Tri- and tetranuclear mixed-metal clusters containing alkyne ligands: Synthesis and structure of [Ru3Ir(CO)11(RCCR')]-, Rru2Ir(CO)9(RCCR')]-, and [HRu2Ir(CO)9(RCCR')]

Article abstract of DOI:10.1002/(SICI)1099-0682(199905)1999:5<853::AID-EJIC853>3.0.CO;2-U

The tetrahedral cluster anion [Ru₃Ir(CO)₁₃]- (1) reacts with internal alkynes RC≡CR' to afford the alkyne derivatives [Ru₃Ir(CO)₁₁(RCCR')]^- (2: R = R' = Ph; 3: R = R' = Et; 4: R = Ph; R' = Me; 5: R = R' = Me) which have a butterfly arrangement of the Ru₃Ir skeleton in which the alkyne is coordinated in a μ₄-η² fashion. Under CO pressure they undergo fragmentation to give the trinuclear cluster anions [Ru₂Ir(CO)₉(RCCR')]- (6: R = R' = Ph; 7: R = R' = Et; 8: R = Ph; R' = Me; 9: R = R' = Me), in which the alkyne ligand is coordinated in a μ3-η² parallel fashion. Protonation of these trinuclear anions leads to the formation of the corresponding neutral hydrido clusters [HRu₂Ir(CO)₉(RC≡CR')] (10: R = R' = Ph; 11: R = R' = Et; 12: R = Ph; R' = Me; 13: R = R' = Me). The protonation of the butterfly anions 2 and 3, however, gives rise to the formation of the neutral tetrahedral clusters [HRu₃Ir(CO)¹¹(RCCR')] (14: R = R' = Ph and 15: R = R' = Et), respectively. The analogous clusters [HRu₃Ir(CO)¹¹(PhCCCH₃)] (16) and [HRu₃Ir(CO)₁₁(CH₃CCCH3)] (17) are only accessible from the reaction of the neutral cluster [HRu₃Ir(CO)₁₃] with the corresponding alkynes. The complexes 2, 4, 5, 6, 10, 12 and 15 are characterised by X-ray structure analysis.

Full text of DOI:10.1002/(SICI)1099-0682(199905)1999:5<853::AID-EJIC853>3.0.CO;2-U

FULL PAPER
Tri- and Tetranuclear Mixed-Metal Clusters Containing Alkyne Ligands:
Synthesis and Structure of [Ru3Ir(CO)11(RCCRЈ)]؊,
[Ru2Ir(CO)9(RCCRЈ)]؊, and [HRu2Ir(CO)9(RCCRЈ)]
Vincent Ferrand,[a] Georg Süss-Fink,*[a] Antonia Neels,[a] and Helen Stoeckli-Evans[a]
Keywords: Cluster compounds / Ruthenium / Iridium / Alkynes / Butterfly structures
–
The tetrahedral cluster anion [Ru3Ir(CO)13
]
(1) reacts with
neutral hydrido clusters [HRu2Ir(CO)9(RCϵCRЈ)] (10: R = RЈ =
Ph; 11: R = RЈ = Et; 12: R = Ph; RЈ = Me; 13: R = RЈ = Me).
The protonation of the butterfly anions 2 and 3, however,
internal alkynes RCϵCRЈ to afford the alkyne derivatives
[Ru3Ir(CO)11(RCCRЈ)]– (2: R = RЈ = Ph; 3: R = RЈ = Et; 4: R =
Ph; RЈ = Me; 5: R = RЈ = Me) which have a butterfly gives rise to the formation of the neutral tetrahedral clusters
arrangement of the Ru3Ir skeleton in which the alkyne is
coordinated in a µ4-η2 fashion. Under CO pressure they
[HRu3Ir(CO)11(RCCRЈ)] (14: R = RЈ = Ph and 15: R = RЈ = Et),
respectively. The analogous clusters [HRu3Ir(CO)11
-
undergo fragmentation to give the trinuclear cluster anions (PhCCCH3)] (16) and [HRu3Ir(CO)11(CH3CCCH3)] (17) are
[Ru2Ir(CO)9(RCCRЈ)]– (6: R = RЈ = Ph; 7: R = RЈ = Et; 8: R =
Ph; RЈ = Me; 9: R = RЈ = Me), in which the alkyne ligand is
coordinated in a µ3-η2 parallel fashion. Protonation of these
trinuclear anions leads to the formation of the corresponding
only accessible from the reaction of the neutral cluster
[HRu3Ir(CO)13 with the corresponding alkynes. The
complexes 2, 4, 5, 6, 10, 12 and 15 are characterised by X-
]
ray structure analysis.
Introduction
Results and Discussion
Synthesis of the Cluster Anions
The chemistry of mixed-metal clusters of transition met-
als has been studied in great detail in recent years,[1][2]
stimulated by their possible catalytic potential and the com-
bination of different metals in the same complex.[3a,3b] The
mixed-metal cluster Pt3Ru6(CO)20(µ3-PhC2Ph)(µ3-H)(µ-H)
has been shown by R. D. Adams et al. to be an very active
catalyst for the hydrogenation of alkynes[3cϪ3e]. Tetranu-
clear clusters with the butterfly structure[4][5] have received
much attention, due to their intermediary position between
tetrahedral and square-planar clusters. They have been also
considered as a model for chemisorption of small mol-
ecules,[6] and they have been studied as intermediates in
homogeneous catalytic processes.[4,7,8] Both, metal atoms
and ligands can vary widely in butterfly-type clusters, which
determines, on the one hand, the structural properties of
the butterfly framework and, on the other hand, the chem-
istry of the coordinated ligands.[4]
[Ru3Ir(CO)11(RCCRЈ)]؊ (2؊5)
The thermal reaction of the tetrahedral cluster anion
[Ru3Ir(CO)13]Ϫ (1) with the internal alkynes diphenylacety-
lene, 3-hexyne, 1-phenyl-1-propyne, or 2-butyne yields, at
90 °C in CH2Cl2 solution (pressure Schlenk tube), the al-
kyne derivatives [Ru3Ir(CO)11(RCCRЈ)]Ϫ (2: R ϭ RЈ ϭ Ph;
3: R ϭ RЈ ϭ Et; 4: R ϭ Ph; RЈ ϭ Me; 5: R ϭ RЈ ϭ Me)
(Scheme 1). These anions can be isolated as the bis(triphen-
ylphosphoranylidene)ammonium salts from a mixture of di-
ethyl ether and hexane (2, 4, and 5), or from a mixture of
ethanol and pentane (3). Complexes 2, 4, and 5 gave suit-
able crystals for X-ray structure analysis.
The infrared spectra of all the compounds display the
same absorption pattern in the νco region, indicating the
presence of terminal as well as bridging CO ligands (Table
1
1). The H-NMR spectra of 2Ϫ5 are complicated by the
In a recent publication,[8] we have described the reactivity
of the neutral tetrahedral cluster [HRu3Ir(CO)13][9] towards
alkynes and its catalytic potential in hydrogenation reac-
tions. We now report the reaction of its precursor, the clus-
ter anion [Ru3Ir(CO)13]Ϫ[9] with internal alkynes, which af-
fords anionic alkyne clusters of the type [Ru3Ir-
(CO)11(RCCRЈ)]Ϫ, and we also report on the reactivity of
the latter anions towards CO and Hϩ.
multiplets of the [N(PPh3)2]ϩ cation; for 2 and 4, the reson-
ances of the phenyl protons of the alkyne ligands overlap
with the signals of the cation. In the case of 4 (containing
an unsymmetrical alkyne ligand), only one singlet at δ ϭ
2.82 is observed for the methyl group, indicating the pres-
ence of only one isomer. In the case of 3 and 5 (containing
a symmetrical alkyne ligand), the two alkyl substituents on
the alkyne are nonequivalent, suggesting the alkyne ligand
to be coordinated in a nonsymmetrical fashion to the Ru3Ir
framework (Table 1). This is confirmed by the X-ray struc-
ture analysis of the bis(triphenylphosphoranylidene)am-
monium salts of 2, 4, and 5.
[a]
´
ˆ
Institut de Chimie, Universite de Neuchatel,
ˆ
Avenue de Bellevaux 51, CH-2000 Neuchatel, Switzerland
Fax: (internat.) ϩ 41-32/718-2400
E-mail: Georg.Suess-Fink@ch.unine.ch
Eur. J. Inorg. Chem. 1999, 853Ϫ862
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
1434Ϫ1948/99/0505Ϫ0853 $ 17.50ϩ.50/0
853

V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans
FULL PAPER
Scheme 1. Synthetic routes to clusters 2Ϫ13
Molecular Structures of [Ru3Ir(CO)11(RCCRЈ)]؊
(2, 4, and 5)
Suitable crystals of 2, 4, and 5 {[N(PPh3)2]ϩ salts} were
grown at room temperature from a mixture of diethyl ether
and hexane. The molecular structures of the anions 2, 4,
and 5 are depicted in Figures 1, 2, and 3, respectively. Selec-
ted bond lengths and angles of complexes 2, 4, and 5 are
summarized in Tables 2, 3, and 4, respectively. The crystal
structures consist of discrete [N(PPh3)2]ϩ cations and
[Ru3Ir(CO)11(RCCRЈ)]Ϫ anions showing normal intermo-
lecular contacts between the atoms of the ions. The cluster
anions 2, 4, and 5 have the same overall structure: The four
metal atoms form a butterfly skeleton where the iridium
atom occupies a hinge position, whereas in the known co-
balt analogue [Ru3Co(CO)11(PhCCPh)]Ϫ,[10] obtained by
reaction of [Ru3Co(CO)13]Ϫ with diphenylacetylene, the co-
balt atom occupies a wingtip position. In other mixed-metal
clusters anions with the butterfly core structure, such as
[Ru3M(CO)10Cp(CH3CCCH3)]Ϫ (M ϭ W, Mo)[11] and
[Co3Ru(CO)10(PhCCPh)]Ϫ,[12a] the single metal atom M al-
ways occupies a hinge position as found in 2, 4, and 5.
All metalϪmetal distances in 2, 4, and 5 are different
(Tables 2, 3, 4), but in the expected range for RuϪRu and
RuϪIr single bonds.[4,8,9] In the three clusters, the coordi-
nation of the eleven carbonyl ligands is the same: While
Figure 1. ORTEP plot of [IrRu3(CO)11(µ4-η2-C2Ph2)]Ϫ (anion 2);
thermal ellipsoids are drawn at 50% of propability
nine carbonyl groups are terminal, one CO ligand [C(6)O(6) bridging to Ru(3) as indicated by the distances car-
˚
in 2, C(20)O(20) in 4, C(10)O(10) in 5] is bridging the bonϪRu(2) [2: C(10)ϪRu(2)
ϭ
1.903(7) A; 4:
˚
˚
IrϪRu(3) edge, one CO ligand [C(10)O(10) in 2, C(14)O(14) C(14)ϪRu(2) ϭ 1.896(3) A; 5: C(15)ϪRu(2) ϭ 1.903(6) A]
in 4, C(15)O(15) in 5] being coordinated to Ru(2) is semi- and the carbonϪRu(3) [2: C(10)ϪRu(3) ϭ 2.8893(3) A; 4:
˚
854
Eur. J. Inorg. Chem. 1999, 853Ϫ862

Tri- and Tetranuclear Mixed-Metal Clusters Containing Alkyne Ligands
FULL PAPER
Table 1. IR and NMR data of the complexes 2؊17
Complexes
νCO [cmϪ1 [a]
]
δ (1H) [ppm][bϪd]
[N(PPh3)2][Ru3Ir(CO)11(PhCCPh)] (2) 2055(m), 2009(vs), 1988(s), 1960(sh), 1913(w), 7.70Ϫ6.80 (C6H5, m)
1801(w)
3
[N(PPh3)2][Ru3Ir(CO)11(EtCCEt)] (3)
2052(m), 2002(vs), 1983(s), 1962(sh), 1937(m), 7.70Ϫ7.40 (C6H5, m); 2.68 (CH3CH2CCCH2CH3, q JHH 7.4
1913(w), 1794(w)
Hz); 2.61 (CH3CH2CCCH2CH3,
(CH3CH2CCCH2CH3,
3JHH
(CH3CH2CCCH2CH3, t 3JHH 7.4 Hz)
q
3JHH 7.4 Hz); 0.94
7.4 Hz); 0.90
t
[N(PPh3)2][Ru3Ir(CO)11(PhCCMe)] (4) 2055(m), 2007(vs), 1986(s), 1963(sh), 1936(m), 7.70Ϫ7.39 (C6H5, m); 2.82 (CH3CCPh, s)
1909(w), 1799(w)
[N(PPh3)2][Ru3Ir(CO)11(MeCCMe)] (5) 2054(m), 2004(vs), 1984(s), 1959(sh), 1934(m), 7.70Ϫ7.42 (C6H5, m); 3.14 (CH3CCCH3, s); 2.91 (CH3CCCH3, s)
1906(w), 1800(w)
2054(m), 2011(s), 1998(vs), 1980(s), 1940(m)
2048(w), 2002(s), 1992(vs), 1971(m), 1932(w)
[N(PPh3)2][Ru2Ir(CO)9(PhCCPh)] (6)
[N(PPh3)2][Ru2Ir(CO)9(EtCCEt)] (7)
6.60Ϫ7.70 (C6H5, m)
7.70Ϫ7.20 (C6H5, m); 3.41 (CH3cCHaHbCCCHaЈHbЈCH3cЈ, dq
3JHaHc 7.2 Hz, JH3aHb 13.3 Hz ); 2.74 (CH3cCHaHb
2
2
CCCHaЈHbЈCH3cЈ, dq JHaЈHcЈ 7.3 Hz, JHaЈHbЈ 13.0 Hz); 2.10
3
2
(CH3cCHaHbCCCHaЈHbЈCH3cЈ, dq JHbHc 7.2 Hz, JHaHb 13.3
3
Hz); 1.97 (CH3cCHaHbCCCHaЈHbЈCH3cЈ, dq JHbЈHcЈ 7.3 Hz,
2JHaЈHbЈ 13.0 Hz);1.14 (CH3cCHaHbCCCHaЈHbЈCH3cЈ, t JHH
3
7.3 Hz); 1.07 (CH3cCHaHbCCCHaЈHbЈCH3cЈ, t 3JHH 7.3 Hz);
7.70Ϫ6.90 (C6H5, m); 2.64 (CH3CCPh, s(isomer 1)); 2.30
(CH3CCPh, s(isomer 2))
[N(PPh3)2][Ru2Ir(CO)9(PhCCMe)] (8) 2052(w), 2007(s), 1996(vs), 1976(m), 1938(w)
[N(PPh3)2][Ru2Ir(CO)9(MeCCMe)] (9) 2049(w), 2002(s), 1993(vs), 1971(m), 1934(w)
7.71Ϫ7.35 (C6H5, m); 2.70 (CH3CCCH3, s); 2.40 (CH3CCCH3, s)
[HRu2Ir(CO)9(PhCCPh)] (10)
2101(w), 2072(vs), 2061(s), 2034(s), 2022(m), 7.20Ϫ6.80 (C6H5, m); Ϫ15.07 (RuHRu, s)
2016(m), 2005(w)
[HRu2Ir(CO)9(EtCCEt)] (11)
2099(w), 2069(s), 2057(s), 2030(vs), 2018(m), 2.93 (CH3CH2CCCH2CH3,
q
3JHH 7.4 Hz); 2.42
2008(m), 1990(w)
(CH3CH2CCCH2 CH3,
(CH3CH2CCCH2CH3,
q
3JHH
3JHH
7.4
7.4
Hz);
Hz);
1.34
1.20
t
(CH3CH2CCCH2CH3, t 3JHH 7.4 Hz); Ϫ15.39 (RuHRu, s)
[HRu2Ir(CO)9(PhCCMe)] (12)
[HRu2Ir(CO)9(MeCCMe)] (13)
[HRu3Ir(CO)11(PhCCPh)] (14)
[HRu3Ir(CO)11(EtCCEt)] (15)
2100(w), 2071(vs), 2060(s), 2032(s), 2021(m), 7.20Ϫ6.90 (C6H5, m); 2.80 (CH3CCPh, s); Ϫ15.27 (RuHRu, s)
2003(m), 1994(w)
2099(w), 2069(vs), 2057(s), 2030(vs), 2018(m), 2.83 (CH3CCCH3, s); 2.37 (CH3CCCH3, s); Ϫ15.31 (RuHRu, s)
2008(m), 1991(w)
2095(w), 2071(s), 2053(s), 2037(vs), 2012(m), 7.30Ϫ7.00 (C6H5, m); Ϫ18.88 (RuHRu, s)
1994(m), 1842(w)
3
2
2095(w), 2070(s), 2051(s), 2034(vs), 2010(m), 2.98 (CH3CHaHbCCCHaЈHbЈCH3, dq JHH 7.3 Hz, JHH 15.0
3
2
1991(m), 1840(w)
Hz); 2.74 (CH3CHaHbCCCHaЈHbЈCH3, dq JHH 7.3 Hz, JHH
15.0 Hz); 1.28 (CH3CHaHbCCCHaЈHbЈCH3, t JHH 7.3 Hz);
3
Ϫ19.10 (RuHRu, s)
[HRu3Ir(CO)11(PhCCMe)] (16)
[HRu3Ir(CO)11(MeCCMe)] (17)
2093(w), 2065(s), 2048(s), 2032(vs), 2006(m), 7.50Ϫ7.20 (C6H5, m); 2.80 (CH3, s) Ϫ18.88 (RuHRu, s)
1989(m), 1842(w)
2094(w), 2068(s), 2049(s), 2033(vs), 2009(m), 2.72 (CH3, s); Ϫ18.98 (RuHRu, s)
1988(m), 1844(w)
[a]
[b]
Recorded in ether (2Ϫ5), CH2Cl2 (6Ϫ9, 14Ϫ17), hexane (10Ϫ12, 13). Ϫ
Measured in CDCl3 solution at 294 K at 200 MHz (2,
[d]
[c]
4Ϫ6, 9, 10, 12Ϫ15, 17). Ϫ Measured in CDCl3 solution at 294 K at 400 MHz (3, 7, 8, 11, 16). Ϫ Measured in CDCl3 solution at
215 K at 400 MHz (7, 8).
˚
C(14)ϪRu(3) ϭ 2.8115(3) A; 5: C(15)ϪRu(3) ϭ 2.8613(7) tron count of 60e is consistent with Wade’s rules which pre-
ϭ
73.7(2)° (2), dict a closo structure.[15]
˚
A]. The angles C(10)ϪRu(2)ϪRu(3)
C(14)ϪRu(2)ϪRu(3)
ϭ 71.86(10)° (4), C(15)ϪRu(2)Ϫ
Ru(3) ϭ 73.00(19)° (5) are found to be similar to the angle
observed in the cluster anion [FeRu3(CO)12NO]Ϫ[13] for a
semibridging CO group.[14] These findings are comfirmed
by the infrared spectra of 2Ϫ5 which exhibit a νco absorp-
Synthesis of [Ru2Ir(CO)9(RCCRЈ)]؊ (6؊9)
The cluster anions [Ru3Ir(CO)11(RCCRЈ)]Ϫ (2: R ϭ RЈ ϭ
Ph; 3: R ϭ RЈ ϭ Et; 4: R ϭ Ph; RЈ ϭ Me; 5: R ϭ RЈ ϭ
tion around 1920 cmϪ1
.
The alkyne ligand in 2, 4, and 5 is coordinated to the Me) undergo fragmentation of the metal core under CO
Ru3Ir metal core in a µ4-η2 fashion. One of the carbon pressure (2 bar) at 90 °C to give the trinuclear alkyne cluster
atoms is σ-bonded to Ir, whereas the second one is σ- anions [Ru2Ir(CO)11(RCCRЈ)]Ϫ (Scheme 1). They can be
bonded to Ru(2), both carbon atoms being π-bonded to isolated as the bis(triphenylphosphoranylidene)ammonium
1
Ru(1) and Ru(3). This observation is confirmed by the H- salts from a mixture of CH2Cl2 and diethyl ether (6) or
NMR spectra of 3 and 5 which display two different chemi- from ethanol and pentane (7Ϫ9). The loss of metal frag-
cal shifts for the two ethyl or methyl substituents, respec- ments from a cluster has already been observed;[16][17] for
tively. The carbonϪcarbon bond is closer to Ru(1) than to example the cluster anion [RuCo3(CO)10(µ4-η2-C2Ph2)]Ϫ
Ru(3) in the three clusters, the torsion angle between the can release a “Co(CO)” fragment to give the trinuclear
carbonϪcarbon backbone and the Ir(1)ϪRu(2) edge is complex [RuCo2(CO)9(µ3-η2-C2Ph2)] in which the alkyne
close to 0° [2: 0.0°(18); 4: Ϫ0.04(11); 5: 0.3°(2)] indicating adopts a parallel coordination.[12][18]
that these two bonds are almost parallel.
The infrared spectra of 6Ϫ9 exhibit in the carbonyl re-
With an electron count of 60e, 2, 4, and 5 are electron- gion absorptions of only terminal CO ligands (Table 1). The
1
deficient, since an M4 butterfly cluster consistent with the room-temperature H-NMR spectrum of 8 reveals, in ad-
noble-gas rule would require 62 electrons. However, con- dition to the signals of the [N(PPh3)2]ϩ cation, two singlets
sidering 2, 4, and 5 as octahedral Ru3IrC2 clusters, an elec- for the methyl group of the MeCCPh ligand in a ratio of
Eur. J. Inorg. Chem. 1999, 853Ϫ862
855

V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans
FULL PAPER
˚
Table 2. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for the anion 2; estimated standard deviations in paren-
theses
Ir(1)ϪRu(1)
Ir(1)ϪRu(3)
Ir(1)ϪRu(2)
Ir(1)ϪC(6)
Ir(1)ϪC(25)
Ru(1)ϪRu(2)
Ru(1)ϪC(25)
Ru(1)ϪC(24)
C(24)ϪC(25)
2.7223(5)
2.7235(6)
2.7756(5)
2.133(7)
2.188(4)
2.7357(6)
2.242(4)
2.258(5)
1.443(6)
Ru(3)ϪC(25)
2.298(4)
2.335(4)
1.993(6)
126.1(4)
127.1(4)
134.9(6)
142.5(6)
73.7(2)
Ru(3)ϪC(24)
Ru(3)ϪC(6)
C(24)ϪC(25)ϪC(18)
C(25)ϪC(24)ϪC(12)
O(6)ϪC(6)ϪIr(1)
O(6)ϪC(6)ϪRu(3)
C(10)ϪRu(2)ϪRu(3)
O(10)ϪC(10)ϪRu(2)
C(25)ϪIr(1)Ϫ-
173.6(7)
0.00(18)
Ru(2)ϪC(24)
˚
Table 3. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for the anion 4; estimated standard deviations in paren-
theses
Ir(1)ϪRu(1)
Ir(1)ϪRu(3)
Ir(1)ϪRu(2)
Ir(1)ϪC(20)
Ir(1)ϪC(2)
2.7025(4)
2.7018(4)
2.8690(4)
2.105(3)
2.132(3)
Ru(3)ϪC(2)
2.338(3)
2.375(3)
1.977(3)
124.8(2)
123.5(2)
135.5(3)
141.6(3)
71.86(10)
167.4(3)
Ru(3)ϪC(3)
Ru(3)ϪC(20)
C(1)ϪC(2)ϪC(3)
C(2)ϪC(3)ϪC(4)
O(20)ϪC(20)ϪIr(1)
O(20)ϪC(20)ϪRu(3)
C(14)ϪRu(2)ϪRu(3)
O(14)ϪC(14)ϪRu(2)
Ru(1)ϪRu(2) 2.7158(5)
Ru(1)ϪC(2)
Ru(1)ϪC(3)
2.282(3)
2.297(3)
Ru(2)ϪRu(3) 2.7483(5)
Ru(2)ϪC(14) 1.896(3)
C(3)ϪRu(2)ϪIr(1)ϪC(2) 0.04(11)
C(2)ϪC(3)
Ru(2)ϪC(3)
2.151(3)
1.429(4)
Figure 2. ORTEP plot of [IrRu3(CO)11(µ4-η2-PhCCMe)]Ϫ (anion
4); thermal ellipsoids are drawn at 50% of propability
˚
Table 4. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for the anion 5; estimated standard deviations in paren-
theses
Ir(1)ϪRu(1)
Ir(1)ϪRu(3)
Ir(1)ϪRu(2)
Ir(1)ϪC(10)
Ir(1)ϪC(2)
2.7044(7)
2.7182(7)
2.8000(8)
2.125(6)
2.150(6)
Ru(3)ϪC(1)
2.356(6)
2.321(5)
2.012(6)
123.7(5)
124.3(5)
136.1(5)
141.8(5)
73.00(19)
170.5(6)
Ru(3)ϪC(2)
Ru(3)ϪC(10)
C(3)ϪC(1)ϪC(2)
C(1)ϪC(2)ϪC(4)
O(10)ϪC(10)ϪIr(1)
O(10)ϪC(10)ϪRu(3)
C(15)ϪRu(2)ϪRu(3)
O(15)ϪC(15)ϪRu(2)
Ru(1)ϪRu(2) 2.7114(9)
Ru(1)ϪC(1)
Ru(1)ϪC(2)
2.272(5)
2.242(6)
Ru(2)ϪRu(3) 2.7647(8)
Ru(2)ϪC(1)
2.154(6)
C(2)ϪIr(1)ϪRu(2)ϪC(1) 0.3(2)
C(1)ϪC(2) 1.406(8)
Ru(2)ϪC(15) 1.903(6)
tiplets at Ϫ58 °C, in a ratio of 1:1:1:1. In a selective decou-
pling experiment by irradiating at the resonances of the
methyl proton, the four methylene multiplets resolve into
four doublets with a coupling constant of 13 Hz, showing
the protons of each methylene group to be diastereotopic
(Table 1).[20,22a,22c,23a]
Figure 3. ORTEP plot of [IrRu3(CO)11(µ4-η2-C2Me2)]Ϫ (anion 5);
thermal ellipsoids are drawn at 50% of propability
Molecular Structure of [Ru2Ir(CO)9(PhCCPh)]؊(6)
45:55. This ratio does not change down to Ϫ58 °C (CDCl3),
suggesting the presence of two isomers.[19Ϫ22] In the case of
[Ru2Ir(CO)9(MeCCMe)]Ϫ (9), two singlets for the methyl
The molecular structure of 6 was confirmed by a single-
substituents are observed in a ratio of 1:1, because the crystal X-ray structure analysis of the bis(triphenylphos-
chemical environment of each CCH3 moiety is different. phoranylidene)ammonium salt. Suitable crystals were ob-
The spectrum of [Ru2Ir(CO)9(EtCCEt)]Ϫ (7) is more com- tained by slow diffusion of diethyl ether into a concentrated
plicated, presenting a temperature dependence of the sig- dichloromethane solution at room temperature. The molec-
nals of the ethyl substituents: At room temperature, four ular structure of the anion is depicted in Figure 4. Selected
broad signals for the hydrogen atoms of the methylene bond lengths and angles are presented in Table 5. The crys-
groups are observed, resulting in four well-resolved mul- tal structure consists of discrete [N(PPh3)2]ϩ cations and
856
Eur. J. Inorg. Chem. 1999, 853Ϫ862

Tri- and Tetranuclear Mixed-Metal Clusters Containing Alkyne Ligands
FULL PAPER
[Ru2Ir(CO)9(PhCCPh)]Ϫ anions showing normal intermo- plexes in which the CϪC bond length varies from 1.33 to
[18]
˚
lecular contacts between the atoms of the ions. The ru- 1.47 A.
Clusters 6Ϫ9 have the expected electron count
thenium and iridium atoms of the cluster anion form a of 48e for trinuclear clusters which obey the noble gas rule.
closed triangle in which all the metalϪmetal distances are
different but within the range of RuϪRu and IrϪRu single
bonds (Table 5). Each metal atom is bonded to three ter-
minal CO groups.
Synthesis of [HRu2Ir(CO)9(RCCRЈ)] (10؊13)
The reaction of the anions [Ru2Ir(CO)9(RCCRЈ)]Ϫ (6Ϫ9)
with an excess of HBF4 • OEt2 at room temperature leads
to the formation of the neutral hydrido clusters [HRu2Ir-
(CO)9(RCCRЈ)] (10: R ϭ RЈ ϭ Ph; 11: R ϭ RЈ ϭ Et; 12:
R ϭ Ph; RЈ ϭ Me; 13: R ϭ RЈ ϭ Me), which can be iso-
lated by chromatographic methods and recrystallized from
hexane at Ϫ18 °C (Scheme 1).
˚
Table 5. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for the anion 6; estimated standard deviations in paren-
theses
Ir(1)ϪRu(1)
Ir(1)ϪRu(2)
Ir(1)ϪC(2)
2.7120(8)
2.7952(10) Ru(2)ϪC(1)
2.117(8) C(1)ϪC(2)
Ru(2)ϪC(1)
2.096(8)
2.096(8)
1.363(11)
125.4(7)
123.5(7)
Ru(1)ϪRu(2) 2.7084(11) C(1)ϪC(2)ϪC(3)
The infrared spectra of 10Ϫ13 display an almost identical
νco absorption pattern in the region of terminal carbonyl
Ru(1)ϪC(1)
Ru(1)ϪC(2)
2.260(8)
2.246(8)
C(2)ϪC(1)ϪC(9)
C(9)ϪC(1)ϪC(2)ϪC(3) Ϫ9.8(13)
1
ligands (Table 1). The H-NMR spectra of 10Ϫ13 indicate,
in addition to the signals of the alkyne substituents, the
resonance of a bridging hydrido ligand at around δ ϭ Ϫ15
(Table 1). In all cases, only one isomer is observed. For
The alkyne ligand is coordinated in a classical µ3-η2 fash-
ion over the metal triangle[18] as observed in [Co2Ru(CO)9-
(C2Ph2)][12] The C(1)ϪC(2) backbone is almost parallel to
the Ir(1)ϪRu(2) edge [C(2)ϪIr(1)ϪRu(2)ϪC(1) 1.2(3)°].
The carbon atoms C(1) and C(2) are σ-coordinated to Ir(1)
and Ru(2), respectively, and are both π-bonded to Ru(1).
[HRu2Ir(CO)9(EtCCEt)]
(11)
and
[HRu2Ir(CO)9-
(MeCCMe)] (13), the two ethyl or methyl groups are found
to be nonequivalent.
Molecular Structure of [HRu2Ir(CO)9(RCCRЈ)]
(10, 12)
Suitable crystals of [HRu2Ir(CO)9(PhCCPh)] (10) and
[HRu2Ir(CO)9(PhCCMe)] (12) have been obtained from a
concentrated hexane solution at Ϫ18 °C. The molecular
structure of 10 is depicted in Figure 5 and that of 12 in
Figure 6. Selected bond lengths and angles are presented in
Tables 6 and 7. The crystal-structure analysis of 10 reveals
two independent molecules per asymmetric unit of the unit
cell, which have the same constitution, but differ slightly in
bond lengths and angles.
The two clusters 10 and 12 have the same overall struc-
ture, showing the same carbonyl and alkyne coordination.
The three metal atoms form a closed triangle. Each metal
atom is bonded to three terminal CO groups. In both com-
plexes the longer Ru(1)ϪRu(2) distance [10: 2.7965(10); 12:
˚
2.7943(7) A] suggests the presence of the hydrido bridge
across this edge.
The alkyne ligand is coordinated in a µ3-η2 fashion over
the Ru2Ir framework as also found in cluster 6. All car-
bonϪcarbon and carbonϪmetal distances compare well
with those in other M3(µ3-η2-RCCRЈ) complexes.[18] The
neutral complexes [HRu2Ir(CO)9 (RCCRЈ)] (10Ϫ13) have,
as the anions 6Ϫ9, the expected electron count of 48e.
Figure 4. ORTEP plot of [IrRu2(CO)9(µ3-η2-C2Ph2)]Ϫ (anion 6);
thermal ellipsoids are drawn at 50% of propability
Reaction of [Ru3Ir(CO)11(RCCRЈ)]؊ with
The carbonϪcarbon bond is shorter in 6 [C(1)ϪC(2)
˚
˚
1.363(11) A] than in 2 [C(24)ϪC(25) 1.443(6) A]. This is
due to the coordination of the alkyne to only three metal
atoms in 6 with respect to 2 where it is coordinated to four
HBF4 • OEt2
Protonation of the anions [Ru3Ir(CO)11(RCCRЈ)]Ϫ gives
metal atoms. The carbonϪcarbon bond length in 6 different results depending on the nature of the coordinated
˚
[C(1)ϪC(2) 1.363(11) A] compares well with that in [Co2- alkyne ligand. For R ϭ RЈ ϭ Ph (14) or R ϭ RЈ ϭ Et (15),
[12]
˚
Ru(CO)9(C2Ph2)] (CϪC 1.370(3) A)
and related com- the neutral hydrido complexes [HRu3Ir(CO)11(PhCCPh)]
Eur. J. Inorg. Chem. 1999, 853Ϫ862
857

V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans
FULL PAPER
˚
Table 6. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for 10; estimated standard deviations in parentheses
Molecule A
Molecule B
Ir(1)ϪRu(2)
Ir(1)ϪRu(1)
Ir(1)ϪC(2)
Ru(1)ϪRu(2)
Ru(1)ϪC(1)
Ru(1)ϪH(1)
Ru(2)ϪC(1)
Ru(2)ϪC(2)
Ru(2)ϪH(1)
C(1)ϪC(2)
2.6901(7) Ir(2)ϪRu(4)
2.7523(8) Ir(2)ϪRu(3)
2.076(6) Ir(2)ϪC(25)
2.7965(10) Ru(3)ϪC(24)
2.113(7) Ru(3)ϪRu(4)
1.77(11) Ru(3)ϪH(2)
2.295(6) Ru(4)ϪC(25)
2.307(6) Ru(4)ϪC(24)
1.85(11) Ru(4)ϪH(2)
1.374(9) C(24)ϪC(25)
2.6936(9)
2.7517(8)
2.080(6)
2.119(7)
2.7938(9)
1.63(11)
2.310(6)
2.325(7)
1.91(11)
1.375(9)
C(2)ϪC(1)ϪC(3)
C(1)ϪC(2)ϪC(9)
C(3)ϪC(1)ϪC(2)ϪC(9) 8.7(10)
123.9(6) C(25)ϪC(24)ϪC(26) 124.4(6)
125.0(6) C(24)ϪC(25)ϪC(32) 124.9(6)
C(26)ϪC(24)Ϫ
C(25)ϪC(32)
Ϫ6.5(10)
˚
Table 7. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for 12; estimated standard deviations in parentheses
Ir(1)ϪRu(1)
Ir(1)ϪRu(2)
Ir(1)ϪC(1)
2.6924(6) Ru(2)ϪC(2)
2.111(6)
1.78(7)
1.372(9)
123.9(6)
124.4(5)
2.7578(5) Ru(2)ϪH(1Ru)
2.074(6)
C(1)ϪC(2)
Ru(1)ϪRu(2)
Ru(1)ϪC(2)
Ru(1)ϪC(1)
2.7943(7) C(2)ϪC(1)ϪC(3)
2.285(6)
2.318(6)
C(1)ϪC(2)ϪC(4)
C(3)ϪC(1)ϪC(2)ϪC(4) Ϫ0.3(10)
Ru(1)ϪH(1Ru) 1.81(7)
Figure 5. ORTEP plot of [HIrRu2(CO)9(µ3-η2-C2Ph2)] 10; thermal
ellipsoids are drawn at 50% of propability
(14) and [HRu3Ir(CO)11(EtCCEt)] (15) are formed (Scheme
2). When R or RЈ is a methyl group, the reaction does not
afford the neutral hydrido complex, but leads to an un-
identified green decomposition product. The expected clus-
ters [HRu3Ir(CO)11(PhCCMe)] (16) and [HRu3Ir(CO)11-
(MeCCMe)] (17) are, however, accessible from the reaction
of the neutral hydrido cluster [HRu3Ir(CO)13] with the cor-
responding alkyne (Scheme 2). Clusters 14 and 17 have al-
ready been reported[8] and they are included here for the
sake of completeness.
The infrared spectra of 14Ϫ17 display in the νco region
the same absorption pattern: Five bands are assigned to
terminal CO ligands and one absorption around 1840 cmϪ1
1
corresponds to a bridging CO group (Table 1). In the H-
NMR spectra of 14Ϫ17, the hydrido ligand resonates as a
singlet around δ ϭ Ϫ19. In 15 the ethyl substituents of the
alkyne ligand are found to be equivalent, but the two hydro-
gen atoms of the methylene groups are diastereotopic (Table
1). The molecular structure of 15 is confirmed by a single-
crystal X-ray structure analysis.
Molecular Structure of [HRu3Ir(CO)11 (EtCCEt)]
(15)
Suitable crystals of 15 were grown at Ϫ18 °C in hexane.
The molecular structure of 15 is depicted in Figure 7. Selec-
ted bond lengths and angles of 15 are listed in Table 8. The
complex 15 has the same overall structure as found in 14
and 17,[8] showing the same carbonyl, alkyne and hydride
coordination pattern.
Figure 6. ORTEP plot of [HIrRu2(CO)9(µ3-η2-PhCCMe)] 12; ther-
mal ellipsoids are drawn at 50% of propability
858
Eur. J. Inorg. Chem. 1999, 853Ϫ862

Tri- and Tetranuclear Mixed-Metal Clusters Containing Alkyne Ligands
FULL PAPER
Scheme 2. Synthetic routes to clusters 14Ϫ17
ruthenium atoms. The longer Ru(1)ϪRu(3) distance
˚
[2.8514(9) A] suggests the presence of the hydrido bridge
across this edge. Two of the three ruthenium atoms are
bonded to three terminal CO groups, whereas Ru(2) and Ir
are bonded to two terminal CO groups and share the bridg-
ing CO ligand. The alkyne is coordinated in a µ3-η2-bond-
ing mode over the Ru3 face of the tetrahedron. Due to the
coordination of the alkyne group to the metal core, the car-
bonϪcarbon bond is lengthened [C(12)ϪC(13) 1.395(11)
[8]
˚
A], but is in the range observed in 14, 17, and other clus-
ters such as HCpWOs3[µ3-η2-C2(Tol)2].[24][25]
˚
Table 8. Selected bond lengths [A], bond angles [°], and torsion
angles [°] for 15; estimated standard deviations in parentheses
Ir(1)ϪRu(1)
2.7727(9) Ru(2)ϪC(12)
2.7228(11) Ru(2)ϪC(13)
2.7833(8) Ru(3)ϪC(12)
2.183(7)
2.168(7)
2.149(8)
1.75(6)
1.395(11)
121.7(7)
122.7(7)
Ir(1)ϪRu(2)
Ir(1)ϪRu(3)
Ru(1)ϪRu(2) 2.7981(10) Ru(3)ϪH(1Ru)
Ru(1)ϪRu(3) 2.8514(9) C(12)ϪC(13)
Ru(1)ϪC(13) 2.154(7)
Ru(1)ϪH(1Ru) 1.81(6)
C(13)ϪC(12)ϪC(14)
C(12)ϪC(13)ϪC(16)
Ru(2)ϪRu(3) 2.8110(9) C(14)ϪC(12)ϪC(13)ϪC(16) 0.4(11)
Figure 7. ORTEP plot of [HIrRu3(CO)11(µ3-η2-C2Et2)] 15; thermal
ellipsoids are drawn at 50% of propability
Conclusions
The four metal atoms form a tetrahedron in which the
˚
The Ru3Ir framework shows a great fexibility with re-
RuϪIr distances vary from 2.7228(11) to 2.7833(8) A and spect to the coordination of alkyne ligands: The tetrahedral
the RuϪRu distances from 2.7981(10) to 2.8514(9) A, in metal skeleton in [Ru3Ir(CO)13]Ϫ (1) opens up upon coordi-
˚
accordance with metalϪmetal single bonds.[8] The cluster nation of an alkyne ligand to give a butterfly framework in
15 presents, as expected for a tetrahedral arrangement, an [Ru3Ir(CO)11(RCCR)]Ϫ (2Ϫ5). Protonation of the butterfly
electron count of 60 e. The short distance Ru(2)ϪIr clusters 2 and 3 leads, with closure of the RuϪRu bond,
˚
[2.7228(11) A] is due to the bridging carbonyl ligand over back to a tetrahedral metal skeleton in the neutral clusters
this edge. The base of the tetrahedron is composed of three [HRu3Ir(CO)11(RCCRЈ)] (14Ϫ15). The second important
Eur. J. Inorg. Chem. 1999, 853Ϫ862
859

V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans
FULL PAPER
dropwise addition of pentane until the solution became cloudy. Then
the solution was cooled to Ϫ18 °C for a few days giving the
[N(PPh3)2]ϩ salt of 3 as dark-violet needles. The crystals were dried
in vacuo. Ϫ 3: Yield 76 mg (75%). Ϫ C53H40IrNO11P2Ru3 • H2O
(1424.28): calcd. C 44.13, H 2.93, N 0.97; found C 43.96, H 2.76,
N 1.02.
feature is the fragmentation of the tetranuclear anions in
[Ru3Ir(CO)11(RCCR)]Ϫ (2Ϫ5) under CO pressure to give
the trinuclear anions [Ru2Ir(CO)9(RCCR)]Ϫ (6Ϫ9). In a
comparison of the 3-hexyne complexes, it is interesting to
note that in the case of 3 and 11, the two protons of the two
different CH2 groups of the 3-hexyne ligand are equivalent,
[N(PPh3)2][Ru2Ir(CO)9(PhCCPh)] (Anion 6): A solution containing
[N(PPh3)2] [Ru3Ir(CO)11(PhCCPh)] (anion 2), prepared from 0.0715
mmol of 1 as described above, in Et2O (20 mL) was placed in a
pressure Schlenk tube and stirred at room temperature for 20 h un-
der a pressure of 2 bar of CO. The colour changed from red-orange
to wine-red, then to orange with precipitation of the [N(PPh3)2]ϩ
salt of 6 as a yellow powder. The precipitate was filtered off, washed
with Et2O (3 ϫ 10 mL) and crystallised at room temperature by slow
diffusion of Et2O into a CH2Cl2 solution. The yellow crystals were
dried in vacuo. 6: Yield (with respect to 1): 73 mg (75%). Ϫ
C59H40IrNO9P2Ru2 (1363.27): calcd. C 51.98, H 2.99, N 1.03; found
C 51.68, H 2.99, N 1.04.
whereas in
7 and 15 they are nonequivalent (dia-
stereotopic). In the case of the tetranuclear cluster [Ru3Ir-
(CO)11(EtCCEt)]Ϫ (3) the averaging of the methylene pro-
tons may be explained by a carbonyl fluxionality involving
the bridging and semi-bridging carbonyl ligands which
could brigde equally well to both wingtip ruthenium atoms.
In the case of the trinuclear cluster [HRu2Ir(CO)9(EtCCEt)]
(11), the µ3-alkyne ligand itself might be fluxional on the
trinuclear metal core, as observed in [H2Ru3(CO)9-
(EtCCEt)],[22a] [Co2Ru(CO)9(EtCCEt)],[19] [FeCo2(CO)9-
(EtCCEt)],[21] [CpNiCoM(CO)6(EtCCEt)] (M ϭ Fe, Ru,
Os),[23a] [H2Os3(CO)9(C9H6)].[23b]
[N(PPh3)2][Ru2Ir(CO)9(RCCRЈ)] (Anions 7, 8, 9): A solution con-
taining [N(PPh3)2][Ru3Ir(CO)11(RCCRЈ)] (3: R ϭ RЈ ϭ Et; 4: R ϭ
Ph; RЈ ϭ Me; 5: R ϭ RЈ ϭ Me), prepared from 0.0715 mmol of 1
as described above, in CH2Cl2 (25ml) was placed in a pressure
Schlenk tube and stirred at 90 °C for 45 min under a pressure of 2
bar of CO. The colour changed, from red-orange to wine-red, then
to orange. After removal of the solvent, the orange residue was
washed with hexane (3 ϫ 10 ml) to remove Ru3(CO)12 formed dur-
ing the reaction. The remaining orange oil was dried and dissolved
in 5Ϫ10 mL of ethanol, followed by the addition of pentane until
the solution became cloudy. In the case of 8 no pentane was added.
Then the solution was cooled to Ϫ18 °C for a few days which gave
the [N(PPh3)2]ϩ salt of 7 as yellow-orange crystals and the
[N(PPh3)2]ϩ salts of 8 and 9 precipitated as a yellow-brown powder.
The solids were dried in vacuo. Ϫ 7: Yield (with respect to 1): 51
mg (56%). Ϫ C51H40IrNO9P2Ru2 • 2.5 H2O (1267.19): calcd. C
46.65, H 3.42, N 1.06; found C 46.42, H 3.02, N 1.11. Ϫ 8: Yield
(with respect to 1): 56 mg (60%). Ϫ C54H38IrNO9P2Ru2 (1301.20):
calcd. C 49.85, H 2.94, N 1.08; found C 49.66, H 3.16, N 1.16. Ϫ
9: Yield (with respect to 1): 49 mg (55%). Ϫ C49H36IrNO9P2Ru2
(1239.13): calcd. C 47.50, H 2.93, N 1.13; found C 47.24, H 3.13,
N 1.19.
Experimental Section
General: All reactions were carried out under pure nitrogen with
standard Schlenk techniques. Solvents were destilled with appropri-
ate drying agents, deoxygenated, and nitrogen-saturated prior to
use.[26] Ϫ Preparative thin-layer chromatography was performed
using 20 cm ϫ 20 cm plates coated with Fluka silica gel G. The
starting complexes [Ru3Ir(CO)13]Ϫ and [HRu3Ir(CO)13] were pre-
pared according to a published method.[9] Ϫ Diphenylacetylene
was purchased from Fluka; 3-hexyne, 1-phenyl-1-propyne, and 2-
butyne were purchased from Aldrich and used as recieved. Ϫ NMR
spectra were recorded with a Varian Gemini 200 BB or a Bruker
AMX 400 spectrometer, using the resonance of the residual protons
of the deuterated solvents as reference. Ϫ Infrared spectra were
recorded with a PerkinϪElmer 1720X FT IR spectrometer. Ϫ
Micro-analyses were carried out by the Mikroelementaranaly-
tisches Laboratorium of the ETH Zürich, Switzerland.
Preparations
[N(PPh3)2][Ru3Ir(CO)11(RCCRЈ)] (Anions 2؊5):
A solution of
[HRu2Ir(CO)9(RCCRЈ)] (10؊13): To a solution of [N(PPh3)2]-
[Ru2Ir(CO)9(RCCRЈ)] (anions 6: R ϭ RЈ ϭ Ph; 7: R ϭ RЈ ϭ Et;
8: R ϭ Ph; RЈ ϭ Me; 9: R ϭ RЈ ϭ Me) (0.0370 mmol) in CH2Cl2
(30 mL) a slight excess of HBF4 • OEt2 (54%, 60 µL) was added
under stirring. After 30 min, the solvent was evaporated, and the
residue was dissolved in the minimum quantity of CH2Cl2. The
solution was separated by thin-layer chromatography with a mix-
ture of CH2Cl2 and hexane (1:6) as eluent. The yellow band con-
taining the product was extracted with CH2Cl2, followed by con-
centration to dryness. The resulting yellow oil was dissolved in hex-
ane and cooled to Ϫ18 °C to give yellow crystals of 10؊13. The
crystals were dried in vacuo. Ϫ 10: Yield 21 mg (68%). Ϫ C23H11-
IrO9Ru2 (825.69): calcd. C 33.46, H 1.34; found C 33.48, H 1.32.
Ϫ 11: Yield 18 mg (66%). Ϫ C15H11IrO9Ru2 (729.61): calcd. C
24.69, H 1.52; found C 24.51, H 1.54. Ϫ 12: Yield 17 mg (60%). Ϫ
C18H9IrO9Ru2 (763.62): calcd. C 28.31, H 1.19; found C 28.40, H
1.24. Ϫ 13: Yield 16 mg (62%). Ϫ C13H7IrO9Ru2 (701.55): calcd.
C 22.26, H 1.01; found C 22.12, H 1.04.
[N(PPh3)2][Ru3Ir(CO)13] (anion 1) (100 mg, 7.15•10Ϫ2 mmol) in
CH2Cl2 (30 mL) was stirred with an excess of RCϵCRЈ (2: 38 mg,
21.46•10Ϫ2 mmol; 3: 24 µL, 21.46•10Ϫ2 mmol; 4: 27 µL, 21.46•10Ϫ2
mmol; 5: 17 µL, 21.46•10Ϫ2 mmol) at 90 °C in a pressure Schlenk
tube. During the reaction the pressure was released once. The reac-
tion was followed by infrared spectroscopy; after 2.5 h, the IR spec-
trum in the νCO region indicated the complete desappearance of the
starting complex 1. Then the solvent was evaporated and the red-
orange oil was washed three times with 10 mL of hexane to remove
the excess of the unreacted alkyne. The residue was dissolved in
20 mL of Et2O, and the solution was filtered. Dark-red air-stable
crystals of the [N(PPh3)2]ϩ salts of 2, 4, 5 were obtained by slow
evaporation (room temperature) of a diethyl ether/hexane solution.
The crystals were dried in vacuo. Ϫ 2: Yield 92 mg (85%). Ϫ
C61H40IrNO11P2Ru3 (1520.36): calcd. C 48.19, H 2.65, N 0.92; found
C 48.32, H 2.58, N 0.93. Ϫ 4: Yield 83 mg (80%). Ϫ C56H38O11N-
P2Ru3Ir (1458.28): calcd. C 46.12, H 2.63, N 0.96, found C 45.94,
H 2.37, N 1.00. Ϫ 5: Yield 75 mg (75%). Ϫ C51H36O11NP2Ru3Ir
(1396.22): calcd. C 43.87, H 2.60, N 1.00; found C 43.77, H 2.45, N
1.01. Ϫ For 3, a different method of crystallisation was used. The
[HRu3Ir(CO)11(RCCRЈ)] (14؊15): To a solution of [N(PPh3)2]-
[Ru3Ir(CO)11(RCCRЈ)] (2: R ϭ RЈ ϭ Ph; 3: R ϭ RЈ ϭ Et), pre-
filtered diethyl ether solution containing 3 was concentrated to dry- pared from 0.0715 mmol of [N(PPh3)2]1 as described above, in
ness, the residue was dissolved in 10 mL of ethanol, followed by the
860
20 mL of Et2O was added a slight excess of HBF4 • OEt2 (54%,
Eur. J. Inorg. Chem. 1999, 853Ϫ862

Tri- and Tetranuclear Mixed-Metal Clusters Containing Alkyne Ligands
FULL PAPER
Table 9. Crystallographic data and refinement details for compounds 2, 4, 5, and 6
2
4
5
6
Formula
C61H40O11NP2IrRu3
0.25 C6H14
1520.42
C56H38O11NP2IrRu3
C51H36O11NP2IrRu3
C59H40O9NP2IrRu3
M
1458.22
1396.16
Triclinic
PϪ1
1363.20
Crystal system
Space group
Triclinic
Triclinic
Triclinic
PϪ1
PϪ1
PϪ1
˚
a [A]
10.1350(8)
15.5218(13)
19.8838(17)
98.652(10)
99.163(10)
94.583(10)
3035.6(4)
2
9.2769(10)
16.7823(16)
17.2250(17)
88.034(12)
84.463(12)
80.982(12)
2635.7(5)
2
10.678(2)
15.741(4)
15.705(3)
102.672(19)
91.363(12)
103.730(13)
2493.7(9)
2
10.5124(11)
15.545(3)
17.830(3)
100.04(2)
101.543(14)
101.551(19)
2726.3(8)
2
˚
b [A]
˚
c [A]
α [°]
β [°]
γ [°]
3
˚
V [A ]
Z
Crystal size [mm]
Colour
0.38 ϫ 0.15 ϫ 0.11
Dark-red
1.687
3.028
Ϫ
0.50 ϫ 0.50 ϫ 0.30
Black
1.837
3.482
0.479/0.832
1416
2.38Ϫ25.88
Ϫ11 to 11, Ϫ20
to 20, Ϫ20 to 21
20460
9406
8994
0.0226/0.0240
0.0567/0.0576
1.065
0.002
1.342/Ϫ1.125
0.65 ϫ 0.58 ϫ 0.53
Black
0.57 ϫ 0.27 ϫ 0.27
Yellow
Dc [g cmϪ3
]
1.859
3.675
1.661
3.097
µ [mmϪ1
]
Transmission factors: min/max
0.3979/0.6612
1352
0.3427/0.3917
1336
F(000)
θ limits [°]
hkl ranges
1505
2.13Ϫ25.88
Ϫ12 to 11, Ϫ19
to 18, Ϫ24 to 24
23865
2.10Ϫ25.48
Ϫ12 to 12, Ϫ19
to 18, 0 to 19
9251
2.01Ϫ25.49
Ϫ12 to 12, Ϫ18
to 18, 0 to 21
10126
Reflections measured
Independent reflections
Observed reflections
10950
7930
9251
8542
10126
8153
R1 [I > 2σ(I)]/R1 (all data)[a]
wR2 [I > 2σ(I)]/wR2 (all data)[b]
Goodness of fit on F2[c]
Maximum δ/σ
0.0316/0.0483
0.0739/0.0783
0.882
0.0371/0.0433
0.1004/0.1107
1.379
0.0551/0.0778
0.1184/0.1334
1.169
0.002
1.070/Ϫ1.829
0.061
1.580/Ϫ1.373
0.019
1.749/Ϫ1.457
3
˚
Largest diff. peak and hole [e A ]
[a]
[b]
2
2 2
[c]
2
2 2
R1 ϭ ΣԽԽFoԽ Ϫ ԽFcԽԽ/ΣԽFoԽ. Ϫ wR2 ϭ [Σw(Fo Ϫ Fc ) /Σw(Fo)4]1/2. Ϫ S ϭ [Σw(Fo Ϫ Fc ) /(n Ϫ p)]1/2 (n: number of reflections; p:
number of parameters).
Table 10. Crystallographic data and refinement details for compounds 10, 12, and 15
10
12
15
Formula
C23H11O9IrRu2
825.66
C18H9O9IrRu2
763.59
C17H11O11IrRu3
886.67
M
Crystal system
Space group
Triclinic
Triclinic
Triclinic
PϪ1
PϪ1
PϪ1
˚
a [A]
10.927(2)
14.480(3)
16.793(2)
70.080(13)
85.071(17)
86.106(19)
2486.8(8)
4
9.1281(5)
9.9456(6)
12.6212(14)
96.966(9)
108.833(9)
96.349(7)
1062.70(15)
2
8.0650(14)
9.4766(13)
16.423(4)
96.392(19)
101.47(2)
109.063(14)
1141.4(4)
2
˚
b [A]
˚
c [A]
α [°]
β [°]
γ [°]
3
˚
V [A ]
Z
Crystal size [mm]
Colour
0.57 ϫ 0.57 ϫ 0.42
Yellow
0.68 ϫ 0.34 ϫ 0.34
Yellow
0.95 ϫ 0.65 ϫ 0.36
Red-orange
2.580
7.811
0.0137/0.0460
820
2.32Ϫ25.46
Ϫ9 to 9, Ϫ11 to 11, 0 to 19
4324
4234
4134
0.0365/0.0387
0.1071/0.1127
1.280
0.001
1.831/Ϫ1.445
Dc [g cmϪ3
]
2.205
6.586
2.386
7.695
µ [mmϪ1
]
Transmission factors: min/max
F(000)
0.0474/0.0845
1544
0.0671/0.1236
708
θ limits [°]
hkl ranges
2.20Ϫ25.47
Ϫ13 to 13, Ϫ16 to 17, 0 to 20
9223
2.09Ϫ25.48
Ϫ11 to 10, Ϫ12 to 11, 0 to 15
3941
Reflections measured
Independent reflections
Observed reflections
R1 [I > 2σ(I)]/R1 (all data)[a]
wR2 [I > 2σ(I)]/wR2 (all data)[b]
Goodness of fit on F2[c]
Maximum δ/σ
9223
8141
3941
3774
0.0360/0.0441
0.0870/0.0920
1.258
0.0290/0.0309
0.0833/0.0849
1.292
0.004
0.001
1.237/Ϫ0.987
3
˚
Largest diff. peak and hole [e A ] 0.916/Ϫ0.876
[a]
[b]
2
2 2
[c]
2
2 2
R1 ϭ ΣԽԽFoԽ Ϫ ԽFcԽԽ/ΣԽFoԽ. Ϫ
number of parameters).
wR2 ϭ [Σw(Fo Ϫ Fc ) /Σw(Fo)4]1/2. Ϫ S ϭ [Σw(Fo Ϫ Fc ) /(nϪ p)]1/2 (n: number of reflections; p:
60 µL). After 30 min at room temperature, the white precipitate
was filtered off, washed twice with 10 mL of Et2O and then dis-
carded. The solution was concentrated, the residue dissolved in
CH2Cl2 (2 mL) and submitted to thin-layer chromatography (silica
gel, CH2Cl2/hexane, 1:3). The product was extracted from the or-
ange main band with CH2Cl2 and crystallised from hexane at
Eur. J. Inorg. Chem. 1999, 853Ϫ862
861

V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans
FULL PAPER
Ϫ18 °C. The orange air-stable crystals were dried in vacuo. Ϫ 14:
thenium(III) chloride hydrate from the Johnson Matthey Research
Yield (starting from 1) 36 mg (51%). Ϫ 15: Yield (starting from 1) Centre is gratefully acknowledged.
29 mg (45%) Ϫ C17H11IrO11Ru3 (886.69): calcd. C 23.02, H 1.25;
found C 23.21, H 1.30.
[1]
R. D. Adams, in Comprehensive Organometallic Chemistry 2
(Eds.: E. W. Abel, F. G. A. Stone, G. Wilkinson), Elsevier, Ox-
ford, 1995, vol. 10, p. 1.
[HRu3Ir(CO)11(PhCCMe)] (16): A solution of [HRu3Ir(CO)13][9] (83
mg, 0.096 mmol) and PhCϵCMe (18 µL, 0.145 mmol) in hexane (30
mL) was stirred at 80Ϫ85 °C in a pressure Schlenk tube. During
the reaction, the pressure was released once. After 1 h, the solution
changed colour from red to orange. After removal of the solvent,
the dark orange residue was dissolved in 5 ml of CH2Cl2 and submit-
ted to thin-layer chromatography (silica gel, CH2Cl2/hexane, 1:3).
From the orange main band, 16 was extracted with CH2Cl2 and
crystallised from hexane at Ϫ18 °C. The orange air-stable crystals
were dried in vacuo. Ϫ 16: Yield 27 mg (31%) Ϫ C20H9IrO11Ru3
(920.71): calcd. C 26.09, H 0.99; found, C 26.02, H 0.99.
[2]
Y. Chi, D. K. Hwang, in Comprehensive Organometallic Chemis-
try 2 (Eds.: E. W. Abel, F. G. A. Stone, G. Wilkinson), Elsevier,
Oxford, 1995, vol. 10, p. 85.
[3] [3a]
´
P. Braunstein, J. Rose, in Comprehensive Organometallic
Chemistry 2 (Eds.: E. W. Abel, F. G. A. Stone, G. Wilkinson),
[3b]
Elsevier, Oxford, 1995, vol. 10, p. 351. Ϫ
For a general re-
view see: Catalysis by Di- and Polynuclear Metal Cluster Com-
plexes (Eds.: R. D. Adams, F. A. Cotton), Wiley-VCH, Chiches-
[3c]
ter, 1998. Ϫ
R. D. Adams, T. S. Barnard, Z. Li, W. Wu, J.
H. Yamamoto, J. Am. Chem. Soc. 1994, 116, 9103. Ϫ [3d] R. D.
Adams, T. S. Barnard, Organometallics 1998, 17, 2567. Ϫ [3e] R.
D. Adams, T. S. Barnard, Organometallics 1998, 17, 2885.
E. Sappa, A. Tiripicchio, A. J. Carty, G. E. Toogood, Prog.
Inorg. Chem. 1987, 35, 437 and references therein.
P. R. Raithby, M. J. Rosales, Adv. Inorg. Chem. Radiochem.
1985, 29, 169.
[4]
[5]
X-ray Structure Analyses: Single crystals of 2, 4, 5, 6, 10, 12, and 15
were obtained as described under Preparations. Selected crystallo-
graphic data for the complexes are summarised in Tables 9 and 10,
and selected bond lengths and bond angles are listed in Tables 2Ϫ8.
Single-crystal X-ray diffraction data of the [N(PPh3)2]ϩ salts of 2
and 4 were collected at room temperature and Ϫ50 °C, respectively
with a Stoe Imaging Plate Diffractometer System (Stoe & Cie, 1995)
equipped with a one-circle goniometer and a graphite monochroma-
tor. 200 exposures (3 min per exposure) were obtained at an image-
plate distance of 70 mm with 0° < ␾ < 200° and with the crystal
oscillating through 1° in ␾. Τhe [N(PPh3)2]ϩ salts of 5 and 6 and
complexes 10, 12, and 15 were measured at room temperature with
[6]
E. L. Muetterties, T. N. Rhodin, E. Band, C. F. Brucker, W. R.
Pretzer, Chem. Rev. 1979, 79, 91.
[7]
A. Fusi, R. Ugo, R. Psaro, P. Braunstein, J. Dehand, J. Mol.
Catal. 1982, 16, 217.
[8]
V. Ferrand, G. Süss-Fink, A. Neels, H. Stoeckli-Evans, J. Chem.
Soc., Dalton Trans. 1998, 3825.
[9]
G. Süss-Fink, S. Haak, V. Ferrand, A. Neels, H. Stoeckli-Evans,
J. Chem. Soc., Dalton Trans. 1997, 3861.
[10]
[11]
O. Benali-Baitich, J. C. Daran, Y. Jeannin, J. Organomet. Chem.
1988, 344, 393.
M. Cazanoue, N. Lugan, J. J. Bonnet, R. Mathieu, Organome-
tallics 1988, 7, 2480.
[12] [12a]
´
P. Braunstein, J. Rose, J. Organomet. Chem. 1983, 252,
a Stoe-Siemens AED2 four-circle diffractometer using Mo-Kα
C101. Ϫ [12b] E. Roland, H. Vahrenkamp, Organometallics 1983,
2, 1048.
D. E. Fjare, W. L. Gladfelter, J. Am. Chem. Soc. 1984, 106,
4799.
˚
graphite-monochromated radiation (λ
ϭ
0.71073 A; ω-2θ
scans). The structures of the [N(PPh3)2]ϩ salts of 2, 4, 5, 6, and that
of complex 15 were solved by direct methods, whereas those of 10
and 12 were solved by Patterson methods using the program
SHELXS-97.[27] All the structures were refined by full-matrix least
squares on F2 with SHELXL-97.[28] The salt [N(PPh3)2]2 crystallises
with a quarter of a disordered molecule of hexane. The five carbon
atoms C62A, C62B, C63A, C63B, and C64 were refined isotropically
using the SHELXL-97 default parameters. In compounds
[N(PPh3)2]5 and [N(PPh3)2]6 one of the carbonyl ligands is found to
be disordered and has been split into C6A-O6A and C6B-O6B
(anion 5), C21A-O21A and C21B-O21B (anion 6), respectively, with
an occupancy of a half for each atom. The position of the hydride
ligands in 10, 12, and 15 were located from Fourier difference maps
and refined isotropically, while the remaining hydrogen atoms of the
methyl, ethyl or phenyl substituents were included in calculated posi-
tions and treated as riding atoms with SHELXL-97 default param-
eters. For [N(PPh3)2]4, an empirical absorption correction was ap-
plied using DIFABS[29] and for [N(PPh3)2]5, [N(PPh3)2]6, 10 12, 15
it was based on ψ scans.[30] The Figures were drawn with ORTEP[31]
(thermal ellipsoids, 50% probability level). Complete tables of bond
lengths and angles and lists of thermal parameters have been de-
posited with the Cambridge Crystallographic Data Centre, 12 Union
Road, Cambridge CB2 1EZ, UK. Copies of the data can be ob-
tained free of charge on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK [Fax: int. code ϩ 44-1223/336-033; E-
mail: deposit@ccdc.cam.ac.uk], on quoting the deposition numbers
CCDC-111752Ϫ111758.
[13]
[14]
[15]
[16]
R. H. Crabtree, M. Lavin, Inorg. Chem. 1986, 25, 805.
K. Wade, Adv. Inorg. Chem. Radiochem. 1976, 18, 1.
J. C. Wang, Y. Chi, S.-M. Peng, G.-H. Lee, S.-G. Shyu, F.-H.
Tu, J. Organomet. Chem. 1994, 481, 143.
M. Bergamo, T. Beringhelli, G. Dalfonso, P. Mercandelli, M.
Moret, A. Sironi, Organometallics 1997, 19, 4129.
S. Deabate, R. Gordiano, E. Sappa, J. Cluster Sci. 1997, 8, 407.
E. Roland, W. Bernhardt, H. Vahrenkamp, Chem. Ber. 1985,
118, 2858.
S. Aime, R. Gobetto, L. Milone, D. Osella, L. Violano, A. J.
Arce, Y. De Sanctis, Organometallics 1991, 10, 2854.
D. Boccardo, M. Botta, R. Gobetto, D. Osella, A. Tiripicchio, M.
Tiripicchio-Camellini, J. Chem. Soc., Dalton Trans. 1988, 1249.
[17]
[18]
[19]
[20]
[21]
[22] [22a]
J. Evans, G. Mc Nulty, J. Chem. Soc., Dalton Trans. 1981,
[22b]
2017. Ϫ
D. Boccardo, M. Botta, R. Gobetto, D. Osella,
A. Tiripicchio, M. Tiripicchio-Camellini, J. Chem. Soc., Dalton
[22c]
Trans. 1988, 1249. Ϫ
M. A. Gallop, B. F. G. Johnson, R.
Khattar, J. Lewis, P. Raithby, J. Organomet. Chem. 1990, 386,
121.
[23] [23a]
F. W. B. Einstein, K. G Tyers, A. S. Tracey, D. Sutton,
[23b]
Inorg. Chem. 1986, 25, 1631. Ϫ
ganomet. Chem. 1978, 150, 123.
A. J. Deemings, J. Or-
[24]
[25]
[26]
J. T. Park, J. R. Shapley, M. Rowen Churchill, C. Bueno, J. Am.
Chem. Soc. 1983, 105, 6182.
J. T. Park, J. R. Shapley, C. Bueno, J. W. Ziller, M. Rowen Chur-
chill, Organometallics 1988, 7, 2307.
D. D. Perrin, W. L. F. Armarego, Purification of Laboratory
Chemicals, 3rd ed., Pergamon Press, Oxford, 1988.
G. M. Sheldrick, Acta Crystallogr., Sect. A 1990, 46, 467.
G. M. Sheldrick, SHELXL-97, Program for crystal structure re-
finement, University of Göttingen, Germany, 1997.
N. Walker, D. Stuart, Acta Crystallogr., Sect. A 1990, 46, 158.
A. C. T. North, D. C. Phillips, F. C. Mathews, Acta Crystallogr.,
Sect. A 1968, 24, 351.
[27]
[28]
[29]
[30]
[31]
C. K. Johnson, ORTEP, Oak Ridge National Laboratory, Oak
Ridge, TN, modified for PC by L. Zsolnai, H. Pritzkow, Univer-
sity of Heidelberg, Germany, 1994.
Acknowledgments
We thank the Fonds National Suisse de la Recherche Scientifique
for financial support of this work. A generous loan of ru-
Received November 30, 1998
[I98407]
862
Eur. J. Inorg. Chem. 1999, 853Ϫ862