Novel structural rearrangements induced by metal-metal interactions in ruthenium(II) ruthenocenyl- and (pentamethylruthenocenyl)acetylide complexes, RcC≡CRuL2(η5-C5R5) and Rc′C≡CRuL2(η5-C5R5)

Article abstract of DOI:10.1021/om960732t

The reaction of RcC≡CH [Rc = (η⁵-C₅H₅)Ru(η⁵-C ₅H₄)] with RuCIL₂(η⁵-C₅R₅) [R = H or Me; L₂ = 2PPh₃ or Ph₂PCH₂CH₂PPh₂ (dppe)] in the presence of NH₄PF₆ and subsequent treatment with base gave Ru(II) ruthenocenylacetylide complexes RcC≡CRuL₂(η⁵-C₅R₅) in good yields. In a similar manner, the pentamethylruthenocene analogues, Rc′C≡CRuL₂(η⁵-C₅R₅) [Rc′ = (η⁵-C₅Me₅)Ru(η⁵-C ₅H₄)], were also prepared. Cyclic voltammograms of the complexes showed two reversible one-electron-oxidation processes, consisting of the processes [Ru(II)Ru′(II] to [Ru(III)Ru′(II] and then to [Ru(III)Ru′(III)]. Chemical oxidation of the complexes induced novel structural rearrangement. The two-electron oxidation of complex RcC≡CRu(PPh₃)₂(η⁵-C₅H ₅) afforded a kind of allenylidene complex, a cyclopentadienyl-idenethylidene complex, [(η⁵-C₅H₅)Ru{μ-η ⁶:η¹-C₅H₄C=C}Ru(PPh ₃)₂(η⁵-C₅H₅)] ²⁺, in 90percent yield. The one-electron oxidation of Rc′C≡CRu(PPh₃)₂(η⁵-C ₅H₅) gave the vinylidene complex (Rc′CH=C)Ru(PPh₃)₂(η⁵-C ₅H₅) in 62percent yield, while the two-electron oxidation led to the fulvene-vinylidene complex [(η⁶-C₅Me₄CH₂)Ru{μ-η ⁵:η¹-C₅H₄CH=C}Ru(PPh ₃)₂(η⁵-C₅R₅)] ²⁺ by an intramolecular hydrogen transfer in 59percent yield.

Full text of DOI:10.1021/om960732t

Organometallics 1997, 16, 1693-1701
1693
Novel Str u ctu r a l Rea r r a n gem en ts In d u ced by
Meta l-Meta l In ter a ction s in Ru th en iu m (II)
Ru th en ocen yl- a n d (P en ta m eth ylr u th en ocen yl)a cetylid e
Com p lexes, RcCtCRu L2(η5-C5R5) a n d
Rc′CtCRu L2(η5-C5R5) [Rc ) Ru th en ocen yl, Rc′ )
P en ta m eth ylr u th en ocen yl, L2 ) 2P P h 3 or
P h 2P CH2CH2P P h 2 (d p p e), R ) H or Me]
Masaru Sato,* Yasushi Kawata, and Hitoshi Shintate
Chemical Analysis Center, Saitama University, Urawa, Saitama 338, J apan
Yoichi Habata and Sadatoshi Akabori
Department of Chemistry, Faculty of Science, Toho University, Funabashi, Chiba 274, J apan
Kei Unoura
Department of Chemistry, Faculty of Science, Yamagata University, Kojirakawa-machi,
Yamagata 990, J apan
Received August 26, 1996X
The reaction of RcCtCH [Rc ) (η5-C5H5)Ru(η5-C5H4)] with RuClL2(η5-C5R5) [R ) H or
Me; L2 ) 2PPh3 or Ph2PCH2CH2PPh2 (dppe)] in the presence of NH4PF6 and subsequent
treatment with base gave Ru(II) ruthenocenylacetylide complexes RcCtCRuL2(η5-C5R5) in
good yields. In a similar manner, the pentamethylruthenocene analogues, Rc′CtCRuL2(η5-
C5R5) [Rc′ ) (η5-C5Me5)Ru(η5-C5H4)], were also prepared. Cyclic voltammograms of the
complexes showed two reversible one-electron-oxidation processes, consisting of the processes
[Ru(II)Ru′(II)] to [Ru(III)Ru′(II)] and then to [Ru(III)Ru′(III)]. Chemical oxidation of the
complexes induced novel structural rearrangement. The two-electron oxidation of complex
RcCtCRu(PPh3)2(η5-C5H5) afforded a kind of allenylidene complex, a cyclopentadienyl-
idenethylidene complex, [(η5-C5H5)Ru{µ-η6:η1-C5H4CdC}Ru(PPh3)2(η5-C5H5)]2+, in 90% yield.
The one-electron oxidation of Rc′CtCRu(PPh3)2(η5-C5H5) gave the vinylidene complex
(Rc′CHdC)Ru(PPh3)2(η5-C5H5) in 62% yield, while the two-electron oxidation led to the
fulvene-vinylidene complex [(η6-C5Me4CH2)Ru{µ-η5:η1-C5H4CHdC}Ru(PPh3)2(η5-C5R5)]2+ by
an intramolecular hydrogen transfer in 59% yield.
In tr od u ction
reversible two-electron-oxidation process, and there is
difficulty in understanding the process.
Both fundamental and applied attention has been
attracted to binuclear complexes containing different
redox sites in close proximity.1 These have the potential
of possessing unique physical properties which are
characteristic of one particular compound, rather than
a sum of the properties of the individual redox sites,
and of contributing to the understanding of biologically
relevant mixed-valence compounds.2 Because of the
well-defined and stable one-electron redox system, fer-
rocene has been recognized as a good trigger and
terminus for electronically switched phenomena.3 Thus,
oxidized species of binuclear ferrocene derivatives have
been extensively investigated in relation to the mixed-
valence state.4-8 However, there have been relatively
few reports about the oxidized species of ruthenocene
derivatives,9-14 because ruthenocene exhibits an ir-
We have been intensively attracted to heterobinuclear
mixed-valence compounds containing ferrocene as a part
of redox centers and have demonstrated new electron
delocalization systems and novel reactions of ferrocen-
ylacetylide complexes of various transition metals.15 In
(4) (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.
(5) (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.
(6) (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. (c) Powers, M. J .; Meyer, T. J . J . Am. Chem. Soc. 1978, 100,
4393.
(7) Amer, S. I.; Sadler, G.; Henry, P. M.; Ferguson, G.; Ruhl, B. L.
Inorg. Chem. 1985, 24, 1517.
X Abstract published in Advance ACS Abstracts, March 15, 1997.
(1) Astruc, D. Electron Transfer and Radical Processes in Transition-
metal Chemistry; VCH Publishers, Inc.: New York, 1995.
(2) Brown, D. B., Ed. Mixed-Valence Compounds; D. Reidel Publish-
ing Company: Dordrecht, Holland, 1980.
(8) Lee, M.-T.; Foxman, B. M.; Rosenblum, M. Organometallics 1985,
4, 539.
(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.
(3) Togni, A.; Hayashi, T. Ferrocenes; VCH Publishers, Inc.: New
York, 1995.
S0276-7333(96)00732-7 CCC: $14.00 © 1997 American Chemical Society

1694 Organometallics, Vol. 16, No. 8, 1997
Sato et al.
Sch em e 1
Sch em e 2
order to extend our previous results concerning ferro-
cenylacetylide complexes to ruthenocenyl derivatives,
we report here syntheses, electrochemistry, and oxida-
tion of ruthenium(II) ruthenocenylacetylides and (pen-
tamethylruthenocenyl)acetylides.
(dppe)(η5-C5H5) (4) could not be obtained under similar
conditions, because RuCl(dppe)(η5-C5H5) was inert to
metathesis with NH4PF6. Therefore, complex 1 was
allowed to react with the solution prepared from RuCl-
(dppe)(η5-C5H5) and AgBF4 in acetone and then the
reaction mixture was treated as described above to give
4 in 68% yield (Scheme 1).
Resu lts a n d Discu ssion
Pentamethylruthenocene (Rc′H) [Rc′ ) (η5-C5Me5)Ru-
(η5-C5H4)] was reated with CH3COCl-AlCl3 in refluxed
1,2-dichloroethane for 3 h to give 1-acetyl-1′,2′,3′,4′,5′-
pentamethylruthenocene (7) and 1,2-diacetyl-1′,2′,3′,4′,5′-
pentamethylruthenocene (8) in 68 and 4% yields, re-
spectively, along with the recovery of the starting
material (28%). The reaction of 7 with DMF/POCl3 gave
1-(R-chloro-â-formylvinyl)-1′,2′,3′,4′,5′-pentamethylru-
thenocene (9) in 92% yield as orange-red crystals.
Complex 9 was refluxed with a mixture of 0.5 N NaOH
aqueous solution and dioxane for 1.5 h to give (penta-
methylruthenocenyl)acetylene (1-ethynyl-1′,2′,3′,4′,5′-
pentamethylruthenocene), Rc′CtCH (2), in 91% yield
as pale yellow crystals (Scheme 2). Rc′CtCRu(PPh3)2-
(η5-C5H5) (10), Rc′CtCRu(PPh3)2(η5-C5Me5) (12), and
Rc′CtCRu(dppe)(η5-C5Me5) (13) were prepared from 2
and the corresponding chlororuthenium complexes in
78, 49, and 82% yields, respectively, by following a
procedure similar to that for 3. Rc′CtCRu(dppe)(η5-
C5H5) (11) was obtained in 77% yield by the method
used in the synthesis of 4 (Scheme 1). For complex 4,
the CtC stretching vibration was observed at 2080 cm-1
in the IR spectrum, and the ring protons of the rutheno-
cenyl group were observed at δ 4.02 (2H), 4.11 (5H), and
4.14 (2H), the methylene protons of dppe at δ 2.31 (2H)
and 2.67 (2H), the protons of the cyclopentadienyl (Cp)
ring of the Ru(dppe)(η5-C5H5) part at δ 4.71 (5H), and
the phenyl protons of dppe at δ 7.22-7.92 (20H) in the
1H NMR spectrum. The 13C NMR spectrum of 5
Syn th esis. Ruthenocenylacetylene, RcCtCH (1) [Rc
) (η5-C5H5)Ru(η5-C5H4)], reacted with RuCl(PPh3)2(η5-
C5H5) in the presence of NH4PF6 in CH2Cl2/MeOH at
room temperature, and the reaction mixture, after
evaporation, was directly chromatographed on basic
alumina to give RcCtCRu(PPh3)2(η5-C5H5) (3) as yellow
crystals in 94% yield. In a similar manner, RcCtCRu-
(PPh3)2(η5-C5Me5) (5) and RcCtCRu(dppe)(η5-C5Me5) (6)
[dppe ) 1,2-bis(diphenylphosphino)ethane] were pre-
pared in 40 and 78% yields, respectively. RcCtCRu-
(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) 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-
Westerhoff, U. T.; Rheingold, A. L.; Swiegers, G. F. Angew. Chem.,
Int. Ed. Engl. 1992, 31, 1352.
(13) Sato, M.; Kudo, A.; Kawata, Y.; Saitoh, H. J . Chem. Soc., Chem.
Commun. 1996, 25.
(14) Hashidzume, K.; Tobita, H.; Ogino, H. Organometallics 1995,
14, 1187.
(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.; Kumakura, S. Organometallics 1995,
14, 3157. (d) Sato, M.; Mogi, E. Organometallics 1995, 14, 4837. (e)
Sato, M.; Hayashi, Y.; Kumakura, S.; Shimizu, N.; Katada, M.; Kawata,
S. Organometallics 1996, 15, 721. (f) Sato, M.; Mogi, E. J . Organomet.
Chem. 1996, 517, 1.

Ru(II) (Ruthenocenyl)acetylide Complexes
Organometallics, Vol. 16, No. 8, 1997 1695
Ta ble 2. Selected Bon d Dista n ces a n d An gles
for 5
Bond Distances (Å)
Ru(1)-P(1)
Ru(1)-C(1)
C(2)-C(11)
Ru(2)-Cp (av)
Cp* ring (av)
2.319(3)
2.019(9)
1.45(1)
2.16
Ru(1)-P(2)
C(1)-C(2)
2.309(2)
1.21(1)
2.27
Ru(1)-Cp* (av)a
Cp ring (av)
1.40
1.42
Bond Angles (deg)
P(1)-Ru(1)-P(2)
P(2)-Ru(1)-C(1)
C(1)-C(2)-C(11)
99.15(9)
86.2(2)
170(1)
P(1)-Ru(1)-C(1)
Ru(1)-C(1)-C(2)
85.6(2)
176.3(8)
a
Cp* ) ring carbon.
Ta ble 3. Oxid a tion P oten tia lsa of Ru (II) Acetylid e
Com p lexes a n d Rela ted Com p ou n d s
E1°′
E2°′
i1pc
/
i2pc/
complex
(E1pa - E1pc
)
(E2pa - E2pc
)
i1pa
i2pa
1
2
3
4
5
6
10
11
12
13
14
15
17
+0.58b,c
+0.38b,c
-0.22 (120 mV) +0.10 (130 mV)
e
e
e
e
-0.23 (100)
-0.20 (100)
-0.39 (110)
-0.30 (110)
-0.31 (110)
-0.40 (100)
-0.42 (110)
+0.05b
+0.05 (110)
F igu r e 1. Molecular structure of 5.
+0.48b
0.98
1.0
e
-0.01 (120)
-0.02 (110)
-0.10 (115)
+0.13b
1.0
e
e
Ta ble 1. Cr ysta l a n d In ten sity Collection
Da ta for 5
e
0.72
0.45
mol formula
mol wt
cryst syst
space group
a, Å
C58H54P2Ru2
1015.15
+0.02b
monoclinic
P21/n (No. 14)
12.872(2)
17.614(2)
20.590(4)
90.23(1)
4668(1)
4
1.444
-0.26 (110)
+0.26b,c
RCtC[Ru]d
R ) n-Bu
b, Å
c, Å
-0.03b
-0.03b
R ) n-Hex
â, deg
R ) CO2Me +0.32b
V, Å3
V vs FcH0/+ and Epa - Epc ) 90 mV. Epa due to irreversible
a
b
Z
D
calc, g cm-3
oxidation. c Two-electron process. [Ru] ) Ru(PPh3)2(η5-C5H5).
e It could not be calculated because E1 and E2 were too close to
each other to obtain an accurate base line.
d
cryst dimens, mm
linear abs coeff, cm-1
radiation (λ, Å)
2θ range, deg
scan type
total no. of rflns measd
no. of unique rflns
no. of rflns used in least squares
no. of variables
0.400 × 0.200 × 0.200
3.7
Mo KR (0.710 73)
28.83-29.47
ω-2θ
1.43 ( 0.02 Å and the Ru-C distances average 2.21 (
0.03 Å in ruthenocene).16 The Ru-C(1) distance [2.019-
(9) Å] and the C(1)-C(2) distance [1.21(1) Å] are similar
to those [2.02(1) and 1.20(1) Å] in (η5-C5H5)(PPh3)2Ru-
{CtCC(OCOCF3)dCMe2}17 and those [2.009(3) and
1.204(5) Å] in (η5-C5H5)(dppe)Ru(CtCPh),18 respec-
tively.
8926
8521 (Rint ) 0.061)
3740 [I > 3.00σ(I)]
613
0.046
0.037
0.51
-0.44
R
Rw
max peak in final Fourier map, e Å-3
min pea, in final Fourier map, e Å-3
Cyclic Volta m m etr y. The cyclic voltammograms of
complexes 3-6, 10-13, and related complexes were
measured in a solution of 0.1 M n-Bu4NClO4 in CH2Cl2
at a glassy carbon electrode and a sweep rate of 0.1 V
s-1. The redox potentials are summarized in Table 3.
The cyclic voltammogram of 10 is shown in Figure 2 as
a typical example. In comparison with the reference
complexes RcCtCH or Rc′CtCH and Ru(CtCPh)-
(PPh3)2(η5-C5H5) (14) or Ru(CtCPh)(PPh3)2(η5-C5Me5)
(15), the first oxidation wave was assigned to the Ru-
(PPh3)2(η5-C5H5) or Ru(PPh3)2(η5-C5Me5) part and the
second oxidation wave to the Rc or Rc′ part. It was
confirmed by thin-layer coulometry that the first and
second oxidation waves in 3 consist of one-electron-
transfer processes, respectively. That is, the first wave
was observed by thin-layer coulometry to be n ) 0.80 (
0.03 and the first and second waves amounted to n )
1.82 ( 0.08. One of the most characteristic points is
exhibited the acetylenic carbons at δ 104.30 and 107.58,
the latter signal being assigned to the carbon atom
connected directly to the Ru atom of the Ru(dppe)(η5-
C5H5) moiety because it was accompanied by coupling
with the phosphorus atoms (2J PC ) 25.4 Hz).
X-r a y Str u ctu r e of Com p lex 5. A single-crystal
X-ray analysis confirmed the structure of complex 5. The
crystallographic data are listed in Table 1. The ORTEP
view of 5 is shown in Figure 1, along with selected
numbering of the atoms. Selected bond distances and
angles are summarized in Table 2. The geometry
around the Ru atom is a typical three-leg piano-stool
configuration although with somewhat of a strain. The
angle P(1)-Ru(1)-P(2) [99.15(9)°] is larger than P(1)-
Ru(1)-C(1) [85.6(2)°] and P(2)-Ru(1)-C(1) [86.2(2)°],
probably because of the steric repulsion between the
triphenylphosphine ligands. The acetylide ligand is
nearly linear [Ru(1)-C(1)-C(2), 176.3(8)°, and C(1)-
C(2)-C(11), 170(1)°]. The C-C distances (average 1.40
Å) and the Ru-C distances (average 2.16 Å) of the
ruthenocenyl moiety are normal (the C-C distances are
(16) Hardgrove, G. L.; Templeton, D. H. Acta Crystallogr. 1959, 12,
28.
(17) Lomprey, J . R.; Selegue, J . P. Organometallics 1993, 12, 616.
(18) Bruce, M. I.; Humphrey, M. G.; Show, M. R.; Tiekink, E. R. T.
J . Organomet. Chem. 1986, 314, 213.

1696 Organometallics, Vol. 16, No. 8, 1997
Sato et al.
oxidation waves and the stabilization of the two-electron-
oxidized species of complexes 3-6 and 10-13. This
effect also seems to be responsible for the one-electron
oxidation observed in the cyclic voltammogram of the
Rc or Rc′ part in complexes 3-6 and 10-13, because
the stabilization of two-electron-oxidized species (one-
electron oxidation per one Ru atom) makes their further
oxidation difficult.
Ch em ica l Oxid a tion . Complex 3 was oxidized with
1 equiv of AgBF4 in CH2Cl2 at -78 °C to give complex
16 as a yellow-brown powder in ca. 50% yield. Complex
16 is considered to be a diamagnetic two-electron-
oxidized species, because 16 showed sharp signals in
F igu r e 2. Cyclic voltammogram of 10.
that the Rc or Rc′ moiety in complexes 3-6 and 10-13
displayed a reversible one-electron-oxidation process
under conditions using Bu4NClO4 as the supporting
electrolyte. Generally, ruthenocene derivatives have
been known to undergo an irreversible two-electron
process when conventional supporting electrolytes such
1
the H NMR spectrum. Actually, 3 was oxidized with
2 equiv of AgBF4 under similar conditions to give 16 in
90% yield (Scheme 3). The IR spectrum of 16 showed
the allenylidene-like stretching absorption at 1980 cm-1
.
1
In the H NMR spectrum of 16, the protons of the two
unsubstituted Cp rings resonated at δ 5.47 (5H) and
5.48 (5H) and the substituted Cp ring protons appeared
at δ 5.64 (2H) and 6.56 (2H). These signals shift to
lower field by more than about 1.0 ppm compared with
those of the starting neutral complex, indicating that
the positive charge is located on both Ru atoms in 16.
The observation of remarkable splitting between the R-
and â-ring protons suggests that a η6-fulvene structural
description contributes to the bonding in 16, because
such a large splitting is observed in Cr(CO)3(η6-C5H4-
CH2) (δ 4.52 and 5.32).25 In the 31P NMR spectrum of
complex 16, the signal of the phosphorus nuclei appears
at δ 40.57 ppm (cf. δ 50.36 ppm in the neutral complex
3). The chemical shift observed here is similar to that
of the related cationic vinylidene complex [(PhHCdC)-
Ru(PPh3)2(η5-C5H5)]BF4 (δ 42.75 ppm) and the neutral
acetylide complex PhCtCRu(PPh3)2(η5-C5H5) (δ 50.29
ppm), suggesting that 16 contains a cationic vinylidene
-
-
as PF6 or ClO4 salts have been used19-21 and a
reversible one-electron-oxidation process only in the case
of the particular electrolyte [Bu4N][B{2,5-C6H3(C-
F3)2}].22,23 However, decamethylruthenocene24 and
octamethyl[3]ruthenocenophane14 show a reversible
one-electron-oxidation wave under usual conditions. The
unusual electrochemical properties observed in com-
plexes 3-6 and 10-13 are probably caused by elec-
tronically coupled fragments in the molecule.
The oxidation potentials of the first waves in com-
plexes 3-6 and 10-13 decrease in comparison to those
of reference complexes 14 and 15, respectively (e.g., ∆E
) 0.23 V in 3). The second oxidation wave also shifts
to a potential lower than that of the reference complex
(RcCtCH or Rc′CtCH) (e.g., ∆E ) 0.35 V in 3). The
shift of the first oxidation wave to a lower potential may
be explained by the electron-donating effect of ru-
thenocene. The low-potential shift of the second oxida-
tion wave is very large and is not readily explained by
the electrostatic influence of the substituents, because
if the electron-attracting effect of the oxidized Ru(PPh3)2-
(η5-C5H5) part is transmitted to the Rc or Rc′ part
through the CtC bond, the second wave should shift to
a higher potential. The shift to a lower potential region
of the oxidation potential and the one-electron-oxidation
process in the Rc part have been similarly observed in
[1,1]ruthenocenophane, which is oxidized to the complex
containing the Ru-Ru bond,12c and in 1,2-bis(pentam-
ethylruthenocenyl)ethylene, which gives a pentafulva-
diene diruthenium complex on the oxidation.13 The
observation of these characteristic behaviors suggests
that there is a certain strong interaction between the
two Ru atoms in complexes 3-6 and 10-13. That is,
the two Ru atoms are oxidized stepwise from Ru(II) to
Ru(III), and the unpaired electrons on the two Ru(III)
atoms form a pair with spins coupled via the conjugated
system connecting the two Ru atoms. Such an interac-
tion may contribute to the lower potential shift of the
1
structure. Such IR and H NMR spectral data indicate
that 16 is a unique complex having an unprecedented
cyclopentadienylidenethylidene ligand, although the full
characterization of 16 could not be completed because
of its extreme instability in solution.
Complex 10, the pentamethyl analogue of 3, was
oxidized with 1 equiv of ferrocenium tetrafluoroborate
(FcH+PF6-) in CH2Cl2 at -78 °C to give complex 17 as
a brown powder in 62% yield (Scheme 3). The IR
spectrum of 17 gave the CdC stretching vibration at
1
1632 cm-1. The H NMR spectrum of 17 showed the
olefinic proton accompanied by coupling with the P
4
atoms at δ 4.62 (t, J PH ) 2.3 Hz). Such long-range
coupling is characteristic of vinylidene complexes.26 In
coincidence with this suggestion, the 13C NMR spectrum
of 17 gave a low-field resonance at δ 355.79 as a triplet
(2J CP ) 16.6 Hz), which can be assigned to the R-vi-
nylidene carbon.26 These spectral data indicate that 17
is assigned to a vinylidene complex, [(Rc′CHdC)Ru-
(PPh3)2(η5-C5H5)]BF4. The structure was confirmed by
regeneration of the starting acetylide complex 10 on
treatment of 17 with base. There has so far been no
example in which a Ru(II) vinylidene complex is ob-
tained from oxidation of a Ru(II) acetylide complex, to
the best of our knowledge. Thus, the one-electron
oxidation of the Ru(II) acetylide complexes Ru(CtCR)-
(19) (a) Kuwata, T.; Bublitz, D. E.; Hoh, G. J . Am. Chem. Soc. 1960,
82, 5811. (b) Bubliz, D. E.; Kuwata, T.; Hoh, G. Chem. Ind. (London)
1959, 78, 365.
(20) Kukharenko, S. V.; Bezrkova, A. A.; Rubezhov, A. Z.; Strelets,
A. Metalloorg. Khim. 1990, 3, 634.
(21) (a) Denisovich, L. I.; Zakurin, N. V.; Bazurukova, A. A.; Gubin,
S. P. J . Organomet. Chem. 1974, 81, 207. (b) Gubin, S. P.; Smirnova,
L. I.; Denisovich, L. I.; Lubovich, A. A. Ibid. 1971, 30, 243.
(22) Gale, R.; J ob, R. Inorg. Chem. 1981, 20, 42.
(23) Hill, M. G.; Lamanna, W. M.; Mann, K. R. Inorg. Chem. 1991,
30, 4688.
(25) Koch, O.; Edelmann, F.; Behrens, U. Chem. Ber. 1982, 115,
1313.
(24) Ko¨lle, U.; Salzer, A. J . Organomet. Chem. 1983, 243, C27.
(26) Bruce, M. I.; Wallis, R. C. Aust. J . Chem. 1979, 32, 1471.

Ru(II) (Ruthenocenyl)acetylide Complexes
Organometallics, Vol. 16, No. 8, 1997 1697
Sch em e 3
Sch em e 4
(PPh3)2(η5-C5H5) (R ) n-Bu, n-Hex, Ph, and CO2Me),
was examined using p-benzoquinone (p-BQ)/BF3‚OEt2
in CH2Cl2 at -78 °C. The expected vinylidene com-
plexes, [Ru(CdCHR)(PPh3)2(η5-C5H5)]BF4, were ob-
tained in good yield (Scheme 4). Contrary to our results,
the one-electron oxidation of Fe(II) acetylides, which
have substituents similar to that in the Ru(II) acetylide
complexes described above, gave stable paramagnetic
Fe(III) species with no structural change.27 Recently,
Lapinte reported that the terminal acetylide complex
Fe(CtCH)(dppe)(η5-C5Me5) gave a vinylidene complex,
[Fe(CdCH2)(dppe)(η5-C5Me5)], on one-electron oxida-
tion.28
for the exo-methylene protons due to the fulvene-like
ligand was observed at δ 5.24 (2H) as a singlet, along
with the two methyl signals (2 × 6H) at δ 1.81 and 2.23,
suggesting that the original C5Me5 ligand changed to
the C5Me4CH2 ligand. The 13C NMR spectrum of 18
gave a resonance due to the exo-methylene carbon of
the fulvene ligand at δ 71.69 (1J CH ) 166.0 Hz), which
was comparable with that in [Ru(η6-C5Me4CH2)(η5-C5-
1
Me5)]BF4 (δ 74.7, J CH ) 166.0 Hz).29 Marks30 and
Suzuki31 point out that the bonding mode of η6-C5Me4-
CH2 ligands to metal atoms can be expressed as a η6-
bonded fulvene or a η5,η1-bonded description. According
to the classification, η6-bonded fulvene complexes show
small 2J HH (0-3 Hz) and large 1J CH (ca. 150 Hz) coupling
constants in the exo-methylene group, while η5,η1-
bonded fulvene complexes have large geminal coupling
(2J HH ) 12-15 Hz) and small 1J CH coupling (ca. 120 Hz).
Complex 10 was oxidized with 2 equiv of p-BQ/
BF3‚OEt2 in CH2Cl2 at -78 °C to give complex 18 in
84% yield (Scheme 3). Complex 18 was fully character-
ized by the spectral data and elemental analysis. The
CdC stretching vibration at 1632 cm-1 in the IR
spectrum, the signal for the vinylidene proton at δ 5.19
2
1
The J HH and J CH values observed in complex 18 are 0
and 166.0 Hz, respectively, supporting the change of the
original pentamethylruthenocenyl moiety in 10 to a η6-
fulvene structure in 18. The structure of 18 was
confirmed by the fact that complex 18 allowed to react
with NaOMe in CH2Cl2/MeOH to give the expected (η5-
C5Me4CH2OMe)Ru{µ-η5:η1-C5H4CtC}Ru(PPh3)2(η5-C5-
H5) (19) in 57% yield (Scheme 5). The structure of 19
4
(t, J PH ) 2.3 Hz, 1H) accompanied by the long-range
coupling with the P nuclei in the 1H NMR spectrum,
and the 13C NMR signal for the vinylidene R-carbon at
δ 346.75 as a triplet (2J CP ) 15.0 Hz) prove that complex
18 contains a vinylidene structure as part of the
1
molecule. In the H NMR spectrum of 18, the signal
(29) Kreindlin, A. Z.; Petrovskii, P. V.; Rybinskaya, M. I.; Yanovskii,
A. I.; Struchkov, Yu. T. J . Organomet. Chem. 1987, 319, 229.
(30) Schock, L. E.; Brock, C. P.; Marks, T. J . Organometallics 1987,
6, 232.
(31) Suzuki, H.; Kakigano, T.; Fukui, H.; Tanaka, M.; Moro-oka, Y.
J . Organomet. Chem. 1994, 473, 295.
(27) Connelly, N. G.; Gamasa, M. P.; Gimeno, J .; Lapinte, C.; Lastra,
E.; Maher, J . P.; Le Narvor, N.; Rieger, A. L.; Rieger, P. H. J . Chem.
Soc., Dalton Trans. 1993, 2575.
(28) Le Narvor, N.; Toupet, L.; Lapinte, C. J . Am. Chem. Soc. 1995,
117, 7129.

1698 Organometallics, Vol. 16, No. 8, 1997
Sato et al.
Sch em e 5
Sch em e 6
Sch em e 7
1
was assigned by IR and H and 13C NMR spectra (see
Experimental Section).
route is negligible, because the direct formation of 18
from 10 was accomplished with 2 equiv of oxidant. In
the other possible route, intramolecular hydrogen trans-
fer from the methyl group of the η5-C5Me5 ligand to the
â-carbon of the acetylide ligand in the intermediate 21
may yield fulvene-vinylidene complex 18 (Scheme 7).
Complex 10 was oxidized with 2 equiv of AgBF4 in
CDCl3 in which trace H2O contamination was removed
by displacement with D2O followed by distillation from
P2O5. Importantly, the product contained no deuterium
on the vinylidene â-carbon. This rules out hydrogen
abstraction from the solvent by intermediate 21 and
seems to support the formation of 18 by intramolecular
hydrogen transfer from the methyl group of the Cp*
ligand. At the present stage, we have no evidence to
decide if the Ru atom in the pentamethylruthenocenyl
moiety intervenes in the rearrangement from 21 to 18
by the intramolecular hydrogen transfer.9,10 In the two-
electron oxidation of complex 3, an allenylidene type of
complex 16 would be formed via structural rearrange-
ment from the two-electron-oxidized species correspond-
ing to the intermediate 21, because of the absence of
the proximate methyl hydrogen atom.
P la u sible Mech a n ism for th e F or m a tion of th e
Oxid a tion P r od u cts of Com p lex 10. Ru(II) (pen-
tamethylruthenocenyl)acetylide complex 10 is stepwise
oxidized electrochemically to give the one-electron-
oxidized intermediate 20 and then the two-electron-
oxidized intermediate 21 (Scheme 6). In the one-
electron oxidation of complex 10, the reactive inter-
mediate 20 is converted to the vinylidene complex 17
by the abstraction of hydrogen from the solvent. The
formation of 18 on two-electron oxidation of 10 may be
explained by two possible mechanisms: In one possible
route, complex 18 may be formed by further oxidation
of vinylidene complex 17, resulting from one-electron
oxidation of 10. However, the cyclic voltammogram of
complex 17 showed an irreversible two-electron-oxida-
tion process at +0.26 V. In fact, complex 17 could be
oxidized with p-BQ/BF3‚OEt2 in CH2Cl2 to give 18 in
84% yield, but the oxidation required 2 equiv of the
oxidant in order to get a sufficient yield of 18. In
coincidence with this, the oxidation of pentamethylru-
thenocene [Epa ) +0.33 V (2e)] with 2 equiv of p-BQ/
BF3‚OEt2 in CH2Cl2 gave the tetramethylfulvene com-
plex [Ru(η5-C5H5)(η6-C5Me4CH2)]BF4 in 95% yield. Thus,
the overall conversion of 10 into 18 by a stepwise process
involving the vinylidene complex 17 requires consump-
tion of 3 equiv of the oxidants. Therefore, the stepwise
Exp er im en ta l Section
All reactions were carried out under an atmosphere of N2,
and workups were performed with no precaution to exclude

Ru(II) (Ruthenocenyl)acetylide Complexes
Organometallics, Vol. 16, No. 8, 1997 1699
1
air. NMR spectra were recorded on Bruker AC200, AM400,
or ARX400 spectrometers. IR spectra were recorded on
Hitachi 270-50 or Perkin-Elmer System 2000 spectrometers.
Cyclic voltammograms were recorded on BAS CV27 in CH2-
Cl2 (freshly distilled from CaH2 and N2 purged) solutions of
10-1 M n-Bu4NClO4 (polarography grade, Nacalai Tesque,
50 MHz): δ 28.04 (t, J PC ) 23.3 Hz, CH2), 68.00 (â-C5H4),
69.95 (C5H5), 72.41 (R-C5H4), 78.67 (ipso-C5H4), 82.20 (C5H5),
2
3
104.30 (RcC), 107.58 (t, J PC ) 25.4 Hz, CRu), 127.48 (t, J PC
3
) 4.6 Hz, m-Ph), 127.78 (t, J PC ) 3.6 Hz, m-Ph), 128.69 (p-
2
Ph), 129.20 (p-Ph), 131.47 (t, J PC ) 5.0 Hz, o-Ph), 134.10 (t,
2J PC ) 4.8 Hz, o-Ph), 137.03 (m, ipso-Ph), 142.43 (m, ipso-Ph).
Anal. Calcd for C43H38P2Ru2: C, 63.07; H, 4.68. Found: C,
63.04; H, 4.81.
Inc.), and the scan rate was 0.1 V s-1
. CV cells were fitted
with glassy carbon (GC) working electrodes, Pt wire counter
electrodes, and Ag/Ag+ pseudo reference electrodes. All po-
tentials were represented vs FcH0/+ (+0.17 V vs Ag/Ag+), which
were obtained by the subsequent measurement of ferrocene
under the same conditions. Thin-layer coulometry was carried
out on the apparatus described earlier.32
Solvents were purified by distillation from a drying agent
before use as follows: CH2Cl2 (CaCl2); MeOH (magnesium
methoxide); acetone (CaSO4); CH3CN (CaH2); diethyl ether
(LiAlH4). Ruthenocenylacetylene,33 pentamethylruthenocene
[(η5-C5H5)(η5-C5Me5)Ru],34 (η5-C5H5)(PPh3)2RuCl,35 (η5-C5H5)-
(dppe)RuCl,36 (η5-C5Me5)(PPh3)2RuCl,37 (η5-C5Me5)(dppe)RuCl,38
and (η5-C5H5)(PPh3)2Ru(CtCPh)39 were prepared according to
the literature, respectively. Other reagents were used as
received from commercial suppliers.
(RcCtC)Ru (P P h 3)2(η5-C5Me5) (5). Complex 5 was pre-
pared from RcCtCH (1) and (η5-C5Me5)(PPh3)2RuCl by a
procedure similar to that for 3 to yield yellow crystals. Yield:
41 mg (40%). Mp: 120 °C dec. IR (KBr): 2060 cm-1 (νCtC).
1H NMR (CDCl3, 400 MHz): δ 1.37 (s, 15H, C5Me5), 4.31 (s,
5H, C5H5), 4.51 (s, 2H, â-C5H4), 4.58 (s, 2H, R-C5H4), 7.06-
7.51 (m, 30H, Ph). 13C NMR (CDCl3, 100 MHz): δ 9.38
(C5Me5), 68.31 (â-C5H4), 70.41 (C5H5), 72.00 (R-C5H4), 93.36 (C5-
Me5), 126.64 (m-Ph), 128.05 (p-Ph), 134.80 (o-Ph), 137.68 (ipso-
Ph). Anal. Calcd for C58H54P2Ru2: C, 68.62; H, 5.36. Found:
C, 68.20; H, 5.49.
(RcCtC)Ru (d p p e)(η5-C5Me5) (6). Complex 6 was pre-
pared from RcCtCH (1) and (η5-C5Me5)(dppe)RuCl by a
procedure similar to that for 3 to yield yellow crystals. Yield:
68 mg (77%). Mp: 180 °C dec. IR (KBr): 2084 cm-1 (νCtC).
1H NMR (CDCl3, 400 MHz): δ 1.52 (s, 15H, C5Me5), 2.07 (m,
2H, CH2), 2.15 (m, 2H, CH2), 4.23 (s, 2H, â-C5H4), 4.29 (s, 2H,
R-C5H4), 4.30 (s, 5H, C5H5), 7.18-7.77 (m, 20H, Ph). 13C NMR
(RcCtC)Ru (P P h 3)2(η5-C5H5) (3). To a solution of (η5-
C5H5)(PPh3)2RuCl (72.7 mg, 0.10 mmol) and RcCtCH (1) (21.0
mg, 0.10 mmol) in CH2Cl2 (5 mL) and MeOH (3 mL) was added
NH4PF6 (24.5 mg, 0.15 mmol) at room temperature. The
solution was stirred for 1 h. After the solvent was removed
from the resulting brown solution by rotary evaporator, the
residue was chromatographed on basic alumina by elution with
CH2Cl2/hexane (1:1, v/v). The fraction of a yellow band was
collected, and the solvent was removed, giving the title Ru(II)
ruthenocenylacetylide complex, (RcCtC)Ru(PPh3)2(η5-C5H5)
(3), as a yellow solid. An analytically pure sample was
obtained by recrystallization from CH2Cl2/MeOH as yellow
needles. Yield: 89 mg (94%). Mp: 215 °C. IR (KBr): 2072
cm-1 (νCtC). 1H NMR (CDCl3, 400 MHz): δ 4.15 (s, 5H,
C5H5), 4.23 (s, 5H, C5H5), 4.38 (s, 2H, â-C5H4), 4.82 (s, 2H,
R-C5H4), 7.10-7.46 (m, 30H, Ph). 13C NMR (CDCl3, 100
MHz): δ 68.00 (â-C5H4), 70.43 (C5H5), 72.45 (R-C5H4), 85.00
(C5H5), 127.15 (m-Ph), 128.34 (p-Ph), 134.00 (o-Ph), 139.05 (t,
1J PC ) 20.3 Hz, ipso-Ph). 31P NMR (CDCl3, 162 MHz, referred
to 85% H3PO4): 50.36 ppm. Anal. Calcd for C53H44P2Ru2‚CH3-
OH: C, 66.38; H, 4.95. Found: C, 66.26; H, 4.65.
(RcCtC)Ru (d p p e)(η5-C5H5) (4). To a suspension of Ag-
BF4 (19.5 mg, 0.10 mmol) in acetone (5 mL) was added (η5-
C5H5)(dppe)RuCl (60.0 mg, 0.10 mmol) in the dark at room
temperature. After the mixture was stirred for 1 h, the
precipitated AgCl was filtered off and washed with acetone (1
mL × 2), giving a yellow solution. To the yellow solution was
added RcCtCH (1) (21.0 mg, 0.10 mmol). The reaction
mixture was stirred for 1 h. A brown solution was obtained.
After the solvent was removed by rotary evaporator, the
residue was chromatographed on basic alumina by eluting with
CH2Cl2/hexane (1:1, v/v). The yellow fraction was collected,
and the solvent was removed, yielding the Ru(II) ruthenoce-
nylacetylide complex (RcCtC)Ru(dppe)(η5-C5H5) (4) as a yellow
polycrystalline solid. Yield: 56 mg (68%). Mp: 196-197 °C.
IR (KBr): 2080 cm-1 (νCtC). 1H NMR (CDCl3, 400 MHz): δ
2.31 (m, 2H, CH2), 2.67 (m, 2H, CH2), 4.02 (t, J ) 1.6 Hz, 2H,
â-C5H4), 4.11 (s, 5H, C5H5), 4.14 (t, J ) 1.6 Hz, 2H, R-C5H4),
4.71 (s, 5H, C5H5), 7.22-7.92 (m, 20H, Ph). 13C NMR (CDCl3,
1
(CDCl3, 100 MHz): δ 9.99 (C5Me5), 29.40 (t, J PC ) 23.0 Hz,
CH2), 67.95 (â-C5H4), 70.18 (C5H5), 72.11 (R-C5H4), 80.43 (ipso-
2
C5H4), 92.33 (C5Me5), 101.37 (RcC), 119.32 (t, J PC ) 25.1 Hz,
3
3
CRu), 127.03 (t, J PC ) 4.4 Hz, m-Ph), 127.32 (t, J PC ) 4.2
Hz, m-Ph), 128.74 (p-Ph), 133.19 (t, 2J PC ) 5.3 Hz, o-Ph), 133.92
2
(t, J PC ) 4.8 Hz, o-Ph), 137.03 (m, ipso-Ph), 142.43 (m, ipso-
Ph). Anal. Calcd for C48H48P2Ru2‚CH2Cl2: C, 60.42; H, 5.17.
Found: C, 60.17; H, 5.27.
Tw o-Electr on Ch em ica l Oxid a tion of 3. To a solution
of 3 (9.4 mg, 0.01 mmol) and p-BQ (2.2 mg, 0.02 mmol) in CH2-
Cl2 was added BF3‚OEt2 (0.03 mL, 1.0 mmol) at -78 °C. The
solution was stirred for 10 min. The initial yellow color of the
solution turned rapidly to green, and then yellow-brown
solution was obtained. Excess diethyl ether (15 mL) was
added. The resulting yellow-brown powder was filtered and
washed with ether (2 mL × 3). Attempts at further purifica-
tion by recrystallization from any solvent failed. The product
was a yellow-brown powder. Yield: 10 mg (90%). Mp: 100
°C dec. IR (KBr): 1980 (νCdC), 1080 cm-1 (νBF4). 1H NMR
(CDCl3, 400 MHz): δ 5.47 (s, 5H, C5H5), 4.48 (s, 5H, C5H5),
5.64 (s, 2H, â-C5H4), 6.56 (s, 2H, R-C5H4), 6.99-7.48 (m, 30H,
Ph). 31P NMR [CDCl3/(CD3)2CO (1:1 v/v), 162 MHz, referred
to 85% H3PO4]: 40.57 ppm. Anal. Calcd for C53H44B2F8P2-
Ru2: C, 56.91; H, 3.96. Found: C, 56.28; H, 3.98.
1-Acetyl-1′,2′,3′,4′,5′-p en ta m eth ylr u th en ocen e (Acetyl-
p en ta m eth ylr u th en ocen e) (7). To a mixture of aluminum
chloride (1.00 g, 7.5 mmol) and acetyl chloride (0.53 mL, 7.5
mmol) in 1,2-dichloroethane (75 mL) was added dropwise (over
a period of 30 min) a solution of pentamethylruthenocene (1.51
g, 5.0 mmol) in 1,2-dichloroethane (75 mL) at room tempera-
ture. The resulting orange solution was refluxed for 3 h and
poured into ice/water. The organic layer was separated, and
the aqueous layer was extracted with CH2Cl2 (50 mL × 4).
The organic layer and the extracts were collected, dried over
MgSO4, concentrated by rotary evaporator, and chromato-
graphed on alumina using CH2Cl2 as the eluent. The second
yellow fraction was collected, and the solvent was removed,
giving crude 7 as a yellow solid. An analytically pure sample
was obtained by recrystallization from hexane. This sample
(yellow crystals) was identical with the authentic sample.
Yield: 1.17 g (68%). Mp: 121.5-122.0 °C (lit.38 mp 116-117
°C). IR (KBr): 1662 cm-1 (νCdO). 1H NMR (CDCl3, 400
MHz): δ 1.85 (s, 15H, C5Me5), 2.14 [s, 3H, C(O)Me], 4.43 (t, J
) 1.8 Hz, 2H, â-C5H4), 4.67 (t, J ) 1.8 Hz, 2H, R-C5H4). Anal.
Calcd for C17H22ORu: C, 59.46; H, 6.46. Found: C, 59.61; H,
6.42.
(32) Unoura, K.; Iwase, A.; Ogino, H. J . Electroanal. Chem. Inter-
facial Electrochem. 1990, 295, 385.
(33) Hofer, O.; Schlo¨gl, K. J . Organomet. Chem. 1968, 13, 443.
(34) Kudinov, A. R.; Rybinskaya, M. I.; Struchkov, Yu. T.; Yanovskii,
A. I.; Petrovskii, P. V. J . Organomet. Chem. 1987, 336, 187.
(35) Bruce, M. I.; Windsor, N. J . Aust. J . Chem. 1977, 30, 1601.
(36) Ashby, G. S.; Bruce, M. I.; Tomkins, I. B.; Wallis, R. C. Aust. J .
Chem. 1979, 32, 1003.
(37) Gassman, P. G.; Winter, C. H. J . Am. Chem. Soc. 1988, 110,
6130.
(38) Oshima, N.; Suzuki, H.; Moro-oka, Y. Chem. Lett. 1984, 1161.
(39) Bruce, M. I.; Wallis, R. C. Aust. J . Chem. 1979, 32, 1471.

1700 Organometallics, Vol. 16, No. 8, 1997
Sato et al.
The starting material, Rc′H, was recovered in 28% yield
(0.43 g) from the first colorless fraction.
2.68 (m, 2H, CH2), 3.50 (s, 2H, â-C5H4), 3.81 (s, 2H, R-C5H4),
4.71 (s, 5H, C5H5), 7.24-7.89 (m, 20H, Ph). 13C NMR (CDCl3,
50 MHz): δ 11.46 (C5Me5), 28.27 (t, 1J PC ) 23.3 Hz, CH2), 70.25
(â-C5H4) 74.59 (R-C5H4), 79.21 (ipso-C5H4), 82.31 (C5H5), 83.99
The third fraction of a yellow band gave 1,2-diacetyl-
1′,2′,3′,4′,5′-pentamethylruthenocene (8) in 4% yield (0.08 g)
(yellow crystals). Mp: 117.0-117.5 °C. IR (KBr): 1668 (νCdO),
1650 cm-1 (νCdO). 1H NMR (CDCl3, 400 MHz): δ 1.80 (s, 15H,
C5Me5), 2.31 [s, 6H, C(O)Me], 4.54 (t, J ) 2.6 Hz, 1H, â-C5H4),
4.67 (d, J ) 2.6 Hz, 2H, R-C5H4). 13C NMR (100 MHz,
CDCl3): δ 10.71 (C5Me5), 29.30 [C(O)Me], 77.05 (â-C5H4), 79.46
(R-C5H4), 85.36 (ipso-C5H4), 87.59 (C5Me5), 199.24 (C(O)Me).
Anal. Calcd for C19H24O2Ru: C, 59.20; H, 6.28. Found: C,
59.22; H, 6.21.
1-(r-Ch lor o-â-for m ylvin yl)-1′,2′,3′,4′,5′-p en ta m eth ylr u -
th en ocen e (9). To a solution of 1-acetyl-1′,2′,3′,4′,5′-penta-
methylruthenocene (7) (1.08 g, 3.0 mmol) in DMF was added
dropwise Vilsmeier’s complex, which was prepared from POCl3
(4.5 mL) and DMF (45 mL), at 0 °C. The resulting orange-
red solution was stirred at 0 °C for 0.5 h and then at room
temperature for 2 h. To the solution was slowly added a
saturated sodium acetate solution at 0 °C. The solution was
stirred at room temperature for 2 h and extracted with CH2-
Cl2 (50 mL × 4). The extracts were collected, washed with
water, dried over MgSO4, concentrated by rotary evaporator,
and chromatographed on alumina using CH2Cl2 as the eluent.
The first orange fraction was collected, and the solvent was
removed, giving crude 9 as a yellow solid. An analytically pure
sample was obtained by recrystallization from CH2Cl2/hexane
as Orange-red crystals. Yield: 1.07 g (92%). Mp: 110 °C dec.
IR (KBr): 1660 (νCdO), 1592 cm-1 (νCdC). 1H NMR (CDCl3, 400
MHz): δ 1.81 (s, 15H, C5Me5), 4.51 (t, J ) 1.7 Hz, 2H, â-C5H4),
4.64 (t, J ) 1.7 Hz, 2H, R-C5H4), 6.16 (d, J ) 7.2 Hz, 1H, dCH),
10.06 (d, J ) 7.2 Hz, 1H, CHO). 13C NMR (100 MHz, CDCl3):
δ 10.93 (C5Me5), 72.06 (â-C5H4), 76.84 (R-C5H4), 83.73 (ipso-
C5H4), 86.57 (C5Me5), 117.84 (dCH), 153.67 [C(Cl)d], 191.03
(CHO). Anal. Calcd for C18H21OClRu: C, 55.45; H, 5.43.
Found: C, 55.67; H, 5.45.
2
3
(C5Me5), 103.48 (t, J PC ) 26.2 Hz, CRu), 127.30 (t, J PC ) 5.1
3
Hz, m-Ph), 127.73 (t, J PC ) 4.5 Hz, m-Ph), 128.57 (p-Ph),
2
2
129.02 (p-Ph), 131.53 (t, J PC ) 5.3 Hz, o-Ph), 134.19 (t, J PC
1
) 5.2 Hz, o-Ph), 137.43 (t, J PC ) 25.1 Hz, ipso-Ph), 142.91 (t,
2J PC ) 18.5 Hz, ipso-Ph). Anal. Calcd for C48H48P2Ru2‚C6H6:
C, 67.07; H, 5.63. Found: C, 66.86; H, 5.59.
(Rc′CtC)Ru (P P h 3)2(η5-C5Me5) (12). Complex 12 was
prepared as a yellow powder from RcCtCH and (η5-C5-
Me5)(PPh3)2RuCl by a procedure similar to that for 2. Yield:
50 mg (49%). Mp: 133 °C dec. IR (KBr): 2060 cm-1 (νCtC).
1H NMR (CDCl3, 400 MHz): δ 1.22 [s, 15H, (η5-C5Me5)Ru], 2.10
[s, 15H, C5Me5 (Rc′)], 4.05 (s, 2H, â-C5H4), 4.15 (s, 2H, R-C5H4),
7.02-7.53 (m, 30H, Ph). 13C NMR (CDCl3, 100 MHz): δ 9.53
(C5Me5), 12.20 (C5Me5), 70.51 (â-C5H4), 73.66 (R-C5H4), 81.28
(ipso-C5H4), 84.53 (C5Me5), 93.14 (C5Me5), 126.63 (m-Ph),
127.92 (p-Ph), 134.76 (o-Ph), 137.69 (ipso-Ph). Anal. Calcd
for C63H64P2Ru2‚CH2Cl2: C, 65.68; H, 5.68. Found: C, 65.96;
H, 5.68.
(Rc′CtC)Ru (d p p e)(η5-C5Me5) (13). Complex 13 was pre-
pared as yellow crystals from RcCtCH and (η5-C5Me5)(dppe)-
RuCl by a procedure similar to that for 2. Yield: 79 mg (82%).
Mp: >230 °C dec. IR (KBr): 2068 cm-1 (νCtC). 1H NMR
(CDCl3, 400 MHz): δ 1.52 (s, 15H, C5Me5), 1.76 (s, 15H, C5-
Me35), 2.10 (m, 2H, CH2), 2.70 (m, 2H, CH2), 3.85 (s, 2H,
â-C5H4), 3.87 (s, 2H, R-C5H4), 7.17-7.78 (m, 20H, Ph). 13C
NMR (CDCl3, 100 MHz): δ 10.04 (C5Me5), 11.79 (C5Me5), 29.69
1
(t, J PC ) 23.3 Hz, CH2), 70.14 (â-C5H4), 74.12 (R-C5H4), 81.03
(ipso-C5H4), 84.29 (C5Me5), 92.33 (C5Me5), 100.91 (RcC), 118.19
(t, 2J PC ) 25.1 Hz, CRu), 127.02 (t, 3J PC ) 9.3 Hz, m-Ph), 127.27
3
(t, J PC ) 8.5 Hz, m-Ph), 128.64 (p-Ph), 128.70 (p-Ph) 133.21
(t, 2J PC ) 10.3 Hz, o-Ph), 134.13 (t, 2J PC ) 9.0 Hz, o-Ph), 137.32
(m, ipso-Ph), 149.49 (m, ipso-Ph). Anal. Calcd for C53H58P2-
Ru2: C, 66.37; H, 6.09. Found: C, 66.36; H, 6.07.
1-Eth yn yl-1′,2′,3′,4′,5′-p en ta m eth ylr u th en ocen e [(P en -
ta m eth ylr u th en ocen yl)a cetylen e] (2). A mixture of com-
plex 9 (641 mg, 1.64 mmol) in dioxane (100 mL) and 0.5 M
NaOH aqueous solution (100 mL) was refluxed vigorously with
stirring for 1.5 h. The orange-red color of the solution turned
to orange. The solution was concentrated by rotary evaporator
and extracted with CH2Cl2 (50 mL × 4). The extracts were
collected, dried over MgSO4, concentrated, and chromato-
graphed on alumina using hexane as the eluent. The first
colorless fraction gave a pale yellow solid of crude 2. An
analytically pure sample (pale yellow crystals) was obtained
by recrystallization from CH2Cl2/methanol. Yield: 487 mg
(91%). Mp: 64-65 °C. IR (KBr): 2100 cm-1 (νCtC). 1H NMR
(CDCl3, 400 MHz): δ 1.89 (s, 15H, C5Me5), 2.74 (s, 1H, CCH),
4.21 (t, J ) 2.0 Hz, 2H, â-C5H4), 4.35 (t, J ) 2.0 Hz, 2H,
R-C5H4). 13C NMR (100 MHz, CDCl3): δ 11.24 (C5Me5), 67.36
(CtCH), 72.94 (CtCH), 73.14 (â-C5H4), 75.98 (R-C5H4), 81.50
(ipso-C5H4), 85.50 (C5Me5). Anal. Calcd for C17H20Ru: C,
62.74; H, 6.19. Found: C, 62.56; H, 6.17.
F or m a t ion of [(η5-C5Me5)R u {µ-η5:η1-C5H 4CH dC}R u -
(P P h 3)2(η5-C5H5)]P F 6 (17) by On e-Electr on Oxid a tion of
Com p lex 10. To a solution of complex 10 (10.2 mg, 0.01
mmol) in CH2Cl2 (2 mL) was added FcHPF6 (3.3 mg, 0.01
mmol) at -78 °C. The solution was stirred for 15 min. The
yellow color of the solution turned yellow-brown via green. An
excess amount of diethyl ether (ca. 15 mL) was added. The
resulting yellow-brown powder was filtered and washed with
diethyl ether (2 mL × 3). An analytically pure sample was
obtained by recrystallization from CH3CN/ether as brown
crystals. Yield: 7 mg (61%). Mp: 152 °C dec. IR (KBr): 1632
(νCdC), 836 cm-1 (νPF6). 1H NMR (CDCl3, 200 MHz): δ 2.00 (s,
15H, C5Me5), 4.05 (t, J ) 1.6 Hz, 2H, â-C5H4), 4.26 (t, J ) 1.6
Hz, 2H, R-C5H4), 4.62 (t, 4J PH ) 2.3 Hz, 1H, Rc*CHd), 5.16 (s,
5H, C5H5), 7.01-7.39 (m, 30H, Ph). 13C NMR (CDCl3, 100
MHz): δ 12.08 (C5Me5), 72.21 (â-C5H4), 74.14 (R-C5H4), 75.66
(ipso-C5H4), 86.12 (C5Me5), 95.79 (C5H5), 114.74 (Rc′CHd),
2
3
129.48 (t, J PC ) 5.1 Hz, o-Ph), 131.72 (p-Ph), 134.05 (t, J PC
2
(Rc′CtC)Ru (P P h 3)2(η5-C5H5) (10). Complex 10 was pre-
pared from Rc′CtCH and (η5-C5H5)(PPh3)2RuCl by a procedure
similar to that for 2. Yield: 74 mg (78%). Mp: 110 °C dec.
IR (KBr): 2074 cm-1 (νCtC). 1H NMR (CDCl3, 400 MHz): δ
2.05 (s, 15H, C5Me5), 4.04 (s, 2H, â-C5H4), 4.05 (s, 2H, R-C5H4),
4.25 (s, 5H, C5H5), 7.05-7.48 (m, 30H, Ph). 13C NMR (CDCl3,
100 MHz): δ 11.76 (C5Me5), 70.40 (â-C5H4), 74.47 (R-C5H4),
) 5.1 Hz, m-Ph), 139.08 (m, ipso-Ph), 355.79 (t, J PC ) 16.6
Hz, CRu). Anal. Calcd for C58H55F6P3Ru2: C, 60.00; H, 4.77.
Found: C, 59.87; H, 4.74.
F or m a tion of [(η6-C5Me4CH2)Ru {µ-η5:η1-C5H4CHdC}-
Ru (P P h 3)2(η5-C5H5)](BF 4)2 (18). P a th A: By Tw o-Electr on
Oxid a tion of Com p lex 10. To a solution of complex 10 (10.2
mg, 0.01 mmol) and p-BQ (2.2 mg, 0.02 mmol) in CH2Cl2 was
added BF3‚OEt2 (0.03 mL, 0.1 mmol) at -78 °C. The solution
was stirred for 10 min. The initial yellow color of the solution
turned rapidly to green, and then a pale red solution was
obtained. Excess diethyl ether (15 mL) was added. The
resulting red powder was filtered and washed with ether (2
mL × 3). Yield: 7 mg (59%).
2
79.47 (ipso-C5H4), 84.16 (C5Me5), 84.87 (C5H5), 103.63 (t, J PC
) 25.5 Hz, CRu), 106.25 (Rc′C), 127.02 (t, 2J PC ) 3.8 Hz, o-Ph),
1
128.20 (p-Ph), 133.92 (m-Ph), 139.08 (t, J PC ) 20.6 Hz, ipso-
Ph). Anal. Calcd for C58H54P2Ru2: C, 68.42; H, 5.36. Found:
C, 66.44; H, 5.39.
(Rc′CtC)Ru (d p p e)(η5-C5H5) (11). Complex 11 was pre-
pared as yellow crystals from Rc′CtCH and (η5-C5H5)(dppe)-
RuCl by a procedure similar to that for 4. Yield: 63 mg (77%).
Mp: 184.0-184.5 °C. IR (KBr): 2084 cm-1 (νCtC). 1H NMR
(CDCl3, 400 MHz): δ 1.78 (s, 15H, C5Me5), 2.28 (m, 2H, CH2),
P a th B: By Tw o-Electr on Oxid a tion of Com p lex 17. In
a procedure similar to that for path A, complex 17 (11.0 mg,
0.01 mmol) was adopted as the starting material instead of
complex 10. Yield: 10 mg (84%).

Ru(II) (Ruthenocenyl)acetylide Complexes
Organometallics, Vol. 16, No. 8, 1997 1701
An analytically pure sample of 18 was obtained by recrys-
tallization from CH3CN/diethyl ether as red crystals. Mp: 180
°C dec. IR (KBr): 1616 (νCdC), 1038 cm-1 (νBF4). 1H NMR
was stirred for 10 min. The color of the solution turned rapidly
from yellow to green, and then to pale red. Excess diethyl
ether (15 mL) was added. The resulting red powder was
filtered and washed with diethyl ether (2 mL × 3).
R ) P h . Yield: 13 mg (74%). IR (KBr): 1620 (νCdC), 1060
cm-1 (νBF4). 1H NMR (200 MHz, CDCl3): δ 5.31 (s, 5H, C5H5),
5.39 (t, 4J PH ) 2.4 Hz, 1H, CHd), 7.00-7.43 (m, 35H, Ph). 31P
NMR [(CD3)2CO, 162 MHz, referred to 85% H3PO4]: 42.75
ppm.
(CDCl3, 200 MHz): δ 1.81 (s, 6H, â-C5Me4CH2), 2.23 (s, 6H,
4
R-C5Me4CH2), 4.98 (t, J ) 1.9 Hz, 2H, â-C5H4), 5.19 (t, J PH
)
2.3 Hz, 1H, Rc′CHd), 5.24 (s, 2H, C5Me4CH2), 5.29 (s, 5H,
C5H5), 5.46 (t, J ) 1.9 Hz, 2H, R-C5H4), 6.95-7.45 (m, 30H,
Ph). 13C NMR (CD3CN, 100 MHz): δ 9.37 (â-C5Me4CH2), 10.74
(R-C5Me4CH2), 71.69 (C5Me4CH2), 82.46 (â-C5H4), 85.17 (R-
C5H4), 93.53 (ipso-C5H4), 92.14 (C5H5), 101.03 (â-C5Me4CH2),
106.32 (R-C5Me4CH2), 108.22 (ipso-C5Me4CH2), 108.88 (Rc′CHd),
R ) n -Hex. Yield: 14 mg (92%). IR (KBr): 1660 (νCdC),
3
1038 cm-1 (νBF4). 1H NMR (200 MHz, CDCl3): δ 0.90 (t, J HH
2
3
129.31 (t, J PC ) 5.3 Hz, o-Ph), 131.73 (p-Ph), 133.72 (t, J PC
) 6.5 Hz, 3H, Me), 1.27 [m, 8H, (CH2)4], 2.26 (m, 2H,
2
3
4
) 5.0 Hz, m-Ph), 133.94 (m, ipso-Ph), 346.75 (t, J PC ) 15.0
dCHCH2), 4.65 (tt, J HH ) 8.1 Hz, J PH ) 2.5 Hz, 1H, CHd),
5.11 (s, 5H, C5H5), 7.01-7.45 (m, 30H, Ph).
Hz, CRu). Anal. Calcd for C58H54B2F8P2Ru2: C, 58.60; H, 4.58.
Found: C, 58.35; H, 4.76.
R ) n -Bu . Yield: 11 mg (64%). IR (KBr): 1658 (νCdC), 1050
(η5-C5Me4CH2OMe)Ru {µ-η5:η1-C5H4CtC}Ru (P P h 3)2(η5-
C5H5) (19). To a solution of complex 18 (11.9 mg, 0.01 mmol)
in CH2Cl2 (2 mL) was added a 10-1 M NaOMe MeOH/diethyl
ether solution, prepared from Na and a mixture of MeOH/
diethyl ether, at room temperature. The solution was stirred
for 10 min. The color of the solution turned from pale red to
yellow. After the solvent was removed, the residue was
chromatographed on alumina using a mixture of hexane and
CH2Cl2 as the eluent. The first fraction of yellow band was
collected, and the solvent was removed, giving crude 19 as a
yellow solid. An analytically pure sample was obtained as
yellow crystals by recrystallization from CH2Cl2/MeOH.
Yield: 6 mg (57%). Mp: 160 °C dec. IR (KBr): 2072 cm-1
(νCtC). 1H NMR (CDCl3, 200 MHz): δ 2.04 (s, 6H, C5Me4), 2.07
(s, 6H, C5Me4), 3.37 (s, 3H, CH2OMe), 4.06 (t, J ) 1.6 Hz, 2H,
â-C5H4), 4.09 (t, J ) 1.6 Hz, 2H, R-C5H4), 4.26 (s, 5H, C5H5),
4.29 (s, 2H, CH2OMe), 7.05-7.52 (m, 30H, Ph). 13C NMR
(C6D6, 100 MHz): δ 11.94 (â-C5Me4), 11.99 (R-C5Me4), 57.21
(CH2OMe), 68.42 (CH2), 71.09 (â-C5H4), 74.85 (R-C5H4), 80.15,
cm-1 (νBF4). 1H NMR (200 MHz, CDCl3): δ 0.90 (m, 3H, Me),
3
1.32 [m, 4H, (CH2)2], 2.27 (m, 2H, dCHCH2), 4.66 (tt, J HH
)
4
8.2 Hz, J PH ) 2.5 Hz, 1H, CHd), 5.13 (s, 5H, C5H5), 7.03-
7.44 (m, 30H, Ph).
R ) C(O)OMe. Yield: 12 mg (70%). IR (KBr): 1698 (νCdC),
1602 (νCdO), 1048 cm-1 (νBF4). 1H NMR (200 MHz, CDCl3): δ
3.47 (s, 3H, OMe), 5.03 (s, 1H, CHd), 5.33 (s, 5H, C5H5), 7.04-
7.47 (m, 30H, Ph).
The spectral data for these samples were identical with
those of an authentic sample.37
Str u ctu r e deter m in ation of 5. Crystal data of 5: C58H54P2-
Ru2, FW ) 1015.15, monoclinic, P21/n; a ) 12.872(2) Å, b )
17.614(2) Å, c ) 20.590(4) Å; â ) 90.23(1)°; V ) 4668(1) Å3; Z
) 4; Dcalc ) 1.444 g cm-3; µ(Mo KR) ) 7.39 cm-1; T ) 296 K;
crystal size 0.40 × 0.20 × 0.20 mm.
Data collection was performed on a Rigaku AFC5R diffrac-
tometer with graphite-monochromated Mo KR radiation and
a 12 kW rotating anode generator. The data was collected
using the ω-2θ scan technique to a maximum 2θ value of 50°.
Cell constants and the orientation matrix for data collection
were obtained from a least-squares refinement using the
setting angles of 25 carefully centered reflections in the range
28.83° < 2θ < 29.47°. Of the 8926 reflections which were
collected, 8521 were unique (Rint ) 0.061). The intensities of
three representative reflections which were measured after
every 150 reflections remained constant throughout data
collection, indicating crystal and electronic stability.
The structure was solved by direct methods. The non-
hydrogen atoms were refined anisotropically. The final cycle
of full-matrix least-squares refinement was based on 3740
observed reflections [I > 3.00σ(I)] and 613 variable parameters
and converged with unweighted and weighted agreement
factors of R ) ∑||Fo| - |Fc||/∑|Fo| ) 0.046 and Rw ) [(∑w(|Fo|
- |Fc|)2/∑wFo2)]1/2 ) 0.037. The standard deviation of an
observation of unit weight was 1.26.
2
84.26, 85.39 (C5H5), 85.67, 85.81, 105.45 (t, J PC ) 25.5 Hz,
CRu), 106.32 (R-C5Me4), 127.42 (t, 3J PC ) 4.5 Hz, m-Ph), 128.58
2
(p-Ph), 134.36 (t, J PC ) 4.9 Hz, o-Ph), 139.62 (m, ipso-Ph).
Anal. Calcd for C59H54OP2Ru2: C, 67.93; H, 5.22. Found: C,
67.97; H, 5.37.
[(η6-C5Me4CH2)(η5-C5H5)Ru ](BF 4)2 fr om Tw o-Electr on
Oxid a tion of P en ta m eth ylr u th en ocen e, (η5-C5Me5)(η5-
C5H5)Ru . To a solution of pentamethylruthenocene (60.2 mg,
0.2 mmol) and p-BQ (43.2 mg, 0.4 mmol) in CH2Cl2 was added
BF3‚OEt2 (0.13 mL, 1.0 mmol) at 0 °C. The solution was
stirred for 10 min. The resulting pale yellow powder was
filtered and washed with diethyl ether (2 mL × 3). An
analytically pure sample (pale yellow crystals) was obtained
by recrystallization from CH3CN/diethyl ether, CH2Cl2/diethyl
ether, and then CH3CN/diethyl ether. Yield: 74 mg (95%).
Mp: 138 °C dec. IR (KBr): 1040 cm-1 (νBF4). 1H NMR (CD3-
CN, 200 MHz): δ 1.74 (s, 6H, â-C5Me4), 2.15 (s, 6H, R-C5Me4),
5.05 (s, 2H, C5Me4CH2), 5.19 (s, 5H, C5H5). 13C NMR (CD3-
CN, 50 MHz): δ 10.05 (â-C5Me4), 11.57 (R-C5Me4), 69.40 (1J CH
) 167 Hz, C5Me4CH2), 85.91 (C5H5), 101.82 (â-C5Me4), 106.74
(R-C5Me4), 108.44 (ipso-C5Me4). Anal. Calcd for C15H19BF4-
Ru: C, 46.53; H, 4.95. Found: C, 46.63; H, 4.94.
Ack n ow led gm en t. We thank Prof. Akira Nagasawa
(Department of Chemistry, Faculty of Science, Saitama
University) for his kind discussion about the electro-
chemical data.
F or m a tion of Ru (II) Vin ylid en e Com p lexes by On e-
Electr on Oxidation of Ru (II) Acetylide Com plexes. Stan -
d a r d P r oced u r e. To a solution of Ru(II) acetylide complex
(RCtC)Ru(PPh3)2(η5-C5H5) [R ) Ph, n-Hex, n-Bu, or C(O)OMe]
(0.02 mmol) and p-BQ (2.2 mg, 0.02 mmol) in CH2Cl2 was
added BF3‚OEt2 (0.03 mL, 0.1 mmol) at -78 °C. The solution
Su p p or tin g In for m a tion Ava ila ble: Single-crystal X-ray
diffraction data for complex 5 (45 pages). Ordering informa-
tion is given on any current masthead page.
OM960732T