Novel polymetallic vinylidene- and allenylideneruthenium(II) complexes

Article abstract of DOI:10.1021/om0300326

Two new triynes, C₆Me₃-1,3,5-[CH₂O(p-C₆H₄) C≡CH]₃ and C₆Me₃-1,3,5-[CH₂O(p-C₆H₄) -PhC(OH)C≡CH]₃ (5), have been prepared and

Full text of DOI:10.1021/om0300326

Organometallics 2003, 22, 2209-2216
2209
Novel P olym eta llic Vin ylid en e- a n d
Allen ylid en er u th en iu m (II) Com p lexes
Dana Weiss and Pierre H. Dixneuf*
Institut de Chimie de Rennes, UMR 6509, Universite´ de Rennes 1-CNRS,
Organome´talliques et Catalyse, Campus de Beaulieu, 35042 Rennes, France
Received J anuary 15, 2003
Two new triynes, C6Me3-1,3,5-[CH2O(p-C6H4)CtCH]3 (3) and C6Me3-1,3,5-[CH2O(p-C6H4)-
PhC(OH)CtCH]3 (5), have been prepared and used for the facile synthesis of several tris-
(vinylideneruthenium) and tris(allenylideneruthenium) complexes via metal-mediated
activation and tautomerization or isomerization and dehydration of the alkyne moieties,
respectively. Complexes C6Me3-1,3,5-{[CH2O(p-C6H4)CHdCdRu(dppe)2Cl]BF4}3 (6) and
C6Me3-1,3,5-{[CH2O(p-C6H4)PhCdCdCdRu(dppe)2Cl]BF4}3 (8) were obtained by activation
of 3 and 5 by [RuCl(dppe)2]BF4. C6Me3-1,3,5-[CH2O(p-C6H4)CHdCdRu(PCy3)2Cl2]3 (7) and
C6Me3-1,3,5-{[CH2O(p-C6H4)PhCdCdCdRu(PCy3)(p-cymene)Cl]OTf}3 (9) resulted from the
reaction of 3 with [RuCl2(p-cymene)]2/2PCy3 and of 5 with [RuCl(PCy3)(p-cymene)]OTf.
In tr od u ction
vinylidene- and allenylideneruthenium(II) complexes
are known as efficient catalysts for olefin metathesis
and provide the advantage that they can be conveniently
prepared from conventional terminal alkynes and
alkynols.8 However, for catalysis purposes coordina-
tively unsaturated complexes with a nonconjugated
backbone are of better value to avoid communication
between the metal centers through the core3 and ensure
the possibility of equal reactivity of all identical catalytic
moieties within the same molecule. This challenge led
us to design new simple organic nonconjugated polyynes
as precursors for suitable stable 18-electron vinylideneru-
thenium(II) and allenylideneruthenium(II) complexes.
We report here the controlled activation of star triynes
by suitable ruthenium derivatives and the synthesis of
novel star trisvinylidene- and trisallenylideneruthe-
nium(II) complexes with identical ruthenium sites.
The design of functional star molecules and dendri-
mers is the focus of a fast evolving field of chemistry.1,2
This interest arises from their potential to incorporate
guest molecules within their cavities and to bind active
molecules in their outer sphere.2 Star molecules con-
stitute key starting components for the synthesis of new
multisite catalyst precursors by interaction of the
multiple periphery functions, acting as ligands, with
suitable metal complexes.2b,c Recently, it was shown that
conjugated terminal polyalkynes can be activated and
easily converted into the isomeric vinylidenes in the
coordination sphere of ruthenium complexes to give
trimetallic complexes in the form of an organometallic
triskelion.3 These complexes displayed a fully conju-
gated, rigid organic spine. Such compounds are of
interest for applications as electron storage devices4 or
as modified electrodes,5 and their model ruthenium-
carbene moieties may become suitable to open the way
to new types of functional star polymers, via ring-
opening metathesis polymerization (ROMP).6,7Indeed,
Resu lts a n d Discu ssion
Syn th esis of th e Tr itop ic P olyyn es. Compound
C6Me3-1,3,5-[CH2O(p-C6H4)CtCH]3 (3) was synthesized
in three reaction steps via the iodo derivative C6Me3-
1,3,5-[CH2O(p-C6H4)I]3 (1) and the protected alkyne
C6Me3-1,3,5-[CH2O(p-C6H4)CtCSi(CH3)3]3 (2). Follow-
ing a procedure described for the synthesis of dendrons
carrying alkoxyaryl moieties in their side chains9 the
tris(p-iodophenoxy)-terminated compound 1 was ob-
tained from the reaction of 4-iodophenol and tris-
(bromomethyl)mesitylene in the presence of a base
(Scheme 1).
* Corresponding author. E-mail: dixneuf@univ-rennes1.fr.
(1) (a) Cloutet, E.; Fillaut, J .-L.; Astruc, D.; Gnanou, Y. Macromol-
ecules 1998, 31, 6748. (b) Martin, K.; Ra¨der, H. J .; Mu¨llen, K.
Macromolecules 1999, 32, 3190. (c) Matyjaszewski, K.; Miller, P. J .;
Pyun, J .; Kickelbick, G.; Diamanti, S. Macromolecules 1999, 32, 6526.
(2) (a) Hecht, S.; Fre´chet, J . M. J . Angew. Chem. 2001, 113, 76;
Angew. Chem., Int. Ed. 2001, 40, 74. (b) Oosterom, G. E.; Reek, J . N.
H.; Kamer, P. C. J .; van Leeuwen, P. W. N. M. Angew. Chem. 2001,
113, 1879; Angew. Chem., Int. Ed. 2001, 40, 1828. (c) Inoue, K. Prog.
Polym. Sci. 2000, 25, 453. (d) Majoral, J .-P.; Caminade, A.-M. Chem.
Rev. 1999, 99, 845. (e) Fischer, M.; Vo¨gtle, F. Angew. Chem. 1999, 111,
934; Angew. Chem., Int. Ed. 2001, 38, 884. (f) Ardoin, N.; Astruc, D.
Bull. Soc. Chim. Fr. 1995, 132, 875.
(3) Uno, M.; Dixneuf, P. H. Angew. Chem. 1998, 110, 1822; Angew.
Chem., Int. Ed. 1998, 37, 1714.
(4) (a) J utzi, P.; Batz, C.; Neumann, B.; Stammler, H.-G. Angew.
Chem. 1996, 108, 272; Angew. Chem., Int. Ed. Engl. 1996, 35, 2118.
(b) Bard, A. J . Nature 1995, 374, 13. (c) Astruc, D. New J . Chem. 1992,
16, 305.
The product is insoluble in almost all common organic
solvents but can be recrystallized from a hot solution
of DMF by addition of methanol. Compound 1 could be
(7) Castarlenas, R.; Semeril, D.; Noels, A.; Demonceau, A.; Dixneuf,
P. H. J . Organomet. Chem. 2002, 663, 235
(5) Alonso, B.; Morain, M.; Casado, C. M.; Lobete, F.; Losada, J .;
Cuadrado, I. Chem. Mater. 1995, 7, 1440.
(6) (a) Risse, W.; Wheeler, D. R.; Cannizzo, L. F.; Grubbs, R. H.
Macromolecules 1989, 22, 3205. (b) Bazan, G. C.; Schrock, R. S.
Macromolecules 1991, 24, 817.
(8) (a) Fu¨rstner, A.; Picquet, M.; Bruneau, C.; Dixneuf, P. H. Chem.
Commun. 1998, 1315. (b) Fu¨rstner, A.; Liebl, M.; Lehmann, C. W.;
Picquet, M.; Kunz, R.; Bruneau, C.; Touchard, D.; Dixneuf, P. H. Chem.
Eur. J . 2000, 6, 1847.
(9) Cordova, A.; J anda, K. D. J . Am. Chem. Soc. 2001, 123, 8248.
10.1021/om0300326 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 04/30/2003

2210 Organometallics, Vol. 22, No. 11, 2003
Weiss and Dixneuf
Sch em e 1a
a
(i) K2CO3, NaI, DMF, 75 °C, 24 h; (ii) PdCl2(PPh3)2, CuI, HN(i-Pr)2, Me3SiCtCH, THF, rt, 48 h; (iii) K2CO3, MeOH/H2O, 50
°C, 5 h.
readily transformed in high yield into the trimethylsilyl-
With an excess of only 10% of lithium ethynyl only the
2-fold alkynylated compound was obtained as a result
of the decreasingly solubility of the 1-, 2-, and 3-fold
lithium-alcoholate-substituted intermediates formed dur-
ing the reaction.
protected alkyne C6Me3-1,3,5-[CH2O(p-C6H4)CtCSi-
(CH3)3]3 (2) by a classical Sonogashira coupling reaction.
Quantitative deprotection of the alkyne was achieved
using aqueous potassium carbonate.10
The 1H NMR spectrum of the product C6Me3-1,3,5-
[CH2O(p-C6H4)CtCH]3 (3) showed two doublets, each
corresponding to six protons, assignable to the aryl
protons of the branches (δ ) 7.49 and 6.98, 3J HH ) 8.81
Hz) along with two singlets in a ratio of 6:9 at δ 5.10
and 2.42, respectively, attributed to the methyleneoxy
and methyl groups of the core. Additionally, a resonance
corresponding to three protons was observed within the
typical range for terminal alkynes (δ 3.01). The char-
acterization by 13C NMR spectroscopy was not possible
due to the low solubility of 3, but a distinct IR absorption
band at 2104 cm-1, consistent with the presence of
CtC bonds, as well as the results of mass spectrometry
(m/e 509: [M - H]+) support the proposed structure.
For the synthesis of the trisalkynol C6Me3-1,3,5-
[CH2O(p-C6H4)PhC(OH)CtCH]3 (5), in the first step of
the sequence depicted in Scheme 2, the benzophenone
derivative C6Me3-1,3,5-[CH2O(p-C6H4)COPh]3 (4) was
obtained in a similar manner as compound 1 by a typical
Williamson ether synthesis. The addition of 4 to a
solution of a large excess of lithium ethynyl generated
in situ by reaction of acetylene gas with n-butylithium
at low temperature, following a procedure described by
Midland,11 resulted in the selective formation of the
alkynol C6Me3-1,3,5-[CH2O(p-C6H4)PhC(OH)CtCH]3 (5)
in 76% isolated yield. No other side product was
detected when a 2-fold excess of the alkynylating
reagent and a sufficient amount of solvent were used.
The 1H NMR spectrum of 5 is consistent with the
proposed structure depicted in Scheme 2 and shows
singlet resonances typical for the CH2O and CH3 units
at δ 5.14 and 2.49 and for the alcohol and alkyne protons
at δ 3.07 and 2.97, respectively, in a ratio of 6:3:3:3.
Interesting features of the 13C{1H} NMR spectrum are
the two signals assignable to the six carbon atoms of
the alkyne moieties at δ 87.10 and 75.88, reflecting the
high symmetry of the complex. The chemical shifts of
the methyleneoxy and the methyl groups at δ 65.43 and
16.38 ppm are similar for all compounds discussed in
this publication. Only a weak ν(CtC) absorption band
was observed in the IR spectrum at 2113 cm-1. How-
ever, fast atom bombardment mass spectrometry re-
vealed a mass peak of m/e 828 consistent with a [M -
H]+ ion. Unfortunately, the crystallization solvent could
not be completely removed from the target compound,
even after several days under vacuum and mild heating.
This problem persisted whether methanol, ethanol,
diethyl ether, or tetrahydrofuran was used for the
purification and might be a consequence of weak
hydrogen bonds between the ether functions and hy-
droxy groups of both solvent and 5. The corresponding
solvent molecules within the product could be easily
replaced by those of another solvent by simple stirring
5 in the new solvent. They could not be replaced by a
solvent of lower polarity such as dichloromethane.
Syn th esis of th e Tr is(vin ylid en er u th en iu m ) a n d
tr is(a llen ylid en er u th en iu m ) Mod el Com p lexes 6
a n d 8. The synthetic approach was based on known
activation processes of terminal alkynes and propargyl
(10) Ohshiro, N.; Takei, F.; Onisuka, K.; Takahashi, S. J . Orga-
nomet. Chem. 1998, 569, 195.
(11) Midland, M. M. J . Org. Chem. 1975, 40, 2250.

Vinylidene and Allenylidene Ru(II) Complexes
Organometallics, Vol. 22, No. 11, 2003 2211
Sch em e 2a
a
(i) K2CO3, NaI, DMF, 75 °C, 24 h; (ii) a) LiCtCH (from n-BuLi and HCtCH at -100 °C), THF, -100 °C, rt, 48 h; (b) HCl/
H2O.
alcohols12 with RuCl2(dppe)2,13 and then with RuCl2-
the formation of the allenylidene 8 was only complete
after three weeks. This might be due to steric reasons
with respect to the crowded environment of both the
dppe-substituted ruthenium center and the alkyne
moiety of the propargylic alcohol derivative 5. The
trisilylated triyne derivative 2 reacted under similar
conditions only to a small extent with [(dppe)2RuCl]BF4,
and the conversion could not be driven to completeness.
(PR3)(arene)14complexes, the former leading to more
stable vinylidene and allenylidene complexes. The stable
18-electron complexes C6Me3-1,3,5-{[CH2O(p-C6H4)CHd
CdRu(dppe)2Cl]BF4}3 (6) and C6Me3-1,3,5-{[CH2O(p-
C6H4)PhCdCdCdRu(dppe)2Cl]BF4}3 (8), displaying C3-
symmetry triskelion shapes,15 were prepared similarly
and in high yield by reaction of the complex [(dppe)2RuCl]-
BF4, in situ generated from (dppe)2RuCl2 in the presence
of AgBF4, with the respective trialkynes 3 and 5 in
dichloromethane at ambient temperature (Schemes 3
and 4). Complexes 6 and 8 were isolated as deep brown
and purple solids, respectively.
The 1H NMR spectrum of 6 showed the expected
characteristics and the high symmetry of the molecule:
one singlet for the six protons of the methyleneoxy
moiety at δ 4.96 and one singlet for the nine protons of
the methyl groups of the core at δ 2.40 are observed. A
multiplet at δ 3.49 is assigned to the â-H atom of the
ruthenium vinylidene moiety RudCdCHR. The corre-
sponding signal of the conjugated complex C6H3-1,3,5-
{[CtC(p-C6H4)CHdCdRu(dppe)2Cl]PF6}3 appears as a
broad resonance at δ 3.75. Characteristic features in the
13C{1H} NMR spectrum of 6 are the positions of the
signals of the R- and â-C atoms of the vinylidene ligand
which appear as a quintet (2J PC ) 13 Hz) at δ 358.77
and as a multiplet at δ 108.83 (for C6H3-1,3,5-{[CtC(p-
C6H4)CHdCdRu(dppe)2Cl]PF6}3: δ 356.6 and 109.5).
During the reaction a 31P{1H} singlet increased at δ
39.69, which indicates the formation of a regularly 3-fold
ruthenium-substituted complex with 12 equivalent 31P
nuclei, with the vinylidene and the chloro ligands in a
trans arrangement. At the same time in the IR spectrum
the vibration band at 2104 cm-1, typical for the presence
of alkyne, disappeared, while a new band ascribed to
the ν(CdC) stretching frequency of the RudCdC group
This method was already applied to the synthesis of
the fully conjugated bimetallic C6H4-1,4-{[CHdCdCd
Ru(dppe)2Cl]PF6}216 and trimetallic C6H3-1,3,5-{[CtC-
(p-C6H4)CHdCdRu(dppe)2Cl]PF6}33 complexes. Whereas
in the case of the vinylidene 6 the conversion was
complete after 17 h according to 31P NMR spectroscopy,
(12) Selegue, J . P. Organometallics 1982, 1, 217.
(13) For review see: (a) Bruce, M. I. Chem. Rev. 1991, 91, 197. (b)
Touchard, D.; Haquette, P.; Pirio, N.; Toupet, L.; Dixneuf, P. H.
Organometallics 1993, 12, 3132. (c) Pirio, N.; Touchard, D.; Dixneuf,
P. H.; Fettouhi, M.; Ouahab, L. Angew. Chem. 1992, 104, 664; Angew.
Chem. Int. Ed. 1992, 31, 651.
(14) (a) Le Bozec, H.; Ouzzine, K.; Dixneuf, P. H. Organometallics
1991, 10, 2768. (b) Piquet, M.; Touchard, D.; Bruneau, C.; Dixneuf, P.
H. New J . Chem. 1999, 141.
(15) The triskelion (plural: triskelia) is a sign related to celtic
symbolism representing three forces and is constituted of three
branches (legs), radiating from a center. A typical example can be found
in the arms of Isle of Man. See also: Doyle, M.; Parker, W.; Gum, P.
A.; Martin, J .; Macnicol, D. D. Tetrahedron Lett. 1970, 42, 3619 and
ref 3.
(16) Guesmi, S.; Touchard, D.; Dixneuf, P. H. Chem. Commun. 1996,
2773.
was observed at 1637 cm-1
.

2212 Organometallics, Vol. 22, No. 11, 2003
Weiss and Dixneuf
Sch em e 3
Sch em e 4
The 1H NMR spectrum of complex 8 displays two
singlets at δ 5.25 and 2.49 arising from the methyl-
eneoxy and methyl protons of the core. The three
allenylidene ligands are equivalent by 13C{1H} NMR
spectroscopy and give rise to three resonances at δ
298.30, 204.21 (m), and 160.44 corresponding to the R,
â, and γ carbons of the allenylidene spine, the former
showing coupling to the phosphorus nuclei (quintet,
2J PC ) 14 Hz). The high symmetry of the complex is
also reflected by the presence of a discrete singlet (δ )
38.6) in the 31P{1H} NMR spectrum for the 12 Ph2P
groups, only consistent with a trans arrangement of the
chloro and allenylidene ligands. The IR spectrum of the
deep violet solid shows the expected strong absorption
peak at 1925 cm-1 for the CdCdC stretching frequency
of the allenylidene unit. Similar values were reported
for the corresponding mononuclear ruthenium com-
Syn th esis of th e Tr isvin ylid en e Com p lex C6Me3-
1,3,5-[CH2O(p-C6H4)CHdCdRu (P Cy3)2Cl2]3 (7). An-
other method to produce stable vinylideneruthenium
complexes from terminal alkyne is based on the con-
comitant modification of the ruthenium source by ad-
dition of stabilizing ligands. Recently, Ozawa et al.
described the synthesis of the vinylidene analogue of
the Grubbs catalyst, (PCy3)2RuCl2(dCdCHPh).18 This
synthetic method was applied to the triyne 3. The
reaction of 3 with 3 equiv of [RuCl2(p-cymene)]2 in the
presence of 6 equiv of PCy3 proceeded very cleanly at
80 °C and led to the isolation of the trisvinylidene 7, as
a grayish-brown solid in high purity and essentially
quantitative yield (Scheme 5).
1
The H NMR spectrum of complex 7 exhibits a triplet
with an integral corresponding to 3 H atoms at low-
field resonance typical for the vinylidene â-hydrogen
atoms at δ 4.33 (4J PH ) 3 Hz). This value compares well
to the corresponding â-H shift of the single-site complex
plex [(dppe)2ClRudCdCdCPh2]PF6 (13C{1H} NMR δ
17
308.57 (RudC, 2J PC ) 14 Hz), 215.90 (RudCdC), 161.47
(RudCdCdC); 31P NMR δ 37.98; IR 1923 cm-1 (s,
ν(CdCdC)).
4
[(PCy3)2RuCl2(dCdCHPh): δ ) 4.70, J PH ) 3.6 Hz18].
The 13C{1H} NMR spectrum of 7 shows a characteristic
resonance at δ 345.27 (t, 2J PC ) 14 Hz) and δ 107.95 (t,
(17) Touchard, D.; Guesmi, S.; Bouchaib, M., Haquette, P.; Daridor,
A.; Dixneuf, P. H. Organometallics 1996, 15, 2579.
(18) Katayama, H.; Ozawa, F. Organometallics 1998, 17, 5190.

Vinylidene and Allenylidene Ru(II) Complexes
Organometallics, Vol. 22, No. 11, 2003 2213
Sch em e 5
ruthenium(II) complexes.8,14 The appearance of a strong
allenylidene absorption in the infrared spectrum of 9
at 1962 cm-1 is comparable to the respective value for
the RudCdCdCPh2 moiety in [(p-cymene)(PCy3)RuCl-
(dCdCdCPh2]OTf (1963 cm-1).14b These data allow us
to propose a structure corresponding to a tripodal
allenylidene complex of the formula C6Me3-1,3,5-{[CH2-
O(p-C6H4)PhCdCdCdRu(PCy3)(p-cymene)Cl]OTf}3 for
product 9.
Sch em e 6
3J PC ) 4 Hz) comparable to the shifts of the R- and
â-vinylidene carbon atoms in (PCy3)2RuCl2(dCdCHPh)18
Con clu sion
2
3
(δ 342.1 (t, J PC ) 14 Hz), 109.6 (t, J PC ) 5 Hz)).
Syn th esis a n d Rea ctivity of C6Me3-1,3,5-{[CH2-
O (p -C 6H 4)P h C dC dC dR u (P C y 3)(p -c y m e n e )C l]-
OTf}3 (9). Ruthenium allenylidene complexes were
shown recently to be efficient catalysts for alkene
metathesis.8 They were easily obtained by activation
and dehydration of propargyl alcohols with (p-cymene)-
(PCy3)RuCl2 in the presence of a noncoordinating salt
according to Scheme 6.
New nonconjugated triynes have been prepared in
order to investigate the first step of possible involvement
of polyvinylidene- and polyallenylidene-metal interme-
diates in the preparation of star polymers by ROMP.
These triynes were suitable substrates for the synthesis
of model tris(vinylideneruthenium) and tris(allenyli-
deneruthenium) complexes in high yield. Whereas com-
plexes containing the RuCl(dppe)2 moiety are stable, two
of the novel trimetallic compounds, C6H3Me3-1,3,5-
[CH2O(p-C6H4)CHdCdRu(PCy3)2Cl2]3 (7) and C6Me3-
1,3,5-{[CH2O(p-C6H4)PhCdCdCdRu(PCy3)(p-cymene)-
Cl]OTf}3 (9), represent interesting arrangements that
may become useful as catalyst precursors for olefin
metathesis and related reactions.
Molecule 5, offering three identical propargyl alcohol
functions, was thus a good candidate for access to the
first tris(allenylidenemetal) complex, a possible multiple
“single-site” catalyst with three active moieties. Treat-
ment of alkynol 5 with 3 equiv of [(p-cymene)(PCy3)-
RuCl]OTf in dichloromethane at ambient temperature
resulted in the instantaneous formation of a deep purple
solution. The reaction was monitored by in situ 31P NMR
spectroscopy and stopped after 55 min, when about 95%
conversion of the starting material was obtained. Evapo-
ration of the solvent led to a dark violet, somewhat air-
sensitive solid (Scheme 7).
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations involving orga-
nometallic compounds and ruthenium complexes were per-
formed under an inert atmosphere of argon, using standard
Schlenk techniques. Dichloromethane, tetrahydrofuran, and
methanol were dried by standard methods and freshly distilled
under argon prior to use. PdCl2(PPh3)2,8b (dmso)4RuCl2,19 cis-
(dppe)2RuCl2,20 [(p-cymene)RuCl2]2,21 (p-cymene)(PCy3)RuCl2, 8b
and [(p-cymene)(PCy3)RuCl]OTf 8b have been prepared accord-
ing to literature procedures. [(dppe)2RuCl]BF4 was synthesized
by the reaction of cis-(dppe)2RuCl2 with a stoichiometric
amount of AgBF4 in dichloromethane at room temperature for
2 h and after filtration of the resulting solution was used
without isolation of the product. N,N-Di-isopropylamine was
The shift of the 31P{1H} NMR signal of the resulting
product 9 at δ 56.36 (s) is in good agreement with the
chemical shift observed for the mononuclear allenyli-
deneruthenium complex [(p-cymene)(PCy3)RuCl(dCd
1
CdCPh2]OTf (δ 59.21).14b The disappearance of the H
NMR signals attributed to the protons of the terminal
alkyne moieties and hydroxy functionalities together
with the IR spectroscopy data shows clearly that no
simple coordination of the alkyne groups by the ruthe-
nium centers took place. Besides, four doublets, each
corresponding to 3 H atoms, were found between δ 6.58
and 6.00; this is the typical range for the four different
signals of the aromatic protons of the three equivalent
p-cymene ligands in comparable chiral allenylidene-
(19) Evans, I. P.; Spencer, A.; Wilkinson, G. J . Chem. Soc., Dalton
Trans. 1973, 204.
(20) Chaudret, B.; Commenges, G.; Poilblanc, R. J . Chem. Soc.,
Dalton Trans. 1984, 1635.
(21) Bennett, M. A.; Smith, A. K. J . Chem. Soc,. Dalton Trans. 1974,
233.

2214 Organometallics, Vol. 22, No. 11, 2003
Weiss and Dixneuf
Sch em e 7
distilled and stored under argon. All other commercially
available chemicals were used without further purification.
Infrared spectra were recorded on a Bruker IFS 28 spec-
trometer. The C, H, and N analyses and mass spectra were
carried out by the Regional Centre of Physical Measurement
(CRMPO) at the University of Rennes 1. High-resolution mass
spectra were recorded using a ZabSpec TOF Micromass
spectrometer (ionization method, LSIMS with Cs+; matrix,
mNBA; acceleration, 8 kV). NMR spectra were recorded on a
Bruker Avance DPX 200 instrument at 200.13 MHz (1H), 81.02
MHz (31P), and 50.33 MHz (13C) or on a Bruker AC 300 P
instrument at 75.47 MHz (13C). Chemical shifts are reported
in ppm and referenced to the residual protons and 13C signals
of deuterated solvents or to the 31P signal of external 85%
H3PO4.
Syn th esis of C6Me3-1,3,5-[CH2O(p-C6H4)I]3 (1). Tris-
(bromomethyl)mesitylene (3.00 g, 7.52 mmol), 4-iodophenol
(4.96 g, 22.56 mmol), K2CO3 (6.24 g, 45.12 mmol), and NaI
(845 mg, 5.64 mmol) were suspended in 90 mL of DMF, and
the reaction mixture was stirred at 75 °C for 48 h. The hot
solution was decanted, and 150 mL of MeOH was added under
vigorous stirring. A white crystalline solid of very low solubility
in common organic solvents was obtained. It was stirred two
times for 30 min in 100 mL of distilled water to remove
residual salt impurities. The product was filtered off, dissolved
in 100 mL of hot DMF, and precipitated again by addition of
100 mL of MeOH. After filtration the product was washed
several times with MeOH and with diethyl ether. Yield: 4.10
g (67%). IR (KBr): ν 2904 (w), 1673 (w), 1582 (m), 1481 (s),
a 10-fold volume of heptane. After filtration, the white crystal-
line material was washed with heptane (3 × 30 mL) and
pentane (20 mL) and dried in vacuo. Yield: 1.89 g (71%). IR
(KBr): 2958 (w), 2156 (m, ν(CdC)), 1604 (m), 1506 (s,), 1237
(vs, ν(C-O), CH2-O-Ar), 171 (w), 992 (m), 843 (s), 759 (w)
cm-1. 1H NMR (δ, CDCl3): 7.53 (d, 6H, 3J HH ) 8.61 Hz, CHmeta
,
3
ArO), 7.02 (d, 6H, J HH ) 8.81 Hz, CHortho, ArO), 5.15 (s, 6H,
CH2O), 2.48 (s, 9H, CH3, Mes), 0.32 (s, 27H, Si(CH3)3). 13C-
{1H} NMR (δ, CDCl3): 159.65 (Cipso, ArO), 139.89 (CCH2O,
Mes), 133.98 (Cmeta, ArO), 131.99 (CH3, Mes), 116.11 (Cpara
,
ArO), 114.93 (Cortho, ArO), 105.56 (CtCSiMe3), 93.10 (Ct
CSiMe3), 65.43 (CH2O), 16.40 (CH3, Mes), 0.55 (Si(CH3)3). Anal.
Calcd for C45H54O3Si3: C, 74.33; H, 7.49. Found: C, 73.41; H,
7.44. MS(FAB+): m/e 726 (M+•).
Syn th esis of C6Me3-1,3,5-[CH 2O(p-C6H4)CtCH]3 (3).
1,3,5-Tris[p-(trimethylsilylethynyl)phenoxymethyl]mesity-
lene (2) (1 g, 1.38 mmol) was dissolved in 100 mL of MeOH.
Following the addition of a solution of K2CO3 (855 mg, 6.19
mmol) in ca. 6 mL of distilled water the white suspension was
stirred at 50 °C for 5 h. After the evaporation of the solvents
the residue was extracted carefully with PhCl (3 × 40 mL,
stirred for 30 min each time). After removing the solvent using
an additional solvent trap the product was obtained as an
electrostatic white powder with very low solubility in all
common solvents besides PhCl. Yield: 688 mg (98%). IR
(KBr): ν 3283 (s, ν(C-H), CdCH), 2971 (m), 2908 (m), 2104
(m, ν(CdC)), 1604 (s), 1502 (s), 1370 (m), 1285 (s), 1235 (s, br,
ν(C-O), CH2-O-Ar), 1170 (s), 1109 (m) 1025 (m), 988 (s), 851
(m), 830 (s), 743 (m), 686 (m), 666 (m), 605 (m), 536 (s) cm-1
.
1370 (w), 1280 (m), 1236 (s), 1173 (m), 985 (m), 816 (m), 634
1H NMR (δ, CDCl3): 7.49 (d, 6H, 3J HH ) 8.81 Hz, CHmeta, ArO),
6.98 (d, 6H, 3J HH ) 8.81 Hz, CHortho, ArO), 5.10 (s, 6H, CH2O),
3.01 10 (s, 3H, CdCH), 2.42 (s, 9H, CH3). The characterization
by 13C NMR spectroscopy was not possible because of the low
solubility of 3. Anal. Calcd for C36H30O3: C, 84.68; H, 5.92.
Found C, 84.18; H, 5.89. MS(FAB+): m/e 509 [M - H]+.
Syn th esis of C6Me3-1,3,5-[CH2O(p-C6H4)COP h ]3 (4). Tris-
(bromomethyl)mesitylene (1.50 g, 3.76 mmol), 4-hydroxyben-
zophenone (2.24 g, 11.28 mmol), K2CO3 (3.12 g, 2.56 mmol),
and NaI (423 mg g, 2.82 mmol) were suspended in 50 mL of
neat DMF, and the reaction mixture was stirred at 75 °C for
24 h. The hot solution was filtered through a glass frit, and
250 mL of MeOH was added under vigorous stirring. After
filtration the white solid was washed several times with MeOH
and dried in vacuo. Yield: 2.43 g (86%). IR (KBr): 3053-2910
(w), 1652 (s, ν(CdO), Ar(CO)Ar), 1599 (s), 1506 (m), 1445 (m),
1418 (m), 1372 (m), 1317 (s), 1281 (s), 1243 (vs, br, ν(C-O),
CH2-O-Ar), 1173 (s), 1148 (s), 1026 (w), 988 (s), 937 (w), 922
3
(w), 503 (w) cm-1
.
1H NMR (δ, CDCl3): 7.61 (d, 6H, J HH
)
3
8.90 Hz, CHmeta, ArO), 6.81 (d, 6H, J HH ) 8.90 Hz, CHortho
,
ArO), 5.04 (s, 6H, CH2O), 2.40 (s, 9H, CH3). 13C{1H} NMR (δ,
CDCl3): 138.72 (Cmeta, ArO), 117.43 (Cortho, ArO), 65.70 (CH2O),
16.19 (CH3), quarternary carbon atoms could not be detected
because of the low solubility of the product. Anal. Calcd for
C
30H27I3O3: C, 44.14; H, 3.33. Found: C, 43.99; H, 3.53.
MS(FAB+): m/e 816 (M+•).
Syn th esis of C6Me3-1,3,5-[CH2O(p-C6H4)CtCSiMe3]3 (2).
1,3,5-Tris(p-iodo-phenoxymethyl)mesitylene (1) (3.00 g, 3.68
mmol), Pd(PPh3)2Cl2 (77 mg, 0.110 mmol), and CuI (42 mg,
0.220 mmol) were suspended in 50 mL of dry THF under argon
atmosphere. Subsequently 70 mL of N,N-di-isopropylamine
and trimethylsilylacetylene (1.88 mL, 1.30 g, 13.23 mmol) were
added with a syringe, and the reaction mixture was stirred
for 62 h at ambient temperature. After filtration and evapora-
tion of all volatile components the resulting product was
redissolved in a small amount of CH2Cl2 and precipitated with
1
(m), 841 (s), 793 (m), 742 (s), 698 (s), 630 (m) cm-1. H NMR

Vinylidene and Allenylidene Ru(II) Complexes
Organometallics, Vol. 22, No. 11, 2003 2215
(δ, CDCl3): 7.96 (d, 6H, 3J HH ) 8.79 Hz, CHmeta, ArO), 7.87 (d,
4.96 (s, 6H, CH2O), 3.49 (m, 3H, RudCdCH), 3.00-2.63 (m,
b, 24H, CH2CH2, dppe), 2.40 (s, 9H, CH3). 13C{1H} NMR (δ,
CDCl3): 358.77 (t, J PC ) 13 Hz, RudC), 157.51 (Cipso, ArO),
139.10 (CCH2O, Mes), 134.14 (Ar), 133.45 (Ar), 131.60 (Ar),
3
6H, J HH ) 8.26 Hz, CHortho, Ph), 7.58 (m, 9H, CHmeta, Ph +
3
2
CHpara, Ph), 7.19 (d, 6H, J HH ) 8.82 Hz, CHortho, ArO), 5.28
(s, 6H, CH2O), 2.56 (s, 9H, CH3). 13C{1H} NMR (δ, CDCl3):
195.96 (CdO), 163.07 (Cipso, ArO), 140.14 (Cipso, Ph), 138.65
(CCH2O, Mes), 133.11 (Cmeta, ArO), 132.46 (Cpara, Ph), 131.87
(Cpara, ArO), 130.98 (CCH3, Mes), 130.23 (Cortho, Ph), 128.69
(Cmeta, Ph), 114.60 (Cortho, ArO), 65.63 (CH2O), 16.50 (CH3).
Anal. Calcd for C51H42O6: C, 81.58; H, 5.64. Found: C, 81.69;
H, 5.65. MS(FAB+): m/e 751 ([M + H]+).
131.34 (Ar), 130.75 (Ar), 128.81 (Ar), 128.03 (Ar), 117.59 (Cpara
,
ArO), 114.68 (Cortho, ArO), 108.83 (m, RudCdC), 65.16 (CH2O),
28.82 (virtual triplet, J ) 11 Hz, PCH2CH2P, dppe), 16.04
(CH3). 31P{1H} NMR (δ, CDCl3): 39.69 (s). Anal. Calcd for
C
192H174B3Cl3F12O3P12Ru3: C, 64.58; H, 4.91. Found: C, 63.66;
H, 5.06.
Syn t h esis of C6Me3-1,3,5-{CH 2O(p -C6H 4)CH dCdR u -
Syn th esis of C6Me3-1,3,5-[CH2O(p-C6H4)C(P h )(OH)Ct
CH]3 (5). A 160 mL sample of dry THF was cooled to -100 °C
(pentane/N2). The argon was removed in vacuo, and the
solution was saturated with acetylene gas (2.0 L, 89 mmol).
n-BuLi was added at -100 °C via a syringe (10 mL of a 1.6 M
solution in hexanes, 15.98 mmol), and the solution was stirred
1 h at this temperature. After the slow addition of a solution
of 1,3,5-tris[p-(phenylcarbonyl)phenoxymethyl]mesitylene (4)
(2.00 g, 2.66 mmol) in 60 mL of THF with a syringe the
resulting clear solution was kept at -100 °C for another 1 h,
then slowly warmed to ambient temperature within the cold
bath and stirred at ambient temperature for 48 h. Following
hydrolysis of the excess lithium ethynyl with ice and distilled
water, the emulsion was neutralized with concentrated HCl
and the organic phase was washed with distilled water. The
combined aqueous phases were extracted with ether (2 × 100
mL). The combined organic phases were dried with MgSO4 and
filtrated, and the solvent was evaporated. The obtained
yellowish oily residue was redissolved in a small amount of
CH2Cl2 and purified by flash chromatography (SiO2 (2 × 6 cm)/
pentane): after extraction of the column with 500 mL of
pentane to remove impurities the product was extracted with
300 mL of MeOH. The solvent was removed in vacuo, 20 mL
of THF were added, the solution was stirred for 30 min, and
the ether was evaporated to remove traces of MeOH (which
otherwise cannot be removed even within 16 h in vacuo). The
product was obtained in the form of a light yellowish solid.
Yield: 1.92 g (76 %). IR (KBr): 3539-3423 (m-s, br) and 3282
(s, ν(O-H)), 3058-2913 (w), 2113 (w, ν(CdC)), 1607 (m), 1507
(s), 1448 (w), 1370 (w), 1297 (w), 1237 (vs, ν(C-O), CH2-O-
(P Cy3)2Cl2]3 (7). 1,3,5-Tris(p-ethynylphenoxymethyl)mesity-
lene (3) (303 mg, 0.594 mmol), [(p-cymene)RuCl2]2 (545 mg,
1.78 mmol), and PCy3 (999 mg, 3.56 mmol) were dissolved in
40 mL of toluene, and the suspension was stirred for 24 h at
80 °C to give a dark brown solution. After complete conversion
was confirmed by 31P NMR spectroscopy the solvent was
removed in vacuo and the resulting residue was washed with
dry MeOH (3 × 10 mL). Yield: 1.593 g (99%). IR (KBr): ν
2926 (s), 2849 (s), 1618 (s, ν(CdC), RudCdCHR), 1504 (s),
1446 (s), 1222 (m, b), 1173 (m), 1003 (m), 848 (m), 829 (w-m),
729 (w), 511 (w-m) cm-1
.
1H NMR (δ, CDCl3): 6.85 (s, 12H,
4
Ar), 5.00 (s, 6H, CH2O), 4.33 (t, J PH ) 3.33 Hz, 3H, RudCd
CH), 2.38 (s, 9H, CH3), 2.72-2.47, 2.15-1.92, 2.85-1.43, 1.36-
1.01 (each m, 198H, Cy). 13C{1H} NMR (δ, CDCl3): 345.27 (t,
2J PC ) 14 Hz, RudC), 156.02 (Cipso, ArO), 138.99 (CCH2O),
132.04 (Cpara, ArO), 129.01 (Cipso, CCH3), 126.31 (Cmeta, ArO),
3
114.83 (Cortho, ArO), 107.95 (t, J PC ) 4 Hz, RudCdC), 65.48
(CH2O), 33.15 (virtual triplet, J ) 9 Hz, C1 of Cy), 30.13 (C3,5
of Cy), 28.01 (C2,6 of Cy), 26.95 (C4 of Cy), 15.97 (CH3). 31P{1H}
NMR (δ, CDCl3): 22.02 (s). Anal. Calcd for C144H228Cl6O3P6-
Ru3: C, 63.84; H, 8.48. Found: C, 63.92; H, 8.53.
Syn th esis of C6Me3-1,3,5-{CH2O(p-C6H4)P h CdCdCd
Ru (d p p e)2Cl]BF 4}3 (8). cis-(dppe)2RuCl2 (88 mg, 0.091 mmol)
and AgBF4 (18 mg, 0.091 mmol) were dissolved in 10 mL of
CH2Cl2, stirred for 2 h, and filtrated, and the resulting AgCl
residue was washed with 2 mL of CH2Cl2. The deep red filtrate
was added to a solution of triyne (5) (25 mg, 0.030 mmol) in
10 mL of CH2Cl2, and the reaction mixture was stirred at
ambient temperature for 23 days. Within that time the color
of the solution changed from red to deep violet. After complete
conversion was confirmed by 31P NMR spectroscopy, the
solution was evaporated to dryness to give a violet crystalline
solid. Yield: 113 mg (97%). IR (KBr): ν 3054 (m), 2921 (w),
1925 (vs, b, ν(CdCdC), RudCdCdCR2), 1637 (s, b), 1680 (m),
1503 (s), 1485 (m), 1434 (s), 1231 (s, ν(C-O), CH2-O-Ar), 1057
Ar), 1174 (s), 1050 (w), 1029 (w), 986 (s), 896 (w), 829 (m), 761
3
(w), 699 (m) cm-1
.
1H NMR (δ, CDCl3): 7.70 (d, 6H, J HH
)
8.21 Hz, CHortho, Ph), 7.66 (d, 6H, 3J HH ) 8.81 Hz, CHmeta, ArO),
7.40 (m, 9H, CHmeta, Ph + CHpara, Ph), 7.08 (d, 6H, 3J HH ) 8.81
Hz, CHortho, ArO), 5.14 (s, 6H, CH2O), 3.07 (s, br, 3H, OH),
2.97 (s, 3H, CdCH), 2.49 (s, 9H, CH3). 13C{1H} NMR (δ,
CDCl3): 159.16 (Cipso, ArO), 145.10 (Cipso, Ph), 139.81 (CCH2O,
(s, b), 998 (m), 827 (m), 711 (s), 696 (s), 530 (s), 492 (m) cm-1
.
1H NMR (δ, CDCl3): 7.32-6.64 (m, 147H, Ar), 4.96 (s, 6H,
CH2O), 3.19-2.68 (m, b, 24H, CH2CH2, dppe), 2.49 (s, 9H,
Mes), 137.58 (Cpara, ArO), 132.15 (CCH3, Mes), 128.79 (Cmeta
,
Ph), 128.29 (Cpara, Ph), 127.93 (Cmeta, ArO), 126.46 (Cortho, Ph),
114.73 (Cortho, ArO), 87.10 (CtCH), 75.88 (CtCH), 74.44 (C-
OH), 65.43 (CH2O), 16.38 (CH3). Anal. Calcd for C57H48O6‚
1.5THF: C, 81.27; H, 5.86. Found: C, 80.81; H, 6.04. MS-
(FAB+): m/e 828 ([M - H]+).
2
CH3). 13C{1H} NMR (δ, CDCl3): 208.30 (t, J PC )14 Hz, Rud
C), 204.21 (m, RudCdC), 163.44 (Cipso, ArO), 160.85 (RudCd
CdC), 144.70 (Cipso, Ph, PhC(Ar)dCdCdRu), 140.26 (Cpara
,
ArO), 138.88 (Cipso, CCH2O), 134.86 (Ar), 134.29 (Ar), 133.85
(Ar), 133.61 (Ar), 133.16 (Ar), 133.01 (Ar), 132.86 (Ar), 132.73
(Ar), 132.10 (Ar), 131.96 (Ar), 131.63 (Ar), 131.45 (Ar), 130.81
(Ar), 129.40 (Ar), 129.29 (Ar), 128.96 (Ar), 128.70 (Ar), 128.60
(Ar), 128.45 (Ar), 127.45 (Ar) 115.4 59 (Cpara, ArO), 66.14
(CH2O), 28.0, 16.3. 31P{1H} NMR (δ, CDCl3): 38.64 (s). Anal.
Calcd for C213H186B3Cl3F12O3P12Ru3: C, 66.70; H, 4.89. Found:
C, 65.68; H, 5.19.
Syn th esis of C6Me3-1,3,5-{CH2O(p-C6H4)P h CdCdCd
Ru (P Cy3)(p-cym en e)Cl]OTf}3 (9). Triyne 5‚1.5THF (100 mg,
0.107 mmol) and 3 equiv of [(p-cymene)RuCl(PCy3)]OTf (224
mg, 0.320 mmol) were dissolved in 20 mL of CH2Cl2 and stirred
at room temperature for 55 min. An immediate color change
from red to deep violet was observed. After about 95%
conversion was confirmed by 31P NMR spectroscopy the solvent
was removed under vacuum. At longer reaction times a
degradation of the product 9, which seems to possess a limited
stability in solution, was observed accompanied by a color
change to deep red. Even in the solid state and at low
Syn t h esis of C6Me3-1,3,5-{CH 2O(p -C6H 4)CH dCdR u -
(d p p e)2Cl]BF 4}3 (6). cis-(dppe)2RuCl2 (1.138 g, 1.175 mmol)
and AgBF4 (229 mg, 1.175 mmol) were dissolved in 40 mL of
CH2Cl2, stirred for 2 h, and filtrated, and the formed AgCl
residue was washed with 10 mL of CH2Cl2. The deep red
filtrate was added to a solution of trisalkyne 3 (200 mg, 0.392
mmol) in 10 mL of CH2Cl2, and the reaction mixture was
stirred at ambient temperature for 17 h. Within that time the
color of the solution changed from deep red to light brown.
Complete conversion was confirmed by 31P NMR spectroscopy,
and then the solvent was evaporated to give a brown crystal-
line solid. The product was washed several times with ether
and dried under vacuum. Yield: 1.30 g (89%). IR (KBr): ν 3054
(m), 2921 (w), 1637 (s, br, ν(CdC), RudCdCHR), 1680 (m),
1503 (s), 1485 (m), 1434 (s), 1231 (s), 1057 (s, br), 998 (m),
1
827 (m), 711 (s), 696 (vs), 530 (s), 492 (m) cm-1. H NMR (δ,
3
CDCl3): 7.48-6.83 (m, 120H, Ph, dppe), 6.43 (d, 6H, J HH
)
8.7 Hz, CHmeta, ArO), 5.70 (d, 6H, 3J HH ) 8.5 Hz, CHortho, ArO),

2216 Organometallics, Vol. 22, No. 11, 2003
Weiss and Dixneuf
temperatures around 0 °C slow but continuous decomposition
of compound 9 could be observed. Yield: 298 mg (97%) of about
95% purity. IR (KBr): ν 2930 (m), 2853 (w-m), 1962 (vs, ν(Cd
CdC), RudCdCdCR2), 1586 (m-s), 1506 (w), 1448 (w), 1258
(s, b, ν(C-O), CH2-O-Ar), 1172 (m), 1030 (m), 849 (w), 729
2.75 (m, 3H, CH, i-Pr of p-cymene), 2.53-1.03 (broad super-
positions, 135H, PCy3, CH3 of Mes and p-cymene). The
characterization by 13C NMR spectroscopy was not possible
because of the low long-term stability of 9 in solution. 31P{1H}
NMR (δ, CDCl3): 56.36 (s).
1
(w), 699 (w), 637 (m), 516 (w) cm-1. H NMR (δ, CDCl3): 8.07
(d, 6H, J ) 8.3 Hz, CH, Ar), 7.86 (d, 6H, J ) 8.4 Hz, CH, Ar),
7.71 (t, 3H, J ) 6.8 Hz, CHpara, Ph), 7.50 (t, 6H, J ) 7.6 Hz,
CHmeta, Ph), 7.22 (d, 6H, J ) 8.9 Hz, CH, Ar), 6.58 (d, 3H, J )
6.0 Hz, CH, Ar, p-cymene), 6.49 (d, 3H, J ) 6.6 Hz, CH, Ar,
p-cymene), 6.12 (d, 3H, J ) 6.6 Hz, CH, Ar, p-cymene), 6.00
(d, 3H, J ) 5.8 Hz, CH, Ar, p-cymene), 5.32 (s, 6H, CH2O),
Ack n ow led gm en t . The Alexander von Humboldt
Foundation and the CNRS are gratefully acknowledged
for generously funding this work through a Feodor
Lynen research fellowship.
OM0300326