Alkyne diruthenium chemistry

Article abstract of DOI:10.1016/S0022-328X(99)00432-5

The reaction of [Ru₂(CO)₄(μ-CO)(μ-dppm)₂] (1) with alkynes RCCR′ gives the alkyne complexes [Ru₂(CO)₄(μ-RC=CR′)(μ-dppm)₂] [2, R′=H; 3, R′=CO₂Me or COMe; 4, R′=CCR], [Ru₂(CO)₄H(CCR)(μ-dppm)₂] (5) or [Ru₂(CO)₂(μ-CO)H(μ-CCR)(μ-dppm)₂] (6), when R=Ph. Complex 6 reacts with chlorinated solvent to give [Ru₂(CO)₂(μ-CO)Cl(μ-CCR)(μ-dppm)₂] (7), R=Ph. Complex 1 reacts with excess alkyne RCCH to give [Ru₂(CO)₂(μ-CO){C(=CH₂)R}(μ-CCR)(μ-dppm)₂] (8), when R=Ph, Bu or CH₂CH₂CCH, and, when R=Ph, 8 reacts with more PhCCH to give [Ru₂(CO)₂(μ-C=CHPh){C(=CH₂)Ph}(μ-CCPh)(μ-dppm)₂] (9), a complex containing three different organic ligands (alkenyl, alkynyl and vinylidene).

Full text of DOI:10.1016/S0022-328X(99)00432-5

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 593–594 (2000) 77–85
Alkyne diruthenium chemistry
Joshi Kuncheria, Hameed A. Mirza, Jagadese J. Vittal, Richard J. Puddephatt *
Department of Chemistry, Uni6ersity of Western Ontario, London, Canada N6A 5B7
Received 22 April 1999; accepted 20 July 1999
Abstract
The reaction of [Ru2(CO)4(m-CO)(m-dppm)2] (1) with alkynes RCCR% gives the alkyne complexes [Ru2(CO)4(m-RCꢀCR%)(m-
dppm)2] [2, R%=H; 3, R%=CO2Me or COMe; 4, R%=CCR], [Ru2(CO)4H(CCR)(m-dppm)2] (5) or [Ru2(CO)2(m-CO)H(m-CCR)(m-
dppm)2] (6), when R=Ph. Complex 6 reacts with chlorinated solvent to give [Ru2(CO)2(m-CO)Cl(m-CCR)(m-dppm)2] (7), R=Ph.
Complex 1 reacts with excess alkyne RCCH to give [Ru2(CO)2(m-CO){C(ꢀCH2)R}(m-CCR)(m-dppm)2] (8), when R=Ph, Bu or
CH2CH2CCH, and, when R=Ph, 8 reacts with more PhCCH to give [Ru2(CO)2(m-CꢀCHPh){C(ꢀCH2)Ph}(m-CCPh)(m-dppm)2]
(9), a complex containing three different organic ligands (alkenyl, alkynyl and vinylidene). © 2000 Elsevier Science S.A. All rights
reserved.
Keywords: Alkyne diruthenium; Metallacyclic compounds; Terminal alkynes
1. Introduction
The chemistry of alkynes with ruthenium complexes
is varied and interesting and the reaction chemistry of
(1)
alkynes with diruthenium complexes is particularly rich
[1–6]. Internal alkynes typically give bridging alkyne
complexes (Eq. (1)) and, by combination with other
ligands, they can give metallacyclic compounds (Eq.
(2)) [2,3]. Terminal alkynes may behave similarly [4],
(2)
(3)
but they can also undergo oxidative addition to give
hydrido(alkynyl) complexes or rearrange to vinylidene
complexes (Eqs. (3) and (4)) [5], or couple with excess
alkyne to give metallacycles [6–8]. This paper reports
new examples of several of these reactions and also
describes a new form of reactivity, in which up to three
terminal alkyne molecules may react with the binuclear
compound [Ru2(CO)4(m-CO)(m-dppm)2] (1), dppm=
Ph2PCH2PPh2, without alkyne coupling, thus leading to
the formation of complexes containing up to three
different functional groups derived from the alkyne at
the diruthenium centre. A preliminary account of parts
of this work has been published [9].
(4)
* Corresponding author.
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00432-5

78
J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
complex products as described below. The diynes RCC-
CCR, R=Me or Ph, reacted similarly (Scheme 1) to give
complexes [Ru2(m-RCꢀCCCR)(CO)4(m-dppm)2] (4), with
one free alkyne group. Attempts to coordinate the free
alkyne group of 4 by reaction with a second equivalent
of the diruthenium complex 1 were unsuccessful. In
complexes 2–4 the coordinated alkyne is present in the
m2-parallel bonding mode in which it acts a two-electron
ligand (dimetalated alkene).
The new complexes were characterized by elemental
analysis and by their spectroscopic properties, and the
structure of 3d was confirmed crystallographically. In
each case, the IR spectra exhibited terminal carbonyl
stretching energies from 2025 to 1880 cm−1 but no
bridging carbonyl stretch. All compounds gave a weak
band at ca. 1600 cm−1 due to w(CꢀC). Other bands were
in similar regions to those in the free ligands. Thus, 2a,
2b and 3a–3c gave bands at ca. 1650 cm−1 due to
w(CꢀO) of the ester substituents, complex 3d showed a
medium intensity band at 1700 cm−1 due to w(CꢀO) of
the acetyl substituent and 4a and 4b gave bands at 2161
and 2132 cm−1 respectively, due to the free alkynyl
group.
Scheme 1.
The symmetrical complex 3a, having C26 symmetry,
gave a singlet in the 31P-NMR but all other complexes
have only Cs symmetry and gave rise to AA%BB% splitting
patterns. In the 1H-NMR spectra, the methylene protons
of the dppm ligand appear as two resonances since the
CHaHb protons of each dppm ligand are non-equivalent.
Complexes 2a and 2b gave l(ꢀCH)=8.40 and 8.55,
respectively, in the region expected for the proposed
structures. If the alkyne had rearranged to a vinylidene
complex, the vinyl proton would appear at lower l [5].
Other resonances due to the alkyne ligands are unre-
markable and are listed in Section 3.
The structure of [Ru2(m-PhCꢀCCOMe)(CO)4(m-
dppm)2] (3d) is shown in Fig. 1 and selected bond
distances and angles are listed in Table 1. The complex
contains the trans,trans-Ru2(m-dppm)2 unit as in the
starting complex 1 [3,11]. Counting the RuꢁRu bond,
each metal has slightly distorted octahedral geometry
with the major distortion arising as a result of the
presence of the Ru2C2 ring [angles RuRuC=66.0(1)
and 70.2(1)°]. The RuꢁC distances to the coordinated
Fig. 1. A view of the structure of complex 3d.
2. Results and discussion
2.1. Formation of bridging alkyne complexes
Several alkynes reacted with complex 1 [10] at room
temperature (r.t.) to form bridging alkyne complexes
,
alkyne [Ru2ꢁC17=2.172(4) A and Ru1ꢁC18=2.196(4)
,
[Ru2(m-RCꢀCH)(CO)4(m-dppm)2]
(2)
or
[Ru2(m-
A] are typical of those for other Ruꢁalkyl and
RCꢀCR%)(CO)4(m-dppm)2] (3), as shown in Scheme 1.
Complex 2 with R=H and complex 3 with R=R%=
CO2Me have been previously reported [3] and several
related complexes with other bridging diphosphines are
also known [2,5]. No intermediates or side-products were
observed in the formation of the new complexes 2
(unlike the case when R=R%=H [3]) and they were
isolated as air-stable yellow solids. The alkynes 3-hexyne
and diphenyl acetylene failed to react with 1 under mild
conditions while several terminal alkynes gave more
Ruꢁalkenyl bonds [2–7]. The C17ꢁC18 distance of
,
1.343(6) A is in the range expected for a double bond and
,
the distance Ru1ꢁRu2=2.963(5) A is in the normal
range for a single bond [2–11].
2.2. The initial reactions of complex 1 with phenyl
acetylene
The first products observed in the reaction of complex
1 with PhCCH are tentatively characterized by their

J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
79
spectroscopic properties as the hydride complexes 5 and
6 which are formed by CꢁH oxidative addition (Scheme
2). These complexes survive for several hours at r.t. but
attempts to separate them have been unsuccessful.
When the reaction was carried out in CH2Cl2 solution
at r.t., complex 5 and, more slowly, 6 were converted to
the chloro derivative 7 on reaction with the solvent.
Complex 7 was identified as the m-h2-acetylide deriva-
tive [Ru2(CO)2(m-CO)Cl(m-h2-CꢂCPh)(m-dppm)2] by its
spectroscopic data and by an X-ray structure determi-
nation. The structure is illustrated in Fig. 2 and is
closely related to that proposed for the hydride deriva-
tive 6. Selected bond distances and angles for 7 are
given in Table 2.
The structure determination was not straightforward
as a result of disorder, which is not shown in Fig. 2.
Table 1
Fig. 2. A view of the structure of complex 7. There is a crystallo-
graphic two-fold axis passing through the m-CO group and only one
of the resulting disorder forms is shown.
,
Selected bond distances (A) and angles (°) in [Ru2(CO)4(m-
PhCꢀCCOMe)(m-dppm)2] (3d)
,
Bond distances (A)
Table 2
Ru(1)ꢁC(2)
Ru(1)ꢁC(18)
Ru(1)ꢁP(4)
Ru(2)ꢁC(4)
Ru(2)ꢁC(17)
Ru(2)ꢁP(2)
O(2)ꢁC(2)
1.900(5)
2.196(4)
2.370(1)
1.882(5)
2.172(4)
2.383(1)
1.140(5)
1.147(5)
1.389(7)
1.343(6)
1.485(7)
Ru(1)ꢁC(1)
Ru(1)ꢁP(1)
Ru(1)ꢁRu(2)
Ru(2)ꢁC(3)
Ru(2)ꢁP(3)
O(1)ꢁC(1)
1.924(5)
2.362(1)
2.9631(5)
1.918(5)
2.347(1)
1.139(5)
1.155(5)
1.249(6)
1.488(6)
1.488(6)
,
Selected bond distances (A) and angles (°) in [Ru2(CO)2(m-CO)(m-
CCPh)Cl(m-dppm)2]·0.25C6H6 (7)
,
Bond distances (A)
Ru(1)ꢁRu(1A)
Ru(1)ꢁP(2)
Ru(1A)ꢁC(1E)
Ru(1)ꢁC(3)
2.914(3)
2.366(5)
1.74(4)
1.85(4)
Ru(1)ꢁP(1)
Ru(1)ꢁCl(1)
Ru(1)ꢁC(2)
Ru(1)ꢁC(4)
2.370(5)
2.54(2)
2.13(2)
2.16(2)
O(3)ꢁC(3)
O(4)ꢁC(4)
O(5)ꢁC(19)
C(16)ꢁC(17)
C(18)ꢁC(19)
C(11)ꢁC(12)
C(17)ꢁC(18)
C(19)ꢁC(20)
Bond angles (°)
P(2)ꢁRu(1)ꢁP(1)
C(5)ꢁC(4)ꢁRu(1A) 112(2)
O(2)ꢁC(2)ꢁRu(1) 137.0(4)
O(3)ꢁC(3)ꢁRu(1A) 164(4)
172.7(2)
Ru(1)ꢁC(4)ꢁRu(1A)
C(5)ꢁC(4)ꢁRu(1)
O(1)ꢁC(1)ꢁRu(1A)
C(5)ꢁC(4)ꢁRu(1)
85(1)
164(3)
163(5)
164(3)
Bond angles (°)
C(2)ꢁRu(1)ꢁC(1)
93.2(2)
C(2)ꢁRu(1)ꢁC(18)
94.7(2)
C(1)ꢁRu(1)ꢁC(18) 172.1(2)
C(1)ꢁRu(1)ꢁRu(2) 106.1(1)
C(2)ꢁRu(1)ꢁRu(2) 160.7(1)
C(18)ꢁRu(1)ꢁRu(2) 66.0(1)
C(4)ꢁRu(2)ꢁC(17) 109.8(2)
C(4)ꢁRu(2)ꢁRu(1) 177.3(1)
C(17)ꢁRu(2)ꢁRu(1) 70.2(1)
O(2)ꢁC(2)ꢁRu(1)
O(4)ꢁC(4)ꢁRu(2)
C(17)ꢁC(18)ꢁC(19) 123.9(4)
C(19)ꢁC(18)ꢁRu(1) 120.3(3)
O(5)ꢁC(19)ꢁC(18)
C(4)ꢁRu(2)ꢁC(3)
98.6(2)
There is a crystallographic two-fold axis running
through the atoms C4ꢁC2ꢁO2 (Fig. 2) and this imposes
50:50 disorder of the other ligand atoms in the
Ru2C4C2O2 plane, with the result that these atoms are
not accurately located. Nevertheless the main features
of the structure are clearly defined. The structure of 7 is
based on the trans,trans-Ru2(m-dppm)2 unit with a
C(3)ꢁRu(2)ꢁC(17) 151.6(2)
C(3)ꢁRu(2)ꢁRu(1)
O(1)ꢁC(1)ꢁRu(1)
O(3)ꢁC(3)ꢁRu(2)
C(18)ꢁC(17)ꢁRu(2) 107.9(3)
C(17)ꢁC(18)ꢁRu(1) 115.2(3)
81.5(1)
174.7(4)
178.1(4)
176.2(4)
171.3(5)
O(5)ꢁC(19)ꢁC(20)
117.6(5)
119.4(5)
,
RuꢁRu single bond (RuꢁRu=2.914(3) A). One ruthe-
nium atom (Ru1 in Fig. 2) is also bonded to terminal
chloride and carbonyl ligands, and to bridging carbonyl
and alkynyl ligands; Ru1 achieves an 18-electron
configuration if the alkynyl group acts as a one-electron
s-bonded ligand at this centre. The second ruthenium
atom (Ru1A in Fig. 2) is bound to a terminal carbonyl
ligand and to the bridging carbonyl and alkynyl lig-
ands; Ru1A achieves the 18-electron configuration if
the alkynyl group acts as a two-electron ligand to this
ruthenium atom. The angles at C4, namely
Ru1ꢁC4ꢁC5=164(3)° and Ru1AꢁC4ꢁC5=112(2)°,
support the assignment of the alkynyl group as a
three-electron s,p-bonded ligand, though the distance
Scheme 2.

80
J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
,
bonyl bands in the range 1896–1985 cm−1 and a
sharper band assigned to w(RuH) of a terminal hydride
at 2028 cm−1. These spectra indicate a structure with
only C2 symmetry which then achieves effective C26
symmetry through stereochemical non-rigidity. The
structure 5, with easy exchange of the hydride and
alkynyl groups between ruthenium centres as shown in
Eq. (5), is consistent with the spectroscopic data.
Ru1AꢁC5=2.70(2) A is considerably longer than
Ru1AꢁC4=2.16(2) A. Complex 7 can then be consid-
,
ered as a Ru(II)Ru(0) complex.
The spectroscopic properties of 7 are consistent with
the solid state structure. Thus, the IR spectrum con-
tains two terminal carbonyl bands at 1970 and 1865
cm−1 and one bridging carbonyl band at 1770 cm−1
.
The 31P-NMR spectrum contained two multiplets due
to the phosphorus atoms bonded to the two different
ruthenium centres, and the 1H-NMR spectrum con-
tained two multiplets due to non-equivalent CHaHb
protons on each dppm ligand.
Complex 5 gives a broad single resonance in the
31P-NMR spectrum at r.t. at l=24.5 and two broad
carbonyl resonances in the 13C-NMR spectrum at l=
1
196 and 205. The H-NMR spectrum gave a quintet
resonance at l= −10.35, JPH=14 Hz, due to the RuH
group. The IR spectrum contained four terminal car-
(5)
Complex 6 is formed from 5 by loss of a carbonyl
ligand and formation of a bridging alkynyl ligand. The
31P-NMR spectrum contains two resonances at l=27.5
and 28.5, and the hydride resonance is observed at
l= −10.46 as a multiplet due to coupling to non-
equivalent phosphorus atoms. The complex was always
formed in the presence of 5 and the stereochemistry
assigned in Scheme 2 is tentative. Complexes 6 and 7
are closely related but the hydride in 6 is tentatively
suggested to be cis to the alkynyl group, compared to
the trans stereochemistry of chloride and alkynyl lig-
ands in 7.
2.3. Formation of alkenyl(alkynyl)diruthenium
complexes
Scheme 3.
The initial reactions of 1 with PhCCH are similar in
acetone or benzene solution to give 5 and 6, but further
reactions with excess alkyne then occur to give 8a and
then 9, R=Ph, as shown in Scheme 3. It has not been
possible to isolate 8a in pure form since it was always
formed in mixtures with 5, 6 and 9, but it was charac-
terized spectroscopically and by its subsequent reaction
to give 9. In addition, the reactions of 1 with 1-hexyne
or with 1,5-hexadiyne in acetone give the corresponding
complexes 8b, R=Bu, and 8c, R=CH2CH2CCH, re-
spectively and, since these complexes did not react
further with excess alkyne, it was possible to isolate
them in pure form. Complex 8c contains two free
alkyne groups but it did not react further, either in-
tramolecularly or by reaction with excess complex 1.
Complex 8c was characterized by a structure determi-
nation and a view of the molecular structure is shown
in Fig. 3 with selected bond parameters listed in Table
3. The same type of crystallographic disorder was
found as for complex 7, so the disordered ligand atoms
are not accurately located.
Fig. 3. A view of the structure of complex 8c. There is a crystallo-
graphic two-fold axis passing through the m-CO group and only one
of the resulting disorder forms is shown.

J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
81
Table 3
Selected bond distances (A) and angles (°) in [Ru2(CO)2(m-CO){m-
CꢂC(CH2)2CꢂCH}{C(ꢀCH2)(CH2)2CꢂCH}(m-dppm)2]·0.5
(8c)
expected by insertion of a second equivalent of alkyne
into the RuꢁH bond of alkynyl(hydrido) complex inter-
mediates analogous to 6. The insertion is regioselective
since only the isomer ꢁC(ꢀCH2)R is formed in each
case, with no evidence for the alternate ꢁCHꢀCHR
unit.
,
acetone
,
Bond distances (A)
Ru(1)ꢁC(2)
Ru(1)ꢁC(1)
Ru(1A)ꢁC(10A)
Ru(1)ꢁP(1)
O(1)ꢁC(1)
1.80(2) Ru(1)ꢁC(3)
2.19(2) Ru(1)ꢁC(4)
2.34(3) Ru(1)ꢁP(2)
2.347(4) Ru(1)ꢁRu(1A)
1.12(2) O(2)ꢁC(2)
2.17(2)
2.33(4)
2.346(4)
2.914(3)
1.16(2)
The spectroscopic properties of complexes 8a–8c are
similar and will be discussed for 8c only. The IR
spectrum of 8c contained three carbonyl bands, two
due to terminal carbonyls at 1918 and 1857 cm−1 and
one due to the bridging carbonyl at 1755 cm−1. There
were also weak bands at 2150 and 2200 cm−1 which,
since they were not present in the spectrum of 8b, are
assigned to the w(CꢂC) stretches of the free alkyne
units. The 1H-NMR spectrum of 8c contained two vinyl
Bond angles (°)
P(2)ꢁRu(1)ꢁP(1)
O(1)ꢁC(1)ꢁRu(1)
O(2)ꢁC(2)ꢁRu(1)
Ru(1A)ꢁC(1)ꢁRu(1)
Ru(1)ꢁC(3)ꢁRu(1A)
170.8(2) C(4)ꢁC(3)ꢁRu(1)
138.2(4) C(4)ꢁC(3)ꢁRu(1A)
C(9A)ꢁC(10A)ꢁRu(1A)
83.6(8) C(11A)ꢁC(10A)ꢁRu(1A) 119(2)
84.2(8)
85(3)
163(3)
116(2)
176(1)
2
resonances at l=4.70 and 5.70 [m, J(HaHb)=2 Hz,
ꢀCHaHb], as expected for the RuC(R)ꢀCH2 group, as
well as other bands of the dppm and alkynyl, alkenyl
ligands (see Section 3). The 31P-NMR spectrum con-
tained an AA%BB% pattern at l=31.5 and 35.0 [m,
dppm].
2.4. The complex [Ru2(CO)2(v-CꢀCHPh){C(ꢀCH2)-
Ph}(v-p2-CꢂCPh)(v-dppm)2] (9)
The reaction of complex 1 with excess phenyl
acetylene slowly gave complex 9, as shown in Scheme 3.
Complex 9 is unique in that it contains alkynyl, alkenyl
and vinylidene groups in the same molecule. The struc-
ture of 9 was established by a structure determination;
a view of the structure is shown in Fig. 4 and selected
bond distances and angles are in Table 4. There was no
disorder in the structure of 9 so the atoms of the
organic ligands are more accurately located than in 7
and 8c.
Fig. 4. A view of the structure of complex 9, with phenyl groups of
the dppm ligands omitted for clarity.
The structure of 9 is again based on the trans,trans-
Ru2(m-dppm)2 unit with a RuꢁRu distance of 2.853(1)
,
A, slightly shorter than in the carbonyl-bridged com-
plexes 7 and 8c. The equatorial plane contains two
terminal carbonyl ligands, bridging phenyl acetylide
and styrenylidene ligands and a s-bonded styrenyl lig-
and ꢁC(ꢀCH2)Ph. The structure is clearly similar to that
of 8a, except that the bridging carbonyl ligand in 8a is
replaced by the bridging CꢀCHPh group in 9 (Scheme
3). The phenyl substituent of the styrenylidene group is
directed syn to the less sterically hindered ruthenium
The structure of 8c is based on the trans,trans-Ru2(m-
,
dppm)2 unit with a RuꢁRu distance of 2.914(3) A,
identical with that in complex 7. The equatorial plane
contains two terminal and one bridging CO ligand, a
bridging acetylide ligand and a s-bonded alkenyl unit
C(ꢀCH2)(CH2)2CꢂCH. The structure is clearly similar
to that of 7, except that the chloride ligand in 7 is trans
to the alkynyl ligand, whereas in 8c the alkenyl and
alkynyl ligands are mutually cis, as also suggested for 6.
Another difference between 8c and 7 is in the geometry
of the bridging alkynyl group, which is more symmetri-
,
center Ru1 and the distance Ru1ꢁC11=1.99(1) A is
,
shorter than Ru2ꢁC11=2.24(1) A. The angle
C11ꢁC12ꢁC13=135(1)° is significantly greater than the
ideal angle of 120°, so as to minimize steric hindrance
between the ortho hydrogen atom and the carbonyl
ligand C1O1. In addition, the angle Ru1ꢁC11ꢁC12=
146(1)° is significantly higher than Ru2ꢁC11ꢁC12=
129(1)°, again to reduce this steric hindrance. The angle
C31ꢁC32ꢁC33=118(1)° of the alkenyl ligand is close to
,
cally p-bonded to Ru1 in 8c [Ru1ꢁC3=2.17(2) A;
,
Ru1ꢁC4=2.33(4) A] than in 7. This difference can be
attributed to greater steric hindrance in the
phenylethynyl derivative 7, as discussed later. The
structure of 8c, and by analogy 8a and 8b, is that

82
J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
the ideal value. Of the ligands derived from phenyl-
acetylene, the CC distance in the alkynyl ligand
this bridging alkynyl group is similar to that in 7 and
appears to be a result of steric effects of the phenyl
substituent. The molecule is sterically congested as
shown in Fig. 5, and the phenyl group lies approxi-
mately parallel to and coplanar with the RuꢁRu axis in
a narrow region between phenyl substituents of the
dppm ligands. It is probably this ability of the planar
phenyl substituents to be accommodated in the
Ru2(CO)2 plane that allows the incorporation of three
units derived from the PhCCH reagent, whereas a
maximum of two such groups can be formed from alkyl
acetylenes.
,
(C21ꢁC22=1.22(2) A) is shorter than in the vinylidene
,
(C11ꢁC12=1.37(2) A) or alkenyl (C31ꢁC32=1.35(2)
,
A) ligand. The bridging phenylethynyl ligand is only
slightly distorted from linearity (Ru2ꢁC21ꢁC22=
175(1)°) and, while C21 is clearly bonded to both
ruthenium atoms (Ru1ꢁC21=2.22(1), Ru2ꢁC21=
,
,
2.07(1) A), the distance Ru1ꢁC22=2.69(1) A indicates
a very weak bonding interaction. The orientation of
Table 4
Complex 9 is stereochemically non-rigid and its
NMR spectra are temperature dependent. Thus, at r.t.,
the 31P-NMR spectrum contained an [AB]2 multiplet
with l=15 and 19 but, at −90°C, this split to give
major resonances at l=18 and 21 due to 9 and minor
ones at l=12 and 20 due to 9%. At r.t., the vinyl
protons were observed at l=5.33 and 5.90 but at low
temperature, each split to give major resonances at
l=5.10 and 6.00 and minor ones at l=4.95 and 5.15.
Finally, the vinylidene resonance at r.t. l=7.75 split at
low temperature to give l=7.8 and 7.7. A likely expla-
nation for these observations is that there is restricted
rotation about the rutheniumꢁvinyl bond, leading to
equilibration with 9% as shown in Eq. (6). However, the
data do not rule out other exchange processes such as
the inversion of the extended chair conformation of the
Ru2(P2C)2 unit. The relative rigidity of the core struc-
ture of 9 is attributed to steric rather than to electronic
effects (see Fig. 5).
,
Selected bond distances (A) and angles (°) in [Ru2(CO)2(m-CCPh)(m-
CꢀCHPh){C(ꢀCH2)Ph}(m-dppm)2]·C6H6·0.5C2H5OH (9)
,
Bond distances (A)
Ru(1)ꢁRu(2)
Ru(1)ꢁP(2)
Ru(2)ꢁP(4)
Ru(2)ꢁC(2)
Ru(2)ꢁC(11)
Ru(2)ꢁC(21)
C(1)ꢁO(1)
C(11)ꢁC(12)
C(21)ꢁC(22)
C(31)ꢁC(32)
2.853(1)
2.365(4)
2.362(4)
1.89(1)
2.24(1)
2.07(1)
1.15(1)
1.37(2)
1.22(2)
1.35(2)
Ru(1)ꢁP(1)
Ru(2)ꢁP(3)
Ru(1)ꢁC(1)
Ru(1)ꢁC(11)
Ru(1)ꢁC(21)
Ru(2)ꢁC(32)
C(2)ꢁO(2)
C(12)ꢁC(13)
C(22)ꢁC(23)
C(32)ꢁC(33)
2.361(4)
2.373(4)
1.85(1)
1.99(1)
2.22(1)
2.17(1)
1.15(2)
1.45(2)
1.45(1)
1.50(2)
Bond angles (°)
C(21)ꢁRu(1)ꢁRu(2) 46.2(3)
P(4)ꢁRu(2)ꢁP(3) 176.7(1)
P(2)ꢁRu(1)ꢁP(1)
171.3(1)
C(11)ꢁRu(1)ꢁRu(2) 51.4(4)
C(11)ꢁRu(1)ꢁC(1) 110.1(5)
C(21)ꢁRu(2)ꢁRu(1) 50.6(3)
C(22)ꢁC(21)ꢁRu(2) 175(1)
Ru(1)ꢁC(11)ꢁRu(2) 84.7(5)
Ru(1)ꢁC(21)ꢁRu(2) 83.2(4)
C(22)ꢁC(21)ꢁRu(1) 98(1)
C(32)ꢁRu(2)ꢁC(11) 176.4(5)
C(21)ꢁRu(2)ꢁC(2) 179.2(5)
C(21)ꢁRu(1)ꢁC(11) 97.4(5)
C(11)ꢁRu(2)ꢁRu(1) 43.9(3)
C(13)ꢁC(12)ꢁC(11) 135(1)
C(12)ꢁC(11)ꢁRu(1) 146(1)
C(12)ꢁC(11)ꢁRu(2) 129(1)
C(31)ꢁC(32)ꢁRu(2) 123(1)
C(31)ꢁC(32)ꢁC(33) 112(1)
O(1)ꢁC(1)ꢁRu(1)
O(2)ꢁC(2)ꢁRu(2)
177(1)
176(1)
(6)
2.5. Mechanisms of the reactions
In terms of mechanism, the vinyl group in complex
8a arises by insertion of alkyne into the RuꢁH bond of
6. This step is likely to be preceded by migration of
carbonyl ligands in 6 to create a vacant site for alkyne
coordination cis to the hydride. It is interesting that the
regiochemistry of the insertion reaction to give the
RuꢁCRꢀCH2 unit in 8 (and hence also in 9) is different
from that observed with mononuclear ruthenium com-
plexes which normally give the E-RuꢁCHꢀCHR unit
[11]. Formation of 9 requires replacement of the m-CO
ligand of 8 by the phenylvinylidene group and this is
likely to be preceded by CꢁH activation of a third
equivalent of phenylacetylene followed by rearrange-
ment of the intermediate hydrido(alkynyl) intermediate,
Fig. 5. A view of the structure of complex 9, with phenyl groups of
the dppm ligands included to illustrate the steric congestion. Note the
orientation of the PhC substituents which are roughly coplanar with
the Ru2(CO)2 unit.

J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
83
which is too short-lived to be detected by spectroscopic
monitoring. There are precedents for the formation of
complexes analogous to 2–6 [2–4] but complexes 8 and
9 are new structural types. Complex 9 is particularly
remarkable since it contains three different ligands,
each derived from phenylacetylene.
3H, COOCH2Me]; l(31P)=26.0 (unresolved multiplet,
dppm). FAB-MS: m/z=1195 [M]+, 1167 [M–CO]+,
1139 [M–2CO]+, 1111 [M–3CO]+ amu. [Ru2(CO)4(m-
EtO2CCꢀCCO2Et)(m-dppm)2]; yield: 65%. Anal. Calc.
for C62H54O8P4Ru2: C, 59.37; H, 4.30. Found: C, 58.76;
H, 4.17%. IR: w(CO)=1998, 1951, 1925, 1897,1662,
1650. NMR (acetone-d6): l(1H)=4.80, 3.40 [m, each
2H, CH2P2]; 3.30 [q, 4H, CH2]; 0.40 [t, 6H, CH3];
l(31P)=26.0 [s, dppm]. [Ru2(CO)4(m-PhCꢀCCOMe)(m-
dppm)2] (3d); yield: 72%. Anal. Calc. for
C64H52O5P4Ru2·3C3D6O: C, 62.52; H, 4.99. Found: C,
62.64; H, 4.54%. IR: w(CO)=1982, 1937, 1929, 1884,
1700. NMR (benzene-d6): l(1H)=5.20, 3.15 [m, each
2H, CH2P2]; 1.9 [s, 3H, CH3]; l(31P)=25.0 (unresolved
multiplet, dppm); l(13C)=216.5, 211.5, 209.5, 202.5
[CO]. FAB-MS: m/z=1227 [M]+, 1199 [M–CO]+,
1171 [M–2CO]+, 1143 [M–3CO]+ amu. [Ru2(CO)4(m-
MeCꢀCCꢂCMe)(m-dppm)2] (4a); yield: 58%. Anal.
Calc. for C60H50O4P4Ru2: C, 62.01; H, 4.30. Found: C,
61.82; H, 4.38%. IR: w(CO)=1979, 1947, 1915, 1894;
1673 (CꢀC); 2161 (CꢂC). NMR (acetone-d6): l(1H)=
4.30, 3.50 [m, each 2H, CH2P2]; 1.9, 1.7 [s, each 3H,
Me]; l(31P)=28.5, 27.0 [m, dppm]. [Ru2(CO)4(m-
PhCꢀCCꢂCPh)(m-dppm)2] (4b); yield: 62%. Anal. Calc.
for C70H54O4P4Ru2: C, 65.36; H, 4.20. Found: C, 65.10;
H, 4.31%. IR: w(CO)=2001, 1948, 1924, 1881; 2132
(CꢂC). NMR (CD2Cl2): l(1H)=4.40, 3.40 [m, each 2H,
CH2P2]; l(31P)=26.5, 27.5 [m, dppm]. l(13C)=215,
212, 202, 197 (CO); 145, 140 (CꢀC); 103, 93 (CꢂC).
3. Experimental
NMR spectra were recorded by using a Varian Gem-
ini 300 MHz spectrometer and referenced to TMS (1H,
13C) or phosphoric acid (31P). IR spectra were recorded
as Nujol mulls by using a Perkin–Elmer IR2000 spec-
trometer. Complex 1 was prepared as described else-
where [10].
3.1. [Ru2(CO)4(v-HCꢀCCOOCH3)(v-dppm)2] (2a)
A solution of [Ru2(CO)4(m-CO)(m-dppm)2] (0.11 g,
0.1 mmol) in THF (20 ml) was treated with a slight
excess of methyl propiolate (10 ml, 0.11 mmol). The
reaction mixture was stirred under nitrogen for about 1
h. The solvent was then removed under reduced pres-
sure to yield the product (0.093 g, 81%). A crystalline,
analytically pure sample of this complex was obtained
from a concentrated acetone solution by slow evapora-
tion. Anal. Calc. for C58H48O6P4Ru2: C, 59.64; H, 4.11.
Found: C, 59.10; H, 4.25%. IR: w(CO)=2016, 1987,
1947, 1923; 1654 (CꢀO); 1600 (CꢀC). NMR (acetone-
d6): l(1H)=4.55, 3.70 [m, each 2H, CH2P2]; 3.1 [s, 3H,
CH3]; 8.4 [s, 1H, CH]; l(31P)=29.3, 30.5 [m, dppm];
l(13C)=217, 211, 202, 198 (CO). FAB-MS: m/z=1167
[M]+, 1139 [M–CO]+, 1111 [M–2CO]+, 1057 [M–
4CO]+ amu.
Similarly prepared were: [Ru2(CO)4(m-H3CCꢀCC-
OOCH3)(m-dppm)2] (3b), (yield: 69%). Anal. Calc. for
C59H50O6P4Ru2: C, 59.94; H, 4.23. Found: C, 59.20; H,
4.23%. IR: w(CO)=1984, 1962, 1954, 1920; 1636
(CꢀC). NMR (acetone-d6): l(1H)=4.50, 3.40 [m, each
2H, CH2P2]; 2.75 [s, 3H, MeO]; 2.00 [s, 3H, MeC];
l(31P)=26.0 (unresolved m, dppm). FAB-MS: m/z=
1181 [M]+, 1153 [M–CO]+, 1125 [M–2CO]+, 1096
[M–3CO]+ amu. [Ru2(CO)4(m-HCꢀCCOOC2H5)(m-
dppm)2] (2b); yield: 90%. Anal. Calc. for
C59H50O6P4Ru2: C, 59.94; H, 4.23. Found: C, 59.10; H,
4.00%. IR: w(CO)=2064, 2025, 1981, 1942; 1674
(CꢀO). NMR (acetone-d6): l(1H)=4.50, 3.70 [m, each
2H, CH2P2]; 3.60 [q, 2H, CH2]; 0.70 [t, 3H, CH3]; 8.55
[s, 1H, CH]; l(31P)=29.0, 30.2 [m, dppm]; l(13C)=
214, 211, 206, 201 [CO]. [Ru2(CO)4(m-MeCꢀCC-
OOEt)(m-dppm)2] (3c); yield: 72%. Anal. Calc. for
C60H52O6P4Ru2: C, 60.25; H, 4.35. Found: C, 59.50; H,
4.20%. IR: w(CO)=1990, 1937, 1917, 1876, 1641.
NMR (acetone-d6): l(1H)=4.50, 3.40 [m, each 2H,
CH2P2]; 3.30 [q, 2H, CH2]; 2.10 [s, 3H, MeC]; 0.45 [t,
3.2. [Ru2(CO)2(v-CO)(v-CCBu){C(ꢀCH2)-
Bu}(v-dppm)2] (8b)
A slight excess of 1-hexyne (35 ml, 0.30 mmol) was
added to a stirred solution of [Ru2(CO)4(m-CO)(m-
dppm)2] (0.15 g, 0.135 mmol) in THF (15 ml) at r.t.,
resulting in an immediate change in color of the solu-
tion to orange–yellow. After 3 h, the solvent was
removed under reduced pressure to give the product as
a yellow solid; yield 90%. It was recrystallized from
acetone by slow evaporation to give orange crystals.
Anal. Calc. for C65H64O3P4Ru2: C, 63.98; H, 5.25.
Found: C, 63.40; H, 5.08%. IR: w(CO)=1916, 1855,
1755; NMR (CD2Cl2): l(1H)=3.95, 2.80 [m, 2H,
CH2P2]; 5.60, 4.60 [br s, each 1H, CꢀCH2]; 1.10 [m, 4H,
a-CH2]; 0.90 [t, 4H, g-CH2]; 0.10 [q, 4H, b-CH2]; 0.70,
0.60 [t, each 3H, CH3]; l(31P)=36.0, 31.5 [m, dppm].
FAB-MS: m/z=1165, 1083, 1055, 1027, 999 amu.
3.3. [Ru2(CO)2(v-CO){CꢂC-
(CH2)2CꢂCH}{C(ꢀCH2)(CH2)2CꢂCH}(v-dppm)2]·0.5
acetone (8c)
This was prepared similarly, but the reaction took 9
h to complete. The product (yield, 82%) was crystallised

84
J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
from a CH2Cl2 solution by slow diffusion of ethanol.
Anal. Calc. for C66.5H59O3.5P4Ru2: C, 64.34; H, 4.75.
Found: C, 65.10; H, 4.71%. IR: w(CO)=1918, 1857,
1755; 2200, 2150 (CꢂC) NMR (CD2Cl2): l(1H)=4.00,
2.80 [m, each 2H, CH2P2]; 5.70, 4.70 [br s, each 1H,
CꢀCH2]; 4.1 [s, 1H, CH]; 0.90, 0.80 [t, each 2H, g-CH2];
1.30 [m, 4H, b-CH2]; 0.70, 0.60 [t, each 3H, CH3];
l(31P)=35.0, 31.5 [m, dppm]. FAB-MS: m/z=1133,
1055, 1027, 999, 971 amu.
was crystallized by slow evaporation of a solution in
benzene. Anal. Calc. for C62.5H50.5O3P4ClRu2: C, 61.93;
H, 4.17. Found: C, 61.40; H, 4.20. IR: w(CO)=1970,
1865, 1770; NMR (CD2Cl2): l(1H)=3.82, 2.92 [m,
each 2H, CH2P2]; l(31P)=19.0, 29.3 [m, dppm];
l(C)=197, 208 [m, t-CO]; 229 [m, m-CO].
3.6. [Ru2(CO)2(v-C2Ph)(v-CꢀCHPh)-
{C(ꢀCH2)Ph}(v-dppm)2]·C6H6·0.5C2H5OH (9)
3.4. Intermediates in reaction of
[Ru2(CO)4(v-CO)(v-dppm)2] with PhCCH
A solution of [Ru2(CO)4(m-CO)(m-dppm)2] (0.20 g,
0.18 mmol) in benzene (20 ml) was stirred with a large
excess of phenyl acetylene (100 ml, 1 mmol) for 5 h.
After the removal of solvent under vacuum, the residue
was redissolved in benzene (3 ml). Crystals of X-ray
quality were obtained from this solution by slow diffu-
sion of ethanol (yield, 25%). Anal. Calc. for
C83H71O2.5P4Ru2: C, 69.43; H, 4.94. Found: C, 69.07;
H, 5.00%. IR: w(CO)=1946, 1886, (CO); NMR
(CD2Cl2): l(1H)=4.52, 3.78 [m, each 2H, CH2P2]; 5.33,
5.90 [d, each 1H, CꢀCH2]; 7.75 [s, 1H, CꢀCH]; l(31P)=
15.3, 19.3 [m, dppm]. FAB-MS: m/z=1334 [M]+,
1306, 1204, 999 amu.
To a solution of [Ru2(CO)4(m-CO)(m-dppm)2] (0.05 g,
0.05 mmol) in CD2Cl2 (0.6 ml) in an NMR tube was
added phenyl acetylene (5.1 ml, 0.05 mmol). The follow-
ing intermediates were detected by their NMR spectra:
5, R=Ph; l(H)=3.25, 4.10 [m, each 2H, CH2P2];
−10.37 [quin, JPH=14 Hz, RuH]; l(P)=24.5 [br s,
dppm]; l(C)=196, 205 [br s, CO]. 6, R=Ph; l(H)=
3.47, 4.44 [m, each 2H, CH2P2]; −10.46 [m, 1H, RuH];
l(P)=27.5, 28.5 [m, dppm].
3.5. [Ru2(CO)2(v-CO)(v-CCPh)Cl(v-dppm)2]·0.25
benzene (7)
3.7. X-ray structure determinations
To a solution of [Ru2(CO)4(m-CO)(m-dppm)2] (0.11 g,
0.1 mmol) in CH2Cl2 (20 ml) was added phenyl
acetylene (10.2 ml, 0.1 mmol). The reaction mixture was
then stirred at r.t. for 10 h. Removal of the solvent
under reduced pressure yielded an orange solid, which
Orange crystals of [Ru2(CO)4(m-PhCꢀCCOMe)-
(m-dppm)2] were obtained from an acetone solution by
slow evaporation. Data were collected using a Sie-
mens diffractometer fitted with a CCD detector; in
Table 5
Experimental details and crystal data
Complex
Formula
Temperature (K)
3d·3Me2CO
C73H70O8P4Ru2
298(2)
7·0.25C6H6
C62.5H50.5ClO3P4Ru2
298(2)
8c·0.5Me2CO
C66.5H59O3.5P4Ru2
296(2)
9·C6H6·0.5Me2CO
C83H71O2.5P4Ru2
296(2)
,
u(Mo–Ka) (A)
0.71073
Triclinic
0.71073
Tetragonal
P41212
0.71073
Tetragonal
P43212
0.71073
Triclinic
Crystal system
Space group
(
(
P1
P1
Cell dimensions
,
a (A)
11.9452(4)
12.3679(4)
25.5382(9)
84.308(1)
80.905(1)
70.693(1)
3511.5(2)
2
1.325
0.573
8947
8935
15.178(2)
26.739(5)
15.315(2)
26.977(4)
14.753(2)
19.691(4)
14.55(5)
94.96(2)
77.12(2)
105.00(1)
3979(2)
2
1.217
0.44
5375
5375
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A3)
Z
6160(2)
4
6327(2)
4
Dc (Mg m−3
)
1.306
0.678
3624
1794
11
1.302
0.622
5492
2752
44
v (mm−1
)
Independent reflections
Data
Restraints
0
0
Parameters
784
1.060
0.0425
0.0970
140
212
329
Goodness-of-fit on F2
R1 [I\2|(I)]
wR2
1.017
0.0788
0.1880
1.062
0.0869
0.1887
0.0695
0.0789

J. Kuncheria et al. / Journal of Organometallic Chemistry 593–594 (2000) 77–85
85
this case a semi-empirical absorption correction was
applied using psi scans. Orange–yellow crystals of
[Ru2(CO)2(m-CO)(m-CCPh)Cl(m-dppm)2]·0.25 benzene
were grown by slow evaporation of a solution in ben-
zene at r.t. A crystal of size 0.44×0.32×0.29 mm was
wedged inside a Lindemann capillary tube, flame-sealed
and used for the diffraction experiments. Dark red
crystals of [Ru2(CO)2(m-CO){CꢂC(CH2)2CꢂCH}{C-
336033; e-mail: deposit@ccdc.cam.ac.uk or www: http:/
/www.ccdc.cam.ac.uk).
Acknowledgements
We thank the NSERC (Canada) for financial
support.
(ꢀCH2)(CH2)2CꢂCH}(m-dppm)2]·0.5
acetone
were
grown by slow evaporation of solution in acetone at
room temperature. A crystal of size 0.47×0.46×0.38
mm was wedged inside a Lindemann capillary tube,
flame-sealed and used for the diffraction experiments.
Orange crystals of [Ru2(CO)2(m-CCPh)(m-CꢀCHPh)-
{C(ꢀCH2)Ph}(m-dppm)2]·C6H6·0.5C2H5OH were ob-
tained by slow diffusion of ethanol into a benzene
solution at r.t. A crystal was cut along (100), (0–10)
and (−11–2) to the size 0.25×0.26×0.21 mm,
wedged inside a Lindemann capillary tube, flame sealed
and used for single crystal diffraction experiments. In
these cases, data were collected by using a Siemens
P4 diffractometer and an analytical absorption correc-
tion was applied. In all cases, refinement was by full-
matrix least-squares on F2. Crystal data are given in
Table 5.
References
[1] H. El Amouri, M. Gruselle, Chem. Rev. 96 (1996) 1077.
[2] (a) K.A. Johnson, W.L. Gladfelter, Organometallics 11 (1992)
2534. (b) K.A. Johnson, W.L. Gladfelter, Organometallics 8
(1989) 2366.
[3] (a) H.A. Mirza, J.J. Vittal, R.J. Puddephatt, J. Coord. Chem. 37
(1996) 131. (b) H.A. Mirza, J.J. Vittal, R.J. Puddephatt,
Organometallics 13 (1994) 3063.
[4] G.Y. Kiel, J. Takats, Organometallics 8 (1989) 841.
[5] (a) K.J. Edwards, J.S. Field, R.J. Haines, B.D. Homann, M.W.
Stewart, J. Sundermeyer, S.F. Woollam, J. Chem. Soc. Dalton
Trans. 4171 (1996). (b) J.S. Field, R.J. Haines, J. Sundermeyer,
S.F. Woollam, J. Chem. Soc. Dalton Trans. 3749 (1993).
[6] (a) L.A. Brady, A.F. Dyke, S.E. Garner, S.A.R. Knox, A.
Irving, S.M. Nicholls, A.G. Orpen, J. Chem. Soc. Dalton Trans.
487 (1993). (b) S.A. R. Knox, Pure Appl. Chem. 56 (1984) 81.
[7] (a) H. Matsuzaka, Y. Takagi, M. Hidai, Organometallics 13
(1994) 13. (b) M. Nishio, H. Matsuzaka, Y. Mizobe, M. Hidai,
Organometallics 15 (1996) 965.
[8] (a) P. Blenkiron, G.D. Enright, N.J. Taylor, A.J. Carty,
Organometallics 15 (1996) 2855. (b) A.J. Carty, Pure Appl.
Chem. 54 (1982) 113.
4. Supplementary material
[9] J. Kuncheria, H.A. Mirza, J.J. Vittal, R.J. Puddephatt, Inorg.
Chem. Commun. 2 (1999) 197.
[10] (a) H.A. Mirza, J.J. Vittal, R.J. Puddephatt, Inorg. Chem. 32
(1993) 1327. (b) D.W. Engel, K.G. Moodly, L. Subramony, R.J.
Haines, J. Organomet. Chem. 349 (1988) 393.
Full X-ray data have been deposited with the Cam-
bridge Crystallographic Data Centre, CCDC No.
XXXXX. Copies of this information may be obtained
free of charge from The Director, CCDC, 12 Union
Road, Cambridge, CB2 1EZ, UK (Fax: +44-1223-
[11] A. Santos, J. Lopez, A. Galan, J.J. Gonzalez, P. Tinoco, A.M.
Echavarren, Organometallics 16 (1997) 3482.