Reaction of alkynes with [RuCp(CO)(CH3CN)2]+ and [RuCp*(CO)(CH3CN)2]+. Convenient synthesis of ruthenium cyclopentadienone complexes

Article abstract of DOI:10.1021/om000663p

The mono-carbonyl complexes [RuCp(CO)(CH₃CN)₂]PF₆ (D and [RuCp*(CO)(CH₃CN)₂]PF₆ (2) react with terminal and internal alkynes to afford the cationic complexes [RuCp(η⁴-cyclopentad

Full text of DOI:10.1021/om000663p

5384
Organometallics 2000, 19, 5384-5391
Rea ction of Alk yn es w ith [Ru Cp (CO)(CH3CN)2]+ a n d
[Ru Cp *(CO)(CH3CN)2]+. Con ven ien t Syn th esis of
Ru th en iu m Cyclop en ta d ien on e Com p lexes
Eva Ru¨ba,† Kurt Mereiter,‡ Kamran M. Soldouzi,† Christian Gemel,†
Roland Schmid,† and Karl Kirchner*,†,#
Institute of Inorganic Chemistry and Institute of Mineralogy, Crystallography, and Structural
Chemistry, Technical University of Vienna, Getreidemarkt 9, A-1060 Vienna, Austria
Emilio Bustelo, M. Carmen Puerta,* and Pedro Valerga
Departamento de Ciencias de los Materiales e Ingenier´ıa Metalu´rgica y Quı´mica Inorga´nica,
Facultad de Ciencias, Universidad de Ca´diz, Apartado 40, Puerto Real 11510, Spain
Received August 1, 2000
The mono-carbonyl complexes [RuCp(CO)(CH3CN)2]PF6 (1) and [RuCp*(CO)(CH3CN)2]PF6
(2) react with terminal and internal alkynes to afford the cationic complexes [RuCp(η4-
cyclopentadienone)(CH3CN)]PF6 (3) and [RuCp*(η4-cyclopentadienone)(CH3CN)]PF6 (4),
respectively, in high yields. These reactions are highly selective, yielding in the case of
terminal alkynes only one regioisomer with the substituents exclusively in the R,R′ positions
of the cyclopentadienone moiety. In contrast, the reaction of 1 with PhCtCPh yields no
cyclopentadienone complex but instead the sandwich complex [RuCp(η6-C6H5PhCtCPh)]+
and the bis-carbonyl complex [RuCp(CO)2(CH3CN)]+ in a 1:1 ratio. X-ray structures of
representative complexes are reported.
In tr od u ction
proceed via metallacyclopentadiene intermediates ac-
cording to Scheme 1 for Co and Rh carbonyl complexes.
Cyclopentadienones are highly unstable molecules
subject to rapid dimerization1 unless hindered by the
presence of bulky substituents or upon coordination to
transition metals. The accessibility of such complexes
is therefore limited since they have to be arrived at in
situ through reactions on suitable precursor complexes.
For instance, some transition metal carbonyl complexes
have been shown to react with acetylenes giving cyclo-
pentadienone complexes where the metal is in a low
oxidation state (0, +I). The first reported cyclopentadi-
enone complex, Fe(η4-C5H4O)(CO)3, has been obtained
by treating Fe(CO)5 with excess HCtCH at high pres-
sure.2 Other examples are complexes of the types M(η4-
cyclopentadienone)(CO)3 (M ) Fe, Ru),3 MCp(η4-cyclo-
pentadienone) (M ) Co, Rh),4 and VCp(η4-cyclo-
pentadienone)(CO)(PMe3).5 All these reactions typically
An alternative approach to cyclopentadienone com-
plexes utilizes oxidative addition of 4-bromo-2-cyclo-
penten-1-ones to low-valent transition metal complexes.
The η3-cyclopentenoyl intermediate reacts either via
hydride abstraction or deprotonation to give a cyclopen-
tadienone complex. Whereas Mo(II) and W(II) cyclopen-
tadienone complexes have been prepared recently via
the hydride abstraction route,6 the deprotonation se-
quence has been developed by us for the synthesis of
Ru(II) cyclopentadienone complexes.
This method is particularly successful for obtaining
the parent cyclopentadienone ligand or ones substituted
at the 2 and/or 3 position, as illustrated in Scheme 2.7,8
It should be mentioned that Ru(II) complexes containing
the parent cyclopentadienone ligand can also be pre-
pared by the reaction of the Ru(IV) complex [RuCp2X]+
(X ) Cl, Br) with water or Ag2O albeit in rather low
yield (<30%).9
† Institute of Inorganic Chemistry.
‡ Institute of Mineralogy, Crystallography, and Structural Chem-
istry.
#
We describe here a new and convenient synthesis of
both Ru(II) Cp and Cp* complexes containing the parent
E-mail: kkirch@mail.zserv.tuwien.ac.at.
(1) (a) Chapman, O. L.; McIntosh, C. L. Chem. Commun. 1971, 770.
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11, 4096.
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(6) (a) Liebeskind, L. S.; Bombrun A. J . Am. Chem. Soc. 1991, 113,
8736. (b) Mauthner, K.; Slugovc, C.; Mereiter, K.; Schmid, R.; Kirchner,
K. Organometallics 1996, 15, 181.
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metallics 1994, 13, 5054.
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10.1021/om000663p CCC: $19.00 © 2000 American Chemical Society
Publication on Web 11/14/2000

Reaction of Alkynes with [RuCp(CO)(CH3CN)2]+
Organometallics, Vol. 19, No. 25, 2000 5385
Sch em e 1
Sch em e 2
Sch em e 3
as well as 2,5-di- and 2,3,4,5-tetrasubstituted cyclopen-
tadienone ligands by the reaction of [RuCp(CO)(CH3-
CN)2]+ and [RuCp*(CO)(CH3CN)2]+ with various alkynes.
X-ray structures of representative complexes are also
included.
Resu lts a n d Discu ssion
[RuCp(CO)(CH3CN)2]+ (1) is prepared according to
Mann et al.10 by stirring a solution of [RuCp(CH3CN)3]+
in CH3CN for a few minutes under an atmosphere of
CO. The analogous complex [RuCp*(CO)(CH3CN)2]+ (2),
thus far not reported, is prepared in similar fashion by
starting from the corresponding tris-acetonitrile complex
[RuCp*(CH3CN)3]+.11 The transformation is essentially
quantitative as monitored by 1H NMR spectroscopy.
This product is stable to air in the solid state but
decomposes slowly in solution on exposure to air.
Sch em e 4
1
Characterization was accomplished by H and 13C{1H}
NMR and IR spectroscopy as well as elemental analysis.
1
The H NMR spectrum of 2 bears no unusual features.
Thus, the Cp* ligand exhibits a singlet at 1.72 ppm, and
the proton resonance of the CH3CN ligands gives a
singlet at 2.39 ppm. In the 13C{1H} NMR spectrum the
Cp* ring gives rise to singlets at 93.7 and 9.6 ppm, while
the CO ligand exhibits a singlet at 200.3 ppm. In the
IR spectrum the characteristic CO stretching frequency
is observed at 1974 cm-1 (cf. 2004 cm-1 in 110).
Treatment of 1 with the alkynes HCtCR (R ) Ph,
n-Bu, C6H9, H) and 2,7-nonadiyne in acetone at 60 °C
for 24 h affords, on workup, the cationic cyclopentadi-
enone complexes 3a -e in high yields (Schemes 3 and
4). In a fashion similar to 1, complex 2 reacts with
HCtCR (R ) Ph, n-Bu, C6H9) to give the corresponding
cyclopentadienone complexes 4a -c in high yields
(Scheme 3).
the bis-carbonyl complex [RuCp(CO)2(CH3CN)]+ (6)14
was obtained in a 1:1 ratio (Scheme 5). At room
temperature no reaction took place. In contrast, Green
et al. have reported15 that the dimeric complex [RuCp-
(13) The molecular structure of [CpRu(η6-C6H5-CtCPh)PF6] (5) was
determined also by an X-ray structure analysis, which showed the
compound to crystallize in space group P1h with a ) 10.17 Å, b ) 10.85
Å, c ) 17.49 Å, R ) 86.97°, â ) 80.21°, γ ) 89.75°. Due to twinning
and large thermal vibration effects, the crystallographic results were
of poor quality (R1 ) 0.114 for 3810 reflections) and thus are not
reported here but have been deposited with the Cambridge Crystal-
lographic Data Centre, CCDC-148111. In the solid state the compound
contains two independent Ru sandwich complexes, the PhCtCPh
moieties of which are not planar but twisted about the CtC bond axes,
by 22° for complex 1 and by 69° for complex 2.
Attempts to prepare the tetracyclone complex [RuCp-
(η4-C5Ph4O)(CH3CN)]+ by treatment of 1 with PhCt
CPh in boiling acetone failed. Instead, the sandwich
complex [RuCp(η6-C6H5-CtCPh)]+ (5)12,13 together with
(10) Gill, T. P.; Mann, K. R. Organometallics 1982, 1, 485.
(11) Steinmetz, B.; Schenk, W. A. Organometallics 1999, 18, 943.
(12) Chaudret, B.; He, X.; Huang, Y. J . Chem. Soc., Chem. Commun.
1989, 1844.
(14) J ungbauer, A.; Behrens, H. Z. Naturforschung. 1978, 33B 1083.

5386 Organometallics, Vol. 19, No. 25, 2000
Ru¨ba et al.
Sch em e 5
(CO)2]2 reacts with PhCtCPh in the presence of Ag+ at
room temperature to give, among bis- and tris-carbonyl
RuCp complexes, the η4-cyclobutadiene complex [RuCp-
(η4-C4Ph4)(CO)]+ rather than 5 or a tetracyclone com-
plex.16
and CR carbon atoms exhibit singlet resonances between
95.8-90.2 and 84.6-80.1 ppm, respectively. The Cp
ligand shows a singlet in the range 88.5-86.4 ppm. The
overall NMR spectra of complexes 4 are very similar to
those of 3 and are not discussed here. In the IR spectra
of complexes 3 and 4 the carbonyl stretching frequency
is observed between 1691 and 1661 cm-1, consistent
with other cyclopentadienone complexes.
All complexes reported are air-stable in the solid state
and have been characterized by a combination of
elemental analysis, 1H and 13C{1H} NMR, and IR
spectroscopy. In addition, the structures of 3b, 3c, 3e,
4a , 5, and 6 have been determined by X-ray crystal-
lography.
A reasonable mechanism that accounts for the forma-
tion of cyclopentadienone complexes is shown in Scheme
6. In the first step a bis-acetylene complex (A) is formed
by the replacement of two CH3CN ligands (the CH3CN
exchange rate constant of 1 is 6.0 × 10-4 s-1 at 40 °C,
cf. 29.1 × 10-2 and 3.0 × 10-2 s-1, respectively, in
[RuCp(CH3CN)3]+ 17 and [RuCp(PMe3)(CH3CN)2]+ 18 at
40 °C). Oxidative coupling affords the unsaturated
metallacyclopentadiene (B), which may be described
also as an 18e metallacyclopentatriene complex (B′), a
resonance form of B. Geometry optimizations and
vibrational analyses on A and B (B′) suggest the
optimized structures and their relative energies as
shown in Figure 1. Accordingly, the oxidative coupling
process is strongly exothermic (-36.6 kcal/mol).19 More-
over, the calculations suggest that the metallacycle
exhibits two rather short Ru-C bonds (1.978 and 1.938
Å) and alternating C-C bonds (1.442, 1.394, and 1.451
Å) and may thus be described as metallacyclopen-
tatriene B′ (cf. the related complex RuCp(σ,σ′-C4Ph2H2)-
1
Both H and 13C{1H} NMR spectra of 3 and 4 clearly
show that only one regioisomer has been formed with
the substituents exclusively in the R,R′ positions of the
1
cyclopentadienone moiety. Accordingly, in the H NMR
spectra of 3a -c the Cp ring and the CH3CN ligand give
rise to a singlet at about 5.70 and 2.65 ppm, respec-
tively. The â,â′-hydrogen atoms of cyclopentadienone
exhibit a characteristic low-field resonance in the range
7.20-6.28 ppm (2H). Complex 3d , on the other hand,
exhibits the typical AA′XX′ splitting pattern of two
apparent multiplets centered at 6.25 and 4.66 ppm
assignable to the HR and Hâ protons, respectively, in
1
agreement with the literature.7 The H NMR spectrum
of 3e is inconspicuous, with the singlet resonances for
Cp, the two Me substituents in the R,R′ position, and
CH3CN in the expected ranges. In the 13C{1H} NMR
spectra the ketonic carbonyl carbon atom displays a
characteristic singlet at about 180 ppm, while the Câ
(17) Luginbu¨hl, W.; Zbinden, P.; Pittet, P. A.; Armbruster, T.; Bu¨rgi,
H.-B.; Merbach, A. E.; Ludi, A. Inorg. Chem. 1991, 30, 2350.
(18) Ru¨ba, E.; Mauthner, K.; Simanko, W.; Soldouzi, K. M.; Slugovc,
C.; Mereiter, K.; Schmid, R.; Kirchner, K. Organometallics 1999, 18,
3843.
(19) Wakatsuki, Y.; Nomura, O.; Kitaura, K.; Morokuma, K.;
Yamazaki, H. J . Am. Chem. Soc. 1983, 105, 1907.
(15) Crocker, M.; Froom, S. F. T.; Green, M.; Nagle, K. R.; Orpen,
A. G.; Thomas, D. M. J . Chem. Soc., Dalton Trans. 1987, 2803.
(16) For tetracyclone complexes see: Gupta, H. K.; Rampersad, N.;
Stradiotto, M.; McGlinchey, M. J . Organometallics 2000, 19, 184, and
references therein.

Reaction of Alkynes with [RuCp(CO)(CH3CN)2]+
Organometallics, Vol. 19, No. 25, 2000 5387
Sch em e 6
Br adopts a similar bis-carbene structure as established
by X-ray crystallography20). With CH3CN, the interme-
diates B (B′) may form rapidly the metallacyclopenta-
diene complex C. Finally, insertion of CO into the Ru-C
bond yields, via intermediate D and a subsequent
reductive elimination step, the respective cyclopenta-
dienone complex. It is worth noting that we have not
observed the formation of an η4-cyclobutadiene complex
E (included in Scheme 6). In fact, DFT calculations show
that the formation of such a species should be thermo-
dynamically favorable but apparently does not occur for
kinetic reasons. In fact, it has been found that [2+2]
F igu r e 1. Optimized geometries and relative energies for [RuCp(CO)(η2-HCtCH)2]+ (A), [RuCp(CO)(σ,σ′-C4H4)]+ (B′),
and [RuCp(CO)(η4-C4H4)]+ (E) calculated at the B3LYP (Ru sdd; C, H, O d95v) level of theory.

5388 Organometallics, Vol. 19, No. 25, 2000
Ru¨ba et al.
F igu r e 4. Structural view of [RuCp(η4-OC5Me2C3H6)(CH3-
CN)]PF6 (3e) showing 20% thermal ellipsoids (PF6- omitted
for clarity).
Figu r e 2. Structural view of [RuCp(η4-C5H2O-2,5-Ph2)(CH3-
CN)]PF6 (3a ) showing 20% thermal ellipsoids (PF6- omitted
for clarity).
F igu r e 5. Structural view of [RuCp*(η4-C5H2O-2,5-
Ph2)(CH3CN)]PF6‚CH2Cl2 (4a ‚CH2Cl2) showing 20% ther-
F igu r e 3. Structural view of [RuCp(η4-C5H2O-2,5-n-
Bu2)(CH3CN)]PF6 (3b) showing 20% thermal ellipsoids
(PF6 omitted for clarity).
-
mal ellipsoids (PF6 and CH2Cl2 omitted for clarity).
-
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) a n d Rin g Dih ed r a l An gles (d eg) for
Com p lexes 3a , 3b, 3d , 3e, a n d 4a ‚CH2Cl2
cycloadditions of coordinated acetylenes are symmetry
forbidden, implying a large energy barrier.21
Structural views of complexes 3a , 3b, 3e, and 4a ‚CH2-
Cl2 are depicted in Figures 2-5. In all of them cyclo-
pentadienone is exo oriented with respect to the CH3CN
ligand. A main feature comprises the envelope confor-
mation of the cyclopentadienone ring, which can be
subdivided into two planes, one defined by C2, C3, C4,
and C5 (butadiene fragment) and the other by C1, C2,
C5, and O. The angles between these planes are 18.5°,
20.4°, 21.9°, and 19.8° for 3a , 3b, 3e, and 4a ‚CH2Cl2,
respectively. The diene C-C bonds in all complexes
adopt a short-long-short pattern, as is the case for
most cyclopentadienone complexes reported thus far.
The bond distances between Ru and the butadiene
fragment for C3 and C4 are shorter than that for C2 and
C5 by about 0.1 Å (see Table 1), a feature that is also
characteristic of η4-cyclopentadienone complexes in
general. Selected bond distances and angles are given
in Table 1.
3a
3b
3d a
3e
4a ‚CH2Cl2
Ru-Cp(av) 2.201(2) 2.178(6) 2.19(1)
2.209(3)
2.254(2)
2.190(2)
2.217(3)
2.274(3)
2.167(2)
2.153(2)
2.255(3)
1.406(4)
1.435(4)
1.410(4)
2.063(2)
174.5(3)
1.211(3)
19.8(2)
Ru-C2
Ru-C3
Ru-C4
Ru-C5
C2-C3
C3-C4
C4-C5
Ru-N
2.289(2) 2.252(6) 2.25(1)
2.168(2) 2.146(6) 2.15(1)
2.162(2) 2.148(6) 2.167(8) 2.195(2)
2.255(2) 2.278(7) 2.276(7) 2.268(4)
1.410(3) 1.403(9) 1.40(1)
1.432(3) 1.44(1)
1.409(3) 1.41(1)
2.070(2) 2.059(5) 2.057(5) 2.076(2)
175.1(1) 176.0(5) 175.5(6) 170.0(2)
1.207(2) 1.209(8) 1.221(7) 1.217(3)
1.392(4)
1.448(4)
1.43(1)
1.379(9) 1.414(4)
Ru-N-C
CdO
dihedral
18.5(1)
20.4(5)
18.0(5)
21.9(2)
angleb
a
b
Ref 7b. Angle formed between the planes defined by C2, C3,
C4, C5, and C1, C2, C5, O.
(20) Albers, M. O.; deWaal, P. J . A.; Liles, D. C.; Robinson, D. J .;
Singleton, E.; Wiege, M. B. J . Chem. Soc., Chem. Commun. 1986, 1680.
(21) Hardesty, J . H.; Koerner, J . B.; Albright, T. A.; Lee, G.-Y. J .
Am. Chem. Soc. 1999, 121, 6055.
The solid-state structure of 6 has also been deter-
mined by single-crystal X-ray diffraction. An ORTEP
diagram is depicted in Figure 6, with important bond

Reaction of Alkynes with [RuCp(CO)(CH3CN)2]+
Organometallics, Vol. 19, No. 25, 2000 5389
for 24 h at 60 °C. The color of the solution changed from yellow
to orange. Slow addition of diethyl ether (15 mL) led to the
precipitation of an orange microcrystalline solid, which was
collected on a glass frit, washed twice with diethyl ether, and
dried under vacuum. Yield: 208 mg (92%). Anal. Calcd for
C24H20F6NOPRu: C, 49.32; H, 3.45. Found: C, 49.40; H, 3.38.
1H NMR (δ, acetone-d6, 20 °C): 7.96 (m, 4H, Ph), 7.35 (m, 6H,
Ph), 7.20 (s, 2Hâ), 5.70 (s, 5H, Cp), 2.78 (s, 3H, CH3). 13C{1H}
NMR (δ, CD3NO2, 20 °C): 180.7 (1C, CO), 132.9 (1C, CN),
130.3 (2C, Ph), 130.1 (4C, Ph), 129.9 (4C, Ph), 128.2 (2C, Ph),
90.2 (2C, Câ), 88.5 (5C, Cp), 82.7 (2C, CR), 5.2 (1C, NCCH3).
IR (KBr, cm-1): 2321, 2291 (m, νCN), 1673 (s, νCO).
[Ru Cp (η4-C5H2O-2,5-n -Bu 2)(CH3CN)]P F 6 (3b). This com-
plex has been prepared analogously to 3a with 1 (125 mg,
0.297 mmol) and HCtCBun (53 µL, 0.594 mmol) as the
starting materials. Yield: 145 mg (90%). Anal. Calcd for
C20H28F6NOPRu: C, 44.12; H, 5.18. Found: C, 44.28; H, 5.22.
1H NMR (δ, acetone-d6, 20 °C): 6.28 (s, 2Hâ), 5.72 (s, 5H, Cp),
2.69 (s, 3H, CH3CN), 1.97 (m, 4H, CH2CH2CH2CH3), 1.36 (m,
8H, CH2CH2CH2CH3), 0.88 (m, 6H, CH2CH2CH2CH3). 13C{1H}
NMR (δ, CDCl3, 20 °C): 182.9 (1C, CO), 133.0 (1C, CN), 95.8
(2C, Câ), 87.6 (5C, Cp), 84.6 (2C, CR), 33.2 (2C, CH2), 25.8 (2C,
CH2), 23.9 (2C, CH2), 14.8 (2C, CH3), 5.2 (1C, NCCH3). IR (KBr,
cm-1): 2332, 2297 (m, νCN), 1690 (s, νCO).
F igu r e 6. Structural view of [RuCp(CO)2(CH3CN)]PF6 (6)-
showing 20% thermal ellipsoids (PF6- omitted for clarity).
Selected bond lengths (Å) and angles (deg): Ru-C(1-5)av
2.200(4), Ru-C(6) 1.899(4), Ru-C(7) 1.894(4), Ru-N 2.056-
(3), O(1)-C(6) 1.130(4), O(2)-C(7) 1.120(4), C(6)-Ru-C(7)
91.6(1), C(6)-Ru-N 89.3(1), C(7)-Ru-N 93.9(1), Ru-N-
C(8) 175.0(3), Ru-C(6)-O(1) 177.7(3), Ru-C(7)-O(2) 174.0-
(4).
[Ru Cp(η4-C5H2O-2,5-(C6H9)2)(CH3CN)]P F6 (3c). This com-
plex has been prepared analogously to 3a with 1 (150 mg,
0.356 mmol) and 1-ethynyl cyclohexene (88 µL, 0.748 mmol)
as the starting materials. Yield: 190 mg (90%). Anal. Calcd
for C24H28F6NOPRu: C, 48.65; H, 4.76. Found: C, 48.69; H,
4.72. 1H NMR (δ, CD3NO2, 20 °C): 6.97 (m, 2H, C6H9), 6.14
(s, 2Hâ), 5.54 (s, 5H, Cp), 2.65 (s, 3H, CH3CN), 2.07 (m, 8H,
C6H9), 1.58 (m, 8H, C6H9). 13C{1H} NMR (δ, CD3NO2, 20 °C):
181.6 (1C, CO), 132.9 (1C, CN), 130.8 (2C, C6H9), 129.7 (2C,
C6H9), 92.9 (2C, Câ), 86.4 (5C, Cp), 80.1 (2C, CR), 26.8 (2C,
C6H9), 26.7 (2C, C6H9), 23.2 (2C, C6H9), 22.5 (2C, C6H9), 4.9
(1C, NCCH3). IR (KBr, cm-1): 2330, 2301 (m, νCN), 1691 (s,
distances and angles reported in the caption. The
complex adopts a typical three-legged piano stool con-
formation with the CO and CH3CN ligands as the legs.
There are no structural features pointing to unusual
deviations or distortions.
In summary, we have shown that the readily avail-
able mono-carbonyl complexes 1 and 2 are valuable
precursors for the synthesis of a variety of Ru(II) cyclo-
pentadienone complexes of types [RuCp(η4-cyclopenta-
dienone)(CH3CN)]+ and [RuCp*(η4-cyclopentadienone)-
(CH3CN)]+. In the case of terminal alkynes, exclusively
the 2,5-disubstituted cyclopentadienone complexes are
formed.
ν
CO).
[Ru Cp (η4-C5H4O)(CH3CN)]P F 6 (3d ). A solution of 1 (100
mg, 0.237 mmol) in acetone (4 mL) was stirred under an
atmosphere of acetylene for 12 h at room temperature. The
orange solution was evaporated to dryness, and the residue
was washed with diethyl ether and dried under vacuum.
Yield: 87 mg (85%). The NMR spectra were in agreement with
those reported in the literature.7
[Ru Cp (η4-C5Me2OC3H6)(CH3CN)]P F 6 (3e). This complex
has been prepared analogously to 3a with 1 (100 mg, 0.237
mmol) and 2,7-nonadiyne (41 µL, 0.260 mmol) as the starting
materials. Yield: 95 mg (80%). Anal. Calcd for C17H20F6-
NOPRu: C, 40.81; H, 4.03. Found: C, 40.79; H, 4.00. 1H NMR
(δ, CD3NO2, 20 °C): 5.08 (s, 5H, Cp), 3.19-3.04 (m, 2H, CH2),
2.82-2.65 (m, 2H, CH2), 2.51 (s, 3H, CH3CN), 2.41-2.13 (m,
2H, CH2), 1.62 (s, 6H, Me). 13C{1H} NMR (δ, CD3NO2, 20 °C):
184.3 (1C, CO), 133.3 (1C, CN), 88.6 (5C, Cp), 82.1 (2C, Câ),
81.9 (2C, CR), 28.2 (2C, CH2), 24.7 (1C, CH2), 9.7 (2C, Me), 4.6
(1C, NCCH3). IR (KBr, cm-1): 2320, 2291 (m, νCN), 1687 (s,
Exp er im en ta l Section
Gen er a l In for m a tion . All manipulations were performed
under an inert atmosphere of argon by using Schlenk tech-
niques. All chemicals were standard reagent grade and used
without further purification. The solvents were purified ac-
cording to standard procedures.22 The deuterated solvents were
purchased from Aldrich and dried over 4 Å molecular sieves.
[RuCp(CO)(CH3CN)2]PF6 (1) was prepared according to the
literature.10 1H and 13C{1H} NMR spectra were recorded on a
Bruker AC-250 spectrometer operating at 250.13 and 101.26
MHz, respectively, and were referenced to SiMe4. IR spectra
where recorded on a Perkin-Elmer 16PC FTIR spectrometer.
[Ru Cp *(CO)(CH3CN)2]P F 6 (2). A solution of [RuCp*(CH3-
CN)3]PF6 (300 mg; 0.594 mmol) in acetonitrile (5 mL) was
stirred for 1 h at room temperature under an atmosphere of
CO. The color of the solution changed from dark orange to
yellow. The solvent was then removed under reduced pressure,
and the residue was collected on a glass frit, washed with
diethyl ether, and dried under vacuum. Yield: 260 mg (89%).
Anal. Calcd for C15H21F6N2OPRu: C, 36.67; H, 4.31. Found:
C, 36.69; H, 4.33. 1H NMR (δ, CD2Cl2, 20 °C): 2.39 (s, 6H,
CH3CN), 1.72 (s, 15H, Cp*). 13C{1H} NMR (δ, CDCl3, 20 °C):
200.3 (1C, CO), 126.4 (2C, CH3CN), 93.7 (5C, Cp*), 9.6 (5C,
Cp*), 3.6 (2C, CH3CN). IR (KBr, cm-1): 2318, 2265 (m, νCN),
1974 (s, νCO).
ν
CO).
[Ru Cp *(η4-C5H2O-2,5-P h 2)(CH3CN)]P F 6 (4a ). A solution
of 2 (100 mg, 0.204 mmol) and HCtCPh (49 µL, 0.448 mmol)
in acetone (3 mL) was stirred at room temperature for 12 h.
After that time the solvent was removed under reduced
pressure and the residue washed with diethyl ether. The dark
red solid was dried under vacuum. Yield: 106 mg (80%). Anal.
Calcd for C29H30F6NOPRu: C, 53.21; H, 4.62. Found: C, 53.30;
1
H, 4.69. H NMR (δ, CD3NO2, 20 °C): 7.92-7.59 (m, 4H, Ph),
7.52-7.18 (m, 6H, Ph), 6.02 (s, 2H, Hâ), 2.90 (s, 3H, CH3CN),
1.72 (s, 15H, Cp*). 13C{1H} NMR (δ, CD3NO2, 20 °C): 178.8
(1C, CO), 133.5 (1C, CN), 129.7 (2C, Ph), 129.4 (4C, Ph), 128.8
(4C, Ph), 127.4 (2C, Ph), 101.4.2 (2C, Câ), 87.0 (5C, Cp), 83.4
(2C, CR), 9.9 (5C, Cp*), 5.1 (1C, NCCH3). IR (KBr, cm-1): 2320,
2284 (m, νCN), 1661 (s, νCO).
[Ru Cp (η4-C5H2O-2,5-P h 2)(CH3CN)]P F 6 (3a ). A solution
of 1 (163 mg, 0.387 mmol) in acetone (5 mL) was treated with
HCtCPh (87 µL, 0.774 mmol), and the mixture was stirred
(22) Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory
Chemicals, 3rd ed.; Pergamon: New York, 1988.

5390 Organometallics, Vol. 19, No. 25, 2000
Ta ble 2. Cr ysta llogr a p h ic Da ta for 3a , 3b, 3e, 4a ‚CH2Cl2, a n d 6
Ru¨ba et al.
3a
3b
3e
4a ‚CH2Cl2
6
formula
fw
C
24H20F6NOPRu
C20H28F6NOPRu
544.47
C17H20F6NOPRu
500.38
C30H32Cl2F6NOPRu
739.51
C9H8F6NO2PRu
408.20
584.45
cryst. size, mm
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
0.55 × 0.40 × 0.16
P1h (No. 2)
10.853(3)
10.922(4)
11.772(5)
101.45(2)
101.94(2)
116.78(2)
1148.8(7)
2
0.34 × 0.30 × 0.03
P1h (No. 2)
10.516(3)
10.704(4)
11.651(5)
68.61(2)
87.40(2)
80.71(2)
1205.0(8)
2
0.70 × 0.40 × 0.08
0.84 × 0.26 × 0.20
P21/c (No. 14)
16.826(6)
11.172(4)
17.217(6)
0.60 × 0.16 × 0.07
C2/c (No. 15)
23.707(5)
10.526(3)
11.954(4)
Cc (No. 9)
14.381(7)
7.779(4)
17.680(9)
103.07(1)
90.59(2)
114.19(2)
1927(2)
4
1.725
297(2)
0.959
1000
3236(2)
4
1.518
297(2)
0.758
1496
2721(1)
8
1.993
295(2)
1.338
1584
Z
F
T, K
calc, g cm-3
1.690
295(2)
0.818
584
1.501
295(2)
0.773
552
µ, mm-1 (Mo KR)
F(000)
abs corr
F(000)
multiscan
584
multiscan
552
multiscan
1000
multiscan
1496
multiscan
1584
transmn factor min/max
0.74/0.86
30
-15 e h e 14
-15 e k e 15
-16 e l e 16
16 359
6495
5665
347
0.91/0.98
25
-12 e h e 12
-12 e k e 12
-13 e l e 13
12 417
4231
3210
282
0.63/0.80
30
0.72/0.86
30
0.78/0.93
27
θ
max, deg
index ranges
-19 e h e 20
-10 e k e 10
-24 e l e 24
16 882
5521
-23 e h e 23
-15 e k e 15
-23 e l e 23
46 221
9345
-30 e h e 30
-13 e k e 13
-15 e l e 15
15 761
2971
no. of rflns measd
no. of unique rflns
no. of rflns I > 2σ(I)
no. of params
5387
248
6867
407
2378
220
R1 (I > 2σ(I))
R1 (all data)
0.028
0.034
0.053
0.076
0.023
0.024
0.038
0.059
0.030
0.044
wR2 (all data)
0.074
0.145
0.060
0.115
0.074
diff Fourier peaks
-0.31/0.53
-0.37/0.61
-0.28/0.28
-0.37/0.60
-0.32/0.31
min/max, e Å-3
R1 ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) [∑(w(Fo - Fc2)2)/∑(w(Fo2)2)]1/2
.
a
2
[Ru Cp*(η4-C5H2O-2,5-n -Bu 2)(CH3CN)]P F6 (4b). This com-
plex has been prepared analogously to 4a with 2 (77 mg, 0.153
mmol) and 1-hexyne (40 µL, 0.351 mmol) as the starting
materials. Yield: 65 mg (70%). Anal. Calcd for C25H38F6-
NOPRu: C, 48.86; H, 6.23. Found: C, 48.91; H, 6.20. 1H NMR
(δ, CD3NO2, 20 °C): 5.23 (s, 2H, Hâ), 2.70 (s, 3H, CH3CN),
2.14-1.62 (m, 4H, CH2CH2CH2CH3), 1.91 (s, 15H, Cp*), 1.46-
1.18 (m, 8H, CH2CH2CH2CH3), 0.99-0.82 (m, 6H, CH2CH2-
CH2CH3). 13C{1H} NMR (δ, CD3NO2, 20 °C): 181.7 (1C, CO),
131.4 (1C, CN), 100.8 (2C, Câ), 92.5 (2C, CR), 89.8 (5C, Cp*),
32.9 (2C, CH2), 24.7 (2C, CH2), 23.3 (2C, CH2), 13.9 (2C, CH3),
9.4 (5C, Cp*), 4.8 (1C, NCCH3). IR (KBr, cm-1): 2323, 2289
(m, νCN), 1672 (s, νCO).
[R u Cp *(η4-C5H 2O-2,5-(C6H 9)2)(CH 3CN)]P F 6 (4c). This
complex has been prepared analogously to 4a with 2 (100 mg,
0.204 mmol) and 1-ethynyl cyclohexene (52.7 µL, 0.448 mmol)
as the starting materials. Yield: 108 mg (80%). Anal. Calcd
for C29H38F6NOPRu: C, 52.56; H, 5.78. Found: C, 52.58; H,
5.72. 1H NMR (δ, CD3NO2, 20 °C): 6.54 (m, 2H, C6H9), 5.35
(s, 2Hâ), 2.74 (s, 3H, CH3CN), 2.33-1.40 (m, 16H, C6H9), 1.86
(s, 15H, Cp*). 13C{1H} NMR (δ, CD3NO2, 20 °C): 179.6 (1C,
CO), 131.6 (1C, CN), 129.8 (2C, C6H9), 129.5 (2C, C6H9), 100.5
(2C, Câ), 91.7 (2C, CR), 86.0 (5C, Cp), 27.4 (2C, C6H9), 26.6 (2C,
C6H9), 23.3 (2C, C6H9), 22.8 (2C, C6H9), 10.2 (5C, Cp*), 5.0 (1C,
NCCH3). IR (KBr, cm-1): 2320, 2286 (m, νCN), 1669 (s, νCO).
Rea ction of 1 w ith Dip h en yla cetylen e. F or m a tion of
[Ru Cp(η6-C6H5-CtCP h )]P F6 (5) an d [Ru Cp(CO)2(CH3CN)]-
P F 6 (6). A solution of 1 (134 mg, 0.318 mmol) in acetone (5
mL) was treated with PhCtCPh (119 mg, 0.668 mmol), and
the mixture was stirred for 24 h at 60 °C. Addition of diethyl
ether (15 mL) led to the precipitation of a pale yellow solid,
which was collected on a glass frit, washed twice with diethyl
ether, and dried under vacuum. The 1H NMR spectrum showed
two products in a 1:1 ratio. The mixture could not be separated
by column chromatography. 5: 1H NMR (δ, CD3NO2, 20 °C):
7.63-7.33 (m, 5H, Ph), 6.53-6.41(m, 2H, η6-Ph), 6.35-6.12
(m, 3H, η6-Ph), 5.47 (s, 5H, Cp). 13C{1H} NMR (δ, CD3NO2, 20
°C): 133.0 (2C, Ph), 131.0 (1C, Ph), 129.8 (2C, Ph), 122.0 (1C,
Ph), 92.1 (1C, η6-Ph), 89.1 (2C, η6-Ph), 87.0 (1C, CtC), 86.8
(2C, η6-Ph), 86.3 (1C, η6-Ph), 84.4 (1C, CtC), 82.3 (2C, η6-Ph).
IR (ΚΒr, cm-1): 2229 (m, νCtC). The NMR and IR spectra of 6
were in agreement with those reported in the literature.23
NMR Sp ectr oscop ic Stu d ies. A 5 mm NMR tube was
charged with a solution of 1 (31 mg, 0.074 mmol) and PhCt
CPh (28 mg, 0.115 mmol) in neat CD3NO2 and was capped
with a septum. The tube was then heated at 60 °C, and 1H
NMR spectra were recorded every 4 h. The reaction was
complete after approximately 24 h, indicating the formation
of 5, 6, and free CH3CN in a 1:1:3 ratio.
Aceton itr ile Exch a n ge Kin etics on 1 in CD3NO2. The
CH3CN exchange in 1 was measured at 40 °C by monitoring
the increase in intensity of the proton NMR signal of free CH3-
CN (at 1.97 ppm) and the decrease of the bound CH3CN (at
2.63 ppm) following the methodology described elsewhere.18,24
Accordingly, 10 mg of 1 was dissolved in 0.5 mL of CD3NO2,
deuterated acetonitrile (41 µL) was added by syringe, and
spectra were taken at regular intervals.
[RuCp(CO)(CH3CN)2]PF6 + 2 CD3CN f
[RuCp(CO)(CD3CN)2]PF6 + 2 CH3CN (1)
X-r a y Str u ctu r e Deter m in a tion for 3a , 3b, 3e, 4a ‚
CH2Cl2, a n d 6. Crystals of 3a , 3b, 3e, 4a ‚CH2Cl2, and 6 were
obtained by diffusion of Et2O into CH2Cl2 solutions. Crystal
data and experimental details are given in Table 2. X-ray data
were collected on a Siemens Smart CCD area detector diffrac-
tometer (graphite-monochromated Mo KR radiation, λ )
(23) J ungbauer, A.; Behrens, H. Z. Naturforsch. 1978, 33b, 1083.
(24) Ru¨ba, E.; Simanko, W.; Mereiter, K. Schmid, R., Kirchner, K.
Inorg. Chem. 2000, 39, 382.
(25) Sheldrick, G. M. SHELXS97: Program for the Solution of
Crystal Structures; University of Go¨ttingen: Germany, 1997.
(26) Sheldrick, G. M. SHELXL97: Program for Crystal Structure
Refinement; University of Go¨ttingen: Germany, 1997.

Reaction of Alkynes with [RuCp(CO)(CH3CN)2]+
Organometallics, Vol. 19, No. 25, 2000 5391
0.71073 Å, 0.3° ω-scan frames covering complete spheres of
the reciprocal space). Corrections for Lorentz and polarization
effects, for crystal decay, and for absorption were applied. All
structures were solved by direct methods using the program
SHELXS97.25 Structure refinement on F2 was carried out with
the program SHELXL97.26 All non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were inserted in
idealized positions and were refined riding with the atoms to
which they were bonded. Orientation disorder of PF6 groups
(3a , 4a ‚CH2Cl2, 6) and one n-butyl chain (3b) was taken into
account.
Com p u ta tion a l Deta ils. All calculations were performed
using the Gaussian98 software package27 on the Silicon
Graphics Power Challenge of the Vienna University of Tech-
nology. The geometry and energy of the complexes [RuCp(η2-
CHtCH)2(CO)]+ (A), [RuCp(σ,σ′-C4H4)(CO)]+ (B′), and [RuCp-
(η4-C4H4)(CO)]+ (E) were optimized at the B3LYP level28 with
the Stuttgart/Dresden ECP (SDD) basis set29 to describe the
electrons of the ruthenium atom. For C, H, and O the
Dunning-Huzinaga valence double-ú basis set (D95v) was
used.30 A vibrational analysis was performed for all structures
to confirm that they have no imaginary frequency. The
geometries were optimized without constraints (C1 symmetry).
(27) Frisch, M. J .; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J . R.; Zakrzewski, V. G.; Montgomery, J . A.,
J r.; Stratmann, R. E.; Burant, J . C.; Dapprich, S.; Millam, J . M.;
Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J .;
Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo,
C.; Clifford, S.; Ochterski, J .; Petersson, G. A.; Ayala, P. Y.; Cui, Q.;
Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.;
Foresman, J . B.; Cioslowski, J .; Ortiz, J . V.; Stefanov, B. B.; Liu, G.;
Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.;
Fox, D. J .; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.;
Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; J ohnson, B. G.; Chen,
W.; Wong, M. W.; Andres, J . L.; Head-Gordon, M.; Replogle, E. S.;
Pople, J . A. Gaussian 98, revision A.5; Gaussian, Inc.: Pittsburgh, PA,
1998.
Ack n ow led gm en t. Financial support by the “O¨ s-
terreichischer Akademischer Austauschdienst” (Ac-
ciones Integradas Project 6/99 and HU 1998-0026) is
gratefully acknowledged.
(28) Becke, A. D. J . Chem. Phys. 1993, 98, 5648. Miehlich, B.; Savin,
A.; Stoll, H.; Preuss, H. Chem. Phys. Lett. 1989, 157, 200. Lee, C.; Yang,
W.; Parr, G. Phys. Rev. B 1988, 37, 785.
(29) (a) Haeusermann, U.; Dolg, M.; Stoll, H.; Preuss, H. Mol. Phys.
1993, 78, 1211. (b) Kuechle, W.; Dolg, M.; Stoll, H.; Preuss, H. J . Chem.
Phys. 1994, 100, 7535. (c) Leininger, T.; Nicklass, A.; Stoll, H.; Dolg,
M.; Schwerdtfeger, P. J . Chem. Phys. 1996, 105, 1052.
Su p p or tin g In for m a tion Ava ila ble: Listings of atomic
coordinates, anisotropic temperature factors, bond lengths and
angles, and least-squares planes for 3a , 3b, 3e, 4a ‚CH2Cl2,
and 6. This material is available free of charge via the Internet
at http://pubs.acs.org.
(30) Dunning, T. H.; Hay, P. J . In Modern Theoretical Chemistry,
Scha¨fer, H. F., III, Ed.; Plenum Press: New York, 1976; p 1.
OM000663P