Reactivity of a triruthenium acetylide complex toward alkynes and the silica-mediated dehydration of cluster-bound alkynols: X-ray crystal structures of the novel butadienyl species [Ru3(CO)8{μ3-η8-C(But)qqCC(Ph)qqC(H) Ph}] and the unusual complex [Ru3(CO)5(μ-CO)

Article abstract of DOI:10.1021/om000048l

The lightly ligated complex [Ru₃(CO)₈(MeCN)(μ-H)(μ-C₂Bu^t)] (4), derived from [Ru₃(CO)₉-(μ-H) (μ-C₂Bu^t)](1), reacts with terminal alkynes and alkynols under very mild conditions to give high yields of products derived from addition of three molecules of alkyne/alkynol. More interestingly, complex 4 also reacts with diphenylacetylene to form the novel butadienylic species [Ru₃(CO)₈{μ₃- η⁸-C(Bu^t)qqCC(Ph)qqC(H)Ph}] (6), stabilized by an uncommon interaction between a phenyl substituent and a cluster metal atom. Its formation represents a key step in understanding the reaction mechanism leading to tri- and tetra-alkyne-substituted derivatives. The acetonitrile derivative of 6 reacts further with diphenylacetylene to afford the complex [Ru₃(CO)₇ {μ₃-η⁸-C(Bu^t)qqCC(Ph)qqC(H)Ph} {μ₃-η⁴-C(Ph)qqC(Ph)}] (7), which, upon heating, isomerizes to give [Ru₃(CO)₇{μ₃- η⁸-C(Bu^t)qqCC(Ph)qqC(Ph)H}{μ₃-η⁴- C(Ph)qqC(Ph)}]-(2) in high yield. The analogous complex [Ru₃(CO)₇{μ₃-η⁸-C(Bu^t)qqCC(Ph)qqC (CPh₂OH)H}-{μ₃-η⁴-C(CPh₂OH)qqC (Ph)}] (8) is formed directly from 4 through reaction with 1,1,3-triphenyl-2-propyn-1-ol. Finally, the tetra-alkyne-substituted metallacyclic complex [Ru₃(CO)₆-{μ₃-η⁶- C(Bu^t)CC(CPh₂OH)CH₂}{μ₃-η⁶- CHC(CPh₂OH)COC(CPh₂OH)CH}] (5a), obtained from reaction of 1,1-diphenyl-2-propyn-1-ol with 4, undergoes facile dehydration in the presence of silica gel to yield the cluster complex [Ru₃(CO)₅(μ-CO){μ₃-η⁵-CC(Bu^t)OC (Ph)₂CCH}{μ₃-η⁶-CHC(CPh₂OH)COC(CPh₂) CH}] (9), a process that involves formation of an unusual heterocycle. In addition, complex 9 contains a terminal carbene unit, one of the first examples of such a ligand in a cluster complex. The structures of complexes 6, 8, and 9 have been determined crystallographically and are discussed in association with possible reaction mechanisms.

Full text of DOI:10.1021/om000048l

2330
Organometallics 2000, 19, 2330-2340
Rea ctivity of a Tr ir u th en iu m Acetylid e Com p lex tow a r d
Alk yn es a n d th e Silica -Med ia ted Deh yd r a tion of
Clu ster -Bou n d Alk yn ols: X-r a y Cr ysta l Str u ctu r es of th e
Novel Bu ta d ien yl Sp ecies
[Ru 3(CO)8{µ3-η8-C(Bu t)dCC(P h )dC(H)P h }] a n d th e
Un u su a l Com p lex [Ru 3(CO)5(µ-CO){µ3-η5-CC(Bu t)-
OC(P h )2CCH}{µ3-η6-CHC(CP h 2OH)COC(CP h 2)CH}]
J onathan P. H. Charmant, Guy Davies, Philip J . King,* and J ames R. Wigginton
School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
E. Sappa*
Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale Amedeo
Avogadro, Corso Borsalino 54, I-15100, Alessandria, Italy
Received J anuary 20, 2000
The lightly ligated complex [Ru3(CO)8(MeCN)(µ-H)(µ-C2But)] (4), derived from [Ru3(CO)9-
(µ-H)(µ-C2But)](1), reacts with terminal alkynes and alkynols under very mild conditions to
give high yields of products derived from addition of three molecules of alkyne/alkynol. More
interestingly, complex 4 also reacts with diphenylacetylene to form the novel butadienylic
species [Ru3(CO)8{µ3-η8-C(But)dCC(Ph)dC(H)Ph}] (6), stabilized by an uncommon interaction
between a phenyl substituent and a cluster metal atom. Its formation represents a key step
in understanding the reaction mechanism leading to tri- and tetra-alkyne-substituted
derivatives. The acetonitrile derivative of 6 reacts further with diphenylacetylene to afford
the complex [Ru3(CO)7{µ3-η8-C(But)dCC(Ph)dC(H)Ph}{µ3-η4-C(Ph)dC(Ph)}] (7), which, upon
heating, isomerizes to give [Ru3(CO)7{µ3-η8-C(But)dCC(Ph)dC(Ph)H}{µ3-η4-C(Ph)dC(Ph)}]-
(2) in high yield. The analogous complex [Ru3(CO)7{µ3-η8-C(But)dCC(Ph)dC(CPh2OH)H}-
{µ3-η4-C(CPh2OH)dC (Ph)}] (8) is formed directly from 4 through reaction with 1,1,3-
triphenyl-2-propyn-1-ol. Finally, the tetra-alkyne-substituted metallacyclic complex [Ru3(CO)6-
{µ3-η6-C(But)CC(CPh2OH)CH2}{µ3-η6-CHC(CPh2OH)COC(CPh2OH)CH}] (5a ), obtained from
reaction of 1,1-diphenyl-2-propyn-1-ol with 4, undergoes facile dehydration in the presence
of silica gel to yield the cluster complex [Ru3(CO)5(µ-CO){µ3-η5-CC(But)OC(Ph)2CCH}{µ3-
η6-CHC(CPh2OH)COC(CPh2)CH}] (9), a process that involves formation of an unusual
heterocycle. In addition, complex 9 contains a terminal carbene unit, one of the first examples
of such a ligand in a cluster complex. The structures of complexes 6, 8, and 9 have been
determined crystallographically and are discussed in association with possible reaction
mechanisms.
In tr od u ction
common to all of the alkyne linkage products and a
“lone” molecule of diphenylacetylene coordinated to the
opposite face of the Ru3 triangle, led to the suggestion
that formation of the dienic ligand occurs first and that
further alkyne addition takes place in a second step.
However, formation of a complex in which only one
molecule of alkyne has added to form a butadienic chain
was never effected under the reaction conditions (∆,
heptane). Loss of carbonyl groups can be effected at
room temperature (or below) via addition of trimethyl-
amine-N-oxide and the resulting species stabilized by
a weakly coordinating ligand.5 Reactions with suitable
two-electron donor molecules can then be carried out
under mild conditions, often leading to the isolation of
The ease of synthesis of the acetylide complex
[Ru3(CO)9(µ-H)(µ-C2But)] (1) has led to numerous stud-
ies being carried out into its reactivity and catalytic
behavior.1 Investigations into the reactivity of complex
1 toward alkynes have led to the isolation of the clusters
2 and 3 (see Scheme 1) via addition of two or three
molecules of alkyne, carbon-carbon bond formation,
hydride migration, and, in some cases, CO insertion.2-4
The isolation of complex 2, containing a butadienic chain
(1) Sappa, E. J . Cluster Sci. 1994, 5, 211.
(2) Aime, S.; Gervasio, G.; Milone, L.; Sappa, E.; Franchini-Angela,
M. Inorg. Chim. Acta 1978, 26, 223.
(3) Aime, S.; Gervasio, G.; Milone, L.; Sappa, E.; Franchini-Angela,
M. Inorg. Chim. Acta 1978, 27, 145.
(4) Gervasio, G.; Sappa, E.; Lanfredi, A.; Tiripicchio, A. Inorg. Chim.
Acta 1982, 61, 217.
(5) See, for example, Foulds, G. A.; J ohnson, B. F. G.; Lewis, J . J .
Organomet. Chem. 1985, 296, 147.
10.1021/om000048l CCC: $19.00 © 2000 American Chemical Society
Publication on Web 05/12/2000

Reactivity of a Triruthenium Acetylide Complex
Organometallics, Vol. 19, No. 12, 2000 2331
Sch em e 1. Rea ctivity of 4 tow a r d Alk yn es
intermediates that are not seen in the corresponding
thermal reactions of the parent carbonyl clusters.6 We
report here on the synthesis of the acetonitrile deriva-
tive of 1, i.e., [Ru3(CO)8(NCMe)(µ-H)(µ-C2But)] (4), and
its reactivity toward alkynes at room temperature. The
reactivity of 4 toward terminal alkynes follows the same
pattern observed for the unsubstituted complex 1 al-
though under much milder conditions. In addition, when
HC2CPh2OH is used in the reaction, an interesting
dehydration process is observed for one of the products.
In contrast, reaction of 4 with diphenylacetylene affords
the title complex 6, containing a butadienic fragment,
the complex being stabilized through an unusual phenyl
interaction with one of the ruthenium atoms. Subse-
quent reactions show this complex to be the “missing
link” in the formation of complexes derived from two
and three molecules of alkyne. Reaction of 4 with the
asymmetric alkyne PhC2CPh2OH results in formation
of the bis-alkyne species 8.
oxide gas, which affords the parent carbonyl species 1
in 95% yield after 5 min.
It was not possible to obtain a H NMR spectrum of
1
good quality, and therefore, without a crystallographic
study of complex 4 it is not clear which of the several
possible sites in complex 1 is being occupied by the
acetonitrile. However, previous studies on monophos-
phine-substituted derivatives of 1 have shown that the
phosphine ligands occupy a “radial” site, approximately
cis to CR of the acetylide unit,7 and it is likely that the
acetonitrile ligand is in an analogous position in 4.
Rea ctivity of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4)
tow a r d Ter m in a l Alk yn es (HCtCR). Complex 4
reacts with an excess of tert-butyl acetylene, at room
temperature, to afford the green complexes [Ru3(CO)6-
{µ3-η6-C(But)CC(But)CH2}{µ3-η6-CHC(But)COC(But)-
CH}] (3a) and [Ru3(CO)6{µ3-η6-C(But)CCH(But)C(But)H}-
{µ3-η6-CHC(But)COC(But)CH}] (3b) in a combined yield
of 50%. These complexes were previously synthesized
from reaction of 1 or [Ru3(CO)12] with excess ButCtCH
in refluxing heptane (albeit in yields of less than 5%)
and were readily characterized through comparison of
their IR, NMR, and mass spectroscopic data.2,8 The
isomers have been shown to arise from the asymmetry
of the alkyne coupling to the R-carbon of the acetylide
Resu lts a n d Discu ssion
Syn th esis of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4).
Complex 4 was obtained by displacement of a carbonyl
ligand from the acetylide complex 1 using trimethyl-
amine-N-oxide in acetonitrile solvent.
The reverse reaction can be readily effected by purg-
ing a dichloromethane solution of 4 with carbon mon-
(7) (a) J angala, C.; Rosenberg, E.; Skinner, D.; Aime, S.; Milone,
L.; Sappa, E. Inorg. Chem. 1980, 19, 1571. (b) Carty, A. J .; MacLaugh-
lin, S. A.; Taylor, N. J .; Sappa, E. Inorg. Chem. 1981, 20, 4437.
(8) Aime, S.; Gervasio, G.; Milone, L.; Sappa, E.; Franchini-Angela,
M. Transition Met. Chem. 1976, 1, 96.
(6) See, for example: Aime, S.; Arce, A.; De Danctis, Y.; Gobetto,
R.; Milone, L.; Osella, D.; Violano, L. Organometallics 1991, 10, 2854.

2332 Organometallics, Vol. 19, No. 12, 2000
Charmant et al.
ligand and forming a butadienic chain. The 1H NMR
spectrum of 3a ,b showed the isomers to be present in a
1:1 ratio, which mirrors the result obtained previously
from the thermal reaction.
It was previously found that thermolysis of complex
1 in the presence of excess ButCtCH led to formation
of a red complex, [Ru3(CO)5(C12H20)(C19H30O)], derived
from addition of four molecules of alkyne.9 The isolation
of trace amounts of a red substance from our reaction
led to the suggestion that some of this complex may be
being produced. However, IR spectroscopy failed to
support this hypothesis, and employing longer reaction
times did not appear to increase the yield of the
unknown complex.
the unsubstituted complex 1 toward alkynes. However,
the facile nature of alkyne addition to the acetylide
complex and of the carbon-carbon bond formation, CO
insertion, and hydride migration processes that take
place is surprising. Further, the failure to isolate any
of the proposed intermediates in the formation of
complexes such as 3a ,b and 5a ,b suggests that, for
terminal alkynes, these processes occur very readily.
Indeed, the use of equimolar amounts of alkyne and
complex 4 in the above reactions gave the same products
but in greatly reduced yields.
As was previously mentioned, heating complex 1 in
the presence of diphenylacetylene gave the bis-diphen-
ylacetylene species 2, a supposed intermediate in the
formation of the tris-alkyne complexes obtained from
terminal alkynes. With this in mind the reactivity of 4
toward internal alkynes was investigated.
Interestingly, complex 4 reacts with an excess of 1,1-
diphenyl-2-propyn-1-ol (HCtCCPh2OH) to afford the
green complexes [Ru3(CO)6{µ3-η6-C(But)CC(CPh2OH)-
CH2}{µ3-η6-CHC(CPh2OH)COC(CPh2OH)CH}] (5a ) and
[Ru3(CO)6 {µ3-η6-C(But)CCHC(CPh2OH)H}{µ3-η6-CHC-
(CPh2OH)COC(CPh2OH)CH}] (5b) in a combined yield
of 60% and a small amount of the black complex
[Ru3(CO)5(µ-CO){µ3-η5-CC(But )OC(Ph)2CCH}{µ3-η6-
CHC(CPh2OH)COC(CPh2)CH}], discussed later. The
spectroscopic data for the new complexes 5a ,b agree
well with those of complexes 3, suggesting that com-
plexes 5a and 5b are isomers with the structures shown
in Scheme 1. Thus, both complexes contain two fused
metallacycles on one face of the Ru3 triangle (formally
formed through head-to-head coupling of two propargyl
alcohol units with CO insertion) and, on the opposite
face, a butadienic chain. For complexes 3 the latter was
shown to be formed through carbon-carbon bond for-
mation between the incoming alkyne and the acetylide
unit of 1 with hydride migration from the Ru-Ru vertex
to the γ-carbon of the chain.2
Rea ctivity of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4)
tow a r d In ter n a l Alk yn es (P h CtCR). Addition of
diphenylacetylene to complex 4 results in formation of
the novel butadienic species [Ru3(CO)8{µ-η8-C(But)d
CC(Ph)dC(H)Ph}] (6) in high yield. The structure of the
product was confirmed by an X-ray diffraction study and
is discussed later. The spectroscopic properties of com-
plex 6 are consistent with the solid-state structure. The
solution IR spectrum contains a band at 1953 cm-1
,
indicative of an asymmetrically bridging carbonyl unit.
1
The H NMR spectrum shows a doublet at δ 5.6 for the
proton attached to the metal-bound ortho-carbon of the
phenyl group on Cγ and a singlet at δ 5.5 for the proton
on Cγ, suggesting it is held in an exo position.
Ruthenium and osmium clusters containing C4 buta-
dienylic (or related) chains are known; they may be
obtained from diynes10 or via C-C bond forming reac-
tions between cluster-coordinated acetylenes or acetyl-
ides and free C2 ligands11 and also by coupling of the
coordinated acetylide of 1 and a phenylacetylide origi-
nating from a diphenylphosphino ligand.12
However, organometallic complexes containing a
metal-phenyl π-interaction analogous to that seen in
6 are rare. One example is the di-iron complex formed
from deoxygenation of the alkynol HC2C(Me)(OH)Ph.13
The most recent example involving a cluster is the
alkyne complex [Ru3(µ-H)(µ3-PPhCH2PPh2)(µ3-PhC2-
1
The H NMR spectrum of 5a ,b showed the isomers
to be present in a ratio of ca. 3:1 (5a :5b), with the major
isomer being that containing a butadienic chain formed
through head-to-tail coupling of a propargyl alcohol with
the acetylide unit of 4, as indicated by the presence of
signals due to a CH2 group in the 1H, 13C{1H}, and
13C{1H} DEPT NMR spectra. The minor isomer is that
in which the butadienic chain has been formed through
head-to-tail coupling of the alkyne and acetylide, with
the unique proton held endo with respect to the metal
center and appearing as a doublet in the 1H NMR
spectrum with J ) 8 Hz, cf. J ) 11 Hz for complex 3b.
This is expected on steric grounds, as it allows the bulky
CPh2OH group of the chain to be held pointing away
from the metal center.
The disparity in the abundance of the isomers 5a ,b
is puzzling given that complexes 3a ,b were formed in a
1:1 ratio regardless of the reaction conditions. Indeed,
from steric considerations complex 5b might be expected
to be present in greater amounts than 5a , as any steric
interactions between the CPh2OH and But groups would
be minimized. It may be that the differences in the
isomer ratios are due to electronic effects.
(10) See, for example: (a) Corrigan, J . F.; Doherty, S.; Taylor, N.
J .; Carty, A. J . Organometallics 1993, 12, 1365. (b) Corrigan, J . F.;
Taylor, N. J .; Carty, A. J . Organometallics 1994, 13, 3378. (c)
Blenkiron, P.; Enright, G. D.; Taylor, N. J .; Carty, A. J . Organometallics
1996, 15, 2855. (d) Blenkiron, P.; Enright, G. D.; Low, P. J .; Corrigan,
J . F.; Taylor, N. J .; Chi, Y.; Saillard, J .-Y.; Carty, A. J . Organometallics
1998, 17, 2447. (e) Blenkiron, P.; Enright, G. D.; Carty, A. J . J . Chem.
Soc., Chem. Commun. 1997, 483. (f) Bruce, M. I.; Zaitseva, N. N.;
Skelton, B. W.; White, A. H.; Zaitseva, N. N. J . Organomet. Chem.
1997, 536, 93. (g) Bruce, M. I.; Zaitseva, N. N.; Skelton, B. W.; White,
A. H.; Zaitseva, N. N. J . Organomet. Chem. 1998, 558, 197.
(11) See, for example: (a) Bruce, M. I.; Skelton, B. W.; White, A.
H.; Zaitseva, N. N. J . Chem. Soc., Dalton Trans. 1999, 13. (b) Eveland,
R. W.; Raymond, C. C.; Shriver, D. F. Organometallics 1999, 18, 534.
(c) Carty, A. J .; Hogarth, G.; Enright, G.; Frapper, G. J . Chem. Soc.,
Chem. Commun. 1997, 1883. (d) Adams, C. J .; Bruce, M. I.; Skelton,
B. W.; White, A. H. J . Chem. Soc., Chem. Commun. 1996, 969. (e)
Carty, A. J .; Chi, Y.; Blenkiron, P.; Delgado, E.; Enright, G. D.; Wang,
W.; Peng, S.-M.; Lee, G.-H. Organometallics 1996, 15, 5269. (f) Shiu,
C- W.; Chi, Y.; Chung, C.; Peng, S.-M.; Lee, G.-H. Organometallics
1998, 17, 2970. (g) Delgado, E.; Chi, Y.; Wang, W.; Hogarth, G.; Low,
P. J .; Enright, G. D.; Peng, S.-M.; Lee, G.-H.; Carty, A. J . Organo-
metallics 1998, 17, 2936.
Isolation of the tetra-alkynic complexes 3a ,b and 5a ,b
in good yields under the mild reaction conditions used
(20 min, room temperature) suggests that, as expected,
the acetonitrile-derived species 4 is more reactive than
(12) Sappa, E.; Pasquinelli, G.; Tiripicchio, A.; Tiripicchio Camellini,
M. J . Chem. Soc., Dalton Trans. 1989, 601.
(9) Gervasio, G.; Sappa, E.; Lanfredi, A.; Tiripicchio, A. Inorg. Chim.
Acta 1983, 68, 171.
(13) Gervasio, G.; Sappa, E. Organometallics 1993, 12, 1458, and
references therein.

Reactivity of a Triruthenium Acetylide Complex
Organometallics, Vol. 19, No. 12, 2000 2333
F igu r e 2. Molecular structure of 8, showing labeling
scheme.
F igu r e 1. Molecular Structure of 6, showing labeling
scheme.
Interestingly, addition of the alkynol PhCtCCPh2OH
to the acetonitrile derivative 4 afforded [Ru3(CO)7{µ-
η6-C(But)dCC(Ph)dC(CPh2OH)H}(µ-η4-C(CPh2OH)d
CPh)] (8), the structural analogue of complex 2, and
trace amounts of a red complex. Complex 8 was fully
characterized through comparison of its spectroscopic
data with those of complexes 2 and 7 and its structure
firmly established through an X-ray diffraction study.
The solid-state structure showed that the organic frag-
ments in 8 were formed through linkage of the phenyl-
substituted end of the incoming alkyne moiety with the
acetylide ligand of 4 and addition of a second alkyne
molecule on the opposite face of the triruthenium center,
bound in the parallel fashion commonly seen for tri-
metallic µ3-alkyne complexes.15
It should be noted that for the asymmetric alkynes
HCtCBut and HCtCCPh2OH the products existed as
isomers arising from the alkynes undergoing both head-
to-tail and tail-to-tail linkage with the R-carbon of the
acetylide unit in 4 to form a butadienylic chain. Con-
versely, for the bis-alkyne derived species 8, only one
form of the butadienylic chain is seen in the NMR
spectra and the solid-state structure. This may mean
that, of the asymmetric alkynes, only triphenyl-1-
propyn-2-ol shows 100% regiospecificity in its linking,
although such a result would be the opposite of that
expected on steric grounds and thus tends to confirm
that electronic effects control the linkage. However, in
this regard it should be noted that trace amounts of an
unstable red complex were isolated from the reaction
of 4 with triphenyl-1-propyn-2-ol, the IR spectrum of
which bears a striking resemblance to that of the
butadienylic complex [Ru3(CO)8{µ-η8-C(But)dCC(Ph)d
C(H)Ph}] (6). Thus, bands at 2078s, 2046vs, 2011vs,
2007s, 1997vs, 1983m(sh), and 1950w cm-1 agree well
with those seen at 2075vs, 2044vs, 2014vs, 2004vs,
1996m(sh), 1985w, and 1953m cm-1 for 8. Further, the
But)(CO)6] synthesized by Bruce and co-workers via
phenyl transfer from a coordinated dppm molecule of
the acetylide complex [Ru3(µ-H)(µ-dppm)(µ3-C2But)-
(CO)7].14
Reaction of 6 with Me3NO/MeCN followed by addition
of excess alkyne afforded the bis-diphenylacetylene
complex [Ru3(CO)7{µ-η6-C(But)dCC(Ph)dC(H)Ph}(µ-
η4-CPhdCPh)] (7) in 70% yield. The spectroscopic data
for complex 7 suggested that it was an isomer of the
previously isolated species 2, but to allow a proper
comparison the spectroscopic data of 2 were rerecorded.
Pertinent differences in these data are as follows: in
the IR spectrum an extra CO stretch at 2033 cm-1 is
1
present for complex 2; in the H NMR spectra a lower
field chemical shift for the unique proton of the buta-
dienic chain is observed for complex 7 (δ 6.2 cf. δ 3.2
for complex 2). All other data agree well.
We propose, therefore, that the complexes 2 and 7 are
isomeric, differing only in the orientation of the Ph and
H substituents on the γ-carbon of the C4-chain. The
following observations support this:
i. The low-field chemical shift for the unique proton
of 7 is close to that of the equivalent proton in complex
6.
ii. Comparison of the X-ray structures of complexes
24 and 6 (the precursor of complex 7) clearly shows the
proton of 2 is held endo, whereas that of 6 is held exo
(see Figure 2). The 1H NMR spectra of the two com-
plexes show that their structures in solution correspond
with those found in the solid state.
iii. Thermolysis of complex 7 in heptane leads to
formation of complex 2 in 80% yield, along with some
decomposition. Presumably, such an isomerization is
driven by the fact that it minimizes interactions be-
tween the bulky phenyl group and the rest of the cluster.
The last observation suggests that complex 2 is the
thermodynamically favored isomer.
(14) Bruce, M. I.; Humphrey, P.; Skelton, B.; White, A.; Costuas,
K.; Halet, J . J . Chem. Soc., Dalton Trans. 1999, 479.
(15) Deabate, S.; Giordano, R.; Sappa, E. J . Cluster Sci. 1997, 8,
407.

2334 Organometallics, Vol. 19, No. 12, 2000
Charmant et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 6
IR spectrum of the reaction mixture indicates that this
compound is formed in significant amounts during the
reaction but apparently degrades rapidly on alumina,
silica gel, and Florosil, even under an atmosphere of
nitrogen. It is tempting to suggest that the unidentified
red complex may be that containing a butadienylic chain
formed via linkage of the CPh2OH-substituted end of
the alkyne with the acetylide fragment of 4 and sta-
bilization of the complex through coordination of the
phenyl substituent on the other alkyne carbon with the
metal center. Such a result would be in keeping with
all of our earlier observations and with the steric
considerations mentioned above.
Ru(1)-C(13)
Ru(1)-Ru(3)
Ru(1)-Ru(2)
Ru(2)-C(4)
Ru(2)-C(14)
Ru(2)-C(15)
Ru(2)-C(16)
Ru(2)-Ru(3)
Ru(3)-C(14)
Ru(3)-C(13)
Ru(3)-C(18)
Ru(3)-C(17)
C(4)-O(4)
2.088(3)
2.6533(5) C(13)-C(14)
2.9728(5) C(14)-C(15)
1.937(4)
2.179(3)
2.198(3)
2.215(3)
C(12)-C(13)
1.534(4)
1.348(4)
1.422(4)
1.454(4)
1.487(5)
1.473(5)
1.416(4)
1.423(4)
1.412(5)
1.358(5)
1.392(6)
1.362(6)
C(15)-C(16)
C(15)-C(23)
C(16)-C(17)
C(17)-C(18)
2.8383(4) C(17)-C(22)
2.120(3)
2.343(3)
2.439(3)
2.538(3)
1.143(4)
C(18)-C(19)
C(19)-C(20)
C(20)-C(21)
C(21)-C(22)
Ru(3)-Ru(1)-Ru(2) 60.275(12) C(16)-C(15)-Ru(2) 71.38(18)
C(4)-Ru(2)-Ru(1) 61.04(10) C(23)-C(15)-Ru(2) 120.9(2)
Ru(3)-Ru(2)-Ru(1) 54.276(12) C(15)-C(16)-C(17) 123.1(3)
Ru(1)-Ru(3)-Ru(2) 65.449(12) C(15)-C(16)-Ru(2) 70.15(18)
Several conclusions can be drawn from the above
results. The fact that the alkynes RCtCR′ (R ) Ph, R′
) Ph or CPh2OH) yield “unsubstituted” butadienylic
complexes such as 6 strongly suggests that such inter-
mediates are only isolated when a stabilizing phenyl-
metal interaction is possible. Further, the failure to iso-
late such a complex from the reaction with HCtCCPh2-
OH implies that such interactions occur only when the
incoming alkyne contains a terminal phenyl group.
O(4)-C(4)-Ru(2)
161.5(3)
C(17)-C(16)-Ru(2) 108.5(2)
C(18)-C(17)-C(22) 117.5(3)
C(18)-C(17)-C(16) 122.6(3)
C(22)-C(17)-C(16) 119.2(3)
C(14)-C(13)-C(12) 124.9(3)
C(14)-C(13)-Ru(1) 99.8(2)
C(12)-C(13)-Ru(1) 135.0(2)
C(14)-C(13)-Ru(3) 63.56(18) C(18)-C(17)-Ru(3) 69.66(18)
C(12)-C(13)-Ru(3) 128.5(2)
Ru(1)-C(13)-Ru(3) 73.30(9)
C(13)-C(14)-C(15) 156.8(3)
C(13)-C(14)-Ru(3) 81.7(2)
C(15)-C(14)-Ru(3) 119.0(2)
C(13)-C(14)-Ru(2) 124.7(2)
C(22)-C(17)-Ru(3) 114.0(2)
C(16)-C(17)-Ru(3) 95.0(2)
C(19)-C(18)-C(17) 119.4(3)
C(19)-C(18)-Ru(3) 109.1(2)
C(17)-C(18)-Ru(3) 77.36(19)
C(20)-C(19)-C(18) 121.0(4)
Isolation of the butadienylic complex 6 from reaction
of 4 with diphenylacetylene supports the earlier hy-
pothesis that for complexes 2 and 5 alkyne addition has
occurred via initial formation of the butadienylic chain
common to all these clusters. That complex 2 (previously
isolated from thermolysis of 1 in the presence of di-
phenylacetylene) can be formed from 6 further suggests
that 6 is a true intermediate in alkyne oligomerization
in this system. The reaction occurs in two steps, the first
involving coordination of a molecule of diphenylacety-
lene in parallel fashion onto the unsubstituted face of
the ruthenium triangle to form complex 7; a molecule
of CO is also lost during the process. The second step is
a thermally induced isomerization of the butadienylic
chain in complex 7, suggesting that complex 2 repre-
sents the thermodynamically favored form of this spe-
cies.
C(15)-C(14)-Ru(2) 71.77(16) C(19)-C(20)-C(21) 120.3(4)
Ru(3)-C(14)-Ru(2) 82.60(10) C(22)-C(21)-C(20) 120.3(3)
C(14)-C(15)-C(16) 111.7(3)
C(14)-C(15)-C(23) 124.7(3)
C(16)-C(15)-C(23) 123.3(3)
C(14)-C(15)-Ru(2) 70.34(16)
C(21)-C(22)-C(17) 121.4(3)
C(28)-C(23)-C(15) 120.4(3)
C(24)-C(23)-C(15) 121.1(3)
In complex 6 the Ru(1)-Ru(2) edge is asymmetrically
bridged by the C(4)O(4) carbonyl unit having a Ru(2)-
C(4)-O(4) angle of 161.5(3)° and Ru(1)-C(4) and Ru(2)-
C(4) lengths of 2.648(5) and 1.937(4) Å, respectively. The
remaining seven carbonyl groups are coordinated in a
terminal fashion [three to Ru(1) and two to each of Ru(2)
and Ru(3)]. The triruthenium center is bridged by an
organic fragment formed through carbon-carbon bond
formation between one end [C(15)] of a molecule of
diphenylacetylene and the R-carbon [C(14)] of the
acetylide unit of complex 4, and hydride migration from
the cluster to C(16) of the alkyne. The ligand bridges
all three metal atoms, acting as a σ-donor to Ru(1) and
π-donor to Ru(2) and Ru(3), formally donating eight
electrons to the metal center. Some donation of the
π-electron density between the phenyl carbons of C(17)-
C(18) to Ru(3) is occurring, with Ru(3)-C(17) and
Ru(3)-C(18) distances of 2.538(3) and 2.439(3) Å,
respectively. This interaction results in localization of
the π-bonding in the phenyl ring, with the C(19)-C(20)
and C(21)-C(22) bonds [of length 1.358(5) and 1.362(6)
Å] being significantly shorter than the remaining four
C-C bonds (all greater than 1.390 Å). Similar results
were obtained for [Ru3(µ-H)(µ3-PPhCH2PPh2)(µ3-PhC2-
But)(CO)6] by Bruce et al.14
It is interesting to note that although complexes such
as 3 and 5, derived from addition of three molecules of
alkyne to complex 4, are readily isolated when terminal
alkynes are used, no analogous species were obtained
from the internal alkynes. One attempt was made at
forming such complexes through formation of the aceto-
nitrile derivative of complex 2 and addition of excess
diphenylacetylene, but the reaction yielded only starting
material and trace amounts of several brown products,
the IR spectra of which were inconsistent with com-
plexes 3 and 5. Prolonged heating of complex 2 in the
presence of excess diphenylacetylene also proved unsuc-
cessful.
X-r a y Str u ctu r es of [Ru 3(CO)8{µ-η8-C(Bu t)dCC-
(P h )dC(H)P h }] (6) a n d [Ru 3(CO)7{µ-η6-C(Bu t)dCC-
(P h )dC(CP h 2OH)H}(µ-η4-C(CP h 2OH)dCP h )] (8). The
molecular structures of complexes 6 and 8 are shown
in Figures 1 and 2, and their relevant structural
parameters presented in Tables 1 and 2, respectively.
The butadienic chain of complex 6 is isomeric with
that found in complex 2. The chains differ from each
other only in the respective orientations of the phenyl
and protonic substituents on C(16). Presumably, this
difference is due to the fact that in complex 6 the phenyl
group is coordinated to Ru(3) via carbons C(17) and
C(18), acting as a two-electron donor ligand and so
requiring to be held endo with respect to the metal
center.
For both complexes 6 and 8 the three ruthenium
atoms form an isosceles triangle, of which the Ru(1)-
Ru(3) edge [2.6533(5) Å, 6; 2.6823(10) Å, 8] is signifi-
cantly shorter than both the Ru(1)-Ru(2) and Ru(2)-
Ru(3) edges [2.9728(5) and 2.8383(4) Å, 6; 2.8672(10)
and 2.8341(10) Å, 8, respectively].

Reactivity of a Triruthenium Acetylide Complex
Organometallics, Vol. 19, No. 12, 2000 2335
Ta ble 2. Selected Bon d Len gth s [Å] a n d An gles
numerous homo- and hetero-trinuclear species and
comparisons have been made between the structural
parameters for such compounds.10 Interestingly, the
alkyne molecule in 8 matches that of the equivalent
diphenylacetylene ligand in 2, in being slightly asym-
metric in its bonding to the ruthenium atoms. Thus,
Ru(2)-C(14), Ru(3)-C(13), Ru(1)-C(13), and Ru(1)-
C(14) bond lengths of 2.127(7), 2.395(8), 2.109(7), and
2.223(6) Å, respectively, are found for 8 [cf. the corre-
sponding lengths of 2.07(2), 2.33(2), 2.10(2), and 2.21(2)
Å previously found for 2].
In principle, an alternative isomer of 8, in which the
C(13) and C(14) substituents were exchanged, could
exist. That this is not the case may be due to the
observed structure having interactions between the
alkyne molecule and the carbonyl groups of the cluster
at a minimum.
The butadienylic chains of both 6 and 8 are best
represented by the allenyl-allyl description previously
used for the analogous organic fragments in the solid-
state structures of complexes 2 and 3a . Thus, the C(13)-
C(16) chain of 6 and the C(8)-C(11) chain of 8 both show
extensive delocalization, with C-C bond distances in
the range 1.348(4)-1.454(4) Å (6) and 1.358(10)-
1.441(10) Å (8). Carbons C(14), C(15), and C(16) in
complex 6 and C(9), C(10), and C(11) of complex 8 form
allylic fragments coordinated to Ru(2) with metal-
carbon distances in the range 2.179(3)-2.215(3) Å (6)
and 2.147(7)-2.295(7) Å (8) [cf. 2.12(1)-2.32(1) Å for 2
and 2.163(7)-2.253(7) Å for 3a ]. Carbon C(14) of
complex 6 has distorted sp-hybridization and, along with
carbons C(13) and C(15), forms an allenyl fragment
coordinated in a σ-fashion to Ru(1) [Ru(1)-C(13) 2.088(3)
Å: cf. 2.04(1) and 2.058(6) Å for 2 and 3a , respectively]
and in a π-fashion to Ru(2) and Ru(3) with Ru-C
distances in the range 2.120(3)-2.343(3) Å [cf. 2.12(1)-
2.27(2) Å for 2 and 2.163(7)-2.287(6) Å for 3a ]. Carbons
C(8)-C(9)-C(10) form a similar allenyl moiety in 8,
having a distance of 2.038(8) Å for the Ru(1)-C(8)
σ-bond and Ru-C distances in the range of 2.147(7)-
2.298(7) Å for the π-interactions with Ru(2) and Ru(3).
The large central angles within these two C3-chains
[156.8(3)° and 146.3(6)° for 6 and 8, respectively] are
also in keeping with the angles seen for the corre-
sponding allenyl fragments in complexes 2 [146°], 3a
[151.8(7)°], and other allenyl complexes.17
[d eg] for 8‚1/2H2O
Ru(1)-C(8)
Ru(1)-C(13)
Ru(1)-C(14)
Ru(1)-C(9)
Ru(1)-Ru(3)
Ru(1)-Ru(2)
Ru(2)-C(14)
Ru(2)-C(9)
Ru(2)-C(10)
Ru(2)-C(11)
Ru(2)-Ru(3)
Ru(3)-C(9)
Ru(3)-C(8)
Ru(3)-C(13)
C(8)-C(9)
2.038(8)
2.109(7)
2.223(6)
2.422(7)
2.6823(10) C(11)-C(12)
2.8672(10) C(12)-O(8)
2.127(7)
2.147(7)
2.246(7)
2.295(7)
C(8)-C(16)
C(9)-C(10)
C(10)-C(11)
C(10)-C(20)
1.523(10)
1.441(10)
1.414(10)
1.495(9)
1.528(10)
1.437(9)
1.525(10)
1.536(11)
1.377(11)
1.491(10)
1.555(10)
1.428(8)
1.537(10)
1.555(9)
2.0411
C(12)-C(32)
C(12)-C(26)
C(13)-C(14)
C(13)-C(38)
2.8341(10) C(14)-C(15)
2.176(7)
2.298(7)
2.395(8)
C(15)-O(9)
C(15)-C(44)
C(15)-C(50)
1.358(10) O(10)‚‚‚H(9)
Ru(3)-Ru(1)-Ru(2) 61.31(3)
Ru(3)-Ru(2)-Ru(1) 56.13(2)
Ru(1)-Ru(3)-Ru(2) 62.56(3)
C(32)-C(12)-C(26) 108.1(6)
C(11)-C(12)-C(26) 111.5(6)
C(14)-C(13)-C(38) 131.8(7)
C(14)-C(13)-Ru(1) 76.0(4)
C(38)-C(13)-Ru(1) 132.4(5)
C(14)-C(13)-Ru(3) 108.9(5)
C(38)-C(13)-Ru(3) 116.2(5)
Ru(1)-C(13)-Ru(3) 72.8(2)
C(13)-C(14)-C(15) 127.7(6)
C(13)-C(14)-Ru(2) 108.0(5)
C(15)-C(14)-Ru(2) 122.5(5)
C(13)-C(14)-Ru(1) 67.0(4)
C(15)-C(14)-Ru(1) 128.5(4)
Ru(2)-C(14)-Ru(1) 82.4(2)
O(9)-C(15)-C(44) 107.9(5)
O(9)-C(15)-C(50) 108.9(6)
C(44)-C(15)-C(50) 112.3(6)
O(9)-C(15)-C(14) 104.4(5)
C(44)-C(15)-C(14) 115.6(6)
C(50)-C(15)-C(14) 107.3(5)
C(21)-C(20)-C(10) 120.3(6)
C(25)-C(20)-C(10) 121.4(6)
C(27)-C(26)-C(12) 123.5(7)
C(31)-C(26)-C(12) 117.5(8)
C(33)-C(32)-C(12) 120.4(7)
C(37)-C(32)-C(12) 121.2(6)
C(43)-C(38)-C(13) 121.7(7)
C(39)-C(38)-C(13) 121.7(6)
C(49)-C(44)-C(15) 124.6(6)
C(45)-C(44)-C(15) 117.4(6)
C(51)-C(50)-C(15) 121.3(7)
C(55)-C(50)-C(15) 120.1(6)
C(9)-C(8)-C(16)
C(9)-C(8)-Ru(1)
131.0(7)
88.6(5)
C(16)-C(8)-Ru(1) 135.8(6)
C(9)-C(8)-Ru(3)
67.5(4)
C(16)-C(8)-Ru(3) 131.5(5)
Ru(1)-C(8)-Ru(3) 76.2(2)
C(8)-C(9)-C(10)
C(8)-C(9)-Ru(2)
146.3(6)
134.2(6)
C(10)-C(9)-Ru(2) 74.6(4)
C(8)-C(9)-Ru(3)
77.3(4)
C(10)-C(9)-Ru(3) 131.6(5)
Ru(2)-C(9)-Ru(3) 81.9(2)
C(8)-C(9)-Ru(1)
57.3(4)
C(10)-C(9)-Ru(1) 139.5(5)
Ru(2)-C(9)-Ru(1) 77.5(2)
Ru(3)-C(9)-Ru(1) 71.1(2)
C(11)-C(10)-C(9)
C(11)-C(10)-C(20) 124.9(6)
C(9)-C(10)-C(20) 117.9(6)
116.9(6)
C(11)-C(10)-Ru(2) 73.7(4)
C(9)-C(10)-Ru(2) 67.2(4)
C(20)-C(10)-Ru(2) 124.8(5)
C(10)-C(11)-C(12) 126.5(6)
C(10)-C(11)-Ru(2) 70.0(4)
C(12)-C(11)-Ru(2) 126.2(5)
O(8)-C(12)-C(32) 106.8(6)
O(8)-C(12)-C(11) 110.2(6)
C(32)-C(12)-C(11) 109.4(6)
O(8)-C(12)-C(26) 110.7(6)
The solid-state structure of complex 8 contains seven
carbonyl groups all of which are bound in a terminal
fashion to the ruthenium atoms [three to Ru(3) and two
to each of Ru(1) and Ru(2)] despite the fact that the IR
spectrum of 8 clearly shows a band at 1934 cm-1, in
the range normally associated with asymmetrically
bridging carbonyl groups.16 A similar situation was seen
for the analogous complex [Ru3(CO)7{µ-η6-C(But)d
CC(Ph)dC(Ph)H}(µ-η4-CPhdCPh)] (2).4 Once again, the
butadienylic moiety of 8 has been formed through
linkage of C(10) of the incoming alkyne unit and the
R-carbon C(9) of the acteylide group. The resulting chain
acts as a six-electron donor, bridging all three metal
atoms through a combination of σ- and π-interactions.
On the opposite side of the triangular cluster is found
a molecule of PhC2CPh2OH, of which the CPh2OH-
substituted carbon C(14) is σ-bound to Ru(2), the
phenyl-substituted carbon C(13) is σ-bound to Ru(3),
and the C(13)-C(14) bond is π-bound to Ru(1). This
bonding mode, in which the alkyne is oriented nearly
parallel to a metal-metal edge, has been described for
Silica -Med ia ted Deh yd r a tion of [Ru 3(CO)6{µ3-η6-
C(Bu t)CC(CP h 2OH)CH2}{µ3-η6-CHC(CP h 2OH)COC-
(CP h 2OH)CH}] (5a ). Coordination of propargyl alco-
hols at tri-iron centers is usually accompanied by
spontaneous dehydration of the alkynol moiety.18,19 In
contrast, such dehydration processes at Ru3 and Os3
centers are only observed under acidic conditions.20-23
(17) (a) Sappa, E.; Manotti Lanfredi, A. M.; Tiripicchio, A. Inorg,
Chim. Acta 1979, 36, 197. (b) Aime, S.; Milone, L.; Osella, D.; Valle,
M. J . Chem. Res., Synop. 1978, 77, and references therein.
(18) See, for example: Sappa, E.; Predieri, G.; Tiripicchio, A.;
Ugozzoli, F. Gazz. Chim. Ital. 1995, 125, 51.
(19) Gervasio, G.; Marabello, D.; Sappa, E. J . Chem. Soc., Dalton
Trans. 1997, 1851.
(20) Aime, S.; Deeming, A. J . J . Chem. Soc., Dalton Trans. 1981,
828.
(21) Aime, S.; Deeming, A. J .; Hursthouse, M. B.; Baker-Dirks, J .
D. J . J . Chem. Soc., Dalton Trans. 1982, 1625.
(22) Ermer, S.; Karpelus, R.; Miura, S.; Rosenborg, E.; Tiripicchio,
A.; Manotti Lanfredi, A. M. J . Organomet. Chem. 1980, 187, 81.
(23) Gervasio, G.; Gobetto, R.; King, P. J .; Marabello D.; Sappa, E.
Polyhedron 1998, 17, 2937.
(16) Cotton, F. A.; Troup, J . M. J . Am. Chem., Soc. 1974, 96, 1233;
1974, 96, 123.

2336 Organometallics, Vol. 19, No. 12, 2000
Sch em e 2. Silica -Med ia ted Deh yd r a tion of 5a
Charmant et al.
There have been several reports on the effect of sup-
ports, such as silica gel, in promoting hydration and
dehydration reactions,24,25 and we have recently shown
how the HCCC(Me)(Ph)OH-derived acetylide complex
[Ru3(CO)9(µ-H){µ3-η5-C2C(Me)(Ph)OH}] undergoes de-
hydration on TLC silica plates, albeit at high temper-
ature.23
We now report that reaction of the isomers 5 with
silica gel results in dehydration and formation of
[Ru3(CO)5(µ-CO){µ3-η5-CC(But )OC(Ph)2CCH}{µ3-η6-
CHC(CPh2OH)COC(CPh2)CH}] (9) (see Scheme 2). Thus,
complex 9 can be afforded either during chromatography
of 5 on silica gel or stirring of a dichloromethane slurry
of 5 and silica gel (the yield varying according to the
amount of time spent on the silica support but never
exceeding 40%). The dehydration is concomitant with
decomposition of most of the starting material.
The molecular structure of 9 was determined via a
single-crystal X-ray diffraction study (discussed below)
and agrees well with the spectoscopic data for solutions.
In the IR spectrum a stretching frequency of 1857m
cm-1 is observed, indicative of a bridging carbonyl. The
organic fragment A of 9 is a dehydroxylated version of
the metallacycles in 5, the loss of OH having altered
the bonding slightly. Thus, in the 1H NMR spectrum
only one OH group is observed (δ 4.4) and there is a
signal at δ 11.7 (s, 1H) typical of a carbene type proton.26
The presence of a carbene unit is supported by the
13C{1H} NMR spectrum, in which a signal at 236.7 ppm
is seen for the CH unit. A second signal at 233.3 ppm is
observed for the CO carbon of A, suggesting that it too
may have some carbene type character. A heterocyclic
ligand B is found on the opposite face of the metal center
from A. This ligand is best described as a furan ring
with exocyclic double bond and is clearly derived from
the butadienyl ligand of 5 through loss of a proton and
ring formation. The presence of a CH2 unit in B implies
that 9 is the dehydration product of complex 5a and not
5b, not withstanding the fact that, presumably, similar
dehydration of 5b would afford a six-membered hetero-
cycle and not the five-membered one found in 9. The
lack of a dehydration product for 5b may be because
the oxygen atom involved in cyclization is held too far
away from the But-substituted carbon for ring for-
mation to occur. In contrast, the CPh2OH unit of 5a is
much closer and orientated toward the relevant carbon
atom.
The failure to retrieve any significant amounts of
complex 5b from the silica-mediated reactions leads us
to propose that this isomer undergoes dehydration, but,
in the absence of ring formation, decomposition occurs.
Overall, the formation of 9 from 5a requires loss of
one water molecule via abstraction of H and OH from
organic fragments on opposing faces of the Ru3 triangle,
ring formation, and movement of a carbonyl unit from
a terminal to a bridging position. The good yield (over
50%, based on 5a ) and the fact that the reaction is
surface mediated add to its interest.
X-r a y St r u ct u r e of [R u 3(CO)5(µ-CO){µ3-η5-CC-
(Bu t)OC(P h )2CCH}{µ3-η6-CHC(CP h 2OH)COC(CP h 2)-
CH}] (9). The molecular structure of complex 9 is shown
in Figure 3, with the two bridging organic fragments
shown individually in Figures 4 and 5. The relevant
structural parameters are given in Table 3.
(24) Deabate, S.; King, P. J .; Sappa, E. In Metal Clusters in
Chemistry; Braunstein, P., Oro, L. A., Raithby, P. R., Eds.; Wiley-
VCH: Weinheim, 1999.
(25) Gervasio, G.; Sappa, E. J . Organomet. Chem. 1995, 498, 73.
(26) Transition Metal Carbene Complexes; Verlag Chimie GmbH:
Weinheim, 1983.
The three ruthenium atoms form a triangle with bond
lengths of 2.8511(5) [Ru(1)-Ru(2)], 2.7661(5) [Ru(1)-
Ru(3)], and 2.8065(5) Å [Ru(2)-Ru(3)]. There are two

Reactivity of a Triruthenium Acetylide Complex
Organometallics, Vol. 19, No. 12, 2000 2337
Ta ble 3. Selected Bon d Len gth s [Å] a n d An gles
[d eg] for 9‚CH2Cl2
Ru(1)-C(1)
Ru(1)-C(18)
Ru(1)-C(4)
Ru(1)-C(12)
Ru(1)-Ru(3)
Ru(1)-Ru(2)
Ru(2)-C(6)
Ru(2)-C(8)
Ru(2)-C(7)
Ru(2)-C(18)
Ru(2)-C(12)
Ru(2)-Ru(3)
Ru(3)-C(6)
Ru(3)-C(11)
Ru(3)-C(4)
Ru(3)-C(5)
Ru(3)-C(12)
C(1)-C(2)
1.944(4) C(2A)-C(30)
1.950(5) C(2A)-C(20)
2.027(4) C(4)-O(3)
2.086(4) C(4)-C(5)
2.7639(9) C(5A)-O(5A)
2.8486(8) C(5A)-C(40)
2.082(4) C(5A)-C(50)
2.246(4) C(5A)-C(5)
2.262(4) C(5)-C(6)
2.316(4) C(7)-C(8)
2.485(4) C(8)-C(12)
2.8032(8) C(8)-C(9)
2.244(4) C(9)-O(10)
2.244(4) C(9)-C(60)
2.254(4) C(9)-C(70)
2.304(4) C(11)-O(10)
2.341(4) C(11)-C(12)
1.420(5) C(11)-C(80)
1.376(5) C(18)-O(18)
1.398(5)
1.479(6)
1.479(5)
1.390(4)
1.441(5)
1.427(5)
1.533(5)
1.537(5)
1.558(5)
1.408(5)
1.387(5)
1.454(5)
1.558(5)
1.454(5)
1.515(6)
1.553(6)
1.441(4)
1.442(6)
1.543(6)
1.172(5)
C(2)-C(2A)
C(2)-O(3)
C(18)-Ru(1)-Ru(2) 53.86(12) O(10)-C(9)-C(60)
Ru(3)-Ru(1)-Ru(2) 59.91(2) O(10)-C(9)-C(70)
C(18)-Ru(2)-Ru(1) 42.85(11) C(60)-C(9)-C(70)
Ru(3)-Ru(2)-Ru(1) 58.55(2) O(10)-C(9)-C(8)
Ru(1)-Ru(3)-Ru(2) 61.55(2) C(60)-C(9)-C(8)
109.0(3)
107.2(3)
109.4(3)
103.3(3)
117.1(4)
110.1(3)
C(2)-C(1)-Ru(1)
C(2A)-C(2)-O(3)
C(2A)-C(2)-C(1)
O(3)-C(2)-C(1)
C(2)-C(2A)-C(30)
C(2)-C(2A)-C(20)
117.8(3) C(70)-C(9)-C(8)
F igu r e 3. Molecular structure of 9.
117.2(4) O(10)-C(11)-C(12) 107.9(3)
128.5(4) O(10)-C(11)-C(80) 108.5(3)
114.3(4) C(12)-C(11)-C(80) 128.9(4)
123.8(4) O(10)-C(11)-Ru(3) 112.8(2)
118.9(4) C(12)-C(11)-Ru(3) 75.4(2)
C(30)-C(2A)-C(20) 117.2(4) C(80)-C(11)-Ru(3) 119.9(3)
O(3)-C(4)-C(5)
O(3)-C(4)-Ru(1)
C(5)-C(4)-Ru(1)
O(3)-C(4)-Ru(3)
C(5)-C(4)-Ru(3)
Ru(1)-C(4)-Ru(3)
115.4(3) C(11)-C(12)-C(8)
117.7(3) C(11)-C(12)-Ru(1) 126.1(3)
126.6(3) C(8)-C(12)-Ru(1) 123.9(3)
126.4(3) C(11)-C(12)-Ru(3) 68.1(2)
73.5(2) C(8)-C(12)-Ru(3) 119.9(3)
80.24(13) Ru(1)-C(12)-Ru(3) 77.03(13)
109.1(3)
O(5A)-C(5A)-C(40) 110.2(3) C(11)-C(12)-Ru(2) 124.6(3)
O(5A)-C(5A)-C(50) 105.2(3) C(8)-C(12)-Ru(2)
C(40)-C(5A)-C(50) 110.7(3) Ru(1)-C(12)-Ru(2) 76.56(13)
O(5A)-C(5A)-C(5) 110.2(3) Ru(3)-C(12)-Ru(2) 70.96(11)
63.3(2)
C(40)-C(5A)-C(5)
C(50)-C(5A)-C(5)
C(6)-C(5)-C(4)
C(6)-C(5)-C(5A)
C(4)-C(5)-C(5A)
C(6)-C(5)-Ru(3)
C(4)-C(5)-Ru(3)
C(5A)-C(5)-Ru(3)
C(5)-C(6)-Ru(2)
C(5)-C(6)-Ru(3)
Ru(2)-C(6)-Ru(3)
C(8)-C(7)-Ru(2)
C(7)-C(8)-C(12)
C(7)-C(8)-C(9)
C(12)-C(8)-C(9)
C(7)-C(8)-Ru(2)
C(12)-C(8)-Ru(2)
C(9)-C(8)-Ru(2)
110.0(3) O(18)-C(18)-Ru(1) 147.0(3)
110.4(3) O(18)-C(18)-Ru(2) 129.5(3)
115.6(4) Ru(1)-C(18)-Ru(2) 83.30(17)
122.7(4) C(25)-C(20)-C(2A) 118.4(4)
121.6(4) C(21)-C(20)-C(2A) 123.7(4)
69.7(2)
69.7(2)
C(31)-C(30)-C(2A) 119.0(4)
C(35)-C(30)-C(2A) 123.4(4)
F igu r e 4. Heterocyclic unit of 9. Other ligands removed
for clarity.
128.7(3) C(45)-C(40)-C(5A) 123.1(4)
129.3(3) C(41)-C(40)-C(5A) 119.1(4)
74.3(2)
C(51)-C(50)-C(5A) 121.1(4)
80.69(14) C(55)-C(50)-C(5A) 119.7(4)
71.5(2)
C(65)-C(60)-C(9)
121.3(4)
120.9(4)
124.9(4)
116.9(4)
111.7(3)
110.9(3)
124.1(4) C(61)-C(60)-C(9)
128.8(4) C(75)-C(70)-C(9)
107.0(4) C(71)-C(70)-C(9)
72.7(2)
81.3(2)
123.7(3)
C(4)-O(3)-C(2)
C(11)-O(10)-C(9)
C(18) 1.950(8) Å, Ru(2)-C(18) 2.316(4) Å; Ru(1)-C(18)-
O(18) 147.0(3)°, Ru(2)-C(18)-O(18) 129.5(3)°].
One face of the Ru3 triangle is capped by a heterocyclic
ring derived by loss of a proton from the hydroxyl group
of the C4-chain in 5a and carbon-oxygen bond forma-
tion between O(10) and C(11). The atoms C(8), C(9),
O(10), C(11), and C(12) make up a furan ring with an
exocyclic double bond [C(7)-C(8)]. The ring and the
double bond are approximately coplanar, with none of
the constituent atoms deviating more than 0.092 Å from
the mean plane. The plane of the organic ligand forms
an angle of 41.4° with the Ru3 plane.
F igu r e 5. Metallacyclic unit of 9. Other ligands removed
for clarity.
terminal carbonyl ligands on each of Ru(2) and Ru(3)
and one on Ru(1). The longer Ru(1)-Ru(2) bond is
asymmetrically bridged by a carbonyl ligand [Ru(1)-

2338 Organometallics, Vol. 19, No. 12, 2000
Charmant et al.
gas, silica gel, and trimethylamine-N-oxide are all commercial
products and were used as supplied.
All reactions were carried out under a nitrogen atmosphere
using Schlenk techniques. Solvents were dried by distillation
over the following reagents: hexane, heptane, toluene, and
diethyl ether from sodium; acetonitrile and dichloromethane
from calcium hydride.
Column chromatography was carried out on alumina (Brock-
mann activity II), under nitrogen, unless otherwise stated.
Products were eluted using hexane and dichloromethane in
variable v/v proportions according to the alkyne substituents.
The products were recrystallized from heptane or hexane-
CH2Cl2 mixtures at -20 °C.
F igu r e 6. Alternative bonding modes of heterocyclic
fragment of 9.
Solution IR spectra were recorded with a Perkin-Elmer 1710
Fourier transform spectrometer, using calcium fluoride cells
of 1 mm path length. 1H and 13C{1H} NMR were obtained
using J EOL GX-270, GX-400 and Lambda-300 spectrometers.
Elemental analyses were performed by the Microanalytical
Laboratory of the School of Chemistry, University of Bristol.
Fast atom bombardment mass spectra were recorded on a
Fisons Autospec instrument.
Syn th esis of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4). A
dichloromethane solution (150 cm3) of complex 1 (360 mg; 0.58
mmol) was cooled to -78 °C, by means of an acetone/dry ice
slush bath, and 9.8 cm3 of a solution of (CH3)3NO (0.50 g) in
acetonitrile (100 cm3) was added dropwise over 5 min. The
mixture was stirred and allowed to warm to room temperature.
Removal of solvent, under reduced pressure, and chromatog-
raphy of the residue, eluting with hexane/dichloromethane/
acetonitrile (14:5:1), yielded two yellow bands corresponding
to the starting complex 1 (ca. 10%) and [Ru3(CO)8(NCMe)(µ-
H)(µ-C2But)] (4) (ca. 80%), respectively. Compound 4 was
collected from the chromatography column and the solvent
removed, under reduced pressure, until precipitation com-
menced, upon which it was placed in the freezer to facilitate
further precipitation. The solvent was decanted from the
yellow microcrystalline solid produced. It should be noted that
[Ru3(CO)8(NCMe)(µ-H)(µ-C2But)] (4) decomposes and ought to
be used immediately or stored as a solid in the freezer for no
longer than 24 h.
The heterocycle bridges all three ruthenium atoms,
formally donating five electrons to the metal center,
although the exact mode of bonding is unclear. The
Ru(1)-C(12) distance of 2.086(4) Å is typical of a Ru-C
σ-bond, whereas Ru(2)-C(7), Ru(2)-C(8), and C(7)-C(8)
lengths of 2.262(4), 2.246(4), and 1.387(5) Å, respec-
tively, are suggestive of an η2-type interaction. Given
the Ru(3)-C(11), Ru(3)-C(12), and Ru(2)-C(12) dis-
tances of 2.244(4), 2.341(4), and 2.485(4) Å, it is sug-
gested that the C(11)-C(12) bond is interacting with
Ru(3) in a η2-manner with C(12) being held accidentally
within bonding distance of Ru(2) (see Figure 6a).
However, the Ru(3)-C(12) bond is longer than expected
for a simple π-interaction, and a bonding scheme in
which C(12) interacts with both Ru(2) and Ru(3) as part
of a two-center one-electron bond may be more accurate
(see Figure 6b). This would be in keeping with the
C(11)-C(12) and C(8)-C(12) bond lengths, which imply
some delocalization of the electron density across C(11)-
C(12)-C(8).
Structures containing a carbon interacting with all
three metals of a trimetallic center, although rare, are
known and have been the subject of theoretical stud-
ies.27,28
Com p lex 4. IR (νCO) in heptane: 2080m, 2051s, 2042vs,
The other face of the Ru3 triangle is capped by an
organic ligand derived from that of 5a via loss of OH
from C(2A). The C(4)-C(5)-C(6) chain forms two σ-bonds
[Ru(1)-C(4) 2.027(4) and Ru(2)-C(6) 2.082(4) Å] and
an allylic π-interaction with Ru(3) [Ru(3)-C(4) 2.254(4),
Ru(3)-C(5) 2.304(4), and Ru(3)-C(6) 2.244(4) Å]. How-
ever, the C(4)-C(5) and C(5)-C(6) bond lengths of
1.441(5) and 1.408(5) Å, respectively, suggest the C(5)-
C(6) bond contains the greater double-bond character.
The atoms Ru(1), C(1), C(2), O(3), C(4), and C(2A) form
a metallacyle with an exocyclic double bond, with all of
the atoms being approximately coplanar (none of the
atoms deviating more than 0.067 Å from the mean
plane). This, together with the short Ru(1)-C(1) and
Ru(1)-C(4) distances [1.944(4) and 2.027(4) Å, respec-
tively] and the distinctly trigonal planar configuration
of both C(1) and C(4), suggests that both these carbons
can be considered as carbene carbon atoms.
2019vs, 2010vs, 1987 m, 1966m, 1953m cm-1
.
Rea ction of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4) w ith
CO. A dichloromethane solution (20 cm3) of [Ru3(CO)8(NCMe)-
(µ-H)(µ-C2But)] (4) (0.10 g; 0.16 mmol) was purged with CO
gas for 5 min. The solvent was removed, under reduced
pressure, and the residue washed with 2 × 10 cm3 portions of
diethyl ether to afford yellow crystalline [Ru3(CO)9(µ-H)(µ-
C2But)] (1) (94 mg; 95%).
Rea ction of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4) w ith
HCtCBu t. To a mixture of [Ru3(CO)8(NCMe)(µ-H)(µ-C2But)]
(4) (0.40 g; 0.63 mmol) and tert-butyl acetylene (0.10 cm3; 0.82
mmol) was added dichloromethane (30 cm3). The mixture was
stirred for 20 min, during which time the solution changed
color from yellow to brown. Chromatography resulted in the
isolation of [Ru3(CO)9(µ-H)(µ-C2But)] (1) (0.04 g; 10%) and the
known green complexes [Ru3(CO)6{µ3-η6-C(But)CC(But)CH2}-
{µ3-η6-CHC(But)COC(But)CH}] (3a) and [Ru3(CO)6{µ3-η6-C(But)-
CCH(But)C(But)H}{µ3-η6-CHC(But)COC(But)CH}] (3b) (0.26 g;
50%). A trace amount of a red complex was also isolated but
could not be characterized.
Com p lexes 3a ,b. IR (νCO) in heptane: 2045vs, 2024vs,
Exp er im en ta l Section
1
1996vs, 1870w cm-1. H NMR (CDCl3): 3a δ 8.4 (s, 1H), 7.0
Gen er a l Com m en ts. [Ru3(CO)9(µ-H)(µ-C2But)] (1) was
(s, 1H), 3.9 (s, 1H), 2.2 (s, 18H), 1.5 (s, 9H), 1.2(s, 9H) and 0.9
(s, 1H); 3b δ 8.2 (s, 1H), 6.8 (s, 1H), 4.8 (δ, J ) 10 Hz, 1H), 2.7
(δ, J ) 10 Hz, 1H), 2.2 (s, 18H), 1.4 (s, 9H), and 1.2 (s, 9H).
Rea ction of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)] (4) w ith
HCtCC(P h )2OH. To a mixture of [Ru3(CO)8(NCMe)(µ-H)(µ-
C2But)] (4) (1.0 g; 1.58 mmol) and 1,1-diphenyl-2-propyn-1-ol
(3.28 g; 15.75 mmol) was added dichloromethane (30 cm3). The
mixture was stirred for 20 min, during which time the solution
prepared according to the literature method.29 Alkynes, CO
(27) Granozzi, G.; Tondello, E.; Cessarin, M.; Aime, S.; Osella, D.
Organometallics 1983, 2, 430.
(28) Halet, J . F.; Saillard, J . Y.; Lissilour, R.; J aouen McGlinchy,
M. J . Inorg. Chem. 1985, 24, 218.
(29) Sappa, E.; Gambino, O.; Milone, L.; Cetini, G. J . Organomet.
Chem. 1972, 39, 169.

Reactivity of a Triruthenium Acetylide Complex
Organometallics, Vol. 19, No. 12, 2000 2339
changed color from yellow to brown. Chromatography afforded
3 bands. The first, yellow, yielded 32 mg of [Ru3(CO)9(µ-H)-
(µ-C2But)] (1) (10%); the second, black, gave 94 mg of [Ru3-
(CO)5(µ-CO){µ3-η5-CC(But)OC(Ph)2CCH}{µ3-η6-CHC(CPh2OH)-
COC(CPh2) CH}] (9) (5%); the third, green, afforded 1.14 g of
the inseparable mixture of isomers [Ru3(CO)6{µ3-η6-C(But)CC-
(CPh2OH)CH2}{µ3-η6-CHC(CPh2OH)COC(CPh2OH)CH}] (5a )
and [Ru3(CO)6{µ3-η6-C(But)CCHC(CPh2OH)H}{µ3-η6-CHC-
(CPh2OH)COC(CPh2OH)CH}] (5b) (60%).
Com p lex 9. IR (νCO) in heptane: 2051s, 2025vs, 2002m,
1980m, 1857m cm-1. 1H NMR (CDCl3): δ 11.7 (s, 1H, RudCH),
8.1 (s, 1H, µ-CH), 7.2 (m, 30H, 6×Ph), 4.4 (s, 1H, OH), 4.0 (δ,
J ) 2 Hz, 1H, CH2), 3.0 (δ, J ) 2 Hz, 1H, CH2) and 0.9 (s, 9H,
But). 13C{1H} NMR (CDCl3): δ 236.7 (RudCH), 233.3 (RudC),
220.1 (µ-CO), 199.8-188.9 (all CO), 161.0 (CH), 147.5-140.0
(all ipso Ph), 130.8-124.8 (all Ph), 45.1 (CH2), 39.2 (CMe3),
32.7 (3×Me), 170.6, 170.2, 110.8, 97.4, 90.9, and 83.1 (all
quaternary carbons). Assignments were aided by a DEPT 135°
experiment. FAB mass spectrum: P+ 1189 m/z + peaks for
consecutive loss of 6 carbonyls. Anal. Found: C% 58.24, H%
3.54. Calc: C% 58.60, H% 3.70.
FAB mass spectrum: P+ 789 m/z + peaks for consecutive loss
of 7 carbonyls. Anal. Found: C% 42.73, H% 2.49. Calc: C%
42.70, H% 2.60.
Rea ction of th e Aceton itr ile Der iva tive of [Ru 3(CO)8-
{µ3-η8-C(Bu t)dCC(P h )dC(H)P h }] (6) w ith P h CtCP h . To
a dichloromethane solution (20 cm3) of [Ru3(CO)8{µ3-η8-C(But)d
CC(Ph)dC(H)Ph}] (6) (200 mg; 0.25 mmol) was added 4.6 cm3
of a solution of Me3NO (500 mg) in acetonitrile (100 cm3). The
mixture was stirred for 30 min, after which time IR spectros-
copy showed only the presence of a new complex having bands
at 2072w, 2061w, 2041vs, 2023s(sh), 2012vs, 2006vs(sh),
1997s, 1988s, 1972m, 1951m, 1935m, and 1908w cm-1, which
were attributed to formation of the acetonitrile derivative of
complex 6. The solvent was removed, under reduced pressure,
and the residue redissolved in dichloromethane (40 cm3) and
diphenyl acetylene (228 mg; 1.27 mmol) added. After stirring
at room temperature for 18 h removal of solvent and chroma-
tography afforded two bands. The first, red, yielded a trace
amount of the starting complex 6. The second, brown, gave
164 mg of [Ru3(CO)7{µ3-η6-C(But)dCC(Ph)dC(H)Ph}(µ3-η4-
CPhdCPh)] (7) (70%).
Com p lex 7. IR (νCO) in heptane: 2071s, 2041vs, 2019s,
2005vs, 1997s, 1986m, 1935s cm-1. 1H NMR (CD2Cl2): δ 7.4-
7.0 (m, 20H, 4×Ph), 6.2 (s, 1H, CH), 1.5 (s, 9H, But). 13C{1H}
NMR (CD2Cl2): δ 202.3 (CO), 201.4 (CO), 198.2 (CO), 193.4
(CO), 180.1 (µ-CPh), 164.1 (µ-CPh), 152.5 (CBut), 149.3, 148.7,
143.2 and 141.8 (all ipso-Ph), 131.4-126.0 (all Ph), 111.3
(CdCBut), 72.3 (CPh), 71.8 (CH), 40.4 (CMe3), and 34.3
(3×Me). Assignments were aided by a DEPT 135° experiment.
FAB mass spectrum: P+ 939 m/z + peaks for consecutive loss
of 7 carbonyls. Anal. Found: C% 52.67, H% 3.23. Calc: C%
52.51, H% 3.22.
Com p lexes 5a ,b. IR (νCO) in heptane: 2052m, 2031vs,
2023vs(sh), 1996vs, 1983s cm-1 1H NMR (CDCl3): 5a δ 8.1
.
(s, 1H, µ-CH), 7.5-6.5 (m, 30H, 6xPh), 6.4 (s, 1H, CH), 3.8 (s,
1H, OH), 3.6 (s, 1H, CH2), 2.6 (s, 1H, OH), 2.3 (s, 1H, OH), 1.3
(s, 1H, CH2) and 1.1 (s, 9H, But); 5b δ 8.3 (s, 1H, µ-CH), 7.5-
6.5 (m, 30H, 6×Ph), 6.4 (s, 1H, CH), 4.9 (δ, J ) 8 Hz, 1H,
CHdC(H)CPh2OH), 3.9 (s, 1H, OH), 2.9 (δ, J ) 8 Hz, 1H,
CHdC(H)CPh2OH), 2.5 (s, 1H, OH), 2.2 (s, 1H, OH) and 1.6
(s, 9H, But). 13C{1H} NMR (CDCl3): 5a δ 232.3 (C-O), 202.9-
189.9 (all CO), 160.5 (µ-CH), 148.2 (ButCdC), 147.4-140.7 (all
ipso Ph), 134.4-126.9 (all Ph), 124.8 (CH), 119.1 (ButCdC),
86.6 (CCPh2OH), 50.0 (CH2), 43.7 (CMe3), 34.1 (3×Me), 165.4,
84.6, 81.9, 79.7, and 77.4 (all quaternary carbons); 5b δ 230.1
(C-O), 202.9-189.9 (all CO), 162.5 (µ-CH), 150.0 (ButCdC),
147.4-140.7 (all ipso Ph), 134.4-126.9 (all Ph), 124.6 (CH),
114.2 (ButCdC), 87.4 (CHdCCPh2OH), 50.0 (CHdCCPh2OH),
41.8 (CMe3), 33.5 (3×Me), 166.2, 82.1, 80.3, 78.7, and 77.0 (all
quaternary carbons). Assignments were aided by a DEPT 135°
experiment. FAB mass spectrum: P+ 1207 m/z + peaks for
loss of H2O and then peaks for loss of up to 6 carbonyls. Anal.
Found: C% 58.10, H% 3.95. Calc: C% 57.80, H% 3.80.
Deh yd r a tion of Com p lexes 5a a n d 5b on Silica Gel.
To a dichloromethane solution (15 cm3) of the mixture of
isomers 5a ,b (100 mg; 0.08 mmol) was added silica gel (280
mg) and the mixture stirred for 24 h, during which time a color
change from dark green to black was observed. The products
were washed from the silica using dichloromethane and
chromatographed on alumina to yield 40 mg of [Ru3(CO)5(µ-
CO){µ3-η5-CC(But)OC(Ph)2CCH}{µ3-η6-CHC(CPh2OH)COC-
Isom er ization of [Ru 3(CO)7{µ3-η6-C(Bu t)dCC(P h )dC(H)-
P h }(µ3-η4-CP h dCP h )] (7). A heptane solution of [Ru3(CO)7-
{µ3-η6-C(But)dCC(Ph)dC(H)Ph}(µ3-η4-CPhdCPh)] (7) (50 mg;
0.05 mmol) was heated at reflux for 17 h, after which time
the IR spectrum showed a peak at 2033 cm-1, indicative of
complex 2. Chromatography led to isolation of the brown
complex
[Ru3(CO)7{µ3-η6-C(But)dCC(Ph)dC(Ph)H}(µ3-η4-
CPhdCPh)] (2) (45 mg) in 90% yield.
Com p lex 2. IR (νCO) in heptane: 2068s, 2042s, 2033s,
2015s, 2003s, 1996vs, 1980m, 1938m cm-1
.
1H NMR
(CD2Cl2): δ 7.3-6.8 (m, 20H, 4xPh), 3.2 (s, 1H, CH), 1.4 (s,
9H, But). 13C{1H} NMR (CD2Cl2): δ 201.4 (CO), 198.5 (CO),
195.4 (CO), 178.9 (µ-CPh), 160.2 (µ-CPh), 157.1 (CBut), 153.3,
152.5, 139.8 and 136.9 (all ipso-Ph), 132.4-128.1 (all Ph), 78.2
(CH), 77.4 (CPh), 40.1 (CMe3), and 34.6 (3×Me). Assignments
were aided by a DEPT 135° experiment. FAB mass spectrum:
P+ 939 m/z + peaks for consecutive loss of 7 carbonyls. Anal.
Found: C% 52.75, H% 3.24. Calc: C% 52.51, H% 3.22.
Rea ction of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)](4) w ith
P h CtC(P h )2OH. To a mixture of [Ru3(CO)8(NCMe)(µ-H)(µ-
C2But)](4) (1.00 g; 1.58 mmol) and 1,1,3-triphenyl-2-propyn-
1-ol (2.69 g; 9.45 mmol) was added dichloromethane (50 cm3).
The mixture was stirred for 30 min, during which time the
solution changed color from yellow to red. Chromatography
afforded 3 bands. The first, yellow, yielded a trace amount of
[Ru3(CO)9(µ-H)(µ-C2But)] (1); the second, red, gave trace
amounts of a red solid, which was not characterized; the third,
brown, afforded 618 mg of complex [Ru3(CO)7{µ3-η6-
C(But)dCC(Ph)dC(CPh2OH)H}{µ3-η4-CPhdC(Ph)2OH}] (8)
(34%).
(CPh2)CH}] (9) (40%) and
4 mg of complex [Ru3(CO)6-
{µ3-η6-C(But)CCHC(CPh2OH)H}{µ3-η6-CHC(CPh2OH)COC-
(CPh2OH) CH}] (5b) (4%).
Rea ction of [Ru 3(CO)8(NCMe)(µ-H)(µ-C2Bu t)](4) w ith
P h CtCP h . To a mixture of [Ru3(CO)8(NCMe)(µ-H)(µ-C2But)]
(4) (500 mg; 0.76 mmol) and diphenyl acetylene (675 mg; 3.80
mmol) was added dichloromethane (40 cm3). The mixture was
stirred for 30 min, during which time the solution changed
color from yellow to red. Chromatography afforded 3 bands.
The first, yellow, yielded a trace amount of [Ru3(CO)9(µ-H)(µ-
C2But)] (1); the second, red, gave trace amounts of a red solid,
which was not characterized; the third, red, afforded 360 mg
of complex [Ru3(CO)8{µ3-η8-C(But)dCC(Ph)dC(H)Ph}] (6) (60%).
Com p lex 6. IR (νCO) in heptane: 2075vs, 2044vs, 2014vs,
Red Com p lex. IR (νCO) in heptane: 2078s, 2046vs, 2011vs,
2007s, 1997vs, 1983m(sh), 1950w cm-1
.
1
2004vs, 1996m(sh), 1985w, 1953m cm-1. H NMR (CDCl3): δ
Com plex 8. IR (νCO) in heptane: 2070m, 2052vs, 2011vs(sh),
2004vs, 1993vs(sh), 1934m cm-1. 1H NMR (CDCl3): δ 7.8-6.8
(m, 30H, 6×Ph), 3.4 (s, 1H, OH), 3.0 (s, 1H, CH), 1.2 (s, 9H,
But). 13C{1H} NMR (CDCl3): δ 202.4 (CO), 200.1 (CO), 194.5
(CO), 193.1 (CO), 180.9 (µ-CPh), 158.9 (µ-CCPh2OH), 147.8
(CBut), 151.9, 149.9, 148.4, 147.3, 145.6 and 136.4 (all ipso-
Ph), 131.7-123.7 (all Ph), 103.4 (CdCBut), 87.2 (CHPh), 83.2
7.3-6.8 (m, 9H, 2×Ph), 5.6 (δ, J ) 6 Hz, 1H, ortho-H), 5.5 (s,
1H, CH), 1.2 (s, 9H, But). 13C{1H} NMR (CDCl3): δ 202.2 (CO),
200.2 (CO), 197.1 (br, CO), 146.3 and 146.2 (both ipso-Ph),
138.7 (CBut), 133.1-123.7 (all Ph), 122.1 (CdCBut), 86.0
(CHPh), 58.9 (CPh), 56.9 (ortho-C), 41.4 (CMe3) and 32.0
(3×Me). Assignments were aided by a DEPT 135° experiment.

2340 Organometallics, Vol. 19, No. 12, 2000
Ta ble 4. Deta ils of Str u ctu r a l An a lyses for Com p lexes 8, 9, a n d 6a
Charmant et al.
8‚1/2H2O
9‚CH2Cl2
6
Formula
recrystallized from
habit
C
55H42O9Ru3‚1/2H2O
heptane
plate
C58H46O9Ru3‚CH2Cl2
hexane/CH2Cl2
plate
C28H20O8Ru3
hexane/CH2Cl2
block
cryst syst
space group (no.)
a/Å
b/Å
c/Å
triclinic
P1h (2)
triclinic
P1h (2)
monoclinic
P21/c (14)
14.212(2)
11.948(1)
16.337(2)
90
96.91(1)
90
2753.8(7)
4
9.816(2)
12.972(3)
19.602(3)
81.76(3)
78.65(2)
87.88(2)
2421.8(8)
2
10.578(2)
15.541(3)
17.914(5)
100.44(1)
96.00(2)
108.79(2)
2699.5(11)
2
R/deg
â/deg
γ/deg
U/Å3
Z
Dc/g cm-3
F(000)
1.589
1162
1.566
1276
1.900
1536
T/K
193
173
193
m(Mo KR)/cm-1
cryst dimens/mm
total data
no. of unique data
no. of obsd data, No
abs corr
9.82
9.84
16.73
0.30 × 0.15 × 0.01
0.15 × 0.10 × 0.02
0.5 × 0.4 × 0.2
7639
23 006
4955
7223
5380
empirical
1.000, 0.774
622
0.044
0.103
0.0480, 17.43
1.051
9461
6377
multiscan
0.934, 0.744
662
0.038
0.054
0.0128, 0
0.921
4779
4493
empirical
0.986, 0.737
360
0.025
0.066
0.0248, 3.6235
1.178
b
max. and min. transmn
no. of least-squares variables, Nv
R1c
wR2d
weighting schemee a, b
Sf
largest diff map features/e Å-3
extinction corrg x
0.703, -0.827
0.0021(2)
0.537, -0.499
none
0.465, -0.393
0.00040(6)
a
b
2
2
Data common to all: wavelength (λ) ) 0.71073 Å, 2θ range 3-55°. Observation criterion: Fo > 2σFo
.
c R1 ) ∑||Fo| - |Fc||/∑|Fo| for
observed reflections. wR2 ) {∑[w(Fo2 - Fc2)2]/∑[w(Fo2)2]}1/2
.
e w-1 ) σ2(Fo2) + (aP)2 + bP, where P ) [max(Fo2, 0) + 2Fc2]/3. f S ) {∑[w(Fo
d
2
- Fc2)2]/(No - Nv)}1/2
.
All Fc multiplied by 1/[1 + 0.001Fc2λ3/sin 2θ]1/4
.
g
for 8 and H(16) for 6 were located in the electron density
(CPh), 77.9 and 75.1 (both CPh2OH), 40.3 (CMe3), and 33.3
(3×Me). Assignments were aided by a DEPT 135° experiment.
FAB mass spectrum: P+ 1150 m/z + peaks for loss of 3-7
carbonyls. Anal. Found: C% 57.05, H% 3.88. Calc: C% 57.39,
H% 3.77.
X-r a y An a lysis of Com p lexes 6, 8, a n d 9. Many of the
details of the structure analyses carried out on complexes 8,
9, and 6 are listed in Table 4. In each case a single crystal
was mounted in vacuum grease on a glass fiber.
Da ta Collection for 8 a n d 6. X-ray diffraction measure-
ments were made using a Bruker P4 diffractometer. Cell
dimensions were determined from the setting angle values of
20-30 centered reflections. Intensity data were collected for
unique portions of reciprocal space and corrected for Lorentz,
polarization, and long-term intensity fluctuations on the basis
of check reflections repeatedly measured during the data
collection. Corrections for X-ray absorption effects were applied
on the basis of azimuthal scan data.30
difference map and refined without positional constraints with
isotropic displacement parameters. All other hydrogen atoms
were assigned fixed isotropic displacement parameters and
constrained to ideal geometries. Final difference syntheses
showed no chemically significant features, the largest being
close to the metal. Refinements proceeded smoothly to give
the residuals listed in Table 4. All calculations were made
using programs of the Bruker SHELXTL packages.30 Complex
neutral-atom scattering factors were used.31
Ack n ow led gm en t. We gratefully acknowledge the
EPSRC for the award of a research studentship (to
J .W.). Finacial support was also obtained by MURST
(Rome) as part of a national research project in cluster
chemistry.
Da ta Collection for 9. X-ray diffraction measurements
were made using a Bruker SMART CCD area-detector dif-
fractometer. Cell dimensions were determined from three sets
of 30 exposures. Intensities were integrated from several series
of exposures, each exposure covering 0.3° in ω, and the total
data set being a sphere. Absorption corrections were applied,
based on multiple and symmetry-equivalent measurements.30
Solu tion a n d Refin em en t. The structures were solved by
heavy-atom (Patterson and Fourier difference) methods and
refined by least squares against F2. All non-hydrogen atoms
were assigned anisotropic displacement parameters and re-
fined without positional constraints. Hydrogen atoms H(11)
Su p p or tin g In for m a tion Ava ila ble: Complete structure
reports including atomic coordinates, thermal parameters, and
bond lengths for the crystal structures of 6, 8, and 9. This
material is available free of charge via the Internet at http://
pubs.acs.org. Complete atomic coordinates, thermal param-
eters, and bond lengths have been deposited at the Cambridge
Crystallographic Data Centre. CCDC refs: 138796, 138797,
and 138798. This information is also available free of charge
via the Internet at http://pubs.acs.org.
OM000048L
(30) SHELXTL program system version 5.1; Bruker Analytical X-ray
Instruments Inc.: Madison, WI, 1998.
(31) International Tables for Crystallography, Kluwer: Dordrecht,
1992; Vol. C.