Compatibility of the vinylidene ligand and perfluorophenoxide

Article abstract of DOI:10.1021/om030646a

The stability of the Ru-vinylidene moiety toward instatllation of a perfluorophenoxide ligand was investigated. Mononuclear complex, containig four nonlabile ligands cis to the vinylidene moiety, was found to be unreactive until it was activated by protonolysis of arlyoxide. The product identities were established by ¹H, ¹³C, and ³¹P NMR and IR spectroscopy, and x-ray crystallography. The results show that the high thermodynamic stability of the ruthenium complex entity, other two complexes exhibited low activity in ring-opening metathesis polymerization of norbornene.

Full text of DOI:10.1021/om030646a

Organometallics 2004, 23, 2583-2590
2583
Com p a tibility of th e Vin ylid en e Liga n d a n d
P er flu or op h en oxid e
Samantha D. Drouin, Heather M. Foucault, Glenn P. A. Yap, and
Deryn E. Fogg*
Center for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa,
10 Marie Curie, Ottawa, Ontario, Canada, K1N 6N5
Received October 28, 2003
This study demonstrates the stability of the Ru-vinylidene moiety toward installation of
a perfluorophenoxide ligand. The room-temperature reaction of RuCl(dcypb)(µ-Cl)3Ru(dcypb)-
(N2) (3) with TlOC6F5 and excess tert-butylacetylene yields mononuclear Ru(OC6F5)2(dcypb)-
(dCdCHBut) (6, dcypb ) 1,4-bis(dicyclohexylphosphino)butane). Intermediates en route to
6 are the face-bridged dimers RuCl(dcypb)(µ-Cl)3Ru(dcypb)(dCdCHBut) (4a ) and [{Ru-
(dcypb)(dCdCHBut)}2(µ-Cl)3]OC6F5 (5‚OC6F5): the cation in the latter was characterized
as its PF6 salt (reaction halting at 5‚PF6 on use of TlPF6 in place of TlOC6F5). Edge-bridged,
dicationic [{RuCl(dcypb)(dCdCHBut)}2(µ-Cl)2](OC6F5)2 (8) is also a probable intermediate
in this reaction pathway: although not observed directly, the dication was isolated in low
yields as its BArf salt, on reaction of 5‚PF6 with NaBArf (BArf - ) [B{C6H3(CF3)2-3,5}4]-).
4
4
4
A minor byproduct in the synthesis of 6 is acetylide Tl[{Ru(CtCBut)(dcypb)}2(µ-Cl)3] (7),
formed by deprotonation of the vinylidene ligand in 5‚OC6F5 by TlOC6F5. (An alternative
representation of 7 as a covalent Ru(µ-Cl)2Tl species is supported by X-ray evidence, at least
in the solid state.) Importantly, the deprotonation reaction is reversible, and competing
reprotonation of 7 by the phenol coproduct enables re-formation of 5‚OC6F5. Nucleophilic
attack by the aryloxide anion on the metal center enables complete and irreversible
transformation to 6, illustrating the mutual compatibility of the vinylidene and perfluo-
rophenoxide ligands. As expected from the high thermodynamic stability of the Ru2(µ-Cl)3
entity, complexes 5‚PF6 and 5‚Cl exhibit low activity in ring-opening metathesis polymer-
ization of norbornene. Mononuclear 6, containing four nonlabile ligands cis to the vinylidene
moiety, is likewise quite unreactive until activated by protonolysis of aryloxide. Product
identities were established by 1H, 13C, and 31P NMR and IR spectroscopy, and (6, 7, 8) X-ray
crystallography.
Ch a r t 1
In tr od u ction
Olefin metathesis by robust, functional-group-tolerant
ruthenium complexes (1a /b, Chart 1; IMes ) N,N′-bis-
(mesityl)imidazol-2-ylidene) is a powerful tool in syn-
thetic organic chemistry.1 The simple chloride ligands
prevalent in the Ru chemistry, however, offer limited
steric definition of the active site and can facilitate
bimolecular deactivation to metathesis-inactive Ru2(µ-
Cl)3 dimers.2 “Pseudohalide” ligands thus hold consider-
able promise for design of novel catalysts with expanded
selectivity and lifetimes. We recently reported the first
highly active Ru-alkylidene catalysts containing pseudo-
halide ligands: in these complexes, the chloride ligands
of 1b are replaced by aryloxide groups.3 Catalyst 2
displayed high activity at very low catalyst concentra-
tions, achieving turnovers of up to 40 000 in ring-closing
metathesis of the benchmark substrate diethyl diallyl-
malonate.
The enhanced robustness and ease of synthesis of
vinylidene derivatives,4 versus alkylidene, prompted our
interest in related Ru-vinylidene species. Such catalysts
promote a range of transformations, including nucleo-
philic addition to alkynes, alkyne coupling, cycloaroma-
tization, and olefin metathesis.4 The vinylidene ligand
is susceptible, however, to deprotonation by alkoxides
and aryloxides4 and can also undergo intramolecular
attack by carboxylates,5,6 alcohols,7 and amides,8a al-
though examples are also known in which vinylidene
ligands are unperturbed by introduction of anionic
* Corresponding author. E-mail: dfogg@science.uottawa.ca. Fax:
(613) 562-5170.
(1) Recent reviews: (a) Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res.
2001, 34, 18. (b) Fu¨rstner, A. Angew. Chem., Int. Ed. 2000, 39, 3012.
(c) Buchmeiser, M. R. Chem. Rev. 2000, 100, 1565.
(2) (a) Amoroso, D.; Yap, G. P. A.; Fogg, D. E. Organometallics 2002,
21, 3335. (b) Amoroso, D.; Snelgrove, J . L.; Conrad, J . C.; Drouin, S.
D.; Yap, G. P. A.; Fogg, D. E. Adv. Synth. Catal. 2002, 344, 757.
(3) Conrad, J . C.; Amoroso, D.; Czechura, P.; Yap, G. P. A.; Fogg,
D. E. Organometallics 2003, 22, 3634.
(4) (a) Bruneau, C.; Dixneuf, P. H. Acc. Chem. Res. 1999, 32, 311.
(b) Bruce, M. I. Chem. Rev. 1991, 91, 197.
(5) Sanford, M. S.; Valdez, M. R.; Grubbs, R. H. Organometallics
2001, 20, 5455.
10.1021/om030646a CCC: $27.50 © 2004 American Chemical Society
Publication on Web 04/21/2004

2584 Organometallics, Vol. 23, No. 11, 2004
Drouin et al.
Sch em e 1. Vin ylid en e (4a ), Allen ylid en e (4b), or
Alk ylid en e (4c) Liga n d s Ar e Obta in ed , Dep en d in g
on th e Na tu r e of th e Alk yn e Su bstitu en t
Sch em e 2
O-O8b or N-O9,10 chelates. In view of this behavior, we
wished to evaluate the compatibility of the vinylidene
ligand with an electron-deficient aryloxide, in which
both basicity and nucleophilicity are much attenuated.
With the intention of restricting reactivity to the aryl-
oxide and vinylidene ligands, we chose to explore this
chemistry with complexes containing a bulky, nonlabile
chelating diphosphine. Dinitrogen-stabilized dimer 311
provides a convenient entry point into dcypb-cumulen-
ylidene complexes, via reaction with terminal alkynes
(Scheme 1).2a,4 We find that a range of dinuclear and
mononuclear vinylidene complexes is accessible on
reaction of 3 with TlOC6F5 and alkyne, in which
perfluorophenoxide functions as counterion or as ligand.
No evidence for attack of aryloxide on CR is found.
Deprotonation of Câ is observed, but this reversible
reaction does not hamper coordination of aryloxide to
the metal to effect quantitative transformation into a
stable Ru(σ-OAr) vinylidene complex.
NMR). Use of excess TlPF6 does not promote further
chloride abstraction.
The identities of 5-7 are supported by spectroscopic
data, by X-ray analysis (vide infra) for 6 and 7, and by
microanalytical data for 5 and 6. The vinylidene ligand
gives rise to a strong IR ν(dCdC) band at 1637 cm-1
and a characteristically low-field NMR triplet for CR at
356.8 or 334.9 ppm for 5 or 6, respectively. The vi-
1
nylidene proton is observed as a H NMR triplet (5, δH
4
3.37; 6, 3.57 ppm; J HP ≈ 3 Hz), which collapses to a
singlet following 31P-decoupling. A sharp singlet due to
the tert-butyl protons (ca. 1.3 ppm) is visible above the
broad, unresolved peaks for the aliphatic dcypb protons.
Complexes 5‚OC6F5 and 5‚PF6 are spectroscopically
identical, neglecting counterion resonances. 31P{1H}
NMR analysis of 5‚PF6 shows, in addition to the high-
field PF6 septet at -144.1 ppm (1J PF ) 705 Hz), a single
AB quartet (44.3, 43.2; 2J PP ) 26 Hz). A symmetry plane
thus relates the two halves of the cation, but not the
Resu lts a n d Discu ssion
We earlier noted that the room-temperature reaction
of 3 with tert-butylacetylene afforded monovinylidene
4a as the sole product, even where the alkyne was
employed in excess (Scheme 1).2a We now find that
addition of TlOC6F5 prior to tert-butylacetylene permits
quantitative transformation of orange 3 into green 6
within 19 h (∼80% isolated yield; Scheme 2, route A).
Reversing this order of addition results in very slow
formation of 6 (19 days, 22 °C; Scheme 2, route B). We
attribute the slow rate of the latter reaction to the
exceptional stability of face-bridged intermediate 5‚
OC6F5 (identified by spectroscopic comparison to the
isolable PF6 salt). Complex 5‚OC6F5 is the major com-
ponent after 22 h, accompanied by 6 and acetylide 7
(ratio 6:3:1). Minor amounts of the acetylide complex
were fortuitously isolated from reactions employing 2
equiv of TlOC6F5, as discussed below. On use of TlPF6
in place of TlOC6F5 (eq 1), reaction is arrested at the
stage of 5‚PF6 (70% isolated yield; quantitative by
two 31P nuclei within a given diphosphine ligand.12
A
similar pattern was reported for [Ru2(µ-Cl)3(PPh3)4(d
CdCdCAr2)2]PF6.13 For 6, the sole 31P NMR resonance
is a singlet at 50.0 ppm, consistent with disposition of
the two equivalent phosphine ligands trans to perfluo-
rophenoxide. In contrast to the vinylidene complexes,
acetylide 7 exhibits a sharp IR band at 2044 cm-1 for
the ν(CtC) stretching vibration, and CR is shifted ca.
200 ppm upfield, to 129 ppm. The location of the tert-
1
butyl singlet in the H NMR spectrum is comparatively
little affected (δH 1.41). A 31P NMR singlet appears at
56.0 ppm.
Acetylide 7 is likely formed in an equilibrium with
cationic 5 (Scheme 3) enabled by the capacity of per-
fluorophenoxide anion to function as a Bronsted, as well
as a Lewis, base. Thus, deprotonation of the vinylidene
ligands initially competes with nucleophilic attack at
the metal. Formation of acetylides by deprotonation at
Câ is well established for both cationic and neutral Ru-
vinylidene complexes;14 a recent example involves reac-
tion of NEt3 with t-[RuCl(dppe)2(dCdCHMe)]PF6.14a
(6) (a) A superficially related example almost certainly involves
attack of carboxylate on
a carbyne species generated in situ by
protonation of a Ru-vinylidene. See: Gonza´lez-Herrero, P.; Webern-
do¨rfer, B.; Ilg, K.; Wolf, J .; Werner, H. Organometallics 2001, 20, 3672.
(b) Gonza´lez-Herrero, P.; Weberndo¨rfer, B.; Ilg, K.; Wolf, J .; Werner,
H. Angew. Chem., Int. Ed. 2000, 39, 3266.
(7) Ru¨ba, E.; Gemel, C.; Slugovc, C.; Mereiter, K.; Schmid, R.;
Kirchner, K. Organometallics 1999, 18, 2275.
(8) (a) Slugovc, C.; Mereiter, K.; Schmid, R.; Kirchner, K. Organo-
metallics 1998, 17, 827. (b) Slugovc, C.; Gemel, C.; Shen, J . Y.; Doberer,
D.; Schmid, R.; Kirchner, K.; Mereiter, K. Monatsh. Chem. 1999, 130,
363.
(9) Opstal, T.; Verpoort, F. J . Mol. Catal. A 2003, 200, 49.
(10) Opstal, T.; Verpoort, F. Synlett. 2002, 935.
(12) NMR analysis does not distinguish between the cisoid and
transoid isomers, though the former is represented in Scheme 2 by
analogy with the crystallographically determined structure for 7: in
principle a 31P NMR singlet would be expected for either structure.
(13) Touchard, D.; Guesmi, S.; Bouchaib, M.; Haquette, P.; Daridor,
A.; Dixneuf, P. H. Organometallics 1996, 15, 2579.
(11) Amoroso, D.; Yap, G. P. A.; Fogg, D. E. Can. J . Chem. 2001,
79, 958.

Compatibility of the Vinylidene Ligand
Organometallics, Vol. 23, No. 11, 2004 2585
Sch em e 3
edge-bridged dimer 8 (eq 3). Only 20% conversion to 8
is observed after 20 h (31P NMR; 52.4 ppm). While the
proportion of 8 increases slightly over a further 24 h in
solution, to a maximum of 30%, residual 5‚PF6 is still
present, and significant decomposition is inferred from
the presence of multiple peaks from 45 to 47 ppm (50%
of total integrated intensity). The identity of 8 was
established by X-ray analysis (vide infra) of crystals that
deposited from solution over 6 days: the crystallo-
graphic observation of two cis-disposed, equivalent
phosphine ligands is consistent with the presence of a
31P NMR singlet in the NMR spectrum of the crude
reaction mixture. The crystals could not be redissolved,
hampering attempts to purify 8 by reprecipitation. IR
analysis of the crude product shows a new dCdC
stretching band at 1610 cm-1 accompanying that for the
starting material. In the 1H NMR spectrum, the vi-
nylidene proton for 8 appears as a broad triplet at 4.13
ppm (4J HP ) 3 Hz), downfield of the characteristic triplet
for 5‚PF6 at 3.37 ppm.
Such reactions have been proposed as an essential
activating step in catalytic coupling15 and stoichiometric
hydration16 of terminal alkynes. Limiting the yields of
7 in the present case (and ultimately permitting com-
plete formation of 6) is reprotonation of the acetylide
ligand by the acidic perfluorophenol coproduct (pKa
5.5).17 Independent reaction of isolated 7 with 10 equiv
of HOC6F5 indeed effects complete transformation into
5‚OC6F5, within 10 min at RT (31P NMR).18 These
observations prompted us to attempt synthesis of 7 via
treatment of 5‚PF6 with TlOEt, which generates the
much weaker conjugate acid ethanol (pKa 18). Isolated
yields of 7 were improved to 40%, although some
decomposition was also evident by NMR analysis: this
could not be separated by reprecipitation, impeding
microanalysis.
Efforts to prepare RuCl(OAr)(dcypb)(dCdCHtBu),
containing one aryloxide per Ru, by protonolysis of 6
with 1 equiv of HCl, were frustrated by disproportion-
ation to 5‚Cl. Addition of a second equivalent of HCl
completed transformation to 5‚Cl (eq 2).19 We have
noted in related work the tendency toward dispropor-
tionation with aryloxide nucleophiles, yielding bis-
(aryloxide) products.20 No evidence was seen in this
chemistry of protonation of the vinylidene to form a
cationic carbyne, or of nucleophilic attack on the vi-
nylidene ligand by the oxygen donor of either the
aryloxide anion or the neutral phenol,4-6,21 consistent
with the attenuated basicity and nucleophilicity of the
OC6F5 entity.
The stability of the Ru2(µ-Cl)3 unit is highlighted by
experiments directed at displacing the vinylidene groups
with CO. Treatment of 5‚Cl with CO in refluxing
chlorobenzene afforded known [{Ru(dcypb)(CO)}2(µ-Cl)3]-
Cl (9)22,23 and RuCl2(dcypb)(CO)2 (10)11 as major prod-
ucts after 48 h (eq 4). Facile displacement of vinylidene
by CO has been reported for several complexes, includ-
ing RuCl(PNP){dC(NHPh)(CH2Ph)}(dCdCHPh) (PNP
) PrnN(CH2CH2PPh2)2),24 RuCl{HB(pz)3}(PPh3)(dCd
CHPh) (pz ) pyrazolyl),25 [RuCl2(TPPMS)2(dCdCPh2)]-
Na2 (TPPMS ) Ph2P(o-C6H4OSO2-),26 and [RuCl(κ2-P,O-
Pri2PCH2CH2OMe)2(dCdCHPh)]OTf.27 We presume that
carbonylation of 5 occurs via an edge-bridged intermedi-
ate of type 8. The observation of nearly equal propor-
tions of mono- and dinuclear, carbonylated products
implies that re-formation of the face-bridged structure
(19) Complexes 5‚Cl and 5‚OC6F5 were identified by comparison of
their spectroscopic features with those of isolated 5‚PF6. The dinuclear
formulation is supported by electrospray mass spectrometric analysis
of 5‚Cl, which revealed a molecular ion peak for the cation at m/z 1409,
with the expected isotope pattern.
(20) Snelgrove, J . L.; Conrad, J . C.; Yap, G. P. A.; Fogg, D. E. Inorg.
Chim. Acta 2003, 345, 268.
In contrast with the experiments involving 5 and 2
equiv of aryloxide, the corresponding reaction of 5‚PF6
with NaBArf4 (BArf - ) [B{C6H3(CF3)2-3,5}4]-) permits
4
abstraction of one bridging chloride and isolation of
(21) Daniel, T.; Mahr, N.; Braun, T.; Werner, H. Organometallics
1993, 12, 1475.
(14) For representative examples, see ref 4 and: (a) Rigault, S.;
Monnier. F.; Mousset, F.; Touchard, D.; Dixneuf, P. H. Organometallics
2002, 21, 2654. (b) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Gonzalez-
Bernardo, C. Organometallics 2001, 20, 5177. (c) Bruce, M. I.; Ellis,
B. G.; Low, P. J .; Skelton, B. W.; White, A. H. Organometallics 2003,
22, 3184. (d) Bustelo, E.; Carbo, J . J .; Lledos, A.; Mereiter, K.; Puerta,
M. C.; Valerga, P. J . Am. Chem. Soc. 2003, 125, 3311.
(15) (a) Bianchini, C.; Innocenti, P.; Peruzzini, M.; Romerosa, A.;
Zanobini, F. Organometallics 1996, 15, 272. (b) Tenorio, M. A. J .;
Puerta, M. C.; Valerga, P. Organometallics 2000, 19, 1333.
(16) Bianchini, C.; Casares, J . A.; Peruzzini, M.; Romerosa, A.;
Zanobini, F. J . Am. Chem. Soc. 1996, 118, 4585.
(17) Birchall, J . M.; Haszeldine, R. N. J . Chem. Soc. 1959, 3653.
(18) Observation of 20% 6 after 20 h presumably reflects dehalo-
genation of 5 by TlOC6F5 coproduct. Complex 6 is a thermodynamic
sink in this reaction manifold, the proportion of which is controlled by
the amount of TlOC6F5 available.
(22) Spectroscopic data do not distinguish between the face-bridged
structure shown in eq 4 and the edge-bridged structure originally
suggested (ref 23). Ongoing work in this laboratory reveals, however,
that the preferred isomer of this and related dimers is strongly solvent-
dependent and that the cationic Ru2(µ-Cl)3 form is favored in chloro-
carbon solvents. Drouin, S. D.; Yap, G. P. A.; Fogg, D. E. Organome-
tallics, in preparation.
(23) Drouin, S. D.; Amoroso, D.; Yap, G. P. A.; Fogg, D. E.
Organometallics 2002, 21, 1042.
(24) Bianchini, C.; Purches, G.; Zanobini, F.; Peruzzini, M. Inorg.
Chim. Acta 1998, 272, 1.
(25) Slugovc, C.; Sapunov, V. N.; Wiede, P.; Mereiter, K.; Schmid,
R.; Kirchner, K. J . Chem. Soc., Dalton Trans. 1997, 4209.
(26) Saoud, M.; Romerosa, A.; Peruzzini, M. Organometallics 2000,
19, 4005.
(27) Martin, M.; Gevert, O.; Werner, H. J . Chem. Soc., Dalton Trans.
1996, 2275.

2586 Organometallics, Vol. 23, No. 11, 2004
Drouin et al.
F igu r e 1. ORTEP diagram for Ru(OC6F5)2(dcypb)(dCd
CHBut), 6. Thermal ellipsoids are shown at the 30%
probability level. For clarity, each cyclohexyl group is
abbreviated to a single carbon and hydrogen atoms are
omitted.
F igu r e 3. ORTEP diagram of the cationic portion of [{Ru-
(dcypb)(dCdCHBut)}2(µ-Cl)2](BArf )2 8. Thermal ellipsoids
4
shown at 30% probability level. For clarity, hydrogen atoms
and BArf counterions are omitted.
4
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Ru (OC6F 5)2(d cyp b)[dCdCH(Bu t)], 6
Ru-P(1)
Ru-P(2)
Ru-C(1)
Ru-O(1)
2.3309(7)
2.3143(6)
1.793(2)
Ru-O(2)
2.0342(16)
1.316(3)
1.305(3)
1.326(3)
C(1)-C(2)
O(1)-C(40)
O(2)-C(46)
2.1260(18)
P(1)-Ru-P(2)
O(1)-Ru-O(2)
O(2)-Ru-P(1)
O(1)-Ru-P(1)
O(2)-Ru-P(2)
O(1)-Ru-P(2)
98.45(2)
88.21(7)
150.38(6)
84.85(5)
82.31(5)
166.16(6)
C(1)-Ru-P(1)
C(1)-Ru-P(2)
C(2)-C(1)-Ru
Ru-O(1)-C(40)
Ru-O(2)-C(46)
C(1)-C(2)-C(3)
85.49(7)
90.19(8)
177.6(2)
134.59(17)
132.81(15)
130.2(2)
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Tl[{Ru (CtCBu t)(d cyp b)}2(µ-Cl)3], 7
Ru-C(1)
Ru-P(1)
Ru-P(2)
Ru-Cl(1)
1.989(5)
Ru-Cl(2)
Ru-Cl(1A)
C(1)-C(2)
Tl-Cl(1)
2.5506(14)
2.5459(13)
1.211(7)
F igu r e 2. ORTEP diagram of Tl[{Ru(CtCBut)(dcypb)}2-
(µ-Cl)3], 7. Thermal ellipsoids shown at 30% probability
level. For clarity, each cyclohexyl group is abbreviated to
a single carbon and hydrogen atoms are omitted.
2.2865(14)
2.2699(15)
2.5211(13)
2.9157(13)
P(1)-Ru-P(2)
P(1)-Ru-Cl(1)
92.62(5)
175.53(5)
C(2)-C(1)-Ru
Cl(1)-Ru-Cl(1A)
Cl(1)-Ru-Cl(2)
172.9(5)
79.61(5)
78.18(4)
77.73(4)
competes with substitution by CO, despite the presence
of CO in excess.
P(2)-Ru-Cl(1A) 170.48(5)
C(1)-Ru-Cl(2)
C(1)-C(2)-C(3)
164.05(14) Cl(1A)-Ru-Cl(2)
170.9(6)
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [{Ru (d cyp b)(dCdCHBu t)}2(µ-Cl)2](BAr f4)2,
8
Ru-C(1)
Ru-P(2)
Ru-P(1)
1.798(4)
2.3210(12)
2.3594(12)
Ru-Cl
2.4500(12)
2.5159(11)
1.308(6)
Ru-Cl#1
C(1)-C(2)
X-r a y An a lysis of 6-8. Crystals of 6, 7, and 8
suitable for X-ray analysis were grown by slow evapora-
tion of CH2Cl2/benzene, benzene, and CH2Cl2 solutions,
respectively. Their ORTEP diagrams are shown in
Figures 1-3, with bond lengths and angles in Tables
1-3. In both mononuclear 6 and dinuclear 8, the Ru
center has approximately square pyramidal geometry,
with apical vinylidene. The two metal centers in 8 are
related by a C2 axis, with transoid vinylidene ligands.
The P(1)-Ru-P(2) bite angle in 6 (98.45(2)°) is larger
than values in bioctahedral complexes of dcypb28 (for
which the value of 92.62(5)° for 7 below is typical), but
is comparable to that found in other Ru-dcypb complexes
(98.45(2)-100.51(7)°),23 including 8 (98.76(9)°). The Ru-
C(1) bond distances of 1.793(2) Å for 6 and 1.798(4) Å
C(1)-Ru-P(2)
C(1)-Ru-P(1)
P(2)-Ru-P(1)
C(1)-Ru-Cl
P(2)-Ru-Cl
P(1)-Ru-Cl
89.06(13)
86.98(13)
98.76(4)
108.66(13)
90.70(4)
C(1)-Ru-Cl#1
P(2)-Ru-Cl#1
P(1)-Ru-Cl#1
C(2)-C(1)-Ru
Cl-Ru-Cl#1
104.01(14)
163.85(4)
91.46(4)
178.4(4)
76.28(4)
125.7(4)
161.94(4)
C(1)-C(2)-C(3)
for 8 are typical for Ru-vinylidenes (cf. values of 1.768-
29
(17) Å in RuBr2(dCdCHtBu)(PPh3)2 and 1.7903 Å in
[RuCl(κ2-P,O-Pri PCH2CH2OMe)2(dCdCHPh)]OTf),27 as
2
are the C(1)-C(2) bond distances of 1.316(3) Å for 6 and
1.308(6) Å for 8. The Ru-O bond lengths in 6 (2.1260-
(18) and 2.0342(16) Å) are similar to values for aryloxide
complexes RuH(OC6H4-p-Me)(CO)(PMe3)3 (2.108(6) Å)30a
and cis-RuH(OC6H4-p-Me)(PMe3)4 (2.145(6) Å),30b as
(28) Amoroso, D.; Haaf, M.; Yap, G. P. A.; West, R.; Fogg, D. E.
Organometallics 2002, 21, 534.
(29) Wakatsuki, Y.; Koga, N.; Yamazaki, H.; Morokuma, K. J . Am.
Chem. Soc. 1994, 116, 8105.

Compatibility of the Vinylidene Ligand
Organometallics, Vol. 23, No. 11, 2004 2587
Ta ble 4. Ru -Ca ta lyzed ROMP of Nor bor n en e
(NBE)a
entry
catalyst
time (min)
% conv
1
2
3
4
5
6
7
5‚Cl
5‚PF6
6
40b
9c
20b
9c
1200
420f
20
1440
120
44d
>99
23
19
>99
6e
6e
11a g,h
11bg
F igu r e 4. Alternative representation of complex 7 as a
covalent, Ru(µ-Cl)2Tl species.
a
Reaction conditions, unless otherwise noted: CH2Cl2 or CD2Cl2
well as those in catalyst 2 (2.076(3), 2.110(3)3 Å). Both
Ru-O bonds in 6 tilt toward the vacant site, and the O
atoms are displaced by 14° and 34° out of the sterically
congested P-Ru-P plane. Alignment of the two per-
fluorophenoxide groups deviates by only 9.3° from
coplanarity, while the centroid-to-centroid distance of
3.28 Å suggests a π-stacking interaction, by comparison
with the interlamellar distance in graphite (3.354 Å).31
We noted a similar interaction between the two per-
fluorophenoxide groups in 2.3
Dinuclear 7 is a cofacial bioctahedron, with a C2 axis
through the chloride bridges, such that only half the
polyhedron is symmetry-independent. This complex
affords a rare example of halide bridges between thal-
lium and transition metals: bonding interactions exist
between the thallium “counterion” and two bridging
chlorides (Tl-Cl ) 2.9157(13) Å), placing the thallium
atom equidistant between the Ru centers (Tl-Ru )
3.437(14) Å). The closest intermolecular approach to
thallium (4 Å) involves a methylene carbon of a cyclo-
hexyl group. The Tl coordination environment is thus
similar to that reported for [Ru(dppe)2(µ2-F)2](Tl)(PF6).32
While Scheme 2 shows 7 as the Tl(I) salt, a comparison
of the Tl-Cl distance with the sum of ionic radii (3.30
Å) suggests that a covalent representation (Figure 4) is
valid, at least in the solid state.
The Ru-C(1) and C(1)-C(2) bond distances (1.989-
(5) and 1.211(7) Å, respectively) are close to those in
Ru(η5-C5Me5)(CtCSiMe3)(PPh3)2 (2.004(4) and 1.213-
(5) Å)33 and ttt-Ru(CtCSiMe3)2(PEt3)2(CO)2 (2.062(2)
and 1.221(2) Å),34 showing little sensitivity to changes
in the ligand environment. The Ru-Ru separation of
3.467(14) Å, similar to that found in [Ru2(µ-Cl)3(PEt2-
Ph)6]+ (3.443(4) Å),35 suggests a repulsive rather than
an attractive metal-metal interaction.36 The acetylide
ligand is nearly linear, with Ru-C(1)-C(2) and C(1)-
C(2)-C(3) bond angles of 172.9(5)° and 170.9(6)°, re-
spectively, the former comparing closely to the Ru-
C(1)-C(2) angle of 173.8(4)° in Ru(η5-C5Me5)-
(CtCSiMe3)(PPh3)2.33
solvent, [norbornene]:[Ru] ) 100, initial [Ru] ) 10 mM, 22 °C;
conversions determined by 1H NMR. Low solubility for isolated
b
polymers precluded GPC analysis. Extreme viscosity prevents
stirring after this time. c Isolated yield. Conversion at 270 min
d
is 11%. Additive: 10 mM [H(OEt2)2]BArf (control experiments
e
4
show no ROMP in the absence of Ru over 24 h). f Solution diluted
g
h
with 1 mL/h CH2Cl2. Ref 37d. Reaction at 40 °C.
and stability; in recent years, numerous Ru-vinylidene
metathesis catalysts have been reported,37 including
examples that show activity under aerobic conditions.37a
Low metathesis activity is anticipated for complexes 5
and 6, in which the coordination sites cis to the
vinylidene ligand are blocked by nonlabile ligands and
in which dissociation to coordinatively unsaturated Ru1
species is inhibited by the high stability of the Ru2(µ-
Cl)3 moiety. We recently reported that such face-bridged
species can function as catalyst sinks in metathesis
chemistry,2a owing to the high stability of the dimers
in noncoordinating solvents. Consistent with this is the
performance of 5‚Cl and 5‚PF6 in ROMP of norbornene
(NBE): at monomer conversions above 8%, the ex-
tremely viscous solutions resisted even dilution, sug-
gesting rates of initiation much lower than propagation
(Table 4). Dramatically higher initiation rates are found
for labile, edge-bridged dimers, which permit access to
monouclear active species.38 In view of the difficulties
in isolating edge-bridged 8 noted above, we attempted
to generate this species in situ in the presence of
norbornene, by treating 5‚PF6 with NaBArf . The rate
of formation of 8 is very slow, however (vide supra), and
the polymerization profile was thus essentially identical
to that observed for catalysis by 5‚PF6.
4
The square pyramidal geometry of 6, in which the
apical vinylidene ligand is cis to four nonlabile phos-
phine or aryloxide donors, was expected to prevent
metathesis until such activity was triggered by (e.g.)
protonolyis of an aryloxide group. Such precisely con-
trollable turn-on behavior, which would enable packag-
ing of precatalyst with monomer, is a target property
in bulk ROMP applications.39 Surprisingly, 6 effects
ROMP of NBE at 22 °C in the absence of additives,
possibly via rate-determining decoordination of one
“arm” of the dcypb ligand or isomerization (vide infra).
Activity is low, however (20 h for 44% conversion;
ROMP via Vin ylid en e Com p lexes. Ruthenium
vinylidene complexes are attractive targets in the design
of novel metathesis catalysts owing to their accessibility
[NBE]:[Ru] ) 100:1), until [H(OEt2)2]BArf is added,
(30) (a) Hartwig, J . F.; Andersen, R. A.; Bergman, R. G. Organo-
metallics 1991, 10, 1875. (b) Osakada, K.; Ohshiro, K.; Yamamoto, A.
Organometallics 1991, 10, 404.
4
following which polymerization is complete in 7 h.40
(31) Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chemistry, 3rd
ed.; J ohn Wiley & Sons: Toronto, 1988.
(32) Barthazy, P.; Togni, A.; Mezzetti, A. Organometallics 2001, 20,
3472.
(33) Kawata, Y.; Sato, M. Organometallics 1997, 16, 1093.
(34) Sun, Y.; Taylor, N. J .; Carty, A. J . Organometallics 1992, 11,
4293.
(35) Alcock, N. W.; Raspin, K. A. J . Chem. Soc., A 1968, 2108.
(36) (a) Crozat, M. M.; Watkins, S. F. J . Chem. Soc., Dalton Trans.
1972, 2512. (b) Cotton, F. A.; Ucko, D. A. Inorg. Chim. Acta 1972, 6,
161. (c) Summerville, R. H.; Hoffmann, R. J . Am. Chem. Soc. 1979,
101, 3821.
(37) For representative examples, see ref 4a and: (a) Louie, J .;
Grubbs, R. H. Angew. Chem., Int. Ed. 2001, 40, 247. (b) Saoud, M.;
Romerosa, A.; Peruzzini, M. Organometallics 2000, 19, 4005. (c)
Schwab, P.; Grubbs, R. H.; Ziller, J . W. J . Am. Chem. Soc. 1996, 118,
100. (d) Katayama, H.; Ozawa, F. Chem. Lett. 1998, 67. (e) del Rio, I.;
van Koten, G. Tetrahedron Lett. 1999, 40, 1401. (f) Katayama, H.;
Yoshida, T.; Ozawa, F. J . Organomet. Chem. 1998, 562, 203.
(38) Hansen, S. M.; Volland, M. A. O.; Rominger, F.; Eisentrager,
F.; Hofmann, P. Angew. Chem., Int. Ed. 1999, 38, 1273.
(39) Dino Amoroso, Promerus LLC (Brecksville, OH), personal
communication.

2588 Organometallics, Vol. 23, No. 11, 2004
Drouin et al.
distilled from sodium under N2. [H(OEt2)2]BArf4 was prepared
by a literature method.42 Thallium and sodium salts (Strem)
and 3,3-dimethyl-1-butyne (Aldrich) were used as received. 1H
NMR (300 or 500 MHz), 31P NMR (121 MHz), and 13C NMR
(75 MHz) spectra were recorded on a Bruker Avance-300 or
Bruker AMX-500 spectrometer. IR spectra were measured on
a Bomem MB100 IR spectrometer. Microanalyses were carried
out by Guelph Chemical Laboratories Ltd., Guelph, Ontario.
[{Ru (d cyp b)(dCdCHBu t)}2(µ-Cl)3]P F 6 (5‚P F 6). (a) A sus-
pension of bright orange 3 (120 mg, 0.094 mmol) and 3,3-
dimethyl-1-butyne (232 µL, 1.88 mmol) in 5 mL of chloroben-
zene was stirred at RT for 18 h, after which time complete
conversion to known2a 4a was confirmed by 31P NMR analysis.
Addition of TlPF6 (33 mg, 0.094 mmol) effected conversion to
5‚PF6 over 3 h. The suspension was filtered through neutral
alumina, the filtrate was reduced in volume, and hexanes were
added to precipitate the pale yellow product, which was
recrystallized from toluene and washed with Et2O and hex-
anes. Yield: 99 mg (70%). 31P{1H} NMR (CD2Cl2, δ): 44.4, 43.2
Periodic dilution was essential for complete reaction
(entry 4). In comparison, ROMP via RuCl2(dcypb)-
(dCHPh) is highly efficient (100% ROMP of 200 equiv
of NBE in <2 min at RT): modeling studies suggested
the energetic accessibility of an isomer with basal
alkylidene,41 precluding the need for phosphine deco-
ordination. It may be noted that the high activity of
perfluorophenoxide catalyst 2 is enabled by loss of the
labile neutral donor pyridine.3
The 6-[H(OEt2)2]BArf system is more active than
4
RuCl2(PR3)2(dCdCHBut) (R ) Ph, 11a , entry 6),37d
attesting to the activating effect of an electron-rich
phosphine, but it is considerably less so than 11b (R )
Cy, entry 7). The latter observation may reflect rate
limitations associated with retention of two bulky
phosphine donors in 6-[H(OEt2)2]BArf . Consistent with
4
enhanced steric definition at the active site is the
increased cis content of the polynorbornene obtained
(25%), relative to that found using 11b (10%; both at
100% conversion).37d
2
1
(ABq, J PP ) 26 Hz), -144.1 (sept, PF6, J PF ) 705 Hz). 1H
4
NMR (CD2Cl2, δ): 3.37 (t, 1 H, RudCdCH, J HP ) 3.9 Hz),
2.71-1.17 (m, 64 H, Cy and CH2 of dcypb; But CH3), 1.22 (s,
But within Cy envelope). 13C{1H} NMR (CD2Cl2, δ): 356.8 (t,
2
RudC, J CP ) 18.6 Hz), 120.8 (s, RuCdC), 40.5-20.6 (ali-
Con clu sion s
phatic). IR (Nujol; cm-1): ν(dCdC) 1636. Anal. Calcd for
C68H124Cl3F6P5Ru2: C, 53.76; H, 8.23. Found: C, 53.48; H, 8.48.
(b) An orange solution of ethereal HCl (150 µL of a 2.0 M
solution; 0.30 mmol) and 6 (150 mg, 0.15 mmol) in 3 mL of
chlorobenzene was stirred at RT for 2 h, after which TlPF6
(26 mg, 0.074 mmol) was added. After a further 2 h, the
suspension was filtered through Celite. Concentration of the
filtrate and addition of toluene and hexanes precipitated the
yellow product, which was filtered off, washed with Et2O, and
reprecipitated from CH2Cl2/hexanes. Yield: 85 mg (76%).
[{Ru (d cyp b)(dCdCHBu t)}2(µ-Cl)3]Cl, 5‚Cl. A solution of
ethereal HCl (60 µL of a 2.0 M solution, 0.12 mmol) and 6 (60
mg, 0.062 mmol) in 5 mL of CH2Cl2 was stirred at RT for 30
min, after which it was concentrated and pentane added. The
orange product was filtered off, washed with pentane, and
reprecipitated from CH2Cl2/pentane. Yield: 33 mg (75%).
Spectroscopic data agree with those for 5‚PF6. ESI-MS: calcd
for C68H124Cl3P4Ru2 (M+) 1409, found m/z 1409.
The foregoing illustrates the differing capacity of
different halide-abstracting agents to cleave the very
stable Ru2(µ-Cl)3 framework of 4a in the presence of
excess tert-butylacetylene, affording access to a range
of vinylidene products. Isolated are dimeric, face-bridged
5‚PF6 (TlPF6), edge-bridged 8 (NaBArf ), or mononuclear
4
6 (TlOC6F5), the major product depending also on the
coordinating ability of the anion. The vinylidene ligand
proves stable against functionalization by perfluoro-
phenoxide. While vinylidene deprotonation was observed
following reaction of 5‚PF6 with TlOC6F5, yielding
acetylide 7, this reaction is reversible, and competing
reprotonation of 7 by the phenol coproduct regenerates
5‚OC6F5. The low ROMP activity of 5‚PF6 and 5‚Cl is
predicted from our earlier identification of Ru2(µ-Cl)3
species as deactivation products accessible from chlo-
roruthenium metathesis catalysts. Indeed, the limited
catalyst lifetimes associated with such deactivation
pathways provide a key motivation for development of
pseudohalide-containing Ru catalysts such as 2. Dem-
onstration of the mutual compatibility of perfluoro-
phenoxide and vinylidene functionalities opens the way
to synthesis and use of vinylidene catalysts related to
2, and we are now pursuing routes to such species.
Ru (OC6F 5)2(d cyp b)(dCdCHBu t), 6. (a) A suspension of
3 (344 mg, 0.270 mmol) and TlOC6F5 (418 mg, 1.08 mmol) in
15 mL of chlorobenzene was stirred at RT for 18 h, over which
time it changed color from orange to brown. 3,3-Dimethyl-1-
butyne (688 µL, 5.59 mmol) was added and stirring continued
for 1 h at RT. The suspension was filtered through Celite.
Concentration of the filtrate and addition of hexanes gave 6
as a green powder, which was washed with MeOH and Et2O
and reprecipitated from CH2Cl2/hexanes. Yield: 410 mg (78%).
X-ray quality crystals were obtained by slow evaporation of a
1
CH2Cl2/C6H6 solution. 31P{1H} NMR (CD2Cl2, δ): 50.0 (s). H
4
Exp er im en ta l Section
NMR (CD2Cl2, δ): 3.57 (t, 1 H, RudCdCH, J HP ) 3.3 Hz),
2.55-1.31(m, 64 H, Cy and CH2 of dcypb; But CH3), 1.33 (s,
But within Cy envelope). 13C{1H} NMR (CD2Cl2, δ): 334.9 (t,
Gen er a l P r oced u r es. All reactions were carried out at RT
(22 °C) under N2 using standard Schlenk or drybox techniques,
unless stated otherwise. Dry, oxygen-free solvents were ob-
tained using an Anhydrous Engineering solvent purification
system and stored over Linde 4 Å molecular sieves. CDCl3,
C6D6, and toluene-d8 were dried over activated sieves (Linde
4 Å) and degassed by consecutive freeze/pump/thaw cycles.
RuCl(dcypb)(µ-Cl)3Ru(dcypb)(N2) (3) was prepared as previ-
ously described.11 Norbornene was purchased from Aldrich and
2
RuC, J CP ) 21.4 Hz), 142.8 (br s, ipso-C of OC6F5), 141.3 (d,
1
1
Ar, J CF ) 237 Hz), 138.3 (d, Ar, J CF ) 244 Hz), 130.9 (d, Ar,
1J CF ) 236 Hz), 126.0 (s, RuCdC), 20-37 (aliphatic). 19F{1H}
NMR (CD2Cl2, δ): -88.10 (m, 2 F), -95.30 (m, 2 F), -106.30
(m, 1 F). IR (Nujol; cm-1): ν(dCdC) 1637. Anal. Calcd for
C
46H62F10O2P2Ru: C, 55.25; H, 6.25. Found: C, 55.15; H, 6.50.
(b) A suspension of 3 (15 mg, 0.012 mmol) and 3,3-dimethyl-
1-butyne (30 µL, 0.24 mmol) in 0.6 mL of chlorobenzene was
stirred at RT for 20 h, as above, after which TlOC6F5 (18.6
mg, 0.048 mmol) was added. Stirring was continued and the
reaction monitored by 31P NMR spectroscopy. After 22 h,
signals for 5‚OC6F5 (58%), 6 (31%), and 7 (11%) were evident.
Slow conversion to 6 was observed (complete after 19 days).
(40) We speculate that activation occurs via initial protonolysis and
dissociation of a perfluorophenoxide ligand. The possibility that
protonolysis occurs at phosphorus seems unlikely in view of in situ
31P NMR experiments that show a single new P-containing species
(72.6 ppm, s) and no evidence of the protonated dcypb ligand.
Consistent with aryloxide protonation is the observation by 19F NMR
of broad multiplets for the free phenol at -87.9 and -93.9 ppm.
(41) Amoroso, D.; Fogg, D. E. Macromolecules 2000, 33, 2815.
(42) Brookhart, M.; Grant, B.; Volpe, A. F. J . Organometallics 1992,
11, 3920.

Compatibility of the Vinylidene Ligand
Organometallics, Vol. 23, No. 11, 2004 2589
Ta ble 5. Cr ysta l Da ta a n d Refin em en t Deta ils for 6, 7, a n d 8
6
7
8
formula
fw
C
46H62F10O2P2Ru
C68H122Cl3P4Ru2Tl
1576.40
C132H148B2Cl2F48P4Ru2
3065.04
999.97
temperature
wavelength
cryst syst, space group
unit cell dimens
203(2) K
0.71073 Å
monoclinic, P2(1)/n
a ) 13.9203(15) Å
R ) 90°
203(2) K
0.71073 Å
monoclinic, C2/c
a ) 14.8162(14) Å
R ) 90°
203(2) K
0.71073 Å
triclinic, P1h
a ) 14.563(2) Å
R ) 68.003(2)°
b ) 15.219(3) Å
â ) 76.178(2)°
c ) 17.602(3) Å
γ ) 86.912(2)°
3509.7(10) Å3
1, 1.450 Mg/m3
0.409 mm-1
b ) 17.5657(19) Å
â ) 91.803(2)°
c ) 18.877(2) Å
γ ) 90°
b ) 20.2544(19) Å
â ) 97.025(2)°
c ) 24.548(2) Å
γ ) 90°
volume
4613.5(9) Å3
7311.4(12) Å3
4, 1.432 Mg/m3
2.840 mm-1
Z, calcd density
absorp coeff
F(000)
4, 1.440 Mg/m3
0.486 mm-1
2072
3240
1564
cryst size
θ range
limiting indices
0.20 × 0.20 × 0.10 mm
1.58 to 28.91°
-18 e h e 18, -23 e k e 22,
-18 e l e 25
31 550/10 720
0.0287
0.05 × 0.05 × 0.03 mm
1.67 to 28.99°
-19 e h e 19, -27 e k e 26,
-30 e l e 31
25 223/8711
0.30 × 0.20 × 0.20 mm
1.44 to 28.71°
-18 e h e 18, -20 e k e 16,
-22 e l e 17
19 818/14 279
0.0283
no. of reflns collected/unique
R(int)
0.0908
max. and min. transmn
no. of data/restraints/params
goodness-of-fit on F2
final R indices [I>2σ(I)]a
1.000000 and 0.860258
10 720/0/550
1.009
R1 ) 0.0353,
wR2 ) 0.0782
R1 ) 0.0529,
wR2 ) 0.0871
0.929 and -0.565 e‚Å-3
0.9196 and 0.8710
8711/0/353
1.000
R1 ) 0.0572,
wR2 ) 0.0704
R1 ) 0.1193,
wR2 ) 0.0831
1.210 and -1.160 e‚Å-3
0.9226 and 0.8870
19 818/14 279
1.017
R1 ) 0.0642,
wR2 ) 0.1356
R1 ) 0.0982,
wR2 ) 0.1549
1.255 and -1.019 e‚Å-3
R indices (all data)
largest diff peak and hole
Definition of R indices: R1 ) ∑(Fo - Fc)/∑(Fo); wR2 ) [∑[w(Fo - Fc2)2] /∑[w(Fo2)2]]1/2
.
a
2
2
Tl[{Ru (CtCBu t)(d cyp b)}2(µ-Cl)3], 7. (a ) Via Dep r oto-
n a tion of 5‚P F 6. Addition of TlOEt (20 µL, 0.34 mmol) to a
stirred solution of 5‚PF6 (90 mg, 0.060 mmol) in 3 mL of
toluene gave a bright yellow solution, which was stirred at
RT for 2 h and then filtered through Celite and neutral
alumina. Concentration of the filtrate and addition of hexanes
precipitated the product, which was filtered off, washed with
hexanes, and reprecipitated from THF/hexanes to yield 38 mg
(39%) of yellow 7 (contaminated, however, by unknown
product(s) observed as a broad multiplet at 44.3 ppm in the
31P NMR spectrum; 5-15% integrated intensity). 31P{1H} NMR
2J PP ) 23 Hz, 10), 17.1 (d, J PP ) 23 Hz, 10). Unidentified
byproducts (several overlapping peaks at δP 20 ppm) account
for 23% of the total integrated intensity.
[{Ru (d cyp b)(dCdCHBu t)}2(µ-Cl)2](BAr f4)2, 8. A solution
of 5‚PF6 (15 mg, 10 µmol) in 0.7 mL of CH2Cl2 was stirred at
RT as NaBArf (19 mg, 20 µmol) was added. After 20 h, a new
4
31P NMR singlet was observed at δP 52.4, accompanying that
for 5 (ratio 1:4). After 44 h, the proportion of 8 reached 30%;
after 6 days, no 31P signal could be observed in solution, but
dark brown, X-ray quality crystals of 8 had deposited. 31P{1H}
NMR (CD2Cl2, δ): 52.4 (s, 50% of total integrated intensity),
other peaks include 5‚PF6 (44.4, 43.2, ABq), and several
unidentified multiplets between 47 and 45 ppm (not present
in the spectrum of the crude reaction mixture). 1H NMR (CD2-
Cl2, δ): 7.72 (br s, BArf ), 7.57 (br s, BArf ), 4.13 (t, 1 H, Rud
1
for 7 (C6D6, δ): 56.0 (br s). H NMR (C6D6 δ): 3.31-1.10 (m,
Cy and CH2 of dcypb; But CH3), 1.41 (s, But within Cy
envelope). 13C{1H} NMR (THF-d8, δ): 129.1 (br s, RuCtCBut);
(C6D6, δ): 66.0 (br s, RuCtCBut). IR (Nujol; cm-1): ν(CtC)
2044.
4
4
4
4
CdCH, J HP ) 3 Hz, 8), 3.37 (t, 1 H, RudCdCH, J HP ) 3.9
Hz, 5‚PF6), 1.17-2.85 (br, Cy and CH2 of dcypb; But CH3), 1.27
(s, But within Cy envelope). 19F{1H} NMR (CD2Cl2, δ): 12.56
(b) Isola ted a s a Byp r od u ct in Syn th esis of 6. A mixture
of 3 (100 mg, 0.079 mmol) and TlOC6F5 (61 mg, 0.16 mmol) in
10 mL of CH2Cl2 was stirred at RT for 10 min. The solvent
was then removed under vacuum, the orange residue redis-
solved in 25 mL of THF, and 3,3-dimethyl-1-butyne (195 µL,
1.58 mmol) added by syringe. The solution was stirred at RT
for 15 h, then filtered through Celite. The filtrate was
concentrated, hexanes were added, and the yellow precipitate
was filtered off, washed with Et2O and hexanes, and dried
under vacuum. Yield: 20 mg (16%). 31P NMR analysis of the
filtrate revealed a mixture of 6 (40%), 5‚Cl (52%), and 7 (8%).
X-ray quality crystals were obtained by slow evaporation of a
benzene solution of isolated 7.
(s, BArf ). IR (CH2Cl2; cm-1): ν(CdC) 1610 (8) and 1638 (5‚
4
PF6).
Gen er al P r ocedu r e for P olym er ization of Nor bor n en e.
A solution of norbornene (65 mg, 0.70 mmol) in 350 µL of CD2-
Cl2 was added to a rapidly stirred solution of 5 or 6 (7.0 µmol
of RudC) in CD2Cl2 (350 µL). The reaction was monitored by
1H NMR. [H(OEt2)2]BArf , if required, was added to the Ru
4
solution prior to addition to monomer (6.9 mg, 7.0 µmol).
Catalyst 5‚Cl was generated in situ by addition of HCl (7.0
µmol) to the solution of 6 prior to adding monomer. For ROMP
catalyzed by 5‚Cl or 5‚PF6, reactions were continued until high
viscosity prevented further stirring (20 min), following which
the polymer was precipitated by addition of MeOH, dried, and
weighed.
P r ot on a t ion of Acet ylid e 7 b y H OC6F 5. Pentafluoro-
phenol (24 mg, 0.13 mmol) was added to a stirred solution of
7 (15.5 mg, 0.010 mmol) in 0.7 mL of benzene. 31P NMR
analysis after 10 min revealed complete conversion to 5‚OC6F5.
After 20 h, the singlet for 6 (18%) was also present.
Ca r bon yla tion of [{Ru (d cyp b)(dCdCHBu t)}2(µ-Cl)3]Cl,
5‚Cl. A solution of 5‚Cl (10.6 mg, 7.5 µmol) in chlorobenzene
(2 mL) was refluxed under CO (1 atm) for 48 h. 31P NMR
showed a mixture of ccc-RuCl2(dcypb)(CO)2 (10,11 33%) and
[{Ru(dcypb)(CO)}2(µ-Cl)3]Cl (9,22,23 43%). 31P{1H} NMR (CDCl3,
Str u ctu r a l Deter m in a tion of 6-8. Suitable crystals were
selected, mounted on thin glass fibers using paraffin oil, and
cooled to 203(2) K. Data were collected on a Bruker AX SMART
1k CCD diffractometer using 0.3° ω-scans at 0°, 90°, and 180°
in φ; λ 0.71073 Å. Initial unit-cell parameters were determined
from 60 data frames collected at different sections of the Ewald
2
2
δ): 50.8 (d, J PP ) 23 Hz, 9), 42.5 (d, J PP ) 23 Hz, 9), 39.4 (d,

2590 Organometallics, Vol. 23, No. 11, 2004
Drouin et al.
sphere. Semiempirical absorption corrections based on equiva-
lent reflections were applied (SADABS, Bruker AXS, Madison,
WI, 2000).
scattering factors are contained in the SHELXTL 6.12 program
library.43 Table 5 compiles the data for the structure deter-
minations.
Systematic absences in the diffraction data and unit-cell
parameters for 6 were uniquely consistent with the space
group P2(1)/n. Those for 7 were consistent with C2/ c (No. 15)
and Cc (No. 9), while no symmetry higher than triclinic was
observed in the diffraction data for 8. For both 7 and 8, solution
in the centrosymmetric space group option yielded chemically
reasonable and computationally stable results of refinement.
Structures were solved by direct methods, completed with
difference Fourier syntheses, and refined with full-matrix
least-squares procedures based on F2. In the case of 7, the
molecule is located at a 2-fold axis; for 8, the dimeric dication
was located at the inversion center. All non-hydrogen atoms
were refined with anisotropic displacement parameters. All
hydrogen atoms were treated as idealized contributions. All
Ack n ow led gm en t. This work was supported by the
Natural Sciences and Engineering Research Council of
Canada, the Canada Foundation for Innovation, the
Ontario Innovation Trust, and the Ontario Research
and Development Corporation.
Su p p or tin g In for m a tion Ava ila ble: NMR spectra for 7
and 8, and tables of crystal data collection, refinement
parameters, atomic coordinates, bond lengths and angles,
anisotropic displacement parameters, and hydrogen coordi-
nates for 6-8. This material is available free of charge via
the Internet at http://pubs.acs.org.
(43) Sheldrick, G. M. SHELXTL 6.12; Bruker AXS: Madison, WI,
2001.
OM030646A