Reactivity of [TpRuCl(PTA)(PPh3)] with alkynes and propargylic alcohols: Occurrence of structurally related cationic vs neutral allenylidene complexes with the ruthenium hydrotris(pyrazolyl)borate moiety

Article abstract of DOI:10.1021/om9005142

[TpRuCl(PTA)(PPh₃)] (1; PTA = l,3,5-triaza-7-phosphaadamantane) reacts with phenylacetylene, yielding the alkynyl complex [TpRu(C≡CPh) (PTA)(PPh₃)] (2) or the neutral vinylidene complex [TpRuCl{C=C(H)Ph}(PTA)] (4), depending on the solvent and the reaction conditions (Tp = hydrotris(pyrazolyl)borate). Protonation of 2 with HOTf(OTf = OSO₂CF₃) in CH₂Cl₂ yields the dicationic vinylidene compound [TpRu{C=C(H)Ph}{PTAH}(PPh₃)](OTf) ₂ (3), bearing a N-protonated PTA ligand. Reaction of 1 with 1,1-diphenyl-2-propyn-l-ol affords the new cationic compound [TpRu(C=C=CPh ₂)(PTA)(PPh₃)]PF₆ (5) or neutral allenylidene compound [TpRuCl(C=C = CPh₂)(PTA)] (6), depending on the reaction solvent (MeOH or toluene, respectively). The reactivity of complexes 5 and 6 toward tertiary phosphines (PTA and PPh₂Me) has been investigated. Remarkably, both the cationic and the neutral allenylidene compounds undergo regioselective nucleophilic attack at the allenylidene Ca position to give the cr-allenyl-phosphonium complexes [TpRu{C(L)=C=CPh₂}(PTA)(PPh ₃)]PF₆ (L = PPh₂Me (8), PTA (9)) and [TpRuCl{C(L)= C=CPh₂)(PTA)] (L = PTA (10), PPh₂Me (11)), respectively. Noticeably, the reaction goes to completion in the case of the neutral allenylidene complex 6, whereas an equilibrium between the phosphonioallenyl adduct and the educt species is observed in the case of the cationic allenylidene compound 5. The thermodynamic parameters for such an equilibrium have been determined by NMR methods at different temperatures. Finally, the hydrolysis of the neutral allenylidene 6 has been briefly considered, showing the formation of the carbonyl compound [TpRuCl(CO)(PTA)] (7).

Full text of DOI:10.1021/om9005142

6020 Organometallics 2009, 28, 6020–6030
DOI: 10.1021/om9005142
Reactivity of [TpRuCl(PTA)(PPh3)] with Alkynes and Propargylic
Alcohols: Occurrence of Structurally Related Cationic vs Neutral
Allenylidene Complexes with the Ruthenium Hydrotris(pyrazolyl)borate
Moiety
,†
†
†
†
~
ꢀ
Sandra Bolano,* M. Mar Rodrıguez-Rocha, Jorge Bravo, Jesus Castro,
´
‡
Enrique Onate, and Maurizio Peruzzini*
,§
~
†
´
Departamento de Quımica Inorganica, Universidad de Vigo, Lagoas-Marcosende, 36310 Vigo, Spain,
Departamento de Quımica Inorganica, Instituto de Ciencia de Materiales de Aragon, Universidad de
ꢀ
ꢀ
‡
´
ꢀ
§
Zaragoza-CSIC, 50009 Zaragoza, Spain, and ICCOM-CNR, Via Madonna del Piano 10, 50019
Sesto Fiorentino, Firenze, Italy
Received June 16, 2009
[TpRuCl(PTA)(PPh3)] (1; PTA = 1,3,5-triaza-7-phosphaadamantane) reacts with phenylacety-
lene, yielding the alkynyl complex [TpRu(CtCPh)(PTA)(PPh3)] (2) or the neutral vinylidene
complex [TpRuCl{CdC(H)Ph}(PTA)] (4), depending on the solvent and the reaction conditions
(Tp = hydrotris(pyrazolyl)borate). Protonation of 2 with HOTf (OTf = OSO2CF3) in CH2Cl2 yields
the dicationic vinylidene compound [TpRu{CdC(H)Ph}{PTAH}(PPh3)](OTf)2 (3), bearing a
N-protonated PTA ligand. Reaction of 1 with 1,1-diphenyl-2-propyn-1-ol affords the new cationic
compound [TpRu(CdCdCPh2)(PTA)(PPh3)]PF6 (5) or neutral allenylidene compound [TpRuCl-
(CdC=CPh2)(PTA)] (6), depending on the reaction solvent (MeOH or toluene, respectively). The
reactivity of complexes 5 and 6 toward tertiary phosphines (PTA and PPh2Me) has been investigated.
Remarkably, both the cationic and the neutral allenylidene compounds undergo regioselective
nucleophilic attack at the allenylidene CR position to give the σ-allenyl-phosphonium complexes
[TpRu{C(L)dCdCPh2}(PTA)(PPh3)]PF6 (L = PPh2Me (8), PTA (9)) and [TpRuCl{C(L)d
CdCPh2}(PTA)] (L = PTA (10), PPh2Me (11)), respectively. Noticeably, the reaction goes to
completion in the case of the neutral allenylidene complex 6, whereas an equilibrium between
the phosphonioallenyl adduct and the educt species is observed in the case of the cationic allenyli-
dene compound 5. The thermodynamic parameters for such an equilibrium have been determined
by NMR methods at different temperatures. Finally, the hydrolysis of the neutral allenylidene
6 has been briefly considered, showing the formation of the carbonyl compound [TpRuCl(CO)-
(PTA)] (7).
Introduction
Cp (cone angles of 183° for Tp and 100° for Cp).2 In addition,
and as far as ruthenium is concerned, the Tp ligand, generally
conforming to a facial disposition in octahedral complexes,
disfavors higher coordination numbers of the metal center,
so that processes involving an increase of the coordination
number (oxidative additions, associative substitutions, etc.)
are very rare. On the other hand and in spite of the many
similarities, there are also significant differences of the
frontier orbitals dictating the stereochemistry of the final
complexes. Thus, Cp is essentially a π-donor, whereas Tp
also behaves as a good σ-donor. In the case of Tp, the
π-bonding properties of the ligand may come into play in
the presence of π-accepting coligands, such as CO.3
The investigation of the chemistry of complexes bearing
the {TpRu} moiety (Tp = hydrotris(pyrazolyl)borate) has
dramatically accelerated in the past decade, the formal
similarity of the Tp ligand to the most widely employed Cp
ligand being one of the most important motivations for most
of these studies.1 Although the topology of both ligands
predisposes their complexes toward pseudo-octahedral geo-
metry, Tp exhibits a significantly greater steric profile than
*To whom correspondence should be addressed. E-mail: bgs@
uvigo.es (S.B.); maurizio.peruzzini@iccom.cnr.it (M.P.).
(1) (a) Trofimenko, S. Scorpionates: Polypyrazolylborate Ligands
and Their Coordination Chemistry; World Scientific: Singapore, 1999.
(b) Trofimenko, S. Scorpionates: The Coordination Chemistry of Poly-
pyrazolborate Ligands; Imperial College Press: London, 1999. (c) Adv-
ances in Organometallic Chemistry; West, R., Hill, A. F., Fink, M. J., Eds.;
Academic Press: New York, 2008; Vol. 56. (d) Pettinari, C. Scorpionates II:
Chelating Borate Ligands; Imperial College Press: London, 2008.
(2) Trofimenko, S.; Calabrese, J. C.; Thompson, J. S. Inorg. Chem.
1987, 26, 1507.
Following the recent increased interest in the chemistry of
CpRu complexes supported by water-soluble phosphines
(3) Becker, E.; Pavlik, S.; Kirchner, K. The Organometallic Chem-
istry of Group 8 Tris(pyrazolyl)borate Complexes. In Advances in
Organometallic Chemistry; West, R., Hill, A. F., Fink, M. J., Eds.; Academic
Press: New York, 2008; Vol. 56, p 155.
r
pubs.acs.org/Organometallics
Published on Web 09/23/2009
2009 American Chemical Society

Article
Organometallics, Vol. 28, No. 20, 2009 6021
such as 1,3,5-triaza-7-phosphaadamantane (PTA),4 we have
recently reported the first example of TpRu complexes
bearing PTA as ancillary ligand, either alone or in combina-
tion with other hydrosoluble, {N-B-PTA(BH3)}, or hydro-
phobic, PPh3, phosphines.5
The crystal structure of the cationic ruthenium(II) R-
phosphonioallenyl compound [TpRu{C(PTA)dCdCPh2}-
(PTA)(PPh3)](PF6) (9) has been also determined to supple-
ment the scarce crystallographic library of this kind of
ruthenium complex studied by X-ray difraction analysis.9
We decided therefore to start an in-depth study of the
chemistry of the intriguing [TpRu(PTA)] fragment. Here,
we report our first results in this area, describing the behavior
of such a moiety as a versatile precursor for the synthesis of
ruthenium unsaturated carbenes such as vinylidenes and
allenylidenes. A rationale for this investigation comes from
the observation that [TpRuCl(PTA)(PPh3)] (1) fulfills a priori
all the requisites necessary for achieving metallacumulene
complexes. These call for metal precursors capable of gener-
ating(normallyina preliminary step) a 16-electron speciesstill
endowed with reactivity toward the organic molecule from
which the unsaturated carbenes may be generated.
Among the results here presented is the remarkable synth-
esis, following Selegue’s protocol,6 from the common pre-
cursor 1 of the pair of related allenylidene species
[TpRu(CdCdCPh2)(PTA)(PPh3)]PF6 (5) and [TpRuCl(Cd
CdCPh2)(PTA)] (6), depending on the polarity of the reac-
tion solvent (MeOH vs toluene). The two complexes repre-
sent rare examples of structurally related cationic and
neutral Ru(II) allenylidenes showing a controllable and
partially diverging reactivity toward nucleophiles. In parti-
cular, addition of tertiary phosphines (PTA or PPh2Me) to
either 5 or 6 results in the formation of R-phosphonioallenyl
species upon delivery of the added phosphine to the CR
allenylidene carbon atom. Although such regioselectivity is
not unusual,7,8 the reaction does not go to completion in the
case of 5, allowing us to calculate for the first time the
thermodynamic parameters of the equilibrium 5 T 1 þ
PR3. In contrast, the neutral allenylidene complex
[TpRuCl(CdCdCPh2)(PTA)] (6) displays an enhanced elec-
trophilic behavior, reacting irreversibly and instantaneously
with tertiary phosphines, to yield [TpRuCl{C(PTA)d
CdCPh2}(PTA)] (10) and [TpRuCl{C(PPh2Me)dCd
CPh2}(PTA)] (11), which represent rare examples of neutral
R-phosphonioallenyl compounds.
Results and Discussion
1. Reaction of [TpRuCl(PTA)(PPh3)] (1) with Phenylace-
tylene. Complex 1 reacts with phenylacetylene, giving differ-
ent products depending on the solvent and the reaction
conditions as well (Scheme 1).
2. Reaction of 1 in MeOH: Synthesis of the Alkynyl
Complex [TpRu(CtCPh)(PTA)(PPh3)] (2). [TpRuCl(PTA)-
(PPh3)]5 (1) reacts with HCtCPh in MeOH at 60 °C,
affording the neutral alkynyl complex [TpRu(CtPh)(PTA)-
(PPh3)] (2) as a yellow solid in high yield. In contrast with
previous findings,10 the reaction with phenylacetylene pro-
ceeds directly to give the neutral alkynyl complex, without
traversing the cationic vinylidene species, which in a subse-
quent deprotonation step may afford the alkynyl 2. 31P{1H}
NMR monitoring of the reaction at room temperature and
near the reflux temperature of MeOH does not show any
intermediate compound. Complex 2 is not soluble in water
and does not react with it. Thus, a suspension of 2 in water
may be heated at 100 °C for 24 h without decomposition. The
IR spectrum (KBr) shows a strong band at 2076 cm-1
characteristic for ν(CtC), as found for other neutral TpRu-
(II) alkynyl complexes.10,11 A weak-intensity νBH vibration is
found at 2472 cm-1 which is characteristic of the B-H
stretching in hydrotris(pyrazolyl)borate bonded to a metal
center.12 Compound 2 was fully characterized in solution by
multinuclear (1H, 31P{1H}, 13C{1H}) and multidimensional
((1H,1H) COSY and (1H,13C) HSQC) NMR experiments.
Both 1H and 13C{1H} NMR spectra of 2 in CD2Cl2 show the
expected signals and do not deserve any particular comment,
apart from the presence of two distinct resonances in the 13C
NMR spectrum ascribable to the CR (126.8 ppm, collapsed
double doublet, 2JCP = 19.1 Hz) and Cβ (111.2 ppm, singlet)
alkynyl carbons. In keeping with the proposed formula, the
31P{1H} NMR spectrum shows two doublets at δ -31.8 and
53.8 ppm (2JPP = 3.7 Hz) assignable to PTA and PPh3
phosphine ligands, respectively. The X-ray crystal structure
of 2 was determined, and an ORTEP view of the molecule is
shown in Figure 1. Relevant bond lengths and angles are
given in Table 1.
(4) (a) Phillips, A. D.; Gonsalvi, L.; Romerosa, A.; Vizza, F.;
Peruzzini, M. Coord. Chem. Rev. 2004, 248, 955. (b) Gonzalez, B.;
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Complex 2 consists of an octahedral coordinated ruthe-
nium atom. Ligands are a N,N0,N00-tridentate tris(pyra-
zolyl)borate (Tp), a P-coordinated 1,3,5-triaza-7-phosphaa-
damantane (PTA), a triphenylphosphine (PPh3), and a
κC-phenylethynyl ligand. The resulting core is RuN3P2C.
There is some distortion in the octahedron, mainly due to
both the chelate angle of the Tp ligand, with N-Ru-N
~
Peruzzini, M. Angew. Chem., Int. Ed. 2005, 44, 2568. (f) Bolano, S.;
Gonsalvi, L.; Zanobini, F.; Vizza, F.; Bertolasi, V.; Romerosa, A.; Peruzzini,
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Sierra-Martin, B.; Fernandez-Barbero, A. Angew. Chem., Int. Ed. 2008, 47,
8665. (h) Romerosa, A.; Saoud, M.; Campos-Malpartida, T.; Lidrissi, C.;
Serrano-Ruiz, M.; Peruzzini, M.; Garrido, J. A.; García-Maroto, F. Eur. J.
Inorg. Chem. 2007, 2803. (i) Romerosa, A.; Campos-Malpartida, T.; Lidrisi,
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C.; Saoud, M.; Serrano-Ruiz, M.; Peruzzini, M.; Garrido-Cardenas, J. A.;
García-Maroto, F. Inorg. Chem. 2006, 45, 1289. (j) Bosquain, S. S.; Dorcier,
A.; Dyson, P. J.; Erlandsson, M.; Gonsalvi, L.; Laurenczy, G.; Peruzzini, M.
Appl. Organomet. Chem. 2007, 21, 947. (k) Rossin, A.; Gonsalvi, L.;
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(9) (a) Esteruelas, M. A.; Gomez, A. V.; Lopez, A. M.; Modrego, J.;
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Phillips, A. D.; Maresca, O.; Lledos, A.; Peruzzini, M. Organometallics
Onate, E. Organometallics 1998, 17, 5434. (b) Arikawa, Y.; Asayama, T.;
Tanaka, C.; Tashita, S.; Tsuji, M.; Ikeda, K.; Umakoshi, K.; Onishi, M.
Organometallics 2008, 27, 1227. (c) Nishimura, Y.; Arikawa, Y.; Inoue, T.;
2007, 26, 3289.
~
(5) Bolano, S.; Bravo, J.; Castro, J. A.; Rodrıguez-Rocha, M. M.;
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Guedes da Silva, M. F. C.; Pombeiro, A. J. L.; Gonsalvi, L.; Peruzzini,
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(6) Selegue, J. P. Organometallics 1982, 1, 217.
(7) Cadierno, V.; Crochet, P.; Gimeno, J. Preparation and Stoichio-
metric Reactivity of Metal Allenylidene Complexes. In Metal Vinyli-
denes and Allenylidenes in Catalysis; Wiley-VCH: Weinheim, Germany,
2008; p 61.
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Valerga, P. Coord. Chem. Rev. 1999, 193-195, 977.
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D.; Puerta, M. C.; Valerga, P. J. Organomet. Chem. 2004, 689, 2776.
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R.; Kirchner, K. J. Chem. Soc., Dalton Trans. 1997, 4209.

~
Bolano et al.
6022 Organometallics, Vol. 28, No. 20, 2009
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˚
Table 1. Selected Bond Distances (A) and Angles (deg) for
[TpRu(CtCPh)(PTA)(PPh3)] (2)
Ru(1)-C(1)
Ru(1)-N(41)
Ru(1)-P(1)
C(1)-C(2)
1.949(14)
2.171(12)
2.276(3)
Ru(1)-N(45)
Ru(1)-N(43)
Ru(1)-P(2)
C(2)-C(3)
2.102(12)
2.193(11)
2.320(4)
1.45(2)
1.246(19)
C(1)-Ru(1)-N(45)
N(45)-Ru(1)-N(41)
N(41)-Ru(1)-N(43)
N(45)-Ru(1)-P(1)
C(1)-Ru(1)-P(2)
N(43)-Ru(1)-P(2)
N(41)-Ru(1)-P(1)
N(45)-Ru(1)-P(2)
C(1)-C(2)-C(3)
85.6(5)
80.6(4)
86.9(4)
88.9(3)
91.2(4)
96.2(3)
168.7(3)
172.9(3)
175.7(18)
C(1)-Ru(1)-N(41)
N(45)-Ru(1)-N(43)
C(1)-Ru(1)-P(1)
N(43)-Ru(1)-P(1)
N(41)-Ru(1)-P(2)
P(1)-Ru(1)-P(2)
C(1)-Ru(1)-N(43)
C(2)-C(1)-Ru(1)
92.2(5)
87.0(4)
91.2(4)
88.3(3)
93.2(3)
97.46(13)
172.6(5)
172.2(13)
backbone shows that the Ru-C bond distance (1.95(1) A) is
relatively shorter with respect to the known ruthenium(II)
alkynyl complexes (dRu-C(sp)(av) = 2.02 A),13 while the
C(1)-C(2) bond distance (1.25(2) A) is relatively longer than
those reported in the literature. The bond lengths found in
the Ru(II)-alkynyl moiety of 2 suggest an important con-
tribution of the zwitterionic vinylidene resonance form
[Ru]-dCdCþ-Ph to represent the bond situation exhibited
by the alkynyl ligand. Finally, the angles Ru-C(1)-C(2) of
172.2(13)° and C(1)-C(2)-C(3) of 175.7(18)° are almost
linear.
Figure 1. ORTEP representation of complex 2. Thermal ellip-
soids are drawn at the 20% probability level. The phenyl groups
of the PPh3 are not shown, their positions being indicated by the
three ipso carbons of the aromatic rings. All of the hydrogen
atoms, except for that of the hydroborate, are omitted for the
sake of clarity.
3. Reaction of the Alkynyl Compound 2 with HOTf. Synth-
esis of the Dicationic Vinylidene Complex [TpRu{CdC(H)-
Ph}{PTAH}(PPh3)](OTf)2 (3). The addition of strong protic
acids to a terminal alkynyl ligand is a straightforward
method to achieve vinylidene compounds. In the case of 2,
the three nitrogen donors of the PTA ligand may, however,
represent a competitive target for electrophiles. Thus, it
seemed of interest to study the reactivity of 2 toward protic
substrates to see which between the vinylidene or the proto-
nated PTA ligand is the preferred product of the protonation
reaction. A sample of compound 2 dissolved in a NMR tube
test (CD2Cl2) was therefore treated sequentially with incre-
mental aliquots of HOTf, and the reaction was monitored by
1H and 31P{1H} NMR spectroscopy (see Figure 2).
Scheme 1
The first addition broadens both doublets of the starting
product (-31.8 and 53.8 ppm) in the 31P{1H} NMR spec-
trum and transforms the 1H NMR singlet at 3.8 ppm, due to
the PCH2N PTA protons, into an AB system, indicating that
protonation of the PTA ligand has occurred.4a By addition
of further aliquots of triflic acid, a new pair of doublets in the
31P{1H} NMR spectrum appears (-34.05 and 34.16 ppm)
which progressively replaces the original one. At the same
time, the two PTA proton multiplets in the 1H NMR
spectrum broaden significantly, suggesting that extensive
proton exchanging processes likely involving both PTA
and protonated alkynyl ligands takes place. Finally, addition
angles ranging from 80.6(4) to 87.0(4)°, and the steric
requirement of the bulky PPh3 ligand. In fact, if the octahe-
dron is defined with the PPh3 ligand in an axial position, the
resulting equatorial plane is significantly bent out of the
PPh3 ligand with all the cis angles around the PPh3 ligand
greater than 90°.
The Ru-N bond distances range from 2.10(1) A (trans to
the PPh3 phosphorus atom) to 2.19(1) A, which refers to the
Ru-N bond length trans to the phenylalkynyl ligand and
reflects the stronger trans influence of this ligand.
The Ru-P bond distances, 2.320(4) A (Ru-PPh3) and
2.276(3) A (Ru-PTA), are similar to those found in other
Ru(II) complexes containing the same ligands disposed
trans to a Tp nitrogen atom.5 Inspection of the Ru-C-C
1
of a slight excess of acid sharpens both 31P and H NMR
resonances with a pair of doublets at δ -30.67, 33.34
appearing in the 31P{1H} NMR spectrum. Similarly, the
1H NMR spectrum shows sharper signals, indicating that
the fast equilibriums occurring at lower acid concentrations
are no longer present. The final reaction product was spec-
troscopically characterized by 1H, 31P{1H}, 13C{1H}, 1H,1H-
COSY, and 1H,13C-HSQC NMR experiments. All the NMR
data indicate that the protonation of the alkynyl compound
2 initially takes place at one of the N-donor atoms of the PTA
ligand with significant scrambling between the possible
protonation sites. Subsequent acid addition generates the
vinylidene complex, which eventually converts 2 into the
(13) (a) Hill, A. F.; Rae, A. D.; Schultz, M; Willis, A. C. Organome-
tallics 2007, 26, 1325. (b) Paul, F.; Ellis, B. G.; Bruce, M. I.; Toupet, L.;
Roisnel, T.; Costuas, K.; Halet, J.-F.; Lapinte, C. Organometallics 2006, 25,
649. (c) Fillaut, J.-L.; Dua, N. N.; Geneste, F.; Toupet, L.; Sinbandhit, S.
J. Organomet. Chem. 2006, 691, 5610. (d) Field, L. D.; Magill, A. M.;
Shearer, T. K.; Dalgarno, S. J.; Turner, P. Organometallics 2007, 26, 4776.

Article
Organometallics, Vol. 28, No. 20, 2009 6023
Figure 2. 31P{1H} (left) and 1H (3.5-5.2 ppm) (right) NMR spectra in CD2Cl2 of the reaction of compound 2 with (a) 0, (b) 1.0, (c) 1.5,
(d) 2.0, and (e) 2.5 equiv of HOTf.
Scheme 2
dicationic PTA-protonated vinylidene complex [TpRu{Cd
C(H)Ph}{PTAH}(PPh3)](OTf)2 (3), as shown in Scheme 2.
The 13C{1H} NMR spectrum of 3 displays a low-field
pseudotriplet at 378.0 ppm characteristic of the vinylidene
R-carbon atom with degenerate coupling (2JCP = 16.0 Hz)
with either of the phosphorus donors.
does not allow us to intercept any putative intermediate
along the path leading to the vinylidene product, which is not
surprising due to the forced reaction conditions and the
facility of π-coordinated terminal alkyne ruthenium(II)
complexes to quickly tautomerize to the vinylidene species.15
5. Reaction of [TpRuCl(PTA)(PPh3)] (1) with 1,1-Dip-
henyl-2-propyn-1-ol. Like the reaction described above be-
tween 1 and phenylacetylene, the reaction of 1 with
1-diphenyl-2-propyn-1-ol also gives different products
depending on the solvent used (Scheme 3).
4. Reaction of 1 in Toluene. Synthesis of the Neutral
Vinylidene Complex [TpRuCl{CdC(H)Ph}(PTA)] (4). When
the reaction of [TpRuCl(PTA)(PPh3)] with HCtCPh is
carried out in refluxing toluene instead of MeOH, labiliza-
tion of the Ru-PPh3 bond occurs, affording in high yield the
neutral vinylidene complex [TpRuCl{CdC(H)Ph}(PTA)]
(4) as a pink solid. Apart from the absorption due to the
Tp ancillary ligand at 2473 cm-1, the IR spectrum of 4
displays a strong band at 1631 cm-1 assignable to the
vinylidene ν(CdC) stretch. The NMR spectral parameters
of the vinylidene ligand in 4 are very similar to those
exhibited by the related [TpRuCl{CdC(H)Ph}(PPh3)]14
complex (see the Experimental Section). Two 13C resonances
at 111.4 (Cβ) and 366.3 (CR) ppm confirm the presence of a
vinylidene ligand. Finally, the 31P{1H} spectrum displays a
singlet at -39.9 ppm assignable to the PTA ligand.
6. Reaction of 1 and HCCCPh2OH in MeOH. Synthesis of
the Cationic Allenylidene Complex [TpRu(CdCdCPh2)-
(PTA)(PPh3)](PF6) (5). The reaction of 1 with an excess of
1,1-diphenyl-2-propyn-1-ol in refluxing methanol (ca. 24 h)
in the presence of NaPF6, which favors the removal of the
coordinated halide, affords the cationic allenylidene com-
plex [TpRu(CdCdCPh2)(PTA)(PPh3)](PF6) (5), which may
be isolated as an air-stable purple solid. Monitoring the
reaction by 31P NMR spectroscopy does not show any
intermediate species preceding the formation of 5. This
suggests that the preliminary π-alkyne coordination and
the following tautomerization to γ-hydroxyvinylidene spe-
cies are fast with respect to the water elimination step,
completing the Selegue scheme leading to the final allenyli-
dene complex.6 Compound 5 is not soluble in water but easily
dissolves in chlorinated solvents. It has been characterized by
Complex 4 is produced selectively, as no trace of
[TpRuCl{CdC(H)Ph}(PPh3)], which should be generated
following PTA dissociation from 1, is observed by NMR
monitoring of the reaction. In agreement with this finding,
formation of free PPh3 during the reaction converting 1 into
4 is observed. Remarkably, NMR monitoring of the reaction
1
microanalysis and IR and NMR (31P{1H}, H, 13C{1H},
1H,1H-COSY, and 1H,13C-HSQC) spectroscopy. The IR
(14) Slugovc, C.; Mereiter, K.; Zobetz, E.; Schmid, R.; Kirchner, K.
Organometallics 1996, 15, 5275.
(15) See, for example: Ciardi, C.; Reginato, G.; Gonsalvi, L.; de los
Rios, I.; Romerosa, A.; Peruzzini, M. Organometallics 2004, 23, 2020.

~
Bolano et al.
6024 Organometallics, Vol. 28, No. 20, 2009
Scheme 3
the carbonyl compound until it becomes the only ruthenium-
containing species (Scheme 4).
Similar addition reactions of water have been already
described for other cationic ruthenium(II) allenylidene com-
plexes16 but only in one case for a neutral ruthenium(II)
allenylidene complex.17 In the latter case the formation of
1,1-diphenylethylene accompanies the generation of the
carbonyl derivative.
8. Reactivity of the Cationic Allenylidene Compound 5 with
Tertiary Phosphines. Synthesis of the R-Phosphonioallenyl
Complexes
[TpRu{C(PR3)dCdCPh2}(PTA)(PPh3)]PF6
(PR3 = PPh2Me (8), PTA (9)). Cationic allenylidene com-
plexes regioselectively add phosphines to CR or Cγ as a
function of both electronic and steric properties of the
ancillary ligands on the metal atom and the substituents of
the γ-carbon.8a,18 An in-depth investigation of the reaction
mechanism carried out on the rhenium(I) allenylidene
[{MeC(CH2PPh2)3}Re(CO)2{CdCdCPh2)]þ 19 and backed
up by a computational analysis20 has confirmed that the
kinetic attack takes place at Cγ to give γ-phosphonioalkynyl
species which thermally isomerize to the thermodynamic
R-phosphioallenyl derivatives (Scheme 5).
spectrum exhibits, in addition to the strong P-F hexafluo-
rophosphate stretching (841 cm-1) and the absorptions due
to the Tp ancillary ligand (2482 cm-1), a strong band at
1937 cm-1 ascribable to an asymmetric ν(CdCdC) stretch-
ing vibration. The 13C{1H} and 31P{1H} NMR spectra also
support the formation of the allenylidene complex, showing
(i) the typical carbene RudCR low-field resonance, which
appears as a broad triplet at δ 309.33 ppm (2JCP = 18.4 Hz),
(ii) two singlet resonances for the Cβ and Cγ carbons at δ
204.06 and 163.13 ppm, and (iii) two doublets in the 31P{1H}
NMR spectrum at δ -46.55 ppm (PTA) and 40.42 ppm
(PPh3) (2JPP = 31.5 Hz).
7. Reaction of 1 in Toluene. Synthesis of the Neutral
Allenylidene Complex [TpRuCl(CdCdCPh2)(PTA)] (6).
When the reaction of 1 with an excess of 1,1-diphenyl-
2-propyn-1-ol, is carried out in refluxing toluene (ca. 24 h)
and in the presence of molecular sieves, the chloride ligand
is retained into the coordination polyhedron while the
Ru-PPh3 bond is labilized and the neutral allenylidene
[TpRuCl(CdCdCPh2)(PTA)] (6) is obtained. 31P{1H}
NMR analysis of the solution confirms the loss of PPh3 (δ
-5.7), but does not disclose any intermediate species pre-
ceding the formation of 6. Compound 6 is an air-stable
purple solid, quite soluble in both chlorinated solvents and
toluene. Confirmatory evidence for the presence of the
allenylidene moiety comes from both the IR spectrum
(ν(CdCdC) band at 1931 cm-1 (s)) and the 13C{1H} NMR
spectrum with resonances at 307.83 (d, JCP = 24.5 Hz, CR),
226.81 (s, Cβ), and 147.89 (s, Cγ) ppm. The 31P{1H} NMR
spectrum displays a singlet at δ -40.37 ppm (PTA).
Noticeably, when the reaction is carried out in the absence
of any drying agent (molecular sieves etc.), the carbonyl
complex [TpRuCl(CO)(PTA)] (7) becomes the principal
product. Complex 7 likely forms from the reaction of the
allenylidene ligand in 6 with the water (1 equiv) released
along the Selegue reaction which assembles the metallacu-
mulene species6 (Scheme 4). The carbonyl compound 7 can
also be obtained by directly replacing the PPh3 ligand of 1
with CO in a carbonylation test. Different evidence con-
firmed the formation of the carbonyl compound by hydro-
lysis of the allenylidene complex. Particularly, monitoring by
31P{1H} NMR spectroscopy a sample containing both 6 and
7 (7:3 molar ratio) with several drops of water at ambient
temperature shows a progressive increase of the signal due to
Steric reasons may, however, hamper any reactivity of the
phosphine.19 Thus, PPh3 reacts neither with [{MeC(CH2-
PPh2)3}Re(CO)2{CdCdCPh2)]þ (CH2Cl2, reflux) nor with
5 (room temperature, NMR tube test in MeOD), probably
due to the steric hindrance of PPh3 which hampers access to
either the diphenylsubstituted Cγ atom or the metallic frag-
ment. In contrast, PPh2Me and PTA, with fewer steric re-
quirements (θPPh = 145°, θPPh Me = 136°, θPTA = 103°),
3
2
add regioselectively to the CR atom of the allenylidene 5,
giving the two novel derivatives 8 and 9, respectively (see
Scheme 6). Monitoring the reaction of 5 with PTA or
PPh2Me at low temperature does not allow us to intercept
any intermediate before the formation of 8 or 9 (the forma-
tion of these compounds is immediate) which do not clarify
whether these R-phosphonioallenyl species are directly
formed or derive from their putative γ-phosphonioalkynyl
tautomers via Cγ to CR PR3 shift.
Remarkably, the reactions of 5 with both the sterically
undemanding phosphines PTA and PPh2Me do not go to
completion but afford solution equilibria, with phosphine
uptake and release, whose thermodynamic parameters may
be figured out by variable-temperature NMR experiments
(Figure 3) using relaxation delays as longer as 10 s in order to
collect reliable integral data of the 31P NMR resonances. The
addition of PPh2Me to a deep purple solution of 5 in MeOD
does not cause any significant color change likely due to the
moderate formation of the adduct species whose color
(probably yellow) is completely masked by the very intense
purple color of the allenylidene precursor (always present in
the reaction mixture). In contrast, the reaction with the more
basic and less encumbering phosphine PTA results in an
ꢀ
ꢀ
(16) (a) Esteruelas, M. A.; Gomez, A. V.; Lahoz, F. J.; Lopez, A. M.;
~
Onate, E.; Oro, L. A. Organometallics 1996, 15, 3423. (b) Bustelo, E.;
Dixneuf, P. H. Adv. Synth. Catal. 2007, 349, 933.
ꢀ
(17) Bianchini, C.; Peruzzini, M.; Zanobini, F.; Lopez, C.; de los
Rios, I.; Romerosa, A. Chem. Commun. 1999, 443.
(18) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J. Eur. J. Inorg. Chem.
ꢀ
ꢀ
2001, 571. (b) Cadierno, V.; Gamasa, M. P.; Gimeno, J.; Lopez-Gonzalez, M.
P.; Borge, J.; García-Granda, S. Organometallics 1997, 16, 4453.
(19) Peruzzini, M.; Barbaro, P.; Bertolasi, V.; Bianchini, C.; de los
Rios, I.; Mantovani, N.; Marvelli, L.; Rossi, R. Dalton Trans. 2003,
4121.
(20) Peruzzini, M.; Re, N. Manuscript in preparation.

Article
Organometallics, Vol. 28, No. 20, 2009 6025
Scheme 4
of this type,9 strongly support the allenyl formulation
(Table 3).
Scheme 5
The phosphonioallenyl complex 9 is air-stable in the solid
state at atmospheric pressure, while in solution it equilibrates
with the parent allenylidene and free PTA (vide supra).
The IR spectrum (KBr pellet) shows the typical allenyl
ν(CdCdC) absorption band at 1840 cm-1 slightly moved
to low frequencies, in line with the presence of an unbalanced
positive charge on the P-phosphonium atom. Remarkably,
grinding of 9 during the preparation of the solid KBr pellet
for the IR analysis results in fading of the yellow color, which
becomes pale reddish, suggesting that also in the solid state
external effects such as an applied physical pressure may
result in the C-P bond cleavage of the R-phosphonioallenyl
derivative. The 31P{1H} spectrum run at -5 °C in CD2Cl2
2
shows three signals at 49.22 (d, JPP = 32.4 Hz, PPh3),
-44.10 (d, 2JPP = 32.4 Hz, Ru-PPTA), and -46.78 (s, CR-
PPTA) ppm, the latter assignable to the R-phosphonioallenyl
P-atom. Noticeably, this phosphorus nucleus does not show
any appreciable coupling with the metal-coordinated P-
phosphorus phosphine atoms (3JPP), which has precedents
in the sparse literature.9a,9d,9e The 13C{1H} NMR spectrum
agrees with the proposed formulation showing a doublet at
102.68 ppm (1JCP = 26 Hz) and a broad singlet at 209.75
ppm, attributable to the Cγ and Cβ of the allenylphosphonio
ligand, respectively.18b Unfortunately, the signal of CR can-
not be safely located, probably being obscured by the signals
of the PTA ligand around 70 ppm (it is not unusual that the
signal of the metal-bonded carbon appears at higher field
than the signals of Cβ and Cγ).16a,21 Although the electro-
philicity of Cγ is greater than that of CR (23% of the LUMO
centered on CR and 31% on Cγ for Esteruelas’ model cation
complex [CpRu(CO)(PH3)(CdCdCH2)]þ),22 it seems that
the presence of the phenyl groups at the Cγ and the relatively
low steric crowding at the ruthenium center (PTA is not
sterically demanding) facilitate the nucleophilic attack at
the CR, giving the allenylphosphonio complex, in contrast
with what observed for the indenyl derivative [(C9H7)-
Ru(dCdCdCPh2)(PPh3)2]þ, in which the indenyl ligand
and the two bulky triphenylphosphine ligands protect this
atom and direct the nucleophile to attack the Cγ position,
thus yielding the γ-phosphonioalkynyl complex.18b
equilibrium more shifted toward the phosphonio adduct also
because of its low solubility in MeOH. In fact, 9 precipitates
from a MeOH solution of 5 and excess PTA, giving 9 as a
yellow solid. When 9 is redissolved in CH2Cl2, the solution
immediately turns to deep violet as soon as 9 equilibrates
back to 5, releasing free PTA (NMR detected). Although
both reactions are slightly endoergonic, that with PTA is
more favored than that with PPh2Me, in accord with their
respective steric requirements and nucleophilic properties
(see Table 2).
The solution characterization of each phosphonium ad-
duct is largely complicated by the occurrence of the equilib-
rium giving back the allenylidene species. Thus, the NMR
spectra of 8 (MeOD solution) or 9 (CD2Cl2 solution) always
display signals of both allenylidene educt and free phos-
phine. Typical NMR experiments were conducted at low
temperature (0 to -5 °C) where the equilibrium is more
shifted toward the formation of the phosphonium complexes
(see the largely entropic factors in Table 2).
To discriminate between the two possible phosphonium
isomers resulting from the nucleophilic attack preferred site,
Cγ vs CR of the phosphine, we investigated by X-ray diffrac-
tion analysis the yellow crystals obtained by slow evapora-
tion of 9 from a dilute MeOH solution. The crystallographic
analysis confirmed that the adduct is a genuine R-phospho-
nioallenyl species with the PTA phosphine is selectively
bound to the R-carbon of a ruthenium coordinated allenyl
ligand (see Figure 4).
In the case of PPh2Me a similar behavior was observed,
but the existence of an equilibrium poorly shifted toward the
addition product does not permit us to clearly establish the
nature of the phosphonium adduct by NMR studies. Rea-
soning similar to the PTA case would imply that a similar
product was obtained, but the attack at Cγ cannot be
completely disregarded. The 31P{1H} spectrum of the reac-
tion mixture in CD3OD shows, apart from the signals of both
5 and PPh2Me (-27.4 ppm), three new slightly broadened
The geometry around the ruthenium center in 9 is close to
octahedral, with the Tp ligand occupying three sites of a face.
ꢀ
The Ru-C(1) distance (2.137(3) A) is that expected for a
Ru-C(sp2) single bond and is comparable to the related
distance in other ruthenium allenyl complexes.9 The
(21) Werner, H.; Flugel, R.; Windmuller, B.; Michenfelder, A.; Wolf,
J. Organometallics 1996, 14, 612.
ꢀ
ꢀ
C(1)-C(2) (1.318(4) A) and C(2)-C(3) (1.320(4) A) bond
lengths, as well as the C(1)-C(2)-C(3) angle (177.1(3)°),
which are in agreement with those reported for compounds
ꢀ
ꢀ
(22) Esteruelas, M. A.; Gomez, A. V.; Lopez, A. M.; Modrego, J.;
~
Onate, E. Organometallics 1997, 16, 5826.

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Bolano et al.
6026 Organometallics, Vol. 28, No. 20, 2009
Scheme 6
Figure 3. Plots of ln Keq vs 1000/T (K-1) for the equilibrium reactions of compound 5 with PPh2Me (left) and with PTA (right).
Table 2. Thermodynamic Parameters for the Formation of
Complexes 8 (MeOD) and 9 (CD2Cl2)
complex
ΔH° (kcal)
ΔS° (cal)
ΔG° (kcal)
Keq(298 K)
8
9
-14.13 ( 0.27 -52.13 ( 0.06 þ1.41 ( 0.27 0.077 ( 0.010
-19.46 ( 0.31 -66.08 ( 0.07 þ0.23 ( 0.31 0.611 ( 0.012
resonances attributable to the phosphonium compound
(δ 54.0 (RuPPh3), 22.8 (C-PPPh Me), and -31.1 (RuPTA)).
9. Reactivity of the Neutral Allenylidene Compound 6 with
2
Tertiary Phosphines. Synthesis of the R-Phosphonioallenyl
Complexes [TpRuCl{C(PR3)dCdCPh2}(PTA)] (PR3
=
PPh2Me (10), PTA (11)). Neutral allenylidene compounds
are not as abundant as cationic ones and do not exhibit the
typical electrophilic behavior proper of the much more
represented cationic derivatives.23 The lack of any positive
charge on the metallocumulene assembly depresses the elec-
trophilic behavior generally observed at the CR and Cγ sites
while emphasizing the nucleophilic behavior at the β-car-
bon.24 In spite of this general tendency, compound 6 reacts
quickly and completely with nucleophiles such as phosphines
(PPh2Me or PTA), sharply contrasting with the uncompleted
reactivity shown by the cationic allenylidene 5 discussed
Figure 4. ORTEP representation of the cation of 9. Thermal
ellipsoids are drawn at 50% probability level. All of the hydro-
gen atoms, except for that of the hydroborate, are omitted for
the sake of clarity.
€
(23) (a) Werner, H.; Wiedemann, R.; Laubender, M.; Windmuller,
B.; Steinert, P.; Gevert, O.; Wolf, J. J. Am. Chem. Soc. 2002, 124, 6966.
(b) Kolobova, N. E.; Ivanov, L. L.; Zhvanko, O. S.; Khitrova, O. M.;
Batsanov, A. S.; Struchkov, Y. T. J. Organomet. Chem. 1984, 265, 271.
above (see Scheme 7). Thus, adding phosphine (PPh2Me or
PTA) in small portions to a solution of [TpRuCl{CdCd
CPh2}(PTA)] in CD2Cl2 (NMR tube test) and monitoring
the reaction course by 1H and 31P{1H} NMR spectro-
scopy confirm the immediate replacement of the allenylidene
signals by a new set of resonances, ascribable to the
€
(c) Berke, H.; Harter, P.; Huttner, G., Zsolnai, L. Z. Naturforsch. B 1981, 36,
ꢀ
929. (d) Bianchini, C.; Peruzzini, M.; Zanobini, F.; Lopez, C.; de los Rios, I.;
Romerosa, A. Chem. Commun. 1999, 443.
ꢀ
(24) Crochet, P.; Esteruelas, M. A.; Lopez, A. M.; Ruiz, N.; Tolosa,
J. I. Organometallics 1998, 3479.

Article
Organometallics, Vol. 28, No. 20, 2009 6027
ꢀ
˚
Table 3. Selected Bond Distances (A) and Angles (deg) for
[TpRu{C(PTA)dCdCPh2}(PTA)(PPh3)]PF6 (9)
Conclusions
The reactivity of [TpRuCl(PTA)(PPh3)] (1) with phenyla-
cetylene and 1,1-diphenyl-2-propyn-1-ol was found to be
strongly dependent on the polarity of the reaction medium,
and different reaction pathways were followed in polar
(MeOH) and apolar (toluene) solvents. Indeed, while the
reaction in the polar solvent proceeded with easy substitu-
tion of the chloride ligand to yield the neutral alkynyl
complex [TpRu(CtCPh)(PTA)(PPh3)] (2) and the cationic
allenylidene species [TpRu(CdCdCPh2)(PTA)(PPh3)]PF6
(5), respectively, the reaction in toluene afforded the neutral
vinylidene complex [TpRuCl{CdC(H)Ph}(PTA)] (4) and
allenylidene species [TpRuCl(CdCdCPh2)(PTA)] (6), re-
spectively, following the substitution of the PPh3 ligand.
The reactivity of these species with selected electrophiles and
nucleophiles was then investigated with the aim of shedd-
ing light on the possible different reactivities exhibited by
related neutral versus cationic pair of unsaturated carbenes
(exemplified by 5 and 6). In keeping with our expectations,
while the protonation of 2 with HOTf gave the expected
dicationic vinylidene [TpRu(CdCHPh)(PTAH)(PPh3)]-
(OTf)2 (3), which bears a protonated PTA ligand, the
systematic study of the nucleophilic additions of different
phosphines (PPh3, PPh2Me, PTA) to both allenylidene
complexes 5 and 6 was of much interest. In particular, in
the case of the cationic allenylidene complex 5, the reaction
with PPh2Me or PTA (the bulkier PPh3 did not react at all)
gave the corresponding R-phosphonioallenyl complexes
[TpRu{C(PPh2Me)dCdCPh2}(PTA)(PPh3)]PF6 (8) and
[TpRu{C(PTA)dCdCPh2}(PTA)(PPh3)]PF6 (9), respec-
tively, which exhibit an interesting solution equilibrium
featuring phosphine uptake and release. These equilibria
could be followed by NMR methods, and the thermody-
namic parameters for the formation of 8 and 9 have been
reported. Even more remarkable was the reaction of the
neutral allenylidene 6 with both PTA and PPh2Me that, in
spite of the general reluctance observed by neutral allenyli-
denes to react with nucleophiles, regioselectively afforded
the R-phosphonioallenyl complexes [TpRuCl{C(PPh2Me)d
CdCPh2}(PTA)] (10) and [TpRuCl{C(PTA)dCdCPh2}-
(PTA)] (11). As a final consideration, the solid-state struc-
ture of compound 9, a rare example of an R-phosphonioal-
lenyl derivative, was determined by X-ray methods, which
confirmed the presence of the P-alkylated water-soluble PTA
phosphine as the pendant group of the phosphonioallenyl
moiety.
Ru-P(2)
2.3337(8)
2.3338(8)
2.151(3)
2.150(2)
2.138(2)
1.836(3)
1.848(3)
Ru-C(1)
2.137(3)
1.812(3)
1.318(4)
1.320(4)
1.496(4)
1.508(4)
1.852(3)
Ru-P(1)
P(3)-C(1)
C(1)-C(2)
C(2)-C(3)
C(3)-C(10)
C(3)-C(4)
P(1)-C(43)
Ru-N(1)
Ru-N(3)
Ru-N(5)
P(1)-C(49)
P(1)-C(37)
C(1)-Ru-P(2)
C(1)-Ru-P(1)
P(2)-Ru-P(1)
C(1)-C(2)-C(3)
91.56(8)
98.66(8)
97.83(3)
177.1(3)
C(2)-C(1)-P(3)
C(2)-C(1)-Ru
P(3)-C(1)-Ru
105.2(2)
131.9(2)
122.56(16)
Scheme 7
R-phosphonioallenyl species 10 and 11, respectively. The
reaction is also accompanied by a color change of the
solution from deep purple to brown. The replacement of
the typical allenylidene asymmetric stretching vibration
at 1931 cm-1 by weak bands at 1853 and 1851 cm-1 for
compounds 10 and 11, respectively, ascribable to the stretch-
ing vibration of the allenyl group,9d also supports the
allenylphosphonio formulation of the adduct species.
In agreement with the formation of the R-phosphonio
adduct, the 13C{1H} spectra show the disappearance of the
allenylidene resonances (307.83 (d, J = 24.5 Hz, CR), 226.81
(s, Cβ), and 147.89 (s, Cγ) ppm) and the appearance of a new
set of signals at 214.9 ppm (Cβ) and 100.7 ppm (d, J = 24.1
Hz, Cγ) for the reaction with PPh2Me and at 210.7 ppm
(s, Cβ) and 102.8 ppm (d, J = 25.8 Hz, Cγ) in the case of the
reaction with PTA. The signal corresponding to CR could not
be safely localized in the spectra of both compounds, likely
due to superimposition with PTA backbone signals around
70 ppm. In the case of the bulkier PPh3, no reaction was again
observed, which is also consistent with the synthesis of 6,
where PPh3 is liberated during the reaction.
Experimental Section
All synthetic operations were performed under a dry argon
atmosphere by following conventional Schlenk techniques.
Solvents were purified by distillation from the appropriate
drying agents26 and degassed before use. 1-Phenyl-2-propyn-
1-ol, phenylacetylene, and triflic acid were Aldrich products and
were used without further purification. The starting material
[TpRuCl(PTA)(PPh3)] (1) was prepared by the published meth-
od.5 IR spectra were recorded in KBr pellets on a Bruker Vector
IFS28 FTIR spectrophotometer. NMR spectra were recorded
on a Bruker AMX 400 instrument. Chemical shifts are given in
parts per million from SiMe4 (1H and 13C{1H}) or 85% H3PO4
(31P{1H}). 1H and 13C{1H} NMR signal assignments were
As a final consideration, it is worth mentioning that
alkyl (R = Me, Et, Bz, Cy) or aryl (Ph) phosphonium salts
of PTA cannot be generated by direct electrophilic attack
on PTA, the nitrogen atoms being much more electrophi-
lic.25 In this respect, it is intriguing that the R-phosphonioal-
lenyl species 10 and 11, representing a rare example of
PTA phosphonium derivatives, may be formed by direct
nucleophilic attack of PTA at an electrophilic carbon center
such as CR.
(25) (a) Fluck, E.; Weissgraber, H. J. Chem.-Ztg. 1977, 101, 204.
(b) Assmann, B.; Angermaier, K.; Schmidbaur, H. J. Chem. Soc., Chem.
Commun. 1994, 941. (c) Assmann, B.; Angermaier, K.; Paul, M.; Riede, J.;
Schmidbaur, H. Chem. Ber. 1995, 128, 891.
(26) Purification of Laboratory Chemicals, 3rd ed.; Perrin, D. D.,
Armarego W. L. F., Eds.; Butterworth and Heinemann: Oxford, U.K., 1988.

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Bolano et al.
6028 Organometallics, Vol. 28, No. 20, 2009
confirmed by 1H-COSY and HSQC (1H-13C) experiments.
Elemental analyses were performed on a Fisons EA-1108
apparatus.
1H, HB(C3H3N2)3), 7.27 (d, 3JH,H = 4.3 Hz, 4H, Ph), 7.59 (br,
1H, HB(C3H3N2)3), 7.63 (br, 1H, HB(C3H3N23)3), 7.74 (d, 3JH,H
= 2.4 Hz, 1H, HB(C3H3N2)3), 7.81 (d, 1H, JH,H = 2.1 Hz,
HB(C3H3N2)3), 8.01 (br, 1H, HB(C3H3N2)3) ppm. 13C{1H}
NMR (CD2Cl2, 100 MHz): δ 52.0 (d, 1JC,P = 16.0 Hz, PCH2N),
Preparation of [TpRu(CtCPh)(PTA)(PPh3)] (2). An excess of
HCꢀCPh (0.4 mL) was added to a solution of [TpRuCl-
(PTA)(PPh3)] (1; 100.0 mg, 0.13 mmol) in 20 mL of methanol.
The mixture was heated to reflux and stirred gently for several
minutes, and then it was cooled to room temperature. A yellow
microcrystalline precipitate was formed that was filtered off
and washed with MeOH and Et2O before being dried under a
stream of nitrogen. Yield: 83.55 mg (77.0%). Anal. Calcd for
C41H42BN9P2Ru (834.67 g/mol): C, 59.00; H, 5.07; N 15.10.
Found: C, 59.12; H, 5.14; N, 15.07. IR (KBr pellet): νBH(Tp) 2472
(w), νCtC 2075 (s) cm-1. 1H NMR (CD2Cl2, 400 MHz): δ 3.80
(s, 6H, PCH2N), 4.00-4.40 (AB system, 6H, NCH2N), 5.75
3
73.7 (d, JC,P = 7.4 Hz, NCH2N), 106.2 (s, HB(C3H3N2)3),
106.3 (s, HB(C3H3N2)3), 106.9 (s, HB(C3H3N2)3), 111.4 (d,
3JC,P = 2.1 Hz, dC(H)Ph), 125.7 (s, C PPh3), 126.2 (s, C PPh3),
129.2 (s, C PPh3), 134.9 (s, HB(C3H3N2)3), 135.8 (s, HB-
(C3H3N2)3), 137.2 (s, HB(C3H3N2)3), 143.4 (s, HB(C3H3N2)3),
143.9 (s, HB(C3H3N2)3), 145.6 (s, HB(C3H3N2)3), 366.3 (d, 2JC,P
= 22.2 Hz, RudC) ppm. 31P{1H} NMR (CD2Cl2, 161 MHz): δ
-34.9 (s, PPTA) ppm.
Preparation of [TpRu(CdCdCPh2)(PTA)(PPh3)]PF6 (5).
A 100 mg portion (0.13 mmol) of 1 was dissolved in MeOH
(30 mL), and 136.8 mg (0.65 mmol) of 1-phenyl-2-propyn-1-ol
was added. The mixture was stirred for 1 min, and 22.3 mg (0.13
mmol) of NaPF6 was added. This solution was refluxed for 24 h,
during which time the color changed from yellow to purple. The
mixture was filtered, and the solvent was removed in vacuo.
The residue was then treated with diethyl ether (3 ꢁ 3 mL) and
n-hexane (5 mL), and a purple solid precipitated. Yield: 136.16
mg (98.0%). Anal. Calcd for C48H47BN9P3F6Ru (1068.75
g/mol): C, 53.94; H, 4.43; N, 11.80. Found: C, 53.89; H, 4.48;
N, 11.73. IR (KBr pellet): νBH(Tp) 2482 (w), νCdCdC 1937 (s)
cm-1. 1H NMR (CD2Cl2, 400 MHz): δ 3.65-3.85 (AB system,
6H, PCH2N), 4.10-4.40 (AB system, 6H, NCH2N), 5.82
3
(br, 1H, HB(C3H3N2)3), 5.82 (t, JH,H = 2.1 Hz, 1H, HB-
(C3H3N2)3), 6.20 (br, 1H, HB(C3H3N2)3), 6.21 (br, 1H, HB-
(C3H3N2)3), 6.64 (br, 1H, HB(C3H3N2)3), 7.03 (t, 3JH,H = 7.4
Hz, 1H, Ph), 7.18-7.39 (m, 13H, Ph), 7.58 (br, 1H, HB-
(C3H3N2)3), 7.62 (br, 1H, HB(C3H3N2)3), 7.65 (d, 3JH,H = 1.9
Hz, 1H, HB(C3H3N2)3), 7.69-7.77 (m, 6H, Ph), 8.27 (br, 1H,
HB(C3H3N2)3) ppm. 13C{1H} NMR (CD2Cl2, 100 MHz): δ 52.8
(d, 1JC,P = 14.6 Hz, PCH2N), 73.4 (d, 3JC,P = 5.4 Hz, NCH2N),
4
104.7 (d, JC,P = 1.6 Hz, HB(C3H3N2)3), 105.3 (s, HB(C3H3-
N2)3), 105.5 (d, JC,P = 2.3 Hz, HB(C3H3N2)3), 111.2
4
(s, CtCPh), 123.1-131.2 (C PPh3), 126.8 (collapsed double
2
doublet, JC,P = 19.1 Hz, CtCPh), 133.8-138.0 (C PPh3),
3
3
134.9 (s, HB(C3H3N2)3), 135.3 (s, HB(C3H3N2)3), 135.6
(s, HB(C3H3N2)3), 144.1 (s, HB(C3H3N2)3), 144.4 (s, HB-
(C3H3N2)3), 144.5 (s, HB(C3H3N2)3) ppm. 31P{1H} NMR
(t, JH,H = 1.9, 1H, HB(C3H3N2)3), 5.97 (d, JH,H = 1.9 Hz,
1H, HB(C3H3N2)3), 6.16 (td, 3JH,H = 2.2 Hz, 4JH,H = 0.6 Hz,
1H, HB(C3H3N2)3), 6.22 (br, 1H, HB(C3H3N2)3), 6.64 (d, 3JH,H
= 1.9 Hz, 1H, HB(C3H3N2)3), 7.22-7.48 (m, 19H, Ph), 7.59
(br, 2H, HB(C3H3N2)3), 7.72-7.77 (m, 6 þ 1H, Ph þ HB-
2
(CD2Cl2, 161 MHz): δ -31.8 (d, JP,P = 33.7 Hz, PPTA),
53.8 (d, 2JP,P = 33.7 Hz, PPh3) ppm.
3
In Situ NMR Formation of [TpRu(CdCHPh)(PTAH)-
(PPh3)](OTf)2 (3). A solution of 2 (16.7 mg, 0.02 mmol) in
0.5 mL of CD2Cl2 was placed in a NMR tube. Different portions
of HOTf were sequentially added through the serum cap via a
microsyringe at room temperature. The progress of the reaction
(C3H3N2)3), 7.93 (d, JH,H = 2.3, 1H, HB(C3H3N2)3) ppm.
13C{1H} NMR (CD2Cl2, 100 MHz): δ 52.6 (d, 1JC,P = 14.9 Hz,
PCH2N), 73.1 (d, JC,P = 6.3 Hz, NCH2N), 105.9 (s, HB-
3
(C3H3N2)3), 106.8 (s, HB(C3H3N2)3), 107.6 (s, HB(C3H3N2)3),
129.0-134.0 (C PPh3), 144.6 (C PPh3) 136.9 (s, HB(C3H3N2)3),
137.4 (s, HB(C3H3N2)3), 143.9 (s, HB(C3H3N2)3), 144.4
(s, HB(C3H3N2)3), 144.6 (s, HB(C3H3N2)3), 145.0 (s, HB-
(C3H3N2)3), 163.1 (s, CdCdCPh2), 204.1 (s, CdCdCPh2),
1
was monitored by H and 31P{1H}, and the acid addition was
finished (4.50 μL, 0.05 mmol) when the NMR analysis revealed
the reaction completeness. 1H NMR (CD2Cl2, 400 MHz): δ
3.68-4.05 (AB system, 6H, PCH2N), 4.51-5.01 (AB system,
7H, NCH2N), 6.00 (t, br, 3JH,H = 2.1, 1H, HB(C3H3N2)3), 6.24
2
309.3 (t, br, JC,P = 18.4 Hz, CdCdCPh2) ppm. 31P{1H}
1
NMR (CD2Cl2, 161 MHz): δ -144.1 (sept, JP,F = 710.4 Hz,
(t, br, 3JH,H = 2.1 Hz, 1H, HB(C3H3N2)3), 6.33 (t, br, 3JH,P
=
PF6), -46.5 (d, 2JP,P = 31.5 Hz, PPTA), 40.4 (d, 2JP,P = 31.2
Hz, PPh3) ppm.
3.0 Hz, 1H, dC(H)Ph), 6.35 (br, 1H, HB(C3H3N2)3), 6.38 (br,
1H, HB(C3H3N2)3), 6.64 (m, 2H, Ph), 6.75 (br, 1H, HB-
(C3H3N2)3), 7.07 (m, 3H, Ph), 7.29-7.52 (m, 15H, Ph), 7.83
(br, 2H, HB(C3H3N2)3), 7.98 (br, 1H, HB(C3H3N2)3), 8.33 (br,
1H, HB(C3H3N2)3) ppm. 13C{1H} NMR (CD2Cl2, 100 MHz):
δ 48.7 (d, 1JC,P = 17.3 Hz, PCH2N), 72.1 (br, NCH2N), 106.8
(s, HB(C3H3N2)3), 108.2 (s, HB(C3H3N2)3), 108.3 (s, HB-
(C3H3N2)3), 115.2 (s, HB(C3H3N2)3), 119.3 (s, dC(H)Ph),
122.0-135.1 (s, C PPh3), 126.2 (C PPh3), 138.2 (s, HB-
(C3H3N2)3), 138.5 (s, HB(C3H3N2)3), 144.3 (s, HB(C3H3N2)3),
144.7 (s, HB(C3H3N2)3), 145.4 (s, HB(C3H3N2)3), 378.0 (m,
RudC) ppm. 31P{1H} NMR (CD2Cl2, 161 MHz): δ -30.7
Preparation
(5 BPh4). This compound was prepared exactly as described
of
[TpRu(CdCdCPh2)(PTA)(PPh3)]BPh4
3
for 5 PF6, but using NaBPh4 instead of NaPF6. Yield: 50.2%.
Anal. Calcd for C72H67B2N9P2Ru (1243.02 g/mol): C, 69.57; H,
5.43; N, 10.14. Found: C, 69.42; H, 5.58; N, 10.44. IR (KBr
3
pellet): νBH(Tp) 2481 (w), νCdCdC 1938 (s) cm-1 1H NMR
.
(CD2Cl2, 400 MHz): δ 3.63-3.82 (AB system, 6H, PCH2N),
4.05-4.38 (AB system, 6H, NCH2N), 5.82 (t, 3JH,H = 2.5 Hz,
1H, HB(C3H3N2)3), 5.95 (br, 1H, HB(C3H3N2)3), 6.15 (t, br,
3JH,H = 2.1 Hz, 1H, HB(C3H3N2)3), 6.23 (br, 1H, HB-
(C3H3N2)3), 6.59 (d, br, 3JH,H = 2.1, 1H, HB(C3H3N2)3), 6.88
2
2
3
(d, JP,P = 28.2 Hz, PPTA), 33.3 (d, JP,P = 28.2 Hz,
PPh3) ppm.
(t, J = 7.16 Hz, 4H, Ph), 7.04 (t, JH,H = 7.38 Hz, 8H, Ph),
7.22-7.49 (m, 28 H, Ph) 7.59 (br, 2H, HB(C3H3N2)3), 7.61
(br, 1H, Ph), 7.74 (br, 1H, HB(C3H3N2)3), 7.75-7.81 (m, 4 H,
Ph), 7.93 (d, br, JH,H = 2.0 Hz, 1H, HB(C3H3N2)3) ppm.
Preparation of [TpRuCl{CdC(H)Ph}(PTA)] (4). A yellow
suspension of 1 (100.0 mg, 0.13 mmol) and phenylacetylene
(245.7 μL) was refluxed for 24 h in toluene (15 mL), giving an
orange solution. The solvent was removed under vacuum, and
the residue was treated with Et2O (3 ꢁ 3 mL), giving a pink solid.
Yield: 50.2 mg (63.4%). Anal. Calcd for C23H28BN9PClRu
(608.84 g/mol): C, 45.37; H, 4.64; N, 20.70. Found: C, 46.03;
H, 4.80; N, 20.58. IR (KBr pellet): νBH(Tp) 2473 (w), νCdC 1631
(m) cm-1. 1H NMR (CD2Cl2, 400 MHz): δ 4.37 (s, 6H, PCH2N),
3
13C{1H} NMR (CD2Cl2, 100 MHz): δ 52.3 (d, 1JC,P = 13.9 Hz,
3
PCH2N), 72.9 (d, JC,P = 6.3 Hz, NCH2N), 105.9 (s, HB-
(C3H3N2)3), 106.7 (s, HB(C3H3N2)3), 107.5 (s, HB(C3H3N2)3),
122.0-136.3 (C PPh3), 136.9 (s, HB(C3H3N2)3), 137.1 (s, HB-
(C3H3N2)3), 137.4 (s, HB(C3H3N2)3), 143.7 (s, HB(C3H3N2)3),
144.4-145.2 (C PPh3), 144.3 (s, HB(C3H3N2)3), 144.7 (s, HB-
(C3H3N2)3), 163.0 (s, CdCdCPh2), 163.7-164.8 (C PPh3),
4.00-4.60 (AB system, 6H, NCH2N), 4.97 (d, 4JH,P = 4.40 Hz,
203.5 (s, CdCdCPh2), 308.7 (dd, JC,P = 18.9 Hz, JC,P
=
2
2
3
1H, dC(H)Ph), 6.14 (br, 1H, HB(C3H33N2)3), 6.24 (t, JH,H =
2.3 Hz, 1H, HB(C3H3N2)3), 6.38 (t, JH,H = 2.4 Hz, 1H,
17.7 Hz, CdCdCPh2) ppm. 31P{1H} NMR (CD2Cl2, 161
MHz): δ -46.0 (d, JP,P = 31.9 Hz, PPTA), 40.5 (d, JP,P
31.9 Hz, PPh3) ppm.
2
2
=
3
HB(C3H3N2)3), 7.05 (q, JH,H = 4.3 Hz, 1H, Ph), 7.15 (br,

Article
Preparation of [TpRuCl(CdCdCPh2)(PTA)] (6). A 200.0 mg
Organometallics, Vol. 28, No. 20, 2009 6029
400 MHz, 0 °C): δ 2.81-4.24 (m, 24H, PTA), 5.80 (t, br, 3JH,H
2.4, 1H, HB(C3H3N2)3), 6.08 (br, 1H, HB(C3H3N2)3), 6.33 (br,
1H, HB(C3H3N2)3), 6.40 (br, 1H, HB(C3H3N2)3), 6.82 (br, 1H,
=
portion (0.26 mmol) of compound 1 was dissolved in toluene
(80 mL, molecular sieves), and 273.5 mg (1.30 mmol) of
1-phenyl-2-propyn-1-ol was added. This solution was refluxed
for 24 h, during which time the color changed from yellow
to purple. The mixture was filtered to eliminate impurities, and
the solvent was removed in vacuo. The residue was treated with
diethyl ether (3 mL) and n-hexane (3 mL), and a purple solid
precipitated. Yield: 142.1 mg (78.3%). Anal. Calcd for
C30H32BN9PClRu (696.95 g/mol): C, 51.70; H, 4.63; N, 18.09.
Found: C, 51.59; H, 4.70; N, 18.20. IR (KBr pellet): νBH(Tp) 2467
(w), νCdCdC 1931 (s) cm-1. 1H NMR (CD2Cl2, 400 MHz): δ 4.18
(s, 6H, PCH2N), 4.29-4.48 (AB system, 6H, NCH2N), 6.14
3
HB(C3H3N2)3), 6.99-7.80 (m, 25H, Ph), 7.71 (d, br, JH,H =
2.3, 1H, HB(C3H3N2)3), 7.95 (br, 1H, HB(C3H3N2)3), 7.98 (br,
1H, HB(C3H3N2)3), 8.01 (br, 1H, HB(C3H3N2)3) ppm. 13C{1H}
1
NMR (CD2Cl2, 100 MHz, 0 °C): δ 52.5 (d, JC,P = 23.4 Hz,
PCH2N), 51.8 (d, 1JC,P = 12.3 Hz, PCH2N), 71.4 (d, 3JC,P = 7.4
Hz, NCH2N), 72.1 (d, JC,P = 6.1 Hz, NCH2N), 105.7
3
(s, HB(C3H3N2)3), 106.6 (s, HB(C3H3N2)3), 108.2 (s, HB-
(C3H3N2)3), 126.0-131.4 (C PPh3), 136.6 (s, HB(C3H3N2)3),
137.9 (s, HB(C3H3N2)3), 138.7 (s, HB(C3H3N2)3), 144.3
(s, HB(C3H3N2)3), 144.7 (s, HB(C3H3N2)3), 146.9 (s, HB-
3
3
(br, 2H, HB(C3H3N2)3), 6.49 (t, br, JH,H = 2.6 Hz, 1H, HB-
(C3H3N2)3), 102.7 (d, JCP = 25.89 Hz, CdCdCPh2), 209.7
(C3H3N2)3), 7.06 (br, 1H, HB(C3H3N2)3), 7.36 (t, 3JH,H = 7.64
Hz, 4H, Ph), 7.48 (br, 1H, HB(C3H3N2)3), 7.63 (br, 1H, HB-
(C3H3N2)3), 7.68-7.76 (t, br, 3JH,H = 7.5, 2H, Ph), 7.71 (br, 1H,
(m, CdCdCPh2) ppm. The signal corresponding to CR could
not be safely localized, likely due to superimposition with signals
of the PTA backbone at ca. 70 ppm. 31P{1H} NMR (CD2Cl2,
161 MHz, 0 °C): δ -144.2 (sept, 1JP,F = 711.2 Hz, PF6), -46.8
HB(C3H3N2)3), 7.92 (br, 1H, HB(C3H3N2)3), 7.94 (d, 3JH,H
=
8.3, 4H, Ph), 8.13 (br, 1H, HB(C3H3N2)3) ppm. 13C{1H} NMR
(s, PPTA), -44.1 (d, 2JP,P = 32.3 Hz, PPTA), 49.2 (d, 2JP,P
32.3 Hz, PPh3) ppm.
=
(CD2Cl2, 100 MHz): δ 52.5 (d, 1JC,P = 16.0 Hz, PCH2N), 73.4
(d, JC,P = 6.4 Hz, NCH2N), 105.6 (d, JCP = 2.57 Hz, HB-
3
In Situ NMR Formation of [TpRuCl{C(PPh2Me)dCd
CPh2}(PTA)] (10). A solution of 6 (30.0 mg, 0.043 mmol) in
0.5 mL of CD2Cl2 was placed in an NMR tube, and PPh2Me
(0.043 mmol, 8.08 μL) was added through the serum cap via a
microsyringe at room temperature. Once the NMR study was
completed, the solvent was removed and the residue was used to
prepare the KBr pellet to record the IR spectrum. IR: νBH(Tp)
2472 (w), νCdCdC 1853 (w) cm-1. 1H NMR (CD2Cl2, 400 MHz):
δ 3.80-4.21 (m, 15H, PTA þ PPh2Me), 6.15 (br, 1H,
HB(C3H3N2)3), 6.42 (br, 2H, HB(C3H3N2)3), 6.83 (br, 1H,
HB(C3H3N2)3), 7.11-7.62 (m, 20H, Ph), 7.00 (br, 1H, HB-
(C3H3N2)3), 7.64 (br, 1H, HB(C3H3N2)3), 7.68 (br, 1H, HB-
(C3H3N2)3), 7.85 (br, 1H, HB(C3H3N2)3) ppm. 13C{1H} NMR
(CD2Cl2, 100 MHz): δ 52.6 (d, br, 3JC,P = 9.0 Hz, PCH2N), 73.3
(br, NCH2N þ PPh2Me), 105.2 (s, 2 HB(C3H3N2)3), 125.5-
133.9 (C PPh3, HB(C3H3N2)3), 136.4 (s, HB(C3H3N2)3), 143.7
(s, HB(C3H3N2)3), 144.9 (s, HB(C3H3N2)3), 147.4 (s, HB-
(C3H3N2)3), 106.5 (s, HB(C3H3N2)3), 106.5 (s, HB(C3H3-
N2)3), 129.3, 129.5, 130.0, 147.0 (C PPh3), 134.4 (s, HB-
(C3H3N2)3), 135.7 (s, HB(C3H3N2)3), 136.6 (s, HB(C3H3N2)3),
142.7 (s, HB(C3H3N2)3), 143.9 (s, HB(C3H3N2)3), 145.2 (s,
HB(C3H32N2)3), 147.9 (s, CdCdCPh2), 226.8 (s, CdCdCPh2),
307.8 (d, JC,P = 24.5 Hz, CdCdCPh2) ppm. 31P{1H} NMR
(CD2Cl2, 161 MHz): δ -40.4 (s, P PTA).
Preparation of [TpRuCl(CO)(PTA)] (7). A nitrogen-purged
solution of 100.0 mg of [TpRuCl(PTA)(PPh3)] in toluene
(20 mL) was placed in a Schlenk flask equipped with a Teflon
stopcock under an atmosphere of CO (pCO = 1 atm). The
Schlenk tube was tightly closed and heated at reflux for 4 h.
Removal of the solvent under vacuum and precipitation of the
residue with Et2O (3 ꢁ 5 mL) gave a white solid. Yield: 75%.
Anal. Calcd for C16H22BClN9OPRu (534.72 g/mol): C, 35.94;
H, 4.15; N, 23.58. Found: C, 35.12; H, 4.09; N, 23.70. IR (KBr
pellet): ν(BH) 2481, ν(CO) 1963 cm-1
.
1H NMR (CD2Cl2,
(C3H3N2)3), 100.7 (d, JCP = 24.06 Hz, CdCdCPh2), 214.9
3
400 MHz): δ 4.21 (s, 6H, PCH2N), 4.40-4.57 (AB system, 6H,
NCH2N), 6.22 (br s, 1H, HB(C3H3N2)3), 6.25 (t, JH,H = 2.2
(br, CdCdCPh2) ppm. The signal corresponding to CR could
not be safely localized, likely due to superimposition with signals
of the PTA backbone at ca. 70 ppm. 31P{1H} NMR (CD2Cl2,
161 MHz, 0 °C): δ -47.3 (s, P PTA), -18.4 (s, C-P PTA) ppm.
In Situ NMR Formation of [TpRuCl{C(PTA)dCd
CPh2}(PTA)] (11). A solution of 6 (30.0 mg, 0.043 mmol) in
0.5 mL of CD2Cl2 was placed in an NMR tube, and a CD2Cl2
solution of PTA (85.0 μL, 0.043 mmol, 0.5 M) was added
through the serum cap via a microsyringe at room temperature.
Once the reaction was completed (NMR monitoring), the
solvent was removed in vacuo and the residue was used to
prepare the KBr pellet to record the IR spectrum. IR: νBH(Tp)
2472 (w), νCdCdC 1851 (w) cm-1. 1H NMR (CD2Cl2, 400 MHz):
δ 3.76-3.93 (m, 6H, PCH2N), 4.21-4.34 (m, 6H, NCH2N),
4.34-4.49 (m, 6H, NCH2N), 4.65-4.90 (m, 6H, PCH2N), 5.65
(br, 1H, HB(C3H3N2)3), 6.13 (br, 2H, HB(C3H3N2)3), 6.56 (br,
1H, HB(C3H3N2)3), 6.86-7.85 (m, 15H, Ph þ HB(C3H3N2)3)
ppm. 13C{1H} NMR (CD2Cl2, 100 MHz): δ 72.7 (d, 3JC,P = 9.0
3
3
Hz, 1H, HB(C3H3N2)3), 6.35 (t, JH,H = 2.1 Hz, 1H, HB-
(C3H3N2)3), 7.39 (br s, 1H, HB(C3H3N2)3), 7.64 (br s, 1H,
HB(C3H3N2)3), 7.74 (br,d, 3JH,H = 2.1 Hz, 1H, HB(C3H3N2)3),
7.78 (br d, 3JH,H = 2.1 Hz, 1 H, HB(C3H3N2)3), 7.80 (br s, 1H,
HB(C3H3N2)3), 7.91 (br d, 3JH,H = 2.4 Hz, 1 H, HB(C3H3N2)3)
1
ppm. 13C{1H} NMR (CD2Cl2, 100 MHz): δ 52.07 (d, JC,P
=
16.43 Hz, PCH2N), 73.33 (d, 3JC,P = 6.32 Hz, NCH2N), 106.10
(d, 4JC,P = 2.53 Hz, HB(C3H3N2)3), 106.19 (s, HB(C3H3N2)3),
106.96 (s, HB(C3H3N2)3), 135.21 (s, HB(C3H3N2)3), 136.02 (s,
HB(C3H3N2)3), 137.03 (s, HB(C3H3N2)3), 143.25 (s, HB(C3H3-
N2)3), 145.44 (s, HB(C3H3N2)3), 146.11 (s, HB(C3H3N2)3),
201.81 (d, J = 17.69, CO) ppm. 31P{1H} NMR (CD2Cl2, 161
MHz): δ -35.40 (s)
In Situ NMR Formation of [TpRu{C(PPh2Me)dCdCPh2}-
(PTA)(PPh3)]PF6 (8). A solution of 5 (20.9 mg, 0.019 mmol) in
0.5 mL of MeOD was placed in an NMR tube, and PPh2Me
(3.67 μL, mL, 0.019 mmol) was added through the serum cap via
a microsyringe at room temperature. 31P{1H} NMR (MeOD,
161 MHz, 0 °C): δ -144.3 (sept, 1JP,F = 707.6 Hz, PF6), -31.2
(br d, 2JP,P = 31.2 Hz P PTA), 22.6 (br s, PPh2Me), 53.9 (br d,
2JP,P = 35.6 Hz, PPh3) ppm.
3
Hz, NCH2N), 73.7 (d, JC,P = 5.1 Hz, NCH2N), 105.0 (s,
HB(C3H3N2)3), 125.5-129.7 (C PPh3, HB(C3H3N2)3), 134.5
(s, HB(C3H3N2)3), 135.2 (s, HB(C3H3N2)3), 135.4 (s, HB-
(C3H3N2)3), 142.3 (s, HB(C3H3N2)3), 143.2 (s, HB(C3H3N2)3),
3
143.9 (s, HB(C3H3N2)3), 102.8 (d, JCP = 25.76 Hz, Cd
Preparation of [TpRu{C(PTA)dCdCPh2}(PTA)(PPh3)]PF6
(9). A 14.7 mg portion (0.093 mmol) of PTA was added to a
solution of 5 (100.0 mg, 0.093 mmol) in 20 mL of MeOH.
The mixture was concentrated by slow evaporation of the
solvent under a stream of nitrogen. A yellow crystalline pre-
cipitate was obtained. Yield: 62.9 mg (54.9%). Anal. Calcd for
C54H59BF6N12P4Ru (1225.91 g/mol): C, 52.91; H, 4.85; N,
13.71. Found: C, 53.01; H, 4.75; N, 13.60. IR (KBr pellet):
CdCPh2), 210.7 (br, CdCdCPh2) ppm. A careful inspection
of the 1H,13C-HSQC experiment indicates that the signal corre-
sponding to the PCH2N group (54.6 ppm) is partially obscured
by the solvent resonance. The signal corresponding to CR could
not be safely localized, likely due to superimposition with signals
of the PTA backbone at ca. 70 ppm. 31P{1H} NMR (CD2Cl2,
161 MHz, 0 °C): δ -47.3 (s, P PTA), -18.4 (s, C-P PTA) ppm.
X-ray Structure Determination. Suitable crystals for X-ray
diffraction studies were obtained for compounds 2 and 9.
1
νBH(Tp) 2518 (w), νCdCdC 1840 (w) cm-1. H NMR (CD2Cl2,

~
Bolano et al.
6030 Organometallics, Vol. 28, No. 20, 2009
Table 4. Crystal Data and Structure Refinement Details for Compounds 2 and 9
2
9
empirical formula
formula wt
temp (K)
wavelength (A)
cryst syst
space group
unit cell dimens
a (A)
b (A)
c (A)
R (deg)
β (deg)
C
41H42BN9P2Ru
C54H59BF6N12P4Ru
1225.89
100
834.66
293(2)
0.71073
triclinic
P1
triclinic
P1
10.180(2)
10.678(2)
19.582(4)
81.850(5)
79.352(4)
67.111(4)
1921.4(7)
2
12.0938(14)
14.2160(16)
17.962(2)
72.991(2)
70.925(2)
67.592(2)
2647.8(5)
2
γ (deg)
V (A3)
Z
calcd density (Mg/m3)
1.443
0.535
1.538
0.490
abs coeff (mm-1
F(000)
cryst size (mm)
)
860
0.20 ꢁ 0.20 ꢁ 0.15
1260.0
0.24 ꢁ 0.10 ꢁ 0.02
θ range for data collecn (deg)
index ranges
no. of rflns collected
no. of indep rflns
no. of obsd rflns (>2σ)
data completeness
abs cor
2.08-23.00
1.22-28.85
-11 e h e 11; -8 e k e 11; -21 e l e 21
8238
-16 e h e 16; -18 e k e 18; -24 e l e 23
251 950
5300 (R(int) = 0.0707)
3031
0.990
12 370 (R(int) = 0.0334)
98 870
0.980
semiempirical from equivalents
1.000 and 0.660
max and min transmissn
refinement method
no. of data/restraints/parameters
goodness of fit on F2
final R indices (I > 2σ(I))
R indices (all data)
0.872 and 0.990
full-matrix least squares on F2
5300/0/488
1.026
12 370/0/706
1.101
R1 = 0.0479, wR2 = 0.1027
R1 = 0.0658, wR2 = 0.1124
1.095 and -0.532
R1 = 0.0925, wR2 = 0.2304
R1 = 0.1528, wR2 = 0.2895
1.556 and -1.259
largest diff peak and hole (e A-3
)
For compound 2, the data collection was carried out on a
Siemens Smart CCD area-detector diffractometer with gra-
phite-monochromated Mo KR radiation. For compound 9,
the data collection was carried out on a Bruker Smart Apex
CCD area-detector diffractometer with graphite-monochro-
mated Mo KR radiation. Absorption corrections were carried
out using SADABS.27
from ref 30. Details of crystal data and structural refinement are
given in Table 4.
Acknowledgment. We obtained financial support from
the Xunta de Galicia (Project CITE08PXIB314206PR)
and the Spanish MCINN (Project Consolider Ingenio
CSD2007-00006). We thank the University of Vigo CAC-
TI services for collecting X-ray data and recording NMR
spectra. S.B. and M.M.R.-R. thank the Xunta de Galicia
for funding through the “Parga Pondal” and “Maria
Barbeito” Programs, respectively. Thanks are also given
to the “Integrated Action” IT09DF82HE: “NMR studies
in water of coordination compounds with PTA of rele-
vance in pharmaceutical chemistry and catalysis”.
The structures of compounds were solved with the Oscail28 (2)
and Shelx programs29 (9) by Patterson methods and refined by
full-matrix least squares based on F2.29 Non-hydrogen atoms
were refined with anisotropic displacement parameters. Hydro-
gen atoms were included in idealized positions and refined with
isotropic displacement parameters. Atomic scattering factors
and anomalous dispersion corrections for all atoms were taken
(27) Sheldrick, G. M. SADABS: An Empirical Absorption Correction
€
Supporting Information Available: CIF files giving crystal-
lographic data for compounds 2 and 9. This material is available
free of charge via the Internet at http://pubs.acs.org.
€
Program for Area Detector Data; University of Gottingen, Gottingen,
Germany, 1996.
(28) McArdle, P. J. Appl. Crystallogr. 1995, 28, 65.
(29) Sheldrick, G. M. SHELX-97: Program for the Solution and
€
€
Refinement of Crystal Structures; University of Gottingen, Gottingen,
Germany, 1997.
(30) International Tables for X-ray Crystallography; Kluwer: Dor-
drecht, The Netherlands, 1992; Vol. C.