The synthesis and reactivity of some indenyl and bis-indenyl ruthenium carbonyl complexes

Article abstract of DOI:10.1016/j.jorganchem.2007.07.023

The reaction of [Ru₃(CO)₁₂] (1), with indene in refluxing xylene affords [{(η⁵-C₉H₇)Ru(CO)₂}₂] (2), in high yield. An analogous reaction of 1 with 2-phenylindene affords the expected dinuclear complex [{(η⁵-C₉H₆Ph)Ru(CO)₂}₂] (5), and a heptaruthenium cluster [(C₉H₄Ph)Ru₇(μ-H)(μ-CO)₂(CO)₁₆] (6). The indenyl ligand in compound 6 exhibits a novel bonding mode in which the benzenoid ring is μ₄,η¹:η¹:η²:η² bound to the cluster. Refluxing 1 with bis-indenyl methane affords the dinuclear complex [Ru₂(CO)₄{μ-(η⁵-C₉H₆)₂CH₂}] (7), which reacts with iodine via Ru-Ru bond cleavage to give [Ru₂I₂(CO)₄{(η⁵-C₉H₆)₂CH₂}] (8).

Full text of DOI:10.1016/j.jorganchem.2007.07.023

Journal of Organometallic Chemistry 692 (2007) 4909–4916
www.elsevier.com/locate/jorganchem
The synthesis and reactivity of some indenyl and bis-indenyl
ruthenium carbonyl complexes
*
Venugopal Shanmugham Sridevi, Weng Kee Leong
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
Received 21 June 2007; received in revised form 5 July 2007; accepted 6 July 2007
Available online 26 July 2007
Abstract
The reaction of [Ru3(CO)12] (1), with indene in refluxing xylene affords [{(g5-C9H7)Ru(CO)2}2] (2), in high yield. An analogous reac-
tion of 1 with 2-phenylindene affords the expected dinuclear complex [{(g5-C9H6Ph)Ru(CO)2}2] (5), and a heptaruthenium cluster
[(C9H4Ph)Ru7(l-H)(l-CO)2(CO)16] (6). The indenyl ligand in compound 6 exhibits a novel bonding mode in which the benzenoid ring
is l4,g1:g1:g2:g2 bound to the cluster. Refluxing 1 with bis-indenyl methane affords the dinuclear complex [Ru2(CO)4{l-(g5-
C9H6)2CH2}] (7), which reacts with iodine via Ru–Ru bond cleavage to give [Ru2I2(CO)4{(g5-C9H6)2CH2}] (8).
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Ruthenium; Indenyl; Bis-indenyl; Cluster
1. Introduction
(where L = monodentate phosphine), and [(g5-C9H7)RuCl-
(COD)].
Transition metal complexes containing the indenyl
ligand have received much attention due to their enhanced
reactivity and catalytic ability as compared to the cyclopen-
tadienyl analogues [1]. For example, [(g5-C9H7)RuCl-
(PPh3)2] showed efficient catalytic activity and selectivity
for the redox isomerisation of allyl and propargyl alcohols
[2], dynamic kinetic resolution of racemic alcohols [3], and
the cycloaddition of 1,6-heptadiyne with bicycloalkenes [4],
when compared to its cyclopentadienyl analogue,
[CpRuCl(PPh3)2]. Cyclopentadienyl complexes of ruthe-
nium have been reported as an excellent catalyst for many
organic reactions [5]. In contrast, catalytic studies involving
indenyl ruthenium complexes are only emerging, but some
reactions investigated have included olefin cyclopropana-
tion [6], cycloaddition reactions [4,7], hydration reactions
[8], dimerisation of terminal alkynes [9], and radical poly-
merization [10]. Most of the catalytic studies for indenyl
ruthenium complexes are based on [(g5-C9H7)RuCl(L)2]
In this study, we would like to report on our studies into
the reaction of indene and its derivatives such as bis-inde-
nyl and phenylindene, with [Ru3(CO)12] (1), to find a con-
venient entry into the chemistry of indenyl and bis-indenyl
ruthenium complexes.
2. Results and discussion
2.1. Indenyl complexes
The reaction of indene with 1 in boiling heptane was
reported to give [{(g5-C9H7)Ru(CO)2}2] (2), in an unspeci-
fied yield [11]. Complex 2 was also reported to be obtainable
in 9.4% yield (together with 9.6% of [Ru4(CO)7(l-CO)2-
(g2,g5,g2-C9H7)(g5-C9H9)]) by refluxing in methylcyclohex-
ane; the yield of 2 was increased to 65% in refluxing methyl
isobutyl ketone [12]. We have found that changing the sol-
vent to xylene afforded 2 in 94% yield (Scheme1). Compound
2 has been completely characterized, including by a single
crystal X-ray diffraction study; the ORTEP plot and selected
bond parameters are given in Fig. 1.
*
Corresponding author. Tel.: +65 6874 5131; fax: +65 6779 1691.
E-mail address: chmlwk@nus.edu.sg (W.K. Leong).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.07.023

4910
V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
˚
(average = 2.249(4) A), and the distortion values of the
O
CO
˚
C
xylene
slip-fold parameters are: slip distortion (D) = 0.119(4) A,
Ru
Ru
+
[Ru3(CO)12
]
hinge angle = 7.09ꢁ and fold angle = 8.51ꢁ. These values
fall within the range for small distortion from a g5 bonding
mode [13].
C
C
O
reflux, 14 h
O
1
2
94%
UV photolysis of a dichloromethane solution of 2 affor-
ded [(g5-C9H7)RuCl(CO)2] (3) in 89% yield (Scheme 2);
compound 3 can also be prepared by stirring 2 with
CCl4. Compound 3 was tested as a catalyst for the dimer-
isation of phenylacetylene in toluene; heating a toluene
solution of phenylacetylene containing 1 mol% of 3 for
17 h gave mostly unreacted phenylacetylene; 2-phenyl
naphthalene was obtained in 4% isolated yield.
Scheme 1.
UV photolysis of 2 with PPh3 gave [(g5-C9H7)RuCl-
(CO)(PPh3)] (4) (Scheme 2); it has earlier been obtained
by stirring [(g5-C9H7)RuCl(PPh3)2] with KOH and wet
chloroform for 40 h in 2-propanol (89% yield) [15]. The
1H NMR spectrum for 4 showed different chemical shifts
for the H1 and H3 protons of the indenyl ligand, which
has been attributed to asymmetry at the Ru centre [16].
We have completely characterized 4, including by a single
crystal X-ray diffraction study; the ORTEP plot and selected
bond parameters are given in Fig. 2. As in 2, the indenyl
ligand in 4 exhibits small distortion from a g5 bonding mode;
the Ru–C distances to the ring junction carbons (C(8,9))
˚
(average = 2.363(4) A) are longer than the Ru–C(1,3) dis-
˚
tances (average = 2.2045(4) A), and the slip-fold parameters
are: slip distortion = 0.159(4) A, hinge angle = 7.52ꢁ and
fold angle = 10.32ꢁ.
Fig. 1. ORTEP plot (thermal ellipsoids are drawn at 50% probability; all
hydrogen atoms omitted) and selected bond parameters for 2. C*–
Ru(1) = 1.952 (4); Ru(1)–Ru(1A) = 2.7412(5); Ru(1)–C(1) = 2.207(4);
Ru(1)–C(2) = 2.262(4); Ru(1)–C(3) = 2.279(4); Ru(1)–C(4) = 2.398(3);
˚
2.2. Phenylindenyl ruthenium complexes
Ru(1)–C(5) = 2.326(3);
Ru(1)–C(11) = 2.049(4);
Ru(1)–C(11A) =
1.992(4); Ru(1A)–C(11) = 1.992(4); Ru(1)–C(12) = 1.854(4); C(11)–
O(11) = 1.167(4); C(12)–O(12) = 1.142(5); Ru(1)–C(11)–O(11) = 135.0(3);
Ru(1A)–C(11)–O(11) = 139.6(3); Ru(1)–C(12)–O(12) = 179.4(4); Ru(1)–
C(11)–Ru(1A) = 85.42(14); C(2)–Ru(1)–C(3) = 35.59(16); C(1)–Ru(1)–
C(3) = 60.81 (16). C* = centroid of the five-membered ring – C(1), C(2),
C(3), C(4) and C(5). Slip-fold parameters: [13] slip distortion (D) = 0.119
Interestingly, the reaction of 1 with 1-phenylindene in
refluxing heptane afforded the expected dinuclear com-
pound [{(g5-C9H6Ph)Ru(CO)2}2] (5), in 17% yield, and a
smaller amount of the novel cluster 6, together with many
unidentified products (Scheme 3). Both 5 and 6 have been
completely characterized, including by single crystal X-ray
diffraction studies; their ORTEP plots, together with
˚
(4) A; hinge angle (HA) = 7.09ꢁ; fold angle (FA) = 8.51ꢁ.
The crystal structure of 2, including its bond parame-
ters, is very similar to that of the cyclopentadienyl analogue
[{CpRu(CO)2}2] [14]. The molecular structure consists of
O
CO
C
two ruthenium atoms at
a
single bond distance
CH2Cl2
Ru
Ru
˚
C
[2.7412(5) A], each carrying one terminal and one bridging
carbonyl ligands, and the indenyl groups are arranged
trans to one another and ligate each metal in an g5-fashion.
The bridging carbonyl groups and the ruthenium atoms are
coplanar.
UV photolysis
1 h
O
OC
Ru
2
CO
PPh3 / CH2Cl2
CO
Cl
UV photolysis
1 h and 15 min
89%
In the description of g5-indenyl complexes, it is useful to
examine the degree of distortion from g5 to g3 coordina-
tion; the latter being equivalent to an allyl–ene bonding
description of the C5-ring. As described by Taylor and
Marder, the degree of distortion can be discussed in terms
of the slip-fold distortion parameters: slip distortion (D),
hinge angle (HA), and fold angle (FA) [13]. The Ru–C dis-
tances to the ring junction carbons (C(4,5)) in 2 (aver-
3
Ru
CO
Cl
Ph3P
97%
4
˚
Scheme 2.
age = 2.362(3) A) are longer than the Ru–C(1,3) distances

V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
4911
Fig. 3. ORTEP plot (thermal ellipsoids are drawn at 50% probability; all
hydrogen atoms omitted) and selected bond parameters for 5. Ru(1)–
Ru(2) = 2.7333(7); C*–Ru(1) = 1.945(6); C*–Ru(2) = 1.953(6); Ru(1)–
C(11) = 1.859(7);
Ru(1)–C(12) = 2.045(6);
Ru(1)–C(22) = 2.034(6);
Ru(2)–C(21) = 1.859(6); Ru(2)–C(12) = 2.027(6); Ru(2)–C(22) = 2.038(6);
C(21)–O(21) = 1.141(7); C(22)–O(22) = 1.156(7); Ru(1)–C(12)–Ru(2) =
84.3(2); Ru(1)–C(22)–Ru(2) = 84.3(2); Slip-fold parameters: [13] D =
˚
˚
0.180(6) A; HA = 7.13ꢁ; FA = 6.96ꢁ for IndRu(1) and D = 0.182(6) A;
HA = 6.96ꢁ; FA = 6.24ꢁ for IndRu(2).
Fig. 2. ORTEP plot (thermal ellipsoids are drawn at 50% probability; all
hydrogen atoms omitted) and selected bond parameters for 4.
example, both the cis and trans isomeric structures of
[CpFe(CO)2]2 have been reported [18]. Thus, the molecular
structure of 5 reported here, in which the indenyl groups
are arranged cis to one another, is the first reported exam-
ple of a structurally characterized cis isomer for ruthenium.
The slip-fold distortion values fall in the range of small dis-
tortion from a g5 bonding mode [15]. The smaller FA value
compared to the corresponding HA value indicates that the
benzenoid ring of the phenylindenyl ligand is bent towards
the ruthenium centre, and is unusual for g5-indenyl
complexes.
The valence electron count for the heptaruthenium clus-
ter 6 is 104, if the benzenoid ring is regarded as a 6-electron
donor, which makes it electron-deficient with 10 metal–
metal bonds. However, the bonding of the benzenoid with
the Ru(3)Ru(4)Ru(5)Ru(6) butterfly metal core may best
be regarded as similar to that found in similar tetranuclear
C*–Ru1 = 1.917(4);
Ru(1)–C(3) = 2.185(5); Ru(1)–C(8) = 2.357(4); Ru(1)–C(9) = 2.369(4);
Ru(1)–Cl(13) = 2.4110(11); Ru(1)–P(2) = 2.3323(9); P(2)–C(21A) =
Ru(1)–C(1) = 2.224(4);
Ru(1)–C(2) = 2.189(4);
1.821(4); P(2)–C(21B) = 1.830(4); P(2)–C(21C) = 1.832(4); C(11)–Ru(1)–
Cl(3) = 94.05(13); C(11)–Ru(1)–P(2) = 87.25(12); P(2)–Ru(1)–Cl(3) =
90.56(4); C(21A)–P(2)–Ru(1) = 113.40(13); C(21B)–P(2)–Ru(1) = 114.49(12);
˚
C(21C)–P(2)–Ru(1) = 117.21(13). Slip-fold parameters: D = 0.159(4) A;
HA = 7.52ꢁ; FA = 10.32ꢁ.
selected bond parameters, are shown in Figs. 3 and 4,
respectively.
The IR spectrum of 5 shows a pattern which is very sim-
ilar to that reported for [Ru2(CO)4{l-(g5-C9H6)2CH2-
CH2}] [22], indicating the presence of both the cis and trans
isomers. Dinuclear g5-dienylruthenium and iron complexes
are known to exist as mixtures of cis and trans isomers in
solution [11,23]. However, it is mostly the trans isomers
that crystallize out in the solid state [14,17]. As a rare
Heptane
[Ru3(CO)12]
+
Reflux
24 h
1
Ph
Ru
Ph
Ph
Ru
+
Ru
O
C
Ru
Ru
OC
Ru
Ru
Ru
C
CO
O
Ru
H
5
6
17%
8%
Scheme 3.

4912
V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
analogous reaction in refluxing heptane afforded a complex
mixture.
The IR spectrum (mCO) of 7 shows a pattern which is very
similar tothose for the related compounds [Ru2(CO)4{l-(g5-
C9H6)2CH2CH2}] [22], [Ru2(CO)4{l-(g5-C5H4)2CH2CH2}]
[23], and [Ru2(CO)4{l-(g5-C9H6)2CHCH3}] [24], all of
which have the g5 rings constrained in a mutually cis config-
uration. The 1H NMR spectrum of 7 exhibits a pair of dou-
blets at 5.48 ppm and 6.24 ppm, due to the ring protons.
These shifts are similar to those reported for related indenyl
ruthenium compounds [25], and are diagnostic of g5 coordi-
nation of each indenyl ligand. Compound 7 has also been
characterized by a single crystal X-ray diffraction study.
There are two crystallographically distinct molecules; the
ORTEP plot of one molecule is given in Fig. 5, together with
selected bond parameters for both molecules. The distortion
value of the slip-fold parameters for 7 falls in the range of
small distortion from a g5 bonding mode [13].
Fig. 4. ORTEP plot (thermal ellipsoids are drawn at 50% probability; all
organic hydrogen atoms omitted) and selected bond parameters for 6.
Ru(1)–Ru(2) = 2.759(2);
2.838(2); Ru(3)–Ru(4) = 2.756(2); Ru(3)–Ru(5) = 2.762(2); Ru(4)–
Ru(6) = 2.780(2); Ru(4)–Ru(7) = 2.796(2); Ru(4)–Ru(5) = 2.952(2);
Ru(5)–Ru(6) = 2.854(2); Ru(6)–Ru(7) = 2.721(2); Ru(1)–C(1) =
Ru(1)–C(2) = 2.26(2); Ru(1)–C(3) = 2.251(17);
Ru(1)–Ru(3) = 2.876(2);
Ru(2)–Ru(3) =
2.219(19);
Ru(1)–
C(4) = 2.218(18);
Ru(1)–C(9) = 2.214(18);
Ru(2)–C(7) = 2.392(17);
Ru(2)–C(8) = 2.304(19); Ru(3)–C(5) = 2.237(17); Ru(3)–C(6) = 2.215(16);
Ru(4)–C(5) = 2.146(17); Ru(5)–C(6) = 2.140(16); Ru(6)–C(5) = 2.200(18);
Ru(6)–C(6) = 2.349(17); C(4)–C(5) = 1.477(2); C(5)–C(6) = 1.446(2);
C(6)–C(7) = 1.430(2); C(7)–C(8) = 1.395(3); C(8)–C(9) = 1.447(3); C(9)–
C(4) = 1.468(2).
butterfly clusters and hence is not electron-deficient [19].
To the best of our knowledge, this is the first example of
such a bonding mode exhibited by the indenyl ligand.
The Ru–Ru contacts span a large range, from 2.756(2) to
Fig. 5. ORTEP plot of complex 7 molecule A (thermal ellipsoids are drawn
at 50% probability; all hydrogen atoms omitted), and selected bond
˚
2.952(2) A. The shortest metal–metal bond (Ru(3)–Ru(4))
˚ ˚
parameters. MoleculeA: C*–Ru(1) = 1.934 A;C*–Ru(2) = 1.930 A;Ru(1)–
is bridged by a carbonyl ligand and the longest metal–metal
bond (Ru(4)–Ru(5)) is bridged by the C6 ring of the indenyl
ligand. The hydride ligand appears to be capping the
Ru(4)–Ru(5)–Ru(6) face, as indicated by a potential energy
calculation [20]; this is also corroborated by a singlet reso-
˚
˚
Ru(2) = 2.6697(6) A; D (Ru(1)) = 0.091(5) A; HA (Ru(1)) = 6.20ꢁ; FA
˚
(Ru(1)) = 7.73ꢁ;
D (Ru(2)) = 0.097(5) A; HA (Ru(2)) = 5.58ꢁ; FA
˚
˚
(Ru(2)) = 7.31ꢁ; C(1)–O(1) = 1.145(7) A; C(1)–O(2) = 1.128(7) A; C(1)–
O(3) = 1.184(6) A; C(1)–O(4) = 1.168(6) A; C(11)–C(5) = 1.507(7) A;
˚
˚
˚
C(1)–Ru(1)–Ru(2) = 108.4(2)ꢁ; C(2)–Ru(2)–Ru(1) = 109.7(2)ꢁ; C(11)–
1
˚
nance at À18.7 ppm in the H NMR spectrum [21].
C(5)–C(21) = 114.4(4)ꢁ.
Ru(2) = 1.931 A; Ru(1)–Ru(2) = 2.6744(6) A;
Molecule B:
C*–Ru(1) = 1.934 A;
C*–
˚
˚
˚
D
(Ru(1)) = 0.104(5) A;
˚
HA (Ru(1)) = 6.01ꢁ; FA (Ru(1)) = 7.80ꢁ; D (Ru(2)) = 0.090(5) A; HA
2.3. Bis(indenyl) complexes
˚
(Ru(2)) = 5.35ꢁ; FA (Ru(2)) = 5.87ꢁ; C(1)–O(1) = 1.132(6) A; C(1)–
˚
˚
˚
O(2) = 1.137(6) A; C(1)–O(3) = 1.181(6) A; C(1)–O(4) = 1.169(6) A;
C(11)–C(5) = 1.510(8) A; C(1)–Ru(1)–Ru(2) = 108.61(17)ꢁ; C(2)–Ru(2)–
˚
The reaction of 1 with 1,2-bis(3-indenyl) methane in
refluxing xylene afforded 7 in 54% yield (Scheme 4); the
Ru(1) = 109.60(17)ꢁ; C(11)–C(5)–C(21) = 114.6(4)ꢁ.
O
xylene
reflux, 24 h
C
+
[Ru3(CO)12]
Ru
Ru
1
CO
CO
C
O
7
54%
Scheme 4.

V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
4913
Compound
7
displayed the same reactivity as
Orange yellow solid. [{(g5-C9H7)Ru(CO)2}2] (2). IR
[Ru2(CO)4{l-(g5-C5H4)2CH2}] and [CpRu(CO)2]2 towards
halogens. Thus, ruthenium–ruthenium bond cleavage
occurred rapidly on treatment with iodine giving [Ru2I2-
(CO)4{(g5-C9H6)2CH2}] (8). The IR spectrum (mCO) of 8
shows two bands at 2046s and 1992vs cmÀ1, similar to that
reported for [Ru2I2(CO)4{(g5-C5H4)2CH2}] [26].
(CH2Cl2): mCO 2000vs, 1959vs, 1784vs cmÀ1. H NMR (d,
1
CDCl3): 5.57 (t, 1H, H2), 5.63 (d, 2H, H1,3), 7.2–7.32 (m,
4H, H4–7). FAB-MS: 546 [M]2+
. Anal. Calc. for
C22H14O4Ru2: C, 48.53; H, 2.59. Found: C, 48.83; H,
2.53%.
4.3. Synthesis of [(g5-C9H7)RuCl(CO)2] (3)
3. Conclusion
A CCl4 solution of 2 (50 mg, 91.91 lmol) was stirred at
room temparature for 48 h. The solvent was then removed
under reduced pressure and the residue obtained was chro-
matographed on a silica gel column. Elution with 100%
CH2Cl2 afforded 3 as a pale yellow band. Yield = 51 mg,
90% with respect to ruthenium.
A high yield synthetic route to dimer 2 has been devel-
oped which allows further exploration of the chemistry
and catalytic activity of indenyl ruthenium carbonyl com-
plexes. Photolysis of 2 in dichloromethane solution gives
3 while carbonyl substitution to afford 4 occurs with
PPh3. The analogous reaction with phenylindene, however,
affords the dinuclear species 5 only in low yield, as well as a
novel heptaruthenium cluster 6, in which the benzenoid
ring of the indenyl ligand behaves like a benzyne. The sym-
metric methylene-bridged dinuclear complex 7 has also
been synthesized, and its reaction with iodine leads to
cleavage of the ruthenium–ruthenium bond.
Compound 3 can also be prepared by UV photolysis of
a dichloromethane solution of 2 (50 mg, 91.91 lmol) for
1 h. The solvent was then removed under reduced pressure
and the residue obtained was chromatographed on a silica
gel column. Elution with 100% CH2Cl2 afforded 3.
Yield = 50.5 mg, 89% with respect to ruthenium. Yellow
solid. [(g5-C9H7)RuCl(CO)2] (3). IR (CH2Cl2): mCO
1
2052vs, 1995vs cmÀ1. H NMR (d, CDCl3): 5.59 (d, 2H,
H1,3), 5.75 (t, 1H, H2), 7.45–7.56 (m, 4H, H4–7). FAB-
MS: 308 (M+). Anal. Calc. for C11H7Cl1O2Ru: C, 42.94;
H, 2.29. Found: C, 42.65; H, 2.44%.
4. Experimental
4.1. General procedures
4.4. Synthesis of [(g5-C9H7)RuCl(CO)(PPh3)] (4)
All reactions were performed under argon using Schlenk
techniques. Solvents were purified, dried, distilled, and
stored under nitrogen prior to use, except for xylene which
was used as supplied. Routine NMR spectra were recorded
on a Bruker ACF300, DPX 300, or AV300 NMR spec-
A
10 ml dichloromethane solution of 2 (20 mg,
36.8 lmol) and PPh3 (9.7 mg, 37.0 lmol) was photolysed
under UV for 1 h and 15 min. The solvent was then
removed under reduced pressure and the residue obtained
was extracted with dichloromethane and chromatographed
on silica gel column. Elution with 100% CH2Cl2 afforded a
dark orange band of 4. Yield = 38.5 mg, 97% with respect
to ruthenium.
1
trometer as CDCl3 solutions unless otherwise stated. H
chemical shifts reported were referenced against the resid-
ual proton signals of the solvents. Mass spectra were
obtained on a Finnigan MAT95XL-T spectrometer in a
3NBA matrix (FAB), or a Macromass VG7035 at 70 eV
(EI). All elemental analyses were performed by the micro-
analytical laboratory at NUS. UV photolyses were carried
out with a Hanovia 450 watt UV lamp with a nominal kmax
of 254 nm. 1,2-Bis(3-indenyl)methane was prepared
according to the literature method [27]. The cluster
Ru3(CO)12 (1) was purchased from Oxkem Ltd. and used
as supplied. All other reagents are commercially available
and used without further purification.
Orange yellow solid. [(g5-C9H7)RuCl(CO)(PPh3)] (4).
1
IR (CH2Cl2): mCO 1953vs cmÀ1. H NMR (d, C6D6): 3.66
(s, 1H, H3), 4.96 (t, J = 2.46 Hz, H2), 5.37 (s, 1H, H1),
6.53–7.52 (m, 19H, Ph and H4–7). 31P NMR (d, C6D6):
46.37(s). FAB-MS: 542 [M]+. Literature values: [15] IR
1
(CH2Cl2): mCO 1954vs cmÀ1. H NMR (d, C6D6): 3.72 (s,
1H, H3), 5.03 (t, J = 2.54 Hz, H2), 5.45 (s, 1H, H1), 6.59–
7.60 (m, 19H). 31P NMR (d, C6D6): 48.88(s). FAB-MS:
542 [M]+.
4.2. Synthesis of [{(g5-C9H7)Ru(CO)2}2] (2)
4.5. Reaction of 3 with phenylacetylene
A xylene solution (20 ml) of indene (0.7 ml, 6.00 mmol)
and 1 (200 mg, 0.313 mmol) was refluxed under argon for
14 h. The solvent was then removed under reduced pressure
and the residue obtained was dissolved in the minimum
amount of dichloromethane and chromatographed on a sil-
ica gel column. Elution with hexane/CH2Cl2 (1/1, v/v) gave
2 as an orange yellow band. Yield = 241 mg, 94% with
respect to ruthenium.
Phenylacetylene (143 lL, 1.30 mmol) and 3 (4 mg,
13.051 lmol) were heated in toluene (4 ml) at 110 ꢁC for
17 h. The solvent was then removed under reduced pressure
and the residue obtained was dissolved in the minimum
amount of dichloromethane and chromatographed on sil-
ica gel TLC plates. Elution with 100% hexane gave 2-phe-
nyl naphthalene as a pale yellow band (Rf = 0.85).
Yield = 5.8 mg, 4.4% wrt phenylacetylene. 1H NMR (d,

4914
V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
CDCl3): 7.34–7.40 (m, 1H), 7.46–7.52 (m, 4H), 7.72–7.77
(m, 3H), 7.88–7.93 (m, 3H) [28]. EI-MS: 204 [M]+.
Ph and H4–7). FAB-MS: 697 [M]+. Anal. Calc. for
C23H14O4Ru2 Æ 1/2CH2Cl2: C, 47.12; H, 2.52. Found: C,
47.51; H, 2.68%.
4.6. Reaction of 1 and phenylindene
4.7. Synthesis of [Ru2(CO)4{l-(g5-C9H6)2CH2}] (7)
A heptane solution (10 ml) of 2-phenylindene (30 mg,
0.156 mmol) and 1 (40 mg, 0.625 mmol) was refluxed under
argon for 24 h. The solvent was then removed under
reduced pressure and the residue obtained was extracted
with dichloromethane and chromatographed on a silica
gel column. Elution with 100% hexane gave the unreacted
ligand (24 mg, 80%) followed by 1 (26 mg, 65%).
Elution with hexane/CH2Cl2 (1/1, v/v) afforded a mixture
of 5, 6 and six other unidentified products. Compounds 5 and
6 were further purified by chromatography on silica gel TLC
plates with hexane/CH2Cl2 (1/1, v/v) as eluant.
A xylene solution (20 ml) of 1,2-bis(3-indenyl)methane
(0.38g, 1.557 mmol) and 1 (250 mg, 0.391 mmol) was
refluxed under argon for 24 h. The solvent was then
removed under reduced pressure and the residue obtained
was extracted with dichloromethane and chromatographed
on silica gel TLC plates. Elution with hexane/CH2Cl2 (1/1,
v/v) gave three bands.
Band 1 (Rf = 0.88), very pale yellow, unreacted ligand.
Yield = 100 mg, 26%.
Band 2 (Rf = 0.75), yellow, unreacted 1. Yield = 80 mg,
32%.
Band 4 (Rf = 0.42), brown solid. [(C9H4Ph)Ru7(l-H)(l-
CO)2(CO)16] (6). Yield = 1 mg, 8% with respect to con-
sumed ruthenium. IR (CH2Cl2): mCO 2106w, 2081vs,
Band 3 (Rf = 0.19), orange yellow solid. [Ru2(CO)4-
{l-(g5-C9H6)2CH2}] (7). Yield = 120 mg, 54% wrt reacted
1
2062s, 2032vs, 2014w, 2000vw, 1941w cmÀ1. H NMR (d,
1. IR (CH2Cl2): mCO 1998vs, 1961m, 1785vs cmÀ1 1H
.
CDCl3): 4.88 (s, 2H, H1,3), 7.34–7.65 (m, 7H, Ph and
H6,7), À18.74 (s, 1H, RuHRu). FAB-MS: 1289 [MÀ4CO]+.
Band 5 (Rf = 0.49), yellow solid. [{(g5-C9H6Ph)Ru-
(CO)2}2] (5). Yield = 4 mg, 17% with respect to consumed
NMR (d, CDCl3): 3.70 (s, 2H, CH2), 5.48 (d, 2H, H2/3),
6.24 (d, 2H, H3/2), 7.29–7.32 (m, 4H, H4–7), 7.50–7.61 (m,
4H, H4–7). FAB-MS: 558 [M]2+. Anal. Calc. for C23H14-
O4Ru2 Æ 1/2CH2Cl2: C, 47.12; H, 2.52. Found: C, 47.52;
H, 2.57%. The presence of dichloromethane in the analyt-
ruthenium. IR (CH2Cl2): mCO 2000vs, 1960vs, 1794vs cmÀ1
.
1H NMR (d, CDCl3): 5.93 (s, 2H, H1,3), 7.39–7.22 (m, 9H,
ical sample was confirmed by H NMR spectroscopy.
1
Table 1
Crystal and refinement data for 2, 4–7
Compound
2
4
5
6
7
Empirical formula
Formula weight
Crystal system
C
544.47
Monoclinic
P21/c
22H14O4Ru2
C28H22ClO1.25PRu
545.95
Triclinic
C35H24Cl2O4Ru2
781.58
Monoclinic
P21/n
C34H12Cl2O18Ru7
1486.83
Monoclinic
P21/c
C47H30Cl2O8Ru4
1197.89
Triclinic
ꢀ
ꢀ
Space group
P1
P1
Unit cell dimensions
˚
a (A)
9.1811(5)
13.1477(7)
8.1203(5)
90
112.178(2)
90
907.68(9)
2
1.992
9.3163(6)
10.3414(7)
12.5301(8)
87.648(2)
82.999(2)
82.796(2)
1188.33(13)
2
13.422(2)
10.2211(17)
22.240(4)
90
101.910(5)
90
2985.5(9)
4
1.739
8.9051(12)
21.294(3)
22.204(3)
90
100.841(3)
90
4135.3(9)
4
2.388
11.2826(6)
12.9353(7)
15.0553(8)
86.7220(10)
82.2890(10)
75.7240(10)
2109.5(2)
2
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
Volume (A )
Z
Dcalc (Mg/m3)
Absorption coefficient (mmÀ1
F(000)
1.526
0.859
552
1.886
1.587
1172
)
1.690
532
1.230
1552
2.691
2808
Crystal size (mm)
h Range for data collection (ꢁ)
Reflections collected
0.28 · 0.18 · 0.06
2.40–26.37
7578
0.20 · 0.14 · 0.06
2.22–28.28
12615
0.18 · 0.10 · 0.03
2.20–26.37
26433
0.09 · 0.08 · 0.06
2.10–26.37
57379
0.21 · 0.16 · 0.06
2.10–30.02
32433
Independent reflections (Rint
Maximum and minimum
transmission
)
1856 (0.0280)
0.9054 and 0.6490
5792 (0.0401)
0.9503 and 0.8470
6097 (0.0724)
0.9640 and 0.8089
8443 (0.1119)
0.8552 and 0.7937
10409 (0.0645)
0.9108 and 0.7317
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
1856/0/155
1.053
5792/0/381
1.077
6097/0/484
1.156
8443/207/557
1.429
10409/6/547
0.537
R1 = 0.0311,
wR2 = 0.0759
R1 = 0.0357,
wR2 = 0.0783
1.072 and À0.301
R1 = 0.0553,
wR2 = 0.1204
R1 = 0.0705,
wR2 = 0.1285
1.302 and À0.383
R1 = 0.0613,
wR2 = 0.1168
R1 = 0.0807,
wR2 = 0.1253
1.224 and À0.782
R1 = 0.1289,
wR2 = 0.2465
R1 = 0.1398,
wR2 = 0.2515
2.310 and À1.625
R1 = 0.0469,
wR2 = 0.0979
R1 = 0.0788,
wR2 = 0.1077
1.191 and À0.698
R indices (all data)
Largest difference in peak and
À3
˚
hole (e A
)

V.S. Sridevi, W.K. Leong / Journal of Organometallic Chemistry 692 (2007) 4909–4916
4915
4.8. Reaction of 7 with I2
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thanks ICES for a Research Scholarship.

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