Preparation and structural characterisation of some ruthenium cluster carbonyls containing allenylidene ligands

Article abstract of DOI:10.1039/a906379j

The chemistry of some ruthenium cluster carbonyls containing allenylidene ligands has been reinvestigated. Treatment of Ru3(u-H){u3-C2CAr2(OH)}(CO)9 [Ar = Ph 15, toi (toi = 4-MeC6H4)] with HBF4-OMe2 gave Ru3(u-H)(u3-CCCAr2)(CO)9 (Ar = Ph, R = H, Me; Ar =

Full text of DOI:10.1039/a906379j

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Preparation and structural characterisation of some ruthenium
cluster carbonyls containing allenylidene ligands†
a
b
b
a
Michael I. Bruce, Brian W. Skelton, Allan H. White and Natasha N. Zaitseva
a
Department of Chemistry, University of Adelaide, Adelaide, South Australia 5005, Australia.
E-mail: michael.bruce@adelaide.edu.au
Department of Chemistry, University of Western Australia, Nedlands, Western Australia 6907,
Australia
b
Received 5th August 1999, Accepted 14th January 2000
The chemistry of some ruthenium cluster carbonyls containing allenylidene ligands has been reinvestigated.
Treatment of Ru (µ-H){µ -C CAr (OH)}(CO) [Ar = Ph 15, tol (tol = 4-MeC H )] with HBF ؒOMe gave
3
3
2
2
9
6
4
4
2
Ru (µ-H)(µ -CCCAr )(CO) (Ar = Ph, R = H, Me; Ar = tol, R = H). Substitution of CO by PPh or dppm gave
3
3
2
9
3
Ru (µ-H)(µ -CCCPh )(µ-OH)(CO) (L) (L = PPh , L = dppm; from 15), while in the presence of HBF , the
3
3
2
7
2
3
2
4
s
hydroxy-free complexes Ru (µ -CCCAr )(µ-dppm)(µ-CO)(CO) were obtained. Reactions of 15 with K[BHBu ],
3
3
2
7
3
followed by HBF or AuCl(PPh ), also resulted in loss of water to give Ru (µ-H)(µ-E)(µ -CCCPh )(CO) [E = H
4
3
3
3
2
9
or Au(PPh ), respectively]. X-Ray structures of six of the complexes are reported.
3
Introduction
The chemistry of unsaturated carbenes as ligands to metal
centres continues to generate strong interest. The simplest
unsaturated carbene is vinylidene, :C᎐CH , and a host of both
᎐
2
1
mono- and polynuclear complexes have been described. Com-
plexes containing allenylidene, :C᎐C᎐CH , are well-established
᎐
᎐
2
for mononuclear systems, but the chemistry of cluster com-
2
plexes is far less well developed. This is in spite of the first such
3
complexes having been obtained over seventeen years ago.
The common route to C unsaturated carbenes is by loss of
3
water or alcohol from an intermediate (and sometimes
undetected) hydroxymethylvinylidene derivative. This reaction
was first described for ruthenium in the synthesis of [Ru(C᎐
᎐
ϩ
C᎐CPh )(PMe ) Cp] from RuCl(PMe ) Cp and HC᎐CCPh
᎐
᎐
2
3
2
3
2
2
4
(
OH). Reactions of propargyl alcohols with ruthenium and
osmium cluster carbonyls were first described in 1980, when the
complexes M (µ-H){µ -C CRRЈ(OH)}(CO) (1; M = Ru; R =
3
3
2
9
Me, RЈ = Me, Et, Ph) were obtained in 4, 58 and 33% yields,
5
respectively, from Ru (CO) and HC᎐CCRRЈ(OH). Reactions
3
12
of the related disubstituted alkynes C {CR (OH)} (R = Me,
2
2
2
Ph) with M (CO) (M = Ru, Os) afforded 1 (R = RЈ = Me, Ph)
3
12
with loss of the corresponding ketone R CO; the ruthenium
2
complexes were obtained in only low yields and were character-
ised spectroscopically, the major products being binuclear com-
plexes, together with some 1,1,4,4-tetraphenylbutadiene from
HC᎐CCMeRЈ(OH) (RЈ = Me, Ph) with KOH in methanol, when
᎐
6,7
the allenyl complexes Ru (µ-H)(µ -CH᎐C᎐CMeRЈ) (CO) (5)
R = RЈ = Ph. The reactions of Ru (CO) have been examined
3
3
᎐ ᎐
9
3
12
9
were obtained.
When R = RЈ = Ph, however, treatment with CF CO H
again recently, with similar results, examples of 1 (M = Ru) with
8
R = Me, RЈ = Me, Et, Pr, Ph and R = RЈ = Ph being described.
3
2
resulted in migration of the OH group to the cluster to give the
allenylidene complexes M (µ-H) (µ -CCCPh )(µ-OH)(CO) (6;
Reactions of HC᎐CCH (OH) or C {CH (OH)} afforded a
᎐
2
2
2
2
variety of other structural types; with Os (µ-H) (CO) , the
3
3
2
9
3
2
10
M = Ru, Os), of which the osmium complex was structurally
alkyne cluster Os {µ -HC CMe (OH)}(µ-CO)(CO) (2) was
3
3
2
2
9
characterised to show the allenylidene attached to the cluster by
obtained in 66% yield, which on heating was converted into
1
1
2
3
5
two carbons in the µ -η :η :η mode. The ruthenium analogue
Os (µ-H){µ -C CMe (OH)}(CO) (3) in 83% yield.
3
3
3
2
2
9
was identified spectroscopically. Other examples of cluster-
Treatment of the hydrido–alkynyl complexes with strong
acids (CF CO H or H SO ) or on TLC silica resulted in
2
bound allenylidenes have been described. Protonation of
3
2
2
4
Os {µ -HC CR (OH)}(µ-CO)(CO) (R = H, Me) is thought to
dehydration to give the vinylalkynyl clusters M (µ-H)
3
3
2
2
9
3
1
2
3
10
produce clusters containing µ -η :η :η -allenylidene ligands,
(
µ -C CR᎐CH )(CO) (4; M = Ru, Os; R = H, Me, Ph). Dehy-
3
3
2
2
9
similar to those structurally characterised in Re W(µ -CCCMe )-
dration also occurred during the reaction of Ru (CO) and
2
3
2
3
12
11
(
µ-OR)(CO) Cp* (R = Me, Et, Ph). In an Ru complex isolated
8
7
from reactions between Ru (CO) and HC᎐CCHMe(OH),
3
12
the allenylidene ligand is coordinated to five of the metal atoms
in the η :η :η :η :η mode.
†
Dedicated to Professor Heinrich Vahrenkamp, a valued colleague and
1
1
1
1
2
12
friend, on the occasion of his 60th birthday.
DOI: 10.1039/a906379j
J. Chem. Soc., Dalton Trans., 2000, 881–890
This journal is © The Royal Society of Chemistry 2000
881

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Ϫ21.11, respectively, and the OH proton is at δ 2.58 in 10;
phenyl proton multiplets are between δ 7.27 and 7.80. For 10,
the Me groups give a singlet at δ 2.29. The ES mass spectra
Ϫ
Ϫ
contain [M Ϫ H] at m/z 764 (for 9) and M at m/z 793 (for 10).
As mentioned above, formation of these complexes is not
limited to aryl-substituted propyn-1-ols. Thus, we have
observed that reactions between Ru (CO) (NCMe) and
3
10
2
HC᎐CCR (OH) (R = H , HMe, Me ) proceed readily under
᎐
2
2
2
2
ambient conditions to give the corresponding alkyne clusters,
of which we have isolated and characterised Ru {µ -HC CR -
3
3
2
2
(
OH)}(µ-CO)(CO) [R = H (11), Me (12)]; the mono-methyl
9
complex was identified spectroscopically. Spectroscopic proper-
ties are consistent with the formulations. Thus, the terminal
Ϫ1
ν(CO) bands are between 2098 and 1985 cm and the bridging
Ϫ1
ν(CO) absorption is near 1881 cm ; ν(OH) bands are at 3631
Ϫ1
1
and 3602 cm , respectively. In the H NMR spectrum, the
acetylenic protons are found at δ 8.30 and 8.22, respectively,
with the CH or CMe protons at δ 4.20 and 1.36. The CMe
2
2
2
carbons are found at δ 35.02 (Me) and 77.42, respectively, in the
13
C NMR spectrum of 12, while only one of the C and Cβ
α
resonances was seen at δ 137.84.
Thermolysis afforded the corresponding hydrido–alkynyl
clusters Ru (µ-H){µ -C CR (OH)}(CO) [R = H (13), Me (14)],
3
3
2
2
9
identification also being largely spectroscopic, with a relatively
imprecise X-ray structure determination confirming the broad
structural features of 13 (see below). Only terminal ν(CO)
Ϫ1
bands are found between 2100 and 1957 cm in their IR spec-
1
tra, while in the H NMR spectra the cluster-bonded protons
are at δ Ϫ21.10 and Ϫ20.99, respectively, in 13 and 14. The CH2
and Me protons are found at δ 4.86 (in 13) and as two singlets at
δ 1.70 and 1.72 (in 14). Recently, it was reported that reactions
1
2
12,13
of Ru (CO) with HC᎐CCRRЈ(OH) (RRЈ = Me2, MeEt,
3
1
12
14
4
MePr, HEt ) in refluxing toluene afforded the corresponding
hydrido–alkynyl complexes directly. The C NMR spectrum of
Scheme 1
13
This paper describes the preparation and structural charac-
terisation of a variety of allenylidene complexes containing Ru3
cores and provides a background to several recent preliminary
14 contains resonances at δ 34.79 (Me), 70.38 (CMe ), 106.99
2
(C ) and 167.07 (C ).
β
α
13
accounts of further reactions of these complexes.
Allenylidene complexes
Results
Treatment of a solution of 9 in CH Cl with HBF ؒOMe results
2 2 4 2
in a deepening of the colour. Conventional work-up afforded two
complexes, which were identified as Ru (µ-H)(µ -CCCPh )-
Alkyne and hydrido–alkynyl complexes
3
3
2
As with the earlier studies, we decided to use hydroxymethyl-1-
alkynes as precursors for the allenylidene ligands. In contrast
to previous studies summarised above, we have used Ru3-
(µ-OR)(CO) [R = H (15), Me (16)]. The former was described
in the earlier study but not fully characterised. Elemental
9
3
analyses confirmed the formulations, with the ES mass spectrum
Ϫ
(
CO) (NCMe) as the source of the Ru cluster, which reacts
of 15 containing an M ion at m/z 765. In their IR spectra, only
10
2
3
Ϫ1
under milder conditions thereby enabling the isolation of
the precursor complexes in much higher yields (Scheme 1).
terminal ν(CO) bands were found between 2101 and 1994 cm .
Ϫ1
1
For 15, a ν(OH) absorption was present at 3632 cm . In the H
NMR spectra, Ru–H resonances were found at δ Ϫ11.13 and
Ϫ10.80 for 15 and 16, respectively, while the OMe singlet for 16
occurred at δ 3.03. Multiplets between δ 7.13 and 7.84 arise
from the phenyl protons. Finally, a single crystal X-ray struc-
ture determination confirmed the identity of 16 (see below).
Substitution of CO groups occurs readily when 15 is heated
with tertiary phosphines in refluxing toluene (Scheme 2). With
Thus, the reactions between HC᎐CCAr (OH) and Ru (CO) -
᎐
2
3
10
(
NCMe) afforded orange Ru {µ -HC CAr (OH)}(µ-CO)(CO)
2 3 3 2 2 9
[
Ar = Ph (7), tol (8)] in 74 and 79% yields respectively. The
3
diphenyl derivative 7 has been described before, but the di-4-
tolyl complex 8 is new. They were characterised by elemental
analyses and from their spectroscopic properties (Table 1).
Thus, their IR spectra contain terminal ν(CO) bands between
Ϫ1
2
097 and 1989 cm and a characteristic bridging ν(CO)
PPh , two equatorial CO ligands on the Ru atoms bridged by
3
Ϫ1
absorption near 1878 cm , while the ν(OH) bands are found
the OH groups are replaced to give Ru (µ-H)(µ -CCCPh )-
3
3
2
Ϫ1
1
near 3605 cm . In their H NMR spectra, the acetylenic
protons are found at δ 7.68 and 7.76, respectively, while in 8,
there are two singlet resonances for the Me groups at δ 2.24 and
(µ-OH)(CO) (PPh ) (17), identified from a single-crystal X-ray
7 3 2
structure determination (see below). Interestingly, subtle alter-
ations in the structures of the substituted complexes have
occurred, so that the OH group is opposite, rather than
adjacent, to the allenylidene ligand. This may be a solid-state
effect, reflecting a lower energy conformation; solubility con-
siderations have precluded a variable temperature NMR study
to determine whether the allenylidene ligand rotates around the
2
.37. The OH proton was found at δ 2.83 for 8. The electrospray
Ϫ
(
ES) mass spectra contain [M Ϫ H] at m/z 792 (for 7) or
Ϫ
[M Ϫ 2H] at m/z 819 (for 8).
Mild heating (refluxing hexane, 15 min) results in decarb-
onylation and formation of the hydrido–alkynyl complexes
Ru (µ-H){µ -C CAr (OH)}(CO) [Ar = Ph (9), tol (10)]. Again,
Ru core, as might be expected. The spectral properties were in
3
3
2
2
9
3
3
9
has been reported on an earlier occasion. The IR spectra
accord with the solid-state structure, with only terminal ν(CO)
Ϫ1
contain only terminal ν(CO) bands between 2099 and 1955
bands found in the IR spectrum between 2062 and 1943 cm ,
Ϫ1
Ϫ1
1
cm , with ν(OH) absorptions near 3610 cm . In the H NMR
spectra, the Ru–H singlet resonance occurs at δ Ϫ21.09 and
the Ru–H resonance at δ Ϫ 13.16 being a doublet (JHP 10 Hz) as
a result of coupling to the phosphorus atom attached to Ru(2).
8
82
J. Chem. Soc., Dalton Trans., 2000, 881–890

View Article Online
Table 1 Analytical and spectroscopic data for some complexes
Ϫ1
Complex
Ru {µ -HC CPh (OH)}(µ-CO)-
IR (cyclohexane/cm
)
NMR (CDCl ; δ, J/Hz)
ES mass spectra (m/z)
3
1
7
ν(OH) 3602vw
H: 7.25–7.46 (m, 10H, 2Ph), 7.68
(MeOH, negative ion): 792,
3
3
2
2
Ϫ
(
CO)9
ν(CO) 2097m, 2062vs, 2053vs,
2029s, 2010m, 1879m(br)
(s, 1H, HC᎐)
[M Ϫ H] , 764, 680, 652, 624
Ϫ
Found: C, 38.28; H, 1.65.
[M Ϫ H Ϫ nCO] (n = 1, 4–6);
Ϫ
C H O Ru calc.: C, 37.93; H,
580, [M Ϫ OH Ϫ 7CO] ; 551, 474
2
5
12 11
3
Ϫ
1
.53%; M, 793
[Ru (C Ph )(CO) ] (n = 2,1)
3
3
n
2
1
8
Ru {µ -HC C(tol) (OH)}(µ-CO)-
ν(OH) 3607w
H: 2.24, 2.37 (2 × s, 2 × 3H,
(MeOH, negative ion): 819,
3
3
2
2
Ϫ
(
CO)9
ν(CO) 2096m, 2074m, 2061vs,
2053vs, 2028s, 2009m, 1989w,
1878m (br)
2 × Me), 2.83 (s, 1H, OH), 6.70–
[M Ϫ 2H] ; 781–623,
Ϫ
Found: C, 39.69; H, 2.01.
7.25 (m, 8H, C H ), 7.76 (s, 1H,
[M Ϫ 2H Ϫ nCO] (n = 1–7);
6
4
C H O Ru calc.: C, 39.56; H,
1
9
Found: C, 37.73; H, 1.58.
C H O Ru calc.: C, 37.75; H,
1
1
HC᎐)
577–493 [M Ϫ 2H Ϫ mCO Ϫ
2
7
16 11
3
Ϫ
.95%; M, 821
Me O] (m = 7–10).
2
1
Ru (µ-H){µ -C CPh (OH)}(CO)
ν(OH) 3609vw
H: Ϫ21.09 (s, 1H, Ru–H), 7.27–
(MeOH, negative ion): 764,
3
3
2
2
9
Ϫ
ν(CO) 2099m, 2074vs, 2054vs,
2025vs, 1990m, 1972vw, 1958w
7.80 (m, 10H, 2Ph)
[M Ϫ H] ; 736–596, [M Ϫ H Ϫ
Ϫ
nCO] (n = 1–6); 551–495,
2
4
12 10
3
Ϫ
.57%; M, 765
[M Ϫ H O Ϫ nCO] (n = 7–9)
2
1
Ϫ
0 Ru (µ-H){µ -C C(tol) (OH)}-
ν(OH) 3610w
H: Ϫ21.11 (s, 1H, Ru–H), 2.29 (s,
(MeOH, negative ion): 793, M ;
3
3
2
2
Ϫ
(
CO)9
ν(CO) 2099m, 2074vs, 2054vs,
2024vs, 1989m, 1970vw, 1955vw
6H, 2Me), 2.58 (s, 1H, OH), 7.37
[dd, J(HH) 8.4, 8H, C H ]
764–596, [M Ϫ H Ϫ nCO]
(n = 1–7)
Found: C, 39.49; H, 2.06.
6
4
C H O Ru calc.: C, 39.44; H,
2
6
16 10
3
2
1
.02%; M, 793
1
1 Ru {µ -HC CH (OH)}(µ-CO)-
ν(OH) 3631vw
H: 4.20 [d, J(HH) 4, 2H, CH2],
(MeOH, negative ion): 639,
3
3
2
2
Ϫ
(
CO)9
ν(CO) 2098w, 2073w, 2060s,
2054vs, 2029s, 2009m, 1991vw,
1882w(br)
8.30 (s, 1H, HC᎐)
[M Ϫ 2H] ; 611–415,
Ϫ
Found: C, 24.59; H, 0.68.
[M Ϫ 2H Ϫ nCO] (n = 1–8)
C H O Ru calc.: C, 24.41; H,
1
3
4
11
3
0
1
.63%; M, 641
1
2 Ru {µ -HC CMe (OH)}(µ-CO)-
ν(OH) 3602w
H: 1.36 (s, 6H, 2Me), 8.22 (s, 1H,
(MeOH, negative ion): 668,
3
3
2
2
Ϫ
Ϫ
(
CO)9
ν(CO) 2097m, 2060s, 2057vs,
2028s, 2007m, 1985 (sh),
1881w(br)
HC᎐)
[M Ϫ H] ; 640, [M Ϫ H Ϫ CO] ;
1
3
Ϫ
Found: C, 26.98; H, 1.28.
C: 35.02 (s, 2 × Me), 77.42 (s,
582, 554, 526, [M Ϫ 3H Ϫ nCO]
C H O Ru calc.: C, 26.99; H,
CMe ), 137.84 (s, C , C ), 191.61,
(n = 3–5)
1
5
8
11
3
2
α
β
1
1
.20%; M, 669
197.19 (2 × s, CO)
1
3 Ru (µ-H){µ -C CH (OH)}(CO)
ν(OH) 3621vw
H: Ϫ21.10 (s, 1H, Ru–H), 4.86 [d,
J(HH) 4.4, 2H, CH2]
(MeOH, negative ion): 612,
3
3
2
2
9
Ϫ
Found: C, 23.57; H, 0.66.
C H O Ru calc.: C, 23.57; H,
0
1
C CMe (OH)}(CO)
Found: C, 26.39; H, 1.26.
C H O Ru calc.: C, 26.29; H,
ν(CO) 2100w, 2073s, 2057s,
2024vs, 1992m, 1971vw, 1960vw
[M Ϫ H] , 583–415,
Ϫ
[M Ϫ 2H Ϫ nCO] (n = 1–7)
1
2
4
10
3
.65%; M, 613
1
4 Ru (µ-H){µ -
ν(OH) 3615w
H: Ϫ20.99 (s, 1H, Ru–H), 1.70 (s,
(MeOH, negative ion): 640,
3
3
Ϫ
Ϫ
ν(CO) 2099w, 2072s, 2055vs,
2021s, 1989m, 1957vw
3H, Me), 1.72 (s, 3H, Me)
[M Ϫ H] ; 612, [M Ϫ H Ϫ CO] ,
2
2
9
1
3
Ϫ
C: 34.79 (s, 2Me), 70.38 (s, CMe ), 582, 554, 526, [M Ϫ 3H Ϫ nCO]
2
106.99 (s, C ), 167.07 (s, C ),
(n = 2–4)
1
4
8
10
3
β
α
1
1
.25%; M, 641
188.36, 188.55, 197.07 (3 × s, CO)
1
Ϫ
5 Ru (µ-H)(µ -CCCPh )(µ-OH)-
ν(OH) 3632w
H: Ϫ11.13 (s, 1H, Ru–H), 7.13–
(MeOH, negative ion): 765, M ;
3
3
2
Ϫ
(
CO)9
ν(CO) 2103w, 2083s, 2062vs,
2040m, 2024 (sh), 2017s, 1994w
7.43 (m, 10H, 2Ph)
748, [M Ϫ OH] ; 720,
Ϫ
Found: C, 37.49; H, 1.62.
[M Ϫ OH Ϫ CO]
C H O Ru calc.: C, 37.75; H,
2
4
12 10
3
1
1
.57%; M, 765
1
6 Ru (µ-H)(µ -CCCPh )(µ-OMe)-
ν(CO) 2101w, 2082s, 2073 (sh),
2061vs, 2051 (sh), 2038m, 2023
(sh), 2019s, 1994w
H: Ϫ10.80 (s, 1H, Ru–H), 3.03 (s,
3
3
2
(
CO)9
3H, OMe), 7.55–7.84 (m, 10H, 2Ph)
Found: C, 38.90; H, 1.90.
C H O Ru calc.: C, 38.61; H,
2
5
14 10
3
1
.80%; M, 779
1
1
7 Ru (µ-H)(µ -CCCPh )(µ-OH)-
ν(OH) 3612w
H: Ϫ13.16 [d, J(HP) 10, 1H, Ru–
3
3
2
(
CO) (PPh )
ν(CO) 2062vs, 2043w, 2027m,
2009s, 1998s, 1981m, 1969m,
1963 (sh), 1943m
H], 6.89–7.59 (m, 40H, 8Ph)
7
3 2
Found: C, 55.99; H, 3.52.
C H O P Ru calc.: C, 56.55; H,
5
8
42
8
2
3
3
.41%; M, 1233
1
1
8 Ru (µ-H)(µ -CCCPh )(µ-OH)-
ν(OH) 3626w
H: Ϫ5.56 [d, J(HP) 2.5, 1H, Ru–
(MeOH, negative ion): 1126,
3
3
2
Ϫ
(
µ-dppm)(CO)7
ν(CO) 2063vs, 2029vs, 2008s,
19986 (sh), 1980s, 1975 (sh),
1944m, 1924w
H], 3.76, 4.26 (2 × m, 2 × 1H,
CH ), 7.10–8.01 (m, 6Ph)
[M ϩ MeOH ϩ H] ; 1098–1014,
Ϫ
Found: C, 50.11; H, 3.22.
C H O P Ru .0.5CH Cl calc.: C,
5
1
[M ϩ MeOH ϩ H Ϫ nCO]
(n = 1–4)
2
4
7
34
8
2
3
2
2
0.27; H, 3.08%; M, 1093
9 Ru (µ-H) (µ -CCCPh )(CO)
9
1
ν(CO) 2106w, 2094w, 2083m,
073s, 2063m, 2052s, 2046m,
033w, 2024vs, 2008w, 1988w
H: Ϫ20.95 (s, 2H, Ru–H), 7.12–
3
2
3
2
2
2
8.53 (m, 10H, 2Ph)
1
2
0 Ru (µ -CCCPh )(µ-dppm)(µ-CO)- ν(CO) 2059s, 2027m, 2017(sh),
H: 2.88 [dt, J(HH) 13, J(HP) 11,
(MeOH, negative ion): 1102,
3
3
2
Ϫ
(
CO)7
1999vs, 1974w, 1859w(br)
1H, CH ], 3.36 [dt, J(HH) 13,
[M Ϫ H] ; 1074–906,
2
Ϫ
Found: C, 51.83; H, 2.99.
J(HP) 11, 2H, CH ], 7.19–7.33 (m,
[M Ϫ H Ϫ nCO] (n = 1–7); 884,
2
Ϫ
C H O P Ru calc.: C, 52.32; H,
30H, 6Ph)
[Ru (CO) (dppm) Ϫ H]
4
8
32
8
2
3
3
7
1
3
2
.91%; M, 1103
C: 34.70 [t, J(CP) 37, CH P ],
2 2
1
15.31 (s, C 0), 125.99–138.62 (m,
γ
Ph), 143.83 (s, C ), 169.16 (s, C ),
β
α
2
15.93, 227.93 (2 × s, CO)
H: 2.37 (s, 6H, 2Me), 2.88, 3.39
1
2
1 Ru {µ -CCC(tol) }(µ-dppm)-
ν(CO) 2075vw, 2058s, 2026m,
2014 (sh), 1998vs, 1974w, 1858w
(MeOH, negative ion): 1130,
3
3
2
Ϫ
(
µ-CO)(CO)7
(2 × m, 2 × 1H, CH ), 7.11–7.35
(m, 28H, C H ϩ Ph)
[M Ϫ H] ; 1073–961,
2
Ϫ
Found: C, 52.57; H, 3.16.
C H O P Ru calc.: C, 53.14; H,
[M Ϫ 2H Ϫ nCO] (n = 2–6)
6
4
5
0
36
8
2
3
3
.21%; M, 1131
1
2
2 AuRu (µ-H)(µ -CCCPh )(CO) -
ν(CO) 2081w, 2076w, 2060m,
2054vs, 2039s, 2028s, 2005m,
1985m, 1979 (sh), 1964m
H: Ϫ20.47 [d, J(HP) 7, 1H, Ru–H],
7.12–7.45 (m, 25H, 5Ph)
(MeOH ϩ NaOMe, negative
3
3
2
9
Ϫ
(
PPh3)
ion): 1238, [M ϩ OMe] ; 1207,
Ϫ
Ϫ
Found: C, 41.74; H, 2.29.
C H AuO PRu calc.: C, 41.87; H,
M ; 1179, 1151, [M Ϫ nCO]
(n = 1, 2); 917–805,
4
2
25
9
3
Ϫ
2
.09%; M, 1207
[M Ϫ PPh Ϫ nCO] (n = 1–5)
3
J. Chem. Soc., Dalton Trans., 2000, 881–890
883

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Ϫ1
1
964 cm in its IR spectrum, the Ru–H doublet resonance at
1
δ Ϫ20.47 in the H NMR spectrum, together with the expected
phenyl multiplets, and [M ϩ OMe] and M at m/z 1238 and
207, respectively, in the ES mass spectrum of a solution
Ϫ
Ϫ
1
containing NaOMe.
Molecular structures
Molecules of each of complexes 16–22 are portrayed in Fig. 1
and Fig. 2 and significant structural parameters are collected in
Table 2. The common numbering system has been chosen so
that C(1) of the allenylidene ligand caps the Ru triangle with
3
the C(1)–C(2) moiety being attached to Ru(3) in all cases. The
Ru(1)–Ru(2) vector is bridged by H (16, 19), OMe (17),
OH ϩ dppm (18), CO ϩ dppm (20, 21) or Au(PPh ) groups
3
(
22).
Complexes 16–18 have 50 cluster valence electrons (c.v.e.),
two more than the 48 c.v.e. required for an M cluster with three
3
M–M bonds. Consequently, a bent Ru geometry is adopted,
3
with the Ru ؒ ؒ ؒ Ru vector being non-bonded [Ru ؒ ؒ ؒ Ru separ-
ations are between 3.194(2) and 3.3198(7) Å]. This non-bonded
vector is bridged by the OH or OMe groups and in 17 or 18,
these two metal atoms are the sites of attachment of the tertiary
phosphine ligands. In 18, therefore, atoms Ru(1) and Ru(2) are
also bridged by the dppm ligand. The relative positions of the
allenylidene and OX ligands in these three complexes has
changed as a result of rotation of the allenylidene ligand, atoms
C(1)–C(2) moving from the terminal Ru (also bonded to O) in
Scheme 2
A similar complex, Ru (µ-H)(µ -CCCPh )(µ-dppm)(µ-OH)-
16 to the central Ru of the Ru chain in 17 and 18. It is likely
3
3
2
3
(
CO) (18) was obtained with dppm, this ligand bridging the
that this occurs as a result of steric interactions between the
respective phenyl groups on the tertiary phosphines and the
allenylidene ligands, resulting in migration of the latter ligand
around the cluster. Although we have as yet no evidence for this
process in 15 or 16, for example, similar processes are common
for cluster-bonded vinylidenes.
7
same rutheniums as are coordinated to PPh ligands in 17. In
1
ν(OH) at 3626 cm . The H NMR spectrum contains a doublet
Ru–H resonance at δ Ϫ5.56 [J(HP) 2.5 Hz] and the dppm CH2
group gives rise to two multiplets at δ 3.76 and 4.26.
3
Ϫ1
8, the ν(CO) bands are between 2063 and 1924 cm and
Ϫ1 1
In seeking to find a route to cluster complexes containing
The separations of bonded pairs of Ru atoms range from
2.7519(5) to 2.920(1) Å. Those bridged only by C(1) are
between 2.7519(5) and 2.887(1) Å. If a hydrogen bridges the
bond, the separation is generally lengthened as expected,
although the range is between 2.7389(9) and 2.920(1) Å. The
distance Ru(1)–Ru(2) is generally shorter [2.7839(9)–2.8418(7)
Å] than between Ru(1 or 2)–Ru(3) [2.847(1)–2.920(1) Å]. In 20
or 21, the Ru(1)–Ru(2) bonds are bridged by CO and dppm and
are 2.7863(6) and 2.7728(4) Å, respectively. In 22, Ru(1)–Ru(2)
allenylidene ligands free from other functional groups such as
s
OH or OMe, we treated 9 with K[BHBu ], followed by
3
Ϫ
ϩ
HBF , i.e. with H /H (Scheme 1). Separation of the products
4
afforded a small amount of the hydrido–allenylidene complex
Ru (µ-H) (µ -CCCPh )(CO) (19), accompanied by some
3
2
3
2
9
Ru (µ-H) (CO) and Ru (µ-H) (CO) , the latter identified
4
4
12
4
2
13
crystallographically. The IR spectrum of 19 contained ν(CO)
Ϫ1
bands between 2106 and 1988 cm , indicating that no bridging
1
CO groups were present. The H NMR spectrum contained an
is bridged by Au(PPh ) and is 2.891(1) Å.
3
Ru–H resonance at δ Ϫ20.95 together with phenyl multiplets
between δ 7.12 and 8.53. The structure of 19 was confirmed by
an X-ray determination (see below).
Atom C(1) is σ-bonded to Ru(1) and Ru(2) [range 2.002(5)–
2.10(1) Å], while the C(1)–C(2) moiety is π-bonded to Ru(3)
[ranges Ru(3)–C(1) 2.16(1)–2.262(5) Å; Ru(3)–C(2) 2.223(5)–
2.29(1) Å]. The C(1)–C(2) and C(2)–C(3) separations somewhat
surprisingly, are similar [1.32(2)–1.35(2) and 1.31(2)–1.357(6)
Å]. The attachment of the allenylidene ligand to the cluster is
generally similar in all molecules examined, with dihedrals
between the Ru(1,2,3) and Ru(1,2)C(1) planes ranging from
62.6(2) to 64.4(6)Њ, with the exception of 16 [55.0, 55.5(2)Њ],
In the presence of dppm, protonation of 9 or 10 afforded
hydroxyl-free phosphine-substituted complexes. With dppm
and HBF , the complexes Ru (µ -CCCAr )(µ-dppm)(µ-CO)-
4
3
3
2
(
CO) [Ar = Ph (20), tol (21)] were obtained. The dppm com-
7
plexes were identified from elemental analyses and their ES
mass spectra initially, together with an X-ray structure deter-
mination. The IR spectra contained ν(CO) bands between 2075
presumably as a result of the open edge of the Ru cluster being
3
Ϫ1
Ϫ1
and 1974 cm and bridging ν(CO) absorptions near 1859 cm .
Ru(2) ؒ ؒ ؒ Ru(3). Angles between C(1)–C(2) and the Ru(1,2)C(1)
plane range between 153.9(2) and 159(1)Њ. Comparisons of
these structures with those of Fe (µ -CCCR )(µ-CO)(CO)
1
In the H NMR spectrum, the CH proton multiplets are near
2
δ 2.88 and 3.36, while for 21, the Me resonance was at δ 2.37.
3
3
2
9
1
5
16
17
No high-field resonance attributable to Ru–H is present. The
(RRЈ = Me2, HPh, Ph2 ) and with Os (µ-H)(µ -CCCPh )-
3
3
2
1
3
3
C NMR spectrum of 21 singlet resonances for the CH2
carbon at δ 34.70 and for C , C and C at δ 169.16, 143.83 and
(µ-OH)(CO)9 confirm the structural rigidity of the allenyl-
idene ligand commented upon earlier, with angles at C(2) of
148.8(8), 153.8(4) and 151.5(2)Њ (for the Fe complexes) and
145(3)Њ (for the Os complex). The coordinated and non-
coordinated C(2)–C(3) separations are also similar to those
found in the present study.
α
β
γ
Ϫ
1
15.31, respectively. In the ES mass spectrum of 20, [M Ϫ H] is
at m/z 1102.
s
Auration of 15 by successive reactions with K[BHBu ] and
3
AuCl(PPh ) also resulted in loss of the cluster-bound OH group
3
and formation of AuRu (µ-H)(µ -CCCPh )(CO) (PPh ) (22;
In organic allenes R C᎐C᎐CR , the C chain is linear and the
3
3
2
9
3
2
2
3
Scheme 2), a complex that is isolobal with 19. This compound
was initially characterised from a single-crystal X-ray study (see
below). The spectral properties are consistent with the solid-
state structure, with terminal ν(CO) bands between 2081 and
dihedral angle between the two CR planes is 90Њ. Coordination
2
of the allenylidene ligand to the cluster results in a bending of
the C3 chain [values found here range between 144(2) and
154.0(5)Њ]. Within the limits of precision, angle sums at C(3) are
8
84
J. Chem. Soc., Dalton Trans., 2000, 881–890

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Fig. 1 Projections of 16 (two molecules)–18, with similar orientation and labelling, oblique to their Ru planes. 20% thermal ellipsoids are shown
3
for the non-hydrogen atoms, hydrogen atoms having arbitrary radii of 0.1 Å.
3
60Њ. Dihedral angles between C(3)C(31,32) and Ru(1,2)C(1)
This complex is a typical example of a hydrido–alkynyl com-
plex, with the latter group sited perpendicularly to the Ru(1)–
Ru(2) vector. However, the crystal appears to show evidence of
disorder with expected consequences for the precision of the
determination; ligand light atom components corresponding to
minor disordered moieties are not resolved, so that their rela-
show considerable differences, ranging between 48.7(5) (for 22)
and 81.0(2)Њ (for 16), with no correlation with the angle at C(3).
In 17, one PPh ligand occupies an axial position on Ru(1),
3
whereas the PPh ligand on Ru(2) is in an equatorial coordin-
3
ation site. This is presumably because of the necessity to min-
imise steric interaction between the phenyl groups of the two
ligands, and results in P(1) and P(2) being approximately trans
and cis, respectively, to C(1) [P(1)–Ru(1)–C(1) 163.7(3), P(2)–
Ru(2)–C(1) 107.2(3)Њ]. In contrast, both P atoms in 18 are in
equatorial sites [P(1)–Ru(1)–C(1) 92.3(4), P(2)–Ru(2)–C(1)
tionship to the Ru clusters is not apparent. The most notable
3
difference between the four independent molecules of the
asymmetric unit is the disposition of the CH (OH)(n#) group,
2
the oxygen atom variously disposed relative to the Ru(n#)-
CO(n33)C(n1,n2,n3) plane, with unduly large amplitudes
possibly a foil for disorder. This is most clearly suggested in
molecule 4 where the associated geometry of an in-plane
substituent is clearly unrealistic.
8
7.8(4)Њ]. In the dppm ligands of 18, 20 and 21, lengthening of
the Ru(1)–Ru(2) vector, accompanied by diminished Ru–P dis-
tances, appears to have no significant effect on the internal
angles at P(1,2) and C(0), differences in these values in analo-
gous complexes 20 and 21 being greater than those with 18.
Discussion
In the AuRu cluster 22, the Au–Ru separations are 2.708(1)
3
and 2.754(2) Å, with an interplanar angle Ru(1,2,3) / AuRu(1,2)
of 65.70(4)Њ. These dimensions are similar to those found in
other complexes of this type. In conformity with the isolobal
Attempts to make ruthenium and osmium cluster complexes
containing propargyl alcohols were first reported in 1982, when
the parent cluster carbonyls M (CO) (M = Ru, Os) were
3
12
3
concept, in this example the Au(PPh ) group occupies the same
heated with the alcohols in refluxing octane. For ruthenium,
only small amounts of the expected Ru (µ-H){µ -C CPh -
3
position as one of the H atoms in 19.
3
3
2
2
In 13, the four independent molecules make up the asym-
metric unit, molecule 2 being depicted in Fig. 3 as represen-
tative while Table 3 contains the important bond parameters.
(OH)}(CO) were obtained, although the analogous osmium
9
compound was isolated in good yield. Use of the activated
ruthenium cluster Ru (CO) (NCMe) has enabled us to
3
10
2
J. Chem. Soc., Dalton Trans., 2000, 881–890
885

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Fig. 2 Projections of 19–22, see notes for Fig. 1.
improve significantly the yields of complexes of this type and to
phosphines to substitute one CO group on each of the terminal
examine further their reactions. In this way, we have isolated
ruthenium atoms of the open Ru cluster. In the case of 18,
3
Ru {µ -HC CR (OH)}(µ-CO)(CO) (R = H, Me, Ph) from
the bidentate ligand bridges the non-bonded Ru ؒ ؒ ؒ Ru vector,
together with the OH group.
3
3
2
2
9
reactions carried out at ambient temperatures in yields of
between 39 and 74%. These complexes resemble the many other
similar derivatives that have been obtained from other alkynes,
as shown by their spectral properties.
For a study of these allenylidene clusters, it was desirable that
other functional groups, such as OH, were not present. Con-
sequently, we have been interested to establish a method of
generating the allenylidene ligand by reactions in which the OH
group is eliminated, rather than transferred to the cluster. The
reactions we have described herein give some insight as to how
this might be achieved.
As commonly found with 1-alkyne derivatives, ready conver-
sion of these complexes into the hydrido–alkynyl clusters
occurs in refluxing hexane in yields of 71 to 89%, some of these
derivatives being isolated from the initial reactions involving the
alkyne, e.g. for R = Me. One example has been characterised
crystallographically, albeit with limited precision. These cluster
complexes retain the hydroxyl group on the alkynyl substituent.
Protonation of the hydroxy–alkynyl clusters is likely to occur
at the alkynyl OH group to give an oxonium ion. Elimination of
ϩ
either H O (formed by combination with the cluster hydride)
3
3
As found previously with the osmium cluster, treatment with
or H O would give the neutral allenylidene or protonated
2
3
strong acid (aqueous CF CO H or HBF ) results in migration
carbocationic cluster, respectively. Either is an unsaturated 46-e
3
2
4
of the hydroxy group from the alkynyl ligand to the cluster
framework, with concomitant generation of an allenylidene
system (A) which would be expected to react with other ligands
if present. The formation of the products from reactions of 15
or 16 carried out in the presence of HBF ؒOMe can be under-
ligand and opening of the M cluster, the hydroxyl group bridg-
3
4
2
ing the non-bonded Ru ؒ ؒ ؒ Ru vector. While for R = Ph, the
stood in the following terms.
In the absence of added ligand, oxidative addition of water
product is obtained in 32% yield, use of HBF ؒOMe allowed
4
2
essentially quantitative conversion and isolation of Ru (µ-H)-
or Me O to A gives the µ-OH (15) or µ-OMe (16) complexes.
3
2
(
µ -CCCPh )(µ-OH)(CO) in 79% yield, together with 7% of
The (H ϩ OR) combination gives an electron-rich 50-e species
with Ru–Ru bond cleavage occurring concomitantly to give the
observed open triangular clusters. The same products are
3
2
9
the analogous µ-OMe derivative 16, apparently formed from
the dimethyl ether. The hydroxy cluster 15 reacts with tertiary
8
86
J. Chem. Soc., Dalton Trans., 2000, 881–890

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Table 2 Significant structural parameters for 16–22. Bond lengths (Å) and bond angles (Њ)
1
6
17
18
19
20
21
22
(
a) Complexes 16–18
(b) Complexes 19–22
Ru(1)–Ru(2)
Ru(1)–Ru(3)
Ru(2)–Ru(3)
Ru(1)–P(1)
Ru(2)–P(2)
2.8418(7), 2.8501(7) 3.234(1)
2.8266(7), 2.8340(6) 2.920(1)
3.3171(7), 3.3198(7) 2.810(1)
2.419(3)
3.194(2)
2.805(2)
2.904(2)
2.317(4)
2.328(4)
2.135(9)
2.11(1)
Au(1)–Ru(1)
Au(1)–Ru(2)
Ru(1)–Ru(2)
Ru(1)–Ru(3)
Ru(2)–Ru(3)
Au(1)–P(1)
Ru(1)–P(1)
Ru(2)–P(2)
Ru(1)–C(1)
Ru(2)–C(1)
Ru(3)–C(1)
Ru(3)–C(2)
Ru(1)–C(13)
Ru(2)–C(13)
P(1)–C(0)
2.708(1)
2.754(2)
2.7863(6) 2.7728(4) 2.891(1)
2.847(1)
2.8747(9) 2.7733(5) 2.7519(5) 2.887(1)
2.7389(9) 2.7610(6) 2.8049(4) 2.779(2)
2.291(3)
2.324(3)
a
Ru(1)–Oa
2.117(6)
2.136(6)
Ru(2)–O
Ru(3)–O
2.100(4), 2.096(4)
2.111(4), 2.110(4)
2.010(5), 2.002(5)
2.097(5), 2.095(5)
2.248(6), 2.262(5)
2.223(5), 2.238(5)
2.361(1)
2.349(1)
2.071(5)
2.026(5)
2.181(4)
2.259(5)
2.084(6)
2.209(6)
1.842(5)
1.847(5)
1.339(6)
1.357(6)
1.479(6)
1.498(7)
2.3472(9)
2.3615(9)
2.043(4)
2.057(3)
2.178(3)
2.258(3)
2.195(5)
2.051(5)
1.846(4)
1.840(4)
1.338(5)
1.352(5)
1.486(5)
1.504(5)
a
Ru(1)–C(1)
Ru(2)–C(1)
Ru(3)–C(1)
Ru(3)–C(2)
P(1)–C(0)
2.10(1)
2.054(9)
2.20(1)
2.24(1)
2.07(1)
2.09(1)
2.16(1)
2.28(1)
1.84(2)
1.84(2)
1.32(2)
1.37(2)
1.48(2)
1.49(2)
2.079(5)
2.020(5)
2.197(5)
2.281(5)
2.07(1)
2.02(1)
2.21(1)
2.29(1)
1.89(1)
P(2)–C(0)
C(1)–C(2)
C(2)–C(3)
C(3)–C(311)
C(3)–C(321)
1.349(6), 1.346(6)
1.337(7), 1.341(7)
1.490(7), 1.499(7)
1.483(8), 1.491(8)
1.35(2)
1.37(2)
1.50(2)
1.48(2)
P(2)–C(0)
C(1)–C(2)
C(2)–C(3)
C(3)–C(311)
C(3)–C(321)
1.328(6)
1.332(7)
1.501(6)
1.473(7)
1.35(2)
1.31(2)
1.51(2)
1.52(2)
Ru(2)–Ru(1)–Ru(3)
Ru(1)–Ru(3)–Ru(2)
Ru(1)–O(1)–Ru(2)
Ru(2)–O(4)–Ru(3)
Ru(1)–P(1)–C(0)
Ru(2)–P(2)–C(0)
P(1)–C(0)–P(2)
Ru(1)–C(1)–Ru(2)
Ru(1)–C(1)–C(2)
Ru(2)–C(1)–C(2)
C(1)–C(2)–C(3)
C(2)–C(3)–C(311)
C(2)–C(3)–C(321)
ΣC(3)
71.63(2), 71.47(2)
54.05(3)
68.68(3)
99.0(3)
57.48(4)
68.01(4)
97.5(2)
Ru(2)–Ru(1)–Ru(3)
Ru(1)–Ru(3)–Ru(2)
Ru(1)–P(1)–C(0)
Ru(2)–P(2)–C(0)
P(1)–C(0)–P(2)
Ru(1)–C(1)–Ru(2)
Ru(1)–C(13)–Ru(2)
Ru(1)–C(13)–O(13)
Ru(2)–C(13)–O(13)
Ru(1)–C(1)–C(2)
Ru(2)–C(1)–C(2)
C(1)–C(2)–C(3)
C(2)–C(3)–C(311)
C(2)–C(3)–C(321)
ΣC(3)
58.22(2)
60.39(3)
59.55(1)
60.46(1)
110.2(1)
109.3(1)
119.3(2)
85.7(2)
61.02(1)
59.86(1)
108.9(1)
111.0(1)
114.1(2)
85.1(1)
103.9(2), 104.3(2)
110.7(5)
113.7(5)
118.4(8)
100.3(6)
132(1)
122(1)
153(1)
123(1)
119(1)
360
87.5(2), 88.1(2)
142.2(4), 142.3(4)
123.1(4), 122.5(4)
148.7(6), 148.8(5)
121.7(5), 120.9(5)
120.4(5), 120.5(4)
359. , 360.
102.2(5)
114.6(7)
133.7(8)
153(1)
122(1)
119(1)
360
88.0(2)
90.0(5)
80.9(2)
81.4(2)
141.4(5)
137.7(5)
128.1(4)
134.5(4)
154.0(5)
119.9(4)
119.3(4)
359.9
134.1(4)
144.3(4)
132.2(3)
131.6(3)
153.0(3)
121.1(3)
120.1(3)
359.9
124.3(4)
138.4(4)
153.4(5)
120.7(5)
121.3(4)
359.9
124(1)
137(1)
144(2)
121(1)
119(1)
355
9
0
Ru(1,2,3)/Ru(1,2)C(1)
Ru(1,2-mid-point)C(1)/ 157, 157
C(1,2)
55.0, 55.5(2)
64.4(6)
159
64.4(6)
159
ORu /Ru3
Ru(1,2)C(1)/C(3,31,32)
44.4(2), 45.9(2)
81.0(2), 81.0(2)
47.7(3)
63.3(4)
54.7(4)
61.6(5)
Ru(1,2,3)/Ru(1,2)C(1)
Ru(1,2-mid-point)C(1)/ 155
C(1,2)
62.6(2)
63.4(2)
154
62.7(1)
155
63.4(5)
155
2
O(Au)Ru /Ru
Ru(1,2)C(1)/C(3,31,32) 50.1(2)
66.7(2)
67.7(1)
65.70(4)
48.7(5)
2
3
50.0(1)
a
O to be read as O(n) (n = 1 or 4) as appropriate.
Table 3 Some structural parameters for 13. Bond distances (Å) and bond angles (Њ) (major component only)
Molecule 1
Molecule 2
Molecule 3
Molecule 4
Average
Ru(1)–Ru(2)
Ru(1)–Ru(3)
Ru(2)–Ru(3)
2.768(2)
2.810(2)
2.810(2)
2.782(2)
2.807(2)
2.813(2)
2.783(2)
2.807(3)
2.815(2)
2.782(2)
2.793(3)
2.792(2)
2.779(7)
2.806(5)
Ru(1)–C(1)
Ru(2)–C(1)
Ru(1)–C(2)
Ru(2)–C(2)
Ru(3)–C(1)
2.22(2)
2.24(2)
2.22(2)
2.24(2)
1.91(2)
2.21(1)
2.17(2)
2.26(2)
2.25(2)
1.88(2)
2.25(2)
2.17(2)
2.22(2)
2.21(2)
1.90(2)
2.25(3)
2.16(2)
2.48(2)
2.48(1)
1.88(2)
2.21(1)
a
2.23(2)
1.89(1)
a
C(1)–C(2)
C(2)–C(3)
C(3)–O
1.33(2)
1.52(3)
1.26(3)
1.37(2)
1.49(3)
1.35(2)
1.33(3)
1.52(2)
1.40(2)
1.09(3)
1.64(3)
1.27(4)
1.34(2)a
1.51(1)
1.32(7)
a
Ru(3)–C(1)–C(2)
C(1)–C(2)–C(3)
C(2)–C(3)–O
151(2)
141(2)
114(2)
156(1)
144(2)
117(2)
152(1)
142(2)
111(1)
173(2)
170(1)
135(2)
153(3)a
142(1)a
114(2)
a
Omitting the values for molecule 4.
obtained in the presence of CO, rather than the sought-after
of one equivalent of HBF ؒOMe , also result in loss of the
4 2
Ru(µ -CCCPh )(µ-CO)(CO) , probably because of the very
limited solubility of CO in the reaction medium.
Reactions of dppm with 9 or 10, carried out in the presence
elements of water (OH ϩ H) with formation of 20 and 21,
respectively. The formation of these products can be under-
stood if the unsaturated intermediate A reacts quickly with the
3
2
9
J. Chem. Soc., Dalton Trans., 2000, 881–890
887

View Article Online
been established. Further accounts of the chemistry of these
interesting complexes are in preparation.
Experimental
General reaction conditions
Reactions were carried out under an atmosphere of nitrogen,
but no special precautions were taken to exclude oxygen during
work-up. Common solvents were dried and distilled under
nitrogen before use. Elemental analyses were performed by
Canadian Microanalytical Service, Delta, B.C., Canada. Pre-
parative tlc was carried out on glass plates (20 × 20 cm) coated
with silica gel (Merck 60 GF254, 0.5 mm thick).
Instrumentation
IR: Perkin-Elmer 1720X FT IR. NMR: Bruker CXP300 or
1
13
ACP300 ( H NMR at 300.13 MHz, C NMR at 75.47 MHz) or
1
13
Varian Gemini 200 ( H at 199.8 MHz, C at 50.29 MHz)
spectrometers. Samples were dissolved in CDCl (Sigma) or
3
(
CD ) SO (Aldrich) and spectra were recorded using 5 mm
3 2
sample tubes. ES MS: VG Platform II: Solutions in MeOH were
injected via a 10 ml injection loop; nitrogen was used as the
drying and nebulising gas. Samples were examined at cone volt-
ages in the range 20–80 V to find the best conditions. Finnegan
LCQ: Solutions were directly infused into this instrument.
17
Chemical aids to ionisation were used as required.
Reagents
1
8
18
HC᎐CCR (OH) [R = H, Me (Aldrich), Ph, tol ], Ru (CO) -
᎐
2
3
10
1
9
20
(
NCMe) , HBF ؒOMe , PPh , dppm, AuCl(PPh )
K[BHBu ] (Aldrich; K-Selectride) either were prepared accord-
and
2
s
4
2
3
3
3
ing to the cited methods or were commercial products, used as
received.
Synthesis of Ru {ꢀ -HC CPh (OH)}(ꢀ-CO)(CO) (7). A solu-
3
3
2
2
9
tion of HC᎐CCPh (OH) (70 mg, 0.312 mmol) was added to one
᎐
2
of Ru (CO) (NCMe) [from Ru (CO) (200 mg, 0.312 mmol)
3
10
2
3
12
prepared as above]. After 1 h at rt, the colour of the mixture
had darkened to orange. Preparative tlc (silica gel, benzene–
Fig. 3 Projection of molecule 2 as representative of 13, normal and
oblique to the principal Ru plane. Primed ruthenium atoms are minor
3
hexane 1:1) gave Ru (CO) (11 mg, 5.4%) and Ru {µ -
disordered components, associated ligand components not being
resolved.
3
12
3
3
HC CPh
2
(OH)}(µ-CO)(CO) (7) (182 mg, 74%), in the major
2
9
orange band (R 0.40) and obtained as orange crystals from
pentane.
f
diphosphine; a molecule of CO is also lost to give the obseved
products. Elsewhere, we have described the unusual transform-
ation of the allenylidene ligand into a diphenylindenyl group by
combination with one of the phenyl groups of the dppm ligand,
Synthesis of Ru {ꢀ -HC C(tol) (OH)}(ꢀ-CO)(CO) (8). A
3
3
2
2
9
solution of HC᎐CC(tol)2
᎐
(OH) (74 mg, 0.312 mmol) in CH Cl2
2
13a
which occurs on heating.
Treatment of 9 with K[BHBu ], followed by protonation,
(2 ml) was added to Ru (CO) (NCMe) [prepared from
3
10
s
Ru (CO) (200 mg, 0.312 mmol) and Me NO (60 mg, 0.8
3 12 3
3
resulted in loss of water and afforded a small amount of Ru3-
mmol) in a mixture of CH Cl (80 ml) and MeCN (20 ml) at
2 2
(
µ-H) (µ -CCCPh )(CO) (19). This complex has limited stabil-
0 ЊC]. The mixture was allowed to warm up to rt and left for 2 h,
after which it had become orange. Evaporation to dryness and
purification of the residue by preparative tlc (acetone–hexane
1:4) gave an orange band (R 0.39) which contained Ru {µ -
2
3
2
9
ity in air and in solution, considerable decomposition occurring
during its preparation, with much of the ruthenium being
recovered as tetranuclear cluster hydrido–carbonyls. This
product may arise by loss of water after protonation, followed
f
3
3
HC C(tol) (OH)}(µ-CO)(CO) (8) (202 mg, 79%), obtained as
2
2
9
by addition of H (present in limited amount in soluton from
an orange solid.
2
s
ϩ
Ϫ
the reaction of K[BHBu ] with acid) or of H /H to the
3
Synthesis of Ru {ꢀ -HC CH (OH)}(ꢀ-CO)(CO) (11). Prop-
argyl alcohol (17 mg, 0.018 mmol) was added to Ru (CO) -
3 10
intermediate A. On the other hand, treatment of the hydroxy–
3
3
2
2
9
s
allenylidene cluster 15 with K[BHBu ], followed by AuCl-
3
(
NCMe) [prepared as above from Ru (CO) (200 mg, 0.312
(
PPh ), results in loss of OH and auration of the cluster. The
2
3
1
2
3
mmol)] at Ϫ50 ЊC. After warming to rt and stirring for 30 min,
the colour of the mixture was dark orange. Preparative tlc
silica gel, acetone–hexane 1:4) separated the major product as
resulting complex 22 is isolobal with 19, and may also result
ϩ
from reaction of A with [Au(PPh )] present in the solution.
3
(
an orange band (R 0.5) which gave orange crystals of Ru -
f
3
Conclusions
{
µ -HC CH (OH)}(µ-CO)(CO) (11) (78 mg, 39%). Two minor
3 2 2 9
The work described above has clarified the chemistry of the Ru3
yellow products were not identified; some decomposition
products were left on the baseline.
cluster with propargyl alcohols and their conversion into
allenylidene complexes. While the elimination of water is not
spontaneous with these complexes, in contrast to their mono-
nuclear counterparts, conditions for the preparation of several
clusters containing allenylidene but no hydroxy groups have
Synthesis of Ru {ꢀ -HC CMe (OH)}(ꢀ-CO)(CO) (12). A
3
3
2
2
9
solution of HC᎐CCMe (OH) (66 mg, 0.196 mmol) in CH Cl
᎐
2
2
2
(2 ml) was added to a solution of Ru (CO) (NCMe) [prepared
3
10
2
8
88
J. Chem. Soc., Dalton Trans., 2000, 881–890

View Article Online
s
3
as above from Ru (CO) (250 mg, 0.39 mmol)] at Ϫ50 ЊC.
Reaction of Ru (ꢀ-H){ꢀ -C CPh (OH)}(CO) with K[BHBu ]
3
12
3
3
2
2
9
After warming to rt and stirrring for 45 min, the colour of the
mixture had changed from pale yellow to orange. Solvents were
removed under vacuum and the residue was purified by pre-
parative tlc (silca gel, acetone–hexane 1:4). The fastest-moving
band contained Ru (CO) (<1%). The second band (yellow, Rf
and HBF ؒMe O. K-Selectride (1M in thf, 0.35 ml) was added
4 2
to Ru (µ-H){µ -C CPh (OH)}(CO) (250 mg, 0.32 mmol) in thf
3
3
2
2
9
(7 ml). After stirring for 5 min at rt, the mixture was treated
with HBF ؒOMe (0.05 ml) and stirred for a further 30 min.
4
2
Evaporation and separation by preparative tlc (hexane) gave
3
12
0
.48) contained Ru (µ-H){µ -C CMe (OH)}(CO) (14) (27.4
several bands. The first yellow band (R 0.49) contained Ru (µ-
3
3
2
2
9
f
4
1
mg, 11%), obtained as yellow crystals (CH Cl –MeOH). Band 3
H) (CO) (9.1 mg, 4%), identified from its IR ν(CO) and H
2
2
4 12
(
(
orange, Rf 0.38) afforded Ru {µ -HC CMe (OH)}(µ-CO)-
NMR spectra. An orange band (R 0.33) contained Ru (µ-
f 4
1
3
3
2
2
CO) (12) (140 mg, 54%) as orange crystals (CH Cl –MeOH).
H) (CO) (11 mg, 6%), identified from its IR ν(CO) and H
2 13
9
2
2
NMR spectra and by an X-ray structure determination. The
Preparation of Ru (ꢀ-H){ꢀ -C CPh (OH)}(CO) (9). A solu-
second yellow band (R 0.26) afforded Ru (µ-H) (µ -CCCPh )-
3
3
2
2
9
f
3
2
3
2
tion of Ru {µ -HC CPh (OH)}(µ-CO)(CO) (7) (130 mg, 0.164
(CO) (19) (4.6 mg, 2%) as yellow crystals (pentane).
3
3
2
2
9
9
mmol) in hexane (20 ml) was heated at reflux point for 1 h, after
which the colour had paled to yellow. Purification by prepar-
ative tlc (acetone–hexane 3:7) gave pale yellow crystals (pen-
tane) of Ru (µ-H){µ -C CPh (OH)}(CO) (9) (108 mg, 86%)
Preparation of Ru (ꢀ -CCCPh )(ꢀ-dppm)(ꢀ-CO)(CO) (20).
3
3
2
7
A few drops of HBF ؒOMe were added to a solution of Ru -
4
2
3
(
(
µ-H){µ -C CPh (OH)}(CO) (60 mg, 0.078 mmol) and dppm
3 2 2 9
3
3
2
2
9
30 mg, 0.078 mmol) in CH Cl2 (10 ml) at rt. The colour
obtained from the band with R 0.54.
2
f
immediately changed to dark red. After 30 min, tlc showed that
reaction was complete. After removal of solvent, the residue
Preparation of Ru (ꢀ-H){ꢀ -C C(tol) (OH)}(CO) (10). A
3
3
2
2
9
was recrystallised (CH Cl –MeOH) to give dark red crystals of
solution of Ru {µ -HC C(tol) (OH)}(µ-CO)(CO) (8) (450 mg,
2
2
3
3
2
2
9
Ru (µ -CCCPh )(µ-dppm)(µ-CO)(CO) (20) (58 mg, 67%).
0
1
.55 mmol) in hexane (50 ml) was heated at reflux point for
h, the colour gradually changing to yellow. Preparative tlc
3
3
2
7
Preparation of Ru {ꢀ -CCC(tol) }(ꢀ-dppm)(ꢀ-CO)(CO) (21).
(
acetone–hexane 1:4) gave a single yellow band (R 0.66), which
3
3
2
7
f
This complex was prepared from Ru (µ-H){µ -C C(tol) (OH)}-
after extraction and crystallisation (pentane) afforded pale
yellow crystals of Ru (µ-H){µ -C C(tol) (OH)}(CO) (10) (383
3
3
2
2
(
CO) (460 mg, 0.58 mmol), dppm (220 mg, 0.58 mmol) and a
9
3
3
2
2
9
few drops of HBF ؒOMe in a similar manner to 20 above.
mg, 88%).
4
2
Separation by preparative tlc gave dark red crystals (CH Cl –
2
2
hexane) of Ru {µ -CCC(tol) }(µ-dppm)(µ-CO)(CO) (21) (506
mg, 77%).
Preparation of Ru (ꢀ-H){ꢀ -C CH (OH)}(CO) (13). A solu-
3
3
2
7
3
3
2
2
9
tion of Ru {µ -HC CH (OH)}(µ-CO)(CO) (11) (100 mg, 0.156
3
3
2
2
9
mmol) in hexane (20 ml) was heated at reflux point for 15 min,
after which time tlc showed complete disappearance of starting
material. Purification by preparative tlc (silica gel, acetone–
hexane 1:4) gave yellow crystals (CHCl ) of Ru (µ-H){µ -
Auration of Ru (ꢀ-H)(ꢀ -CCCPh )(ꢀ-OH)(CO) (15). A solu-
3
3
2
9
tion of Ru (µ-H)(µ -CCCPh )(µ-OH)(CO) (50 mg, 0.07 mmol)
3
3
2
9
in thf (7 ml) was treated with K-Selectride (0.2 ml of a 1M
3
3
3
solution in thf). After stirring at rt for 15 min, AuCl(PPh ) (35
3
C CH (OH)}(CO) (13) (68 mg, 71%).
2
2
9
mg, 0.07 mmol) was added to the mixture, which was stirred for
a further 30 min. Separation of the product by preparative tlc
silica gel, acetone–hexane 1:4) gave yellow crystals of
Preparation of Ru (ꢀ-H){ꢀ -C CMe (OH)}(CO) (14). A
3
3
2
2
9
(
solution of Ru {µ -HC CMe (OH)}(µ-CO)(CO) (12) (84 mg,
3
3
2
2
9
AuRu (µ-H)(µ -CCCPh )(CO) (PPh ) (22) (16.5 mg, 21%) from
3
3
2
9
3
0.126 mmol) in hexane (15 ml) was heated at reflux point for 15
the band with R 0.47. Several other products are formed, but in
f
min, after which time the colour had changed from orange to
pale yellow. Purification by preparative tlc (silica gel, acetone–
hexane 1:4) gave yellow Ru (µ-H){µ -C CMe (OH)}(CO) (14)
amounts too small to isolate and characterise satisfactorily.
3
3
2
2
9
Structure determinations
(
72 mg, 90%).
For 17–19 and 22, unique single-counter/four-circle diffract-
ometer data sets were measured at ca. 295 K within the specified
2θmax limit, yielding N independent reflections, No with
I > 3σ(I) being used in the full matrix least squares refinements
after gaussian absorption correction. For the remainder, full
spheres of data were measured using a Bruker AXS CCD
instrument at ca. 300 K, Ntot reflections being merged after
‘empirical’ absorption correction (proprietary software
Reaction of Ru (ꢀ-H){ꢀ -C CPh (OH)}(CO) with HBF4ؒ
3
3
2
2
9
Me O. Six drops of HBF ؒMe O were added to a solution of
2
4
2
Ru (µ-H){µ -C CPh (OH)}(CO) (60 mg, 0.079 mmol) in
3
3
2
2
9
CH Cl (7 ml), whereupon the colour changed immediately
2
2
from pale yellow through dark red to red-orange. After stirring
at rt for 15 min, tlc showed that two new complexes were pres-
ent. Separation by preparative tlc (silica gel, acetone–hexane
22
3
:7) gave two yellow bands. The first (R 0.063) contained
SMART, SAINT, SADABS ) to N unique (R quoted),
f
int
Ru (µ-H)(µ -CCCPh )(µ-OMe)(CO) (16) (4.2 mg, 7%) as
N with F > 4σ( F ) being used in the refinement. All data were
3
3
2
9
o
yellow crystals (hexane). The second band (R 0.56) gave Ru -
measured using monochromatic Mo-Kα radiation, λ = 0.71073
Å. In the refinements, anisotropic thermal parameter forms
were used for the non-hydrogen atoms, (x, y, z, Uiso)H being
constrained at estimated values. Conventional residuals R, Rw
on |F| are quoted, statistical weights being employed. Neutral
atom complex scattering factors were used; computation used
f
3
(
µ-H)(µ -CCCPh )(µ-OH)(CO) (15) (47.5 mg, 79%) as a yellow
3 2 9
powder.
Reactions of Ru (ꢀ-H)(ꢀ -CCCPh )(ꢀ-OH)(CO) (15) with
3
3
2
9
tertiary phosphines. (a) PPh . A mixture of Ru (µ-H)(µ -
3
3
3
21
CCCPh )(µ-OH)(CO) (60 mg, 0.08 mmol) and PPh (42 mg,
the XTAL 3.4 program system. Pertinent results are given in
the Figures (which show non-hydrogen atoms with 20% prob-
ability amplitude displacement ellipsoids) and Tables. See Table
4 for crystal and refinement data.
2
9
3
0
.16 mmol) was heated in refluxing toluene (10 ml) for 15 min.
After evaporation of solvent, the residue was separated by pre-
parative tlc (silica gel, acetone–hexane 3:7) to give a major
yellow band (R 0.37) which afforded yellow-orange crystals of
Individual variations associated with particular structures
follow: 13. Four distinct molecules comprise the asymmetric
f
Ru (µ-H)(µ -CCCPh )(µ-OH)(CO) (PPh ) (17) (26.2 mg, 27%)
3
3
2
7
3 2
from CHCl –MeOH.
unit of the structure. As is not uncommon, the Ru triangles
3
3
(
b) dppm. A similar reaction between Ru (µ-H)(µ -CCCPh )-
were found to be disordered, site occupancies refining to
0.861(2), 0.774(2), 0.825(2) and 0.718(2), and complements for
the disordered component. The mode of disorder is unusual,
however, the sites not conforming to the usual ‘Star of David’
3
3
2
(
µ-OH)(CO)9 (75 mg, 0.10 mmol) and dppm (38 mg, 0.10
mmol) afforded orange crystals of Ru (µ-H)(µ -CCCPh )(µ-
OH)(µ-dppm)(CO) (18) (60 mg, 56%) from CH Cl –MeOH.
3
3
2
7
2
2
J. Chem. Soc., Dalton Trans., 2000, 881–890
889

View Article Online
Table 4 Crystal and refinement data
Compound
Formula
13
16
17
18
19
20
21
22
C H AuO -
C H O Ru
1
C H O Ru C H O P -
25 14 10
C H O P -
C H O Ru
24 12
C H O -
C H O P -
2
4
10
3
3
58 42
8
2
47 34
8
2
9
3
48 32
8
50 36
8
2
42 25
9
Ru3
Ru ؒ0.56CH -
Cl2
1134.4
P Ru
2
Ru ؒ≈0.64CH - PRu3
Cl2
1182.6
3
2
3
3
2
M
611.4
777.6
1232.1
747.6
1101.9
1204.8
Crystal system Triclinic
Triclinic
P1
Monoclinic
P2 /c
1
Orthorhombic
Pca21
Monoclinic
P2 /c
1
Monoclinic
P2 /c
1
Monoclinic
P2 /n
1
Triclinic
P1
¯
¯
¯
Space group
P1
a/Å
b/Å
c/Å
α/Њ
β/Њ
γ/Њ
V/Å
Z
D /g cm
c
14.611(2)
16.761(2)
17.082(2)
88.463(2)
65.661(2)
66.170(2)
3437
19.279(2)
18.672(2)
7.7598(9)
90.257(2)
97.639(2)
99.825(2)
2727
10.660(1)
14.393(4)
34.288(11)
20.743(6)
11.600(5)
19.813(4)
10.477(3)
12.434(3)
20.465(9)
10.3021(8)
10.0375(8)
42.729(3)
13.078(2)
24.641(3)
15.348(2)
16.573(7)
13.754(6)
9.797(6)
99.18(4)
95.47(4)
106.11(3)
2095
95.38(2)
105.19(3)
94.181(1)
96.585(2)
3
5237
4
1.562
4767
4
1.580
2573
4
1.927
4407
4
1.661
4913
4
1.599
8
4
2
Ϫ3
2.362
1.894
1.910
Crystal size/
mm
0.17 × 0.15 × 0.55 × 0.40 × 0.28 × 0.10 × 0.18 × 0.14 ×
0.25 × 0.45 × 0.36 × 0.25 × 0.31 × 0.28 ×
0.10 × 0.07 ×
0.24
0.62, 0.76
46.4
0.07
0.25
0.57, 0.89
16.9
0.12
0.91, 0.93
9.7
0.51
0.82, 0.86
11.1
0.28
0.21
0.78, 0.89
11.4
0.11
0.65, 0.86
10.9
T (min, max)
0.71, 0.89
26.5
0.60, 0.67
17.9
Ϫ1
µ/cm
2
N
θmax/Њ
58
40329
58
30524
50
55
55
58
48061
58
53658
50
12339
5903 (0.041)
4060
0.040
0.037
N (Rint)
No
R
12029 (0.039) 13318 (0.050) 9206
4972
143
48
11111 (0.024) 12360 (0.035)
7359
4591
0.049
0.046
r
7869
0.062
0.064
8703
0.046
0.048
5018
0.055
0.054
9632
0.049
0.056
9458
0.041
0.050
Rw
57
dispositions, coplanar with the parent, but subject to rotation
and displacement and twisting in the third dimension; Ru(1–3)/
Ru(1Ј–3Ј) interplanar dihedrals are 62.3(3), 60.6(2), 60.3(2) and
3091; (i) R. Stegmann and G. Frenking, Organometallics, 1998, 17,
089; (j) H. Werner, S. Jung, B. Weberndörfer and J. Wolf, Eur. J.
Inorg. Chem., 1999, 951.
M. I. Bruce, Chem. Rev., 1998, 98, 2797.
S. Aime, A. J. Deeming, M. B. Hursthouse and J. D. J. Backer-Dirks,
J. Chem. Soc., Dalton Trans., 1982, 1625.
4 J. P. Selegue, Organometallics, 1982, 1, 217.
5 S. Ermer, R. Karpelus, S. Miura, E. Rosenberg, A. Tiripicchio and
A. M. Manotti Lanfredi, J. Organomet. Chem., 1980, 187, 81.
S. Aime, L. Milone and A. J. Deeming, J. Chem. Soc., Chem.
Commun., 1980, 1168.
S. Aime and A. J. Deeming, J. Chem. Soc., Dalton Trans., 1981, 828.
G. Gervasio, R. Gobetto, P. J. King, D. Marabello and E. Sappa,
Polyhedron, 1998, 17, 2937.
9 S. Aime, A. Tiripicchio, M. Tiripicchio-Camellini and A. J.
Deeming, Inorg. Chem., 1981, 20, 2027.
0 V. V. Krivykh, O. A. Kizas, E. V. Vorontsov, F. M. Dolgushin, A. I.
Yanovsky, Yu. T. Struchkov and A. A. Koridze, J. Organomet.
Chem., 1996, 508, 39.
1 (a) P.-S. Cheng, Y. Chi, S.-M. Peng and G.-H. Lee, Organometallics,
1993, 12, 250; (b) J.-J. Peng, K.-M. Horng, P.-S. Cheng, Y. Chi,
S.-M. Peng and G.-H. Lee, Organometallics, 1994, 13, 2365.
2 C. S.-W. Lau and W.-T. Wong, J. Chem. Soc., Dalton Trans., 1998,
2
2
3
6
1.7(2)Њ for the four molecules. Molecule 2, shown in Fig. 1, is
fairly typical. Not infrequently, such disorder is found to be
temperature dependent; a separate experiment conducted with
this material at 150 K, using a smaller specimen, showed no
appreciable change in site occupancies and the more precise
room temperature determination is offered as typical. Dis-
ordered components of the remainder of the molecule were not
resolved, presumably encompassed by some rather large ellips-
oid amplitudes and, in turn, accounting for the rather high
residuals. Hydroxyl and hydrido hydrogen atoms were not
located in difference maps. 16. (x, y, z, Uiso)H were refined
throughout, excepting those associated with the methyl groups,
which were constrained at estimated values; two molecules
comprise the asymmetric unit of the structure. 17. Hydride and
hydroxyl hydrogen atoms were defined in difference maps but
not refined. 18. Residuals were the same for both hands. The
6
7
8
1
1
1
1
hydroxyl hydrogen atom was not located. The N criterion was
o
3
391.
I > 2σ(I). 19. Data were measured for a hemisphere, Rint 0.041.
3 (a) M. I. Bruce, B. W. Skelton, A. H. White and N. N. Zaitseva,
Inorg. Chem.Commun., 1999, 2, 17; (b) M. I. Bruce, B. W. Skelton,
A. H. White and N. N. Zaitseva, Inorg. Chem. Commun., 1999, 2, 453.
(
x, y, z, Uiso)H were refined throughout. The N criterion was
o
I > 2σ(I).
CCDC reference number 186/1807.
See http://www.rsc.org/suppdata/dt/a9/a906379j/ for crystal-
lographic files in .cif format.
14 E. Sappa, G. Predieri, A. Tiripicchio and F. Ugozzoli, Gazz. Chim.
Ital., 1995, 125, 51.
1
1
1
5 G. Gervasio, D. Marabello and E. Sappa, J. Chem. Soc., Dalton
Trans., 1997, 1851.
6 M. Iyoda, Y. Kuwatani and M. Oda, J. Chem. Soc., Chem.
Commun., 1992, 399.
7 W. Henderson, J. S. McIndoe, B. K. Nicholson and P. J. Dyson,
J. Chem. Soc., Dalton Trans., 1998, 519.
Acknowledgements
We thank the Australian Research Council for financial support
and Johnson Matthey plc for a generous loan of RuCl ؒnH O.
3
2
18 M. M. Midland, J. Org. Chem., 1975, 40, 2250.
1
9 G. A. Foulds, B. F. G. Johnson and J. Lewis, J. Organomet. Chem.,
985, 296, 147.
1
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