Synthesis and redox properties of trinuclear ruthenium-acetylide complexes with tri(ethynylphenyl)amine bridge

Article abstract of DOI:10.1039/b600736h

Novel trinuclear ruthenium complexes have been prepared by using tri(4-ethynylphenyl)amine as a bridging ligand. Cyclic voltammetry of the trinuclear ruthenium complexes revealed stepwise quasi-reversible redox behavior of three ruthenium-acetylide specie

Full text of DOI:10.1039/b600736h

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www.rsc.org/dalton | Dalton Transactions
Synthesis and redox properties of trinuclear ruthenium–acetylide
complexes with tri(ethynylphenyl)amine bridge
Kiyotaka Onitsuka,* Naoko Ohara, Fumie Takei and Shigetoshi Takahashi
Received 23rd January 2006, Accepted 23rd May 2006
First published as an Advance Article on the web 8th June 2006
DOI: 10.1039/b600736h
Novel trinuclear ruthenium complexes have been prepared by using tri(4-ethynylphenyl)amine as a
bridging ligand. Cyclic voltammetry of the trinuclear ruthenium complexes revealed stepwise quasi-
reversible redox behavior of three ruthenium–acetylide species and the central triphenylamine
unit, whereas the mononuclear analog showed two sequential quasi-reversible redox waves. The
−
spectroelectrochemical UV-VIS spectral studies suggested that the 1e oxidized triruthenium species
was stable and showed a characteristic absorption at kmax = 505 nm. Chemical oxidation of the
−
triruthenium complex with ferrocenium hexafluorophosphate led to the isolation of the 1e oxidized
complex, the near-IR spectrum of which revealed an intervalence charge transfer band due to the
−
electronic coupling among three ruthenium species. The 1e oxidized triruthenium complexes can
be classified as class II mixed-valence compounds.
Introduction
Results and discussion
Organometallic complexes with p-conjugated bridges are versatile
The synthetic approach to trinuclear ruthenium complexes shown
in Scheme 1 was based on known activation processes of ter-
minal acetylenes with ruthenium complexes. The Sonogashira
building blocks for carbon-rich networks that are applicable to the
1
6
development of new optical materials and electronic devices. As
a model of linear multi-metallic systems, many dinuclear metal–
acetylide complexes have been prepared and their electrochemical
behaviors studied. The dinuclear metal–acetylide complexes often
show electronic interaction between metal species, which stabilizes
the mixed valence state by changing the bonding mode of the
coupling of tri(4-bromophenyl)amine with trimethylsilylacetylene
produced tri[4-(trimethylsilylethynyl)phenyl]amine (1), which was
converted to tri(4-ethynylphenyl)amine (2) by desilylation under
21
basic conditions. Ruthenium moieties were introduced by react-
ing with cis-Ru(dppe)
2
Cl
2
(3) in the presence of KPF , followed
6
2,3
bridging ligands. Recently, trinuclear metal–acetylide complexes
have been attracting increasing interest as a model of dendritic
4
–17
multi-metallic systems.
However, only a few examples of such
5,7
complexes show strong interaction among the metal species.
Thus, we have decided to design a new bridging ligand that
incorporates the heteroatom into the bridging unsaturated ligand,
to increase the interaction among the metal species as well as the
stability of the mixed valence state.
Triphenylamine derivatives have attracted considerable inter-
18
est due to their unique electronic and magnetic properties.
Especially, polymeric materials containing triphenylamine units
are widely used as hole transport components in optoelectronic
19
devices. Therefore, the acetylene compounds derived from triph-
enylamine may act as a bridging ligand for multinuclear organo-
metallic complexes that have strong metal–metal interactions.
However, no reports on multinuclear systems bridged by triph-
enylamine derivatives are found in the literature, while only one
example of a mononuclear acetylide complex having triphenyl-
20
amine units is known. We report herein the synthesis and redox
properties of trinuclear ruthenium complexes bridged by tri(p-
ethynylphenyl)amine.
The Institute of Scientific and Industrial Research, Osaka University, 8-1
Mihogaoka, Ibaraki, Osaka, 567-0047, Japan. E-mail: onitsuka@sanken.
osaka-u.ac.jp; Fax: +81 6 6879 8469
Scheme 1
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by treatment with Et
complex (4) in 74% yield. The reaction of 4 with phenylacetylene
in the presence of KPF and Et N in refluxing THF for 24 h
resulted in the formation of the ruthenium–bis(acetylide) complex
5) in 94% yield. Mononuclear ruthenium–acetylide derivatives
3
N to give the trinuclear ruthenium–acetylide
of the central triphenylamine unit because 1 showed a redox
wave at E1/2 = 0.77 V. Complex 5 showed a similar CV that
contained four quasi-reversible waves at E1/2 = −0.17, 0.10, 0.23
and 0.51 V. On the other hand, complex 8 underwent two quasi-
reversible oxidations at E1/2 = −0.03 and 0.48 V, suggesting that the
22
6
3
(
II
were prepared in a similar manner as shown in Scheme 2. The Pd-
catalyzed amination of 4-bromo(triisopropylsilylethynyl)benzene
with diphenylamine gave a triphenylamine derivative (6) having
Ru moiety acts as an strong electron-donating group. Although it
has been reported that some dinuclear metal–acetylide complexes
produce coupled oxidation waves due to the electronic interaction
through the conjugated ligands, all ruthenium–acetylide species
23
a protected ethynyl group. (4-Ethynylphenyl)diphenylamine (7)
was obtained by deprotection of the ethynyl group of 6, and
was treated with 3 to give ruthenium–acetylide complex (8) in
6
are coincidentally oxidized at the same potential in the trinuclear
15
and larger ruthenium–acetylide complexes. This is a rare example
of a transition-metal acetylide system having electronic interaction
8
4% yield. Bis(acetylide)-type complex (9) was also prepared by
5,7
reacting 8 with phenylacetylene in 85% yield.
among three metal species.
The UV-VIS spectra of 8 and 9 showed the MLCT band (kmax
=
−1
4
4
3
−1
3
49 nm, 8: e = 4.99 × 10 , 9: e = 5.20 × 10 dm mol cm )
24
that is characteristic of metal–acetylide complexes (Fig. 2). In the
spectrum of 5, the MLCT band was observed to show a significant
5
3
−1
−1
bathochromic shift (kmax = 381 nm, e = 1.11 × 10 dm mol cm ).
Complex 4 also showed the MLCT band at kmax = 380 nm (e =
4
3
−1
−1
6
.88 × 10 dm mol cm ) with slightly lower absorptivity.
These results suggest that 4 and 5 exhibit metal–metal interactions
15
through the tri(p-ethynylphenyl)amine bridge.
Scheme 2
As shown in Fig. 1, the cyclic voltammogram (CV) of 4 displayed
four quasi-reversible waves in the region between −0.8 and +0.8 V
vs. Ag/AgCl reference. The three waves at low potential (E1/2
=
II
III
−
0.17, 0.11, 0.29 V) were assignable to the stepwise Ru –Ru
redox of the three ruthenium–acetylide units, whereas the wave
at the highest potential (E1/2 = 0.60 V) was due to the redox
−
3
Fig. 1 Cyclic voltammogram (steady state) of 4 (0.8 × 10 M, CH
2 2
Cl )
containing 0.1 M [Bu N][PF ] at room temperature with a scan rate of
0 mV s . The external ferrocene/ferrocenium standard was observed at
.16 V.
4
6
Fig. 2 Spectroelectrochemical UV-VIS spectra of 5 in CH
temperature under argon atmosphere. (a) 4e redox reaction; (b) 1e redox
reaction.
2
Cl
2
at room
−
1
−
−
5
0
3
694 | Dalton Trans., 2006, 3693–3698
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To examine the properties of the mixed-valence complexes, the
spectroelectrochemical UV-VIS spectra were measured. When a
CH
2
Cl
2
solution of 5 was kept at −0.05 V potential that was
−
appropriate for 1e oxidation, the absorption in the 300–400 nm
region was decreased and new bands were noted to emerge in the
4
00–550 nm region, with discernible maxima at 450 and 505 nm
(
Fig. 2(a)). Further oxidation led to a decrease in the absorption
in the 300–400 nm region and in the absorption at kmax = 505 nm,
whereas the absorption at kmax = 450 nm underwent only minimal
4
+
changes. The spectrum of 5 was essentially the same as that
3
+
of 5 . These results may suggest that the interaction among
three ruthenium species through the tri(p-ethynylphenyl)amine
+
2+
4+
4+
bridge in 5 is larger than those in 5 –5 . When 5 was reduced
stepwise, the spectra reverted to the original one with slightly
smaller absorbance in each oxidation state. Although a similar
phenomenon was observed in the redox experiment up to the
−
−
−
3
e or 2e oxidation, the 1e redox experiment resulted in a
Fig. 4 Spectroelectrochemical UV-VIS spectra of 10 in CH
temperature under argon atmosphere.
2
Cl
2
at room
completely reversible change of the spectra, accompanied by
isosbestic points at 307 and 411 nm (Fig. 2(b)). These results
suggest that 5 is stable compared to the higher oxidized species.
+
+
−
6
The treatment of 5 with an equimolar amount of [Cp
2
Fe ][PF
]
+
−
In the spectroelectrochemical UV-VIS spectra of 9, an absorption
at room temperature gave brown complex [5 ][PF
6
] in 73% yield
2
+
26
+
−
at kmax = 456 nm, which is similar to the kmax value found in 5 –
(Scheme 3). Although the NMR spectra of [5 ][PF
6
] could not
4
+
+
5
, was observed for 9 (Fig. 3). Although the spectra returned
be obtained because of its paramagnetic property, the UV-VIS
spectrum coincided with that observed in the electrochemical 1e
−
to the original one upon reduction, the intensity was slightly
decreased. The successive redox cycles led to a gradual decrease in
the intensity. An irreversible change was observed in the spectro-
electrochemical UV-VIS spectra of bis(phenylethynyl)ruthenium
complex (10) (Chart 1 and Fig. 4). These results clearly suggest
that not only the tri(p-ethynylphenyl)amine bridge but also the
trinuclear ruthenium–acetylide skeleton plays an important role
oxidation of 5. Elemental analysis also supported the structure of
+
−
+
−
[5 ][PF
6
]. The IR spectrum of [5 ][PF
6
] showed an absorption
−
1
27
at 1957 cm , which is characteristic of the allenylidene complex,
as well as a C≡C absorption (2020 cm ). As seen in Fig. 5,
25
−1
−
in stabilizing the 1e oxidized species of ruthenium–acetylide
complexes.
Scheme 3
Fig. 3 Spectroelectrochemical UV-VIS spectra of 9 in CH
temperature under argon atmosphere (five cycles of 1e redox reaction).
2
Cl
2
at room
−
+
−
6 2 2
] in CH Cl .
Chart 1
Fig. 5 Near-IR spectrum of [5 ][PF
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Scheme 4
+
−
the near-IR spectrum of [5 ][PF
6
] showed a broad absorption
Tri[p-(trimethylsilylethynyl)phenyl]amine (1)
−
1
4
3
−1
−1
at kmax = 4760 cm with e = 6.05 × 10 dm mol cm ,
which is attributable to the intervalence charge transfer (ICT),
whereas no absorption was detected in the near-IR region for
To a solution of tri(p-bromophenyl)amine (1.0 g, 2.07 mmol),
PdCl
2
(PPh
3
)
2
(84 mg, 120 lmol) and PPh (16 mg, 61 lmol) in
3
triethylamine (40 mL) was added trimethylsilylacetylene (1.3 mL,
9.32 mmol) and CuI (11 mg, 58 lmol), and the reaction mixture
was refluxed overnight. After removal of the solvent, the residue
was dissolved in benzene and passed through a short silica gel
column. The solvent was evaporated, and the residue was purified
by silica gel column chromatography. The eluent was gradually
changed from hexane to a mixture of hexane–benzene (1 : 5 v/v).
5
. The energy levels of the ICT bands were significantly lower
3
than those observed in the dinuclear ruthenium–acetylide system.
Although the exact value of the half-width (Dm1/2) could not be
determined due to the wavelength range limit of the spectrometer,
the approximate value was estimated to be 3000 cm from the
shape of the spectrum in the high-energy region, which was
−
1
1
/2
−1
close to the calculated value Dm1/2 = (2310mmax
)
= 3316 cm
28
Recrystallization from hexane gave pale yellow crystals (0.86 g,
for class II mixed-valence compounds. Based on the data
1
+
80%). H NMR (CDCl
3
): d 7.34 (d, J = 8.5 Hz, 6H, Ar), 6.95 (d,
): d
46.8 (Ar), 133.2 (Ar), 123.8 (Ar), 117.8 (Ar), 104.8 (C≡), 93.9
C≡). IR [KBr, mmax/cm ]: 2155 (C≡C). FAB MS: m/z 533 (M ).
Anal. Calc. for C33 : C, 74.23; H, 7.36; N, 2.62. Found: C,
4.33; H, 7.38; N, 2.62%.
described above, 5 may have a structure that consists of one
1
3
J = 8.8 Hz, 6H, Ar), 0.23 (s, 27H, TMS). C NMR (CDCl
3
ruthenium–allenylidene unit stabilized by the central nitrogen
atom and electronic delocalization through the ICT (Scheme 4).
Although the preliminary measurement of the ESR spectrum of
1
(
−
1
+
+
−
H
39NSi
3
[5 ][PF
6
] was unsuccessful, we will continue further investigation
7
to elucidate electron coupling in this system by ESR measurements
under various conditions as well as MO calculations.
In summary, we have synthesized novel trinuclear ruthenium–
acetylide complexes having unique redox properties and shown the
electronic coupling between ruthenium species through the tri(p-
ethynylphenyl)amine bridge. As this skeleton has the potential to
expand into larger molecules,
of multi-redox organometallic dendrimers based on this triruthe-
nium unit are in progress.
Tri[p-(ethynyl)phenyl]amine (2)
To a methanol solution (500 mL) of tri[p-(trimethylsilylethynyl)-
phenyl]amine 1 (5.0 g, 9.36 mmol) was added K
2
CO
3
(3.88 g,
2
8.1 mmol), and the reaction mixture was stirred at room
15–17
investigations on the synthesis
temperature for 48 h. The solvent was evaporated, and the residue
was extracted with diethyl ether. The organic layer was dried over
MgSO , and the solvent was removed again. The residue was
4
purified by silica gel column chromatography using a mixture of
hexane–ethyl acetate (9 : 1, v/v) as the eluent to give a pale yellow
Experimental
1
solid (2.89 g, 97%). H NMR (CDCl
3
): d 7.38 (d, J = 8.5 Hz, 6H,
1
13
31
H, C and P NMR spectra were recorded on JEOL JNM-
LA400 and Bruker ARX-400 spectrometers using SiMe as the
as the external
13
Ar), 7.01 (d, J = 8.8 Hz, 6H, Ar), 3.06 (s, 3H, ≡CH). C NMR
4
(
(
CDCl
): d 144.4 (NC), 138.8 (Ar), 124.4 (Ar), 117.3 (CC≡), 83.8
3
1
13
internal standard for H and C nuclei and H
3
PO
4
−1
C≡CH), 77.5 (≡CH). IR [KBr, mmax/cm ]: 3268 (≡C–H). FAB
3
1
standard for the P nucleus. IR and FAB mass spectra were
taken on Perkin-Elmer system 2000 FT-IR and JEOL JMS-
+
MS: m/z 317 (M ). Anal. Calc. for C24
H
15N: C, 90.82; H, 4.76; N,
4
.41. Found: C, 90.95; H, 4.97; N, 4.37%.
6
00H instruments, respectively. UV-VIS and Near-IR spectra were
measured on JASCO V-560 and V-570 spectrometers, respec-
tively. Cyclic voltammograms were recorded on an ALS 630A
apparatus.
N[C
6
H
4
C≡CRu(dppe)
2
Cl]
3
(4)
cis-RuCl
2
(dppe) 3 (2.02 g, 2.08 mmol) and tri[p-(ethynyl)phenyl]-
2
All reactions were carried out under an atmosphere of argon,
and the workup was performed in air. THF was distilled over
sodium benzophenone ketyl under argon, and dichloromethane,
amine 2 (0.20 g, 0.63 mmol) were dissolved in dichloromethane
(80 mL), and KPF (1.16 g, 6.3 mmol) was added. The reaction
6
mixture was stirred at room temperature for 17 h, and triethy-
lamine (4 mL) was added. After stirring for 30 min, the reaction
mixture was filtered off and the filtrate was concentrated under
reduced pressure. The residue was purified by alumina column
chromatography with benzene followed by recrystallization from
toluene and triethylamine were distilled over CaH
2
under ar-
gon. Other chemicals available commercially were used without
2
9
further purification. cis-RuCl
2
(dppe)
2
,
4-bromo(triisopropyl-
16
30
silylethynyl)benzene and trans-Ru(C≡CPh)
2
(dppe)
2
10 were
1
prepared by the literature methods.
THF to give a pale yellow solid (1.46 g, 74%). H NMR
3
696 | Dalton Trans., 2006, 3693–3698
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1
3
(
(
1
C
C
6
D
D
6
6
): d 7.67–6.92 (m, 132H, Ar), 2.58 (br, 24H, CH
): d 147.4–127.3 (Ar), 122.5 (qnt, JP–C = 16 Hz, RuC≡),
). P NMR (C ):
2
). C NMR
(4-ethynylphenyl)diphenylamine 7 (0.20 g, 0.74 mmol), and was
1
6
isolated as a yellow solid (0.75 g, 84%). H NMR (C
6
D
6
): d 7.63–
): d 64.5. IR
Ru: C,
3
1
31
13.4 (s, RuC≡C), 31.1 (qnt, J = 12 Hz, PCH
2
6
D
6
6.85 (m, 54H, Ar), 2.59 (br, 8H, CH
[KBr, mmax/cm ]: 2063 (C≡C). Anal. Calc. for C72
2
). P NMR (C
6
D
62ClNP
6
−
1
−1
d 64.3. IR [KBr, mmax/cm ]: 2065 (C≡C). FAB MS: m/z 3114
H
4
+
(
M − 3). Anal. Calc. for C180
H
156Cl
3
NP12Ru
3
: C, 69.42; H, 5.05;
71.96; H, 5.20; N, 1.17. Found: C, 71.77; H, 5.64; N, 0.99%.
N, 0.45. Found: C, 69.37; H, 5.30; N, 0.78%.
N[C (CCPh)] (5)
C≡CRu(dppe)
A THF solution (30 mL) of complex 4 (0.30 g, 96 lmol), phen-
ylacetylene (90 mg, 0.86 mmol), triethylamine (1.8 mL) and KPF
0.12 g, 0.58 mmol) was stirred under reflux for 24 h. The reaction
mixture was filtered off, and the filtrate was concentrated under
reduced pressure. The residue was dissolved in benzene and passed
through a short alumina column. Recrystallization from hexane–
Ph N[C (C≡CPh)] (9)
2
6
H
4
C≡CRu(dppe)
2
6
H
4
2
3
The title complex was prepared by a similar manner to that for
complex 5 using complex 7 (0.50 g, 0.42 mmol) and phenylacety-
lene (85 mg, 0.83 mmol), and was isolated as a pale yellow solid
6
(
1
(
(
0.45 g, 85%). H NMR (C
6
D
D
6
): d 7.71–6.83 (m, 59H, Ar), 2.54
): d 149.2–123.0 (Ar), 127.0 (C≡),
13
br, 8H, CH ). C NMR (C
2
6
6
1
24.0 (C≡), 117.7 (C≡), 117.3 (C≡), 32.3 (t, J = 11 Hz, PCH
2
).
31
−1
P NMR (C
6
D
6
): d 68.6. IR [KBr, mmax/cm ]: 2061 (C≡C). FAB
1
THF gave a pale yellow solid (0.30 g, 94%). H NMR (C
6
D
6
): d
): d
47.5–126.4 (Ar), 128.5 (s, C≡), 126.4 (s, C≡), 120.3 (s, C≡), 119.8
CH P). P NMR (C ): d
8.5. IR [KBr, mmax/cm ]: 2059 (C≡C). FAB MS: m/z 3312 (M ).
: C, 73.99; H, 5.20; N, 0.42. Found:
+
MS: m/z 1267 (M ). Calc. for C80
H
67NP Ru: C, 75.82; H, 5.33; N,
4
1
3
7
1
(
.71–6.90 (m, 147H, Ar), 2.54 (br, 24H, CH
2
). C NMR (C
6
D
6
1
.11%. Found: C, 75.41; H, 5.67; N, 1.02%.
3
1
s, C≡), 34.7 (qnt, J = 12 Hz, PCH
2
2
6
D
6
Chemical oxidation of 5
−
1
+
6
To a dichloromethane solution of 5 (50 mg, 16 lmol) was
added ferrocenium hexafluorophosphate (5 mg, 16 lmol), and
the reaction mixture was stirred at room temperature for 8 h.
After concentration under reduced pressure, diethyl ether was
added. The resulting precipitate was collected and dried under
Anal. Calc. for C204
C, 73.94; H, 5.39; N, 0.42%.
H
171NP12Ru
3
[4-(Triisopropylsilylethynyl)phenyl]diphenylamine (6)
A toluene solution (20 mL) containing diphenylamine (0.30 g,
.8 mmol), 4-bromo(triisopropylsilylethynyl)benzene (0.54 g,
(23 mg, 22 lmol), di(tert-butyl)(2-
biphenyl)phosphine (26 mg, 89 lmol), NaOBu (0.28 g, 2.88 mmol)
reduced pressure to give a brown solid (38 mg, 73%). Anal. IR
1
1
−1
[
C
KBr, mmax/cm ]: 2020 (C≡C), 1957 (M=C=C=C). Calc. for
.6 mmol), Pd
2
dba
3
·CHCl
3
180
H
156Cl
3
F
6
NP13Ru
C, 64.80; H, 4.92; N, 0.58%.
3
·CH
2
Cl : C, 65.00; H, 4.76; N, 0.42. Found:
2
t
◦
was stirred at 100 C for 7 h. After diethyl ether was added, the
reaction mixture was filtered with Celite and was concentrated
under reduced pressure. Purification by silica gel column chro-
Acknowledgements
matography with hexane gave a yellow viscous oil (0.43 g, 63%).
This work was partially supported in part by a Grant-in-Aid
for Scientific Research from the Ministry of Education, Culture,
Sports, Science and Technology, and by the Izumi Science and
Technology Foundation. We thank the members of the Material
Analysis Center, ISIR, Osaka University, for spectral measure-
ments.
1
H NMR (acetone-d
Pr ). C NMR (CDCl
1
6
): d 7.37–6.92 (m, 14H, Ar), 1.13 (s, 21H,
): d 147.9 (Ar), 147.2 (Ar), 132.7 (Ar),
29.3 (Ar), 124.8 (Ar), 123.4 (Ar), 122.2 (Ar), 116.6 (Ar), 107.3
i
13
3
−
1
(
C≡), 89.3 (C≡). IR [KBr, mmax/cm ]: 2152 (C≡C). FAB MS: m/z
+
4
3
26 (M + 1). Anal. Calc. for C29
H35NSi: C, 81.82; H, 8.29; N,
.29. Found: C, 81.92; H, 8.53; N, 3.17%.
(
4-Ethynylphenyl)diphenylamine (7)
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◦
diphenylamine 6 (0.95 g, 2.2 mmol) was cooled at −78 C, and 1 M
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4
N (2.2 mL, 2.2 mmol) was added dropwise.
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8
1
(
3%). H NMR (acetone-d
6
): d 7.36–6.92 (m, 14H, Ar), 3.54 (s,
): d 148.8 (Ar), 147.1 (Ar), 133.5
1
3
H, ≡CH). C NMR (CDCl
3
Ar), 129.8 (Ar), 125.5 (Ar), 124.1 (Ar), 122.5 (Ar), 115.1 (Ar),
4 T. Weyland, C. Lapinte, G. Frapper, M. J. Calhorda, J.-F. Halet and L.
Toupet, Organometallics, 1997, 16, 2024; T. Weyland, K. Costuas, A.
Mari, J.-F. Halet and C. Lapinte, Organometallics, 1998, 17, 5569.
−
1
8
4.3 (C≡), 76.6 (C≡). IR [KBr, mmax/cm ]: 3266, (≡C–H). FAB
+
MS: m/z 269 (M ). Anal. Calc. for C20
H
15N: C, 89.19; H, 5.61; N,
5
T. Weyland, K. Costuas, L. Toupet, J.-F. Halet and C. Lapinte,
Organometallics, 2000, 19, 4228.
M. Uno and P. H. Dixneuf, Angew. Chem., Int. Ed., 1998, 37, 1714.
N. J. Long, A. J. Martin, F. F. de Biani and P. Zanello, J. Chem. Soc.,
Dalton Trans., 1998, 2017.
Q. Y. Hu, W. X. Lu, H. D. Tang, H. H. Y. Sung, T. B. Wen, I. D.
Williams, G. K. L. Wong, Z. Lin and G. Jia, Organometallics, 2005, 24,
3966.
5
.20. Found: C, 89.02; H, 5.82; N, 5.34%.
Ph N[C Cl] (8)
C≡CRu(dppe)
The title complex was prepared by a similar manner to that for
6
7
2
6
H
4
2
8
complex 4 using cis-RuCl (dppe) 3 (0.72 g, 0.74 mmol) and
2
2
This journal is © The Royal Society of Chemistry 2006
Dalton Trans., 2006, 3693–3698 | 3697

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698 | Dalton Trans., 2006, 3693–3698
This journal is © The Royal Society of Chemistry 2006