 141.68 (m, ipso-Ph). 31P NMR (162 MHz,

Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide
Organometallics, Vol. 18, No. 16, 1999 3219
11.31 (CH3), 28.07 (m, PCH2), 89.50 (η-C5H5), 94.89 (η-C5H5),
103.43 (η-C5Me4), 110.98 (η-C5Me4), 116.55 (ipso-C5Me4), 130.16
(d, J ) 5.1 Hz, m-Ph), 130.25 (d, J ) 4.9 Hz, m-Ph), 132.21
(p-Ph), 132.16 (d, J ) 5.7 Hz, o-Ph), 132.68 (p-Ph), 133.71 (d,
J ) 5.4 Hz, o-Ph), 167.01 (RuCC), and 313.45 (t, J ) 16.7 Hz,
RuCC). No signal was observed for ipso-Ph. 31P NMR (162
MHz, acetone-d6): δ 76.98. Anal. Calcd for C47H46B2F8P2Ru2:
C, 53.84; H, 4.42. Found: C, 53.63; H, 4.41.
squares procedure. Absorption correction with the ψ-scan
method and anisotropic refinement for non-hydrogen atoms
were carried out. Data collections of crystal data for 10, 14,
and 19 were performed at room temperature by the Weissen-
berg method on a Mac Science DIP3000 image processor with
graphite-monochromated Mo KR radiation and an 18-kW
rotating anode generator. The structures were solved with the
Dirdif-Patty or SIR method in Crystan-G (software-package
for structure determination) and refined finally by a full-
matrix least-squares procedure. Absorption correction with the
Difab method and anisotropic refinement for non-hydrogen
atoms were carried out. The hydrogen atoms, located from
difference Fourier maps or calculation, were isotopically
refined.
[(η-C5H 5)R u (µ-η6:η1-C5Me4CdCd)R u (d p p e)(η-C5Me5)]
(BF 4)2 (20). This complex was prepared from 11 according to
the procedure described for complex 17. The complex was
recrystallized from acetone/diethyl ether, to give dark brown
needles (70%). Mp: 207 °C dec. IR (KBr): 1803 cm-1. 1H NMR
(400 MHz, acetone-d6): δ 1.76 (s, 6H, CH3), 1.84 (s, 15H,
η-C5Me5), 2.07 (s, 6H, CH3), 3.00 (m, 2H, PCH2), 3.22 (s, 2H,
PCH2), 4.92 (s, 5H, η-C5H5 in Rc), and 7.19-7.72 (m, 20H, Ph).
13C NMR (100 MHz, acetone-d6): δ 10.96 (CH3), 11.32 (CH3),
28.88 (m, PCH2), 88.75 (η-C5H5), 102.73 (η-C5Me4), 106.54 (η-
C5Me5), 111.97 (η-C5Me4), 116.48 (ipso-C5Me4), 129.92 (d, J )
10.0 Hz, m-Ph), 130.34 (d, J ) 10.0 Hz, m-Ph), 132.58 (p-Ph),
132.84 (p-Ph), 133.32 (d, J ) 10.0 Hz, o-Ph), 133.36 (d, J )
10.0 Hz, o-Ph), 134.33 (m, ipso-Ph), 134.90 (m, ipso-Ph), 169.57
(RuCC), and 311.58 (t, J ) 16.0 Hz, RuCC). 31P NMR (162
MHz, acetone-d6): δ 72.50. Anal. Calcd for C52H56B2F8P2Ru2:
C, 55.82; H, 5.05. Found: C, 56.10; H, 5.18.
Str u ctu r e Deter m in a tion . The crystallographic data are
listed in Table 1 for 9, 10, 14, and 19. Data collection for 9
was performed at room temperature on a Mac Science MXC18K
diffractometer with graphite-monochromated Mo KR radiation
and an 18-kW rotating anode generator. The structure was
solved with the SIR method in CRYSTAN-G (software package
for structure determination) and refined by a full-matrix least-
Ack n ow led gm en t. The present work was supported
by a Grant-in Aid for Science Research (No. 10640538)
from the Ministry of Education, Science, and Culture
of J apan. We thank Dr. Akiko Nakano at Mac Science
Co., Ltd. for some valuable advice in the structural
analysis of complex 19.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic data, fractional atomic coordinates, anisotropic
thermal parameters, interatomic distances, bond angles, and
least-squares planes and ORTEP drwawings showing the
complete numbering system for complexes 9, 10, 14, and 19.
This material is available free of charge via the Internet at
http://pubs.acs.org.
OM990138U