Synthesis and characterization of η6-arene ruthenium complexes bearing oxopentadienyl and phosphine ligands

Article abstract of DOI:10.1002/zaac.201300104

An addition reaction of dinuclear [(η⁶-C₆Me ₆)Ru(η^{3, 1}-exo-syn-CH₂CHCHCHO)] ₂(BF₄)₂ (1) with different Lewis bases in acetone results in the formation of mononuclear [(η⁶-C ₆Me₆)Ru(η³-exo-syn-CH₂CHCHCHO) (L)](BF₄) (L = PMe₃, 2; PPh₃, 3; PHPh ₂, 4; Ph₂PEtPy, 6; CO, 7) and dinuclear [{(η⁶-C₆Me₆)Ru(η³-exo-syn- CH₂CHCHCHO)}₂(μ₂-dppe)](BF₄) ₂ (5). The addition of Ph₂PCH₂CH ₂PPh₂ to the dinuclear product 1 affords 5 which show a bridging phosphine between two ruthenium centers. A comparative study of the new cationic arene derivatives and the corresponding isoelectronic Cp*Ru(heteropentadienyl) is established. All compounds were characterized by IR spectroscopy, high resolution mass spectrometry, NMR spectroscopy and the crystal structures of 2 and 3 are also described. Copyright

Full text of DOI:10.1002/zaac.201300104

ARTICLE
DOI: 10.1002/zaac.201300104
Synthesis and Characterization of η6-Arene Ruthenium Complexes Bearing
Oxopentadienyl and Phosphine Ligands
José Ignacio de la Cruz-Cruz,[a] Julio Cesar Romano-Tequimila,[a]
Patricia Juarez-Saavedra,[a] and M. Angeles Paz-Sandoval*[a]
Dedicated to Professor Heinrich Nöth on the Occasion of His 85th Birthday
Keywords: Arenes; Oxopentadienyl; Phosphines; Ruthenium
Abstract. An addition reaction of dinuclear [(η6-C6Me6)Ru(η3,1-exo- bridging phosphine between two ruthenium centers. A comparative
syn-CH2CHCHCHO)]2(BF4)2 (1) with different Lewis bases in acetone
results in the formation of mononuclear [(η6-C6Me6)Ru(η3-exo-syn- electronic Cp*Ru(heteropentadienyl) is established. All compounds
CH2CHCHCHO)(L)](BF4) (L PMe3, 2; PPh3, 3; PHPh2, 4; were characterized by IR spectroscopy, high resolution mass spectrom-
Ph2PEtPy, 6; CO, 7) and dinuclear [{(η6-C6Me6)Ru(η3-exo-syn- etry, NMR spectroscopy and the crystal structures of 2 and 3 are also
study of the new cationic arene derivatives and the corresponding iso-
=
CH2CHCHCHO)}2(μ2-dppe)](BF4)2
(5).
The
addition
of
described.
Ph2PCH2CH2PPh2 to the dinuclear product 1 affords 5 which show a
Introduction
Because of the interesting chemistry displayed by the half-
open ruthenocene complexes with oxopentadienyl ligands,[1]
and their major differences relative to the pentadienyl com-
plexes,[1,2] raises considerable interest in the chemistry of the
isoelectronic cationic (η6-arene)RuII(heteropentadienyl) ana-
logues.[3]
Scheme 1. Synthesis of the mixture of 1 and [(η6-C6Me6)Ru(η5-
CH2CHCHCHO)]BF4.
Additionally, it has also been reported that reactions of ar-
enes with organometallic species to form η6-arene ruthenium
compounds have been found numerous applications in organic
synthesis[4] and as chemical entities of biological interest.[5]
Previous results showed that there is a greater competition
among alternative bonding modes for the (η6-arene)Ru(hetero-
pentadienyl) derivatives compare to the Cp*Ru(heteropentadi-
enyl) analogues. In fact, a mixture of η5- and η3,1-oxopentadi-
enyl compounds [(η6-C6Me6)Ru(η5-CH2CHCHCHO)]BF4 and
[(η6-C6Me6)Ru(η3,1-exo-syn-CH2CHCHCHO)]2(BF4)2
(1)
Results and Discussion
was obtained from the reaction of 1-trimethylsilyloxy-1,3-
butadiene and [(η6-C6Me6)Ru(acetone)3](BF4)2, where the di-
nuclear oxopentadienyl product 1 has been the first structurally
characterized example of a complex bearing a bridging
oxopentadienyl ligand,[3] Scheme 1.
In this report, we described the study of the reactivity of
the dicationic complex 1 towards addition reactions, and the
contrastingly results upon addition of Lewis bases to the iso-
electronic neutral Cp*Ru(η5-oxopentadienyl) derivatives.
Synthesis
and
Spectroscopic Characterization
of
[(η6-C6Me6)Ru(η3,1-exo-syn-CH2CHCHCHO)(L)](BF4) (L =
PMe3, 2; PPh3, 3; PHPh2, 4; 2-(2-diphenylphosphinoethyl)
pyridine (Ph2PEtPy), 6; CO, 7) and [{(η6-C6Me6)Ru(η3-exo-
syn-CH2CHCHCHO)}2(μ2-dppe)](BF4)2 (5)
The new compounds 2–7 were prepared by addition of
Lewis bases, such as PPh3, PMe3, PHPh2, dppe, Ph2PEtPy and
CO, by thermal reactions (2–6), and at room temperature (7),
as described in Scheme 2. Compounds 2–7 are yellow solids,
air-stable in solid state and slightly sensitive in solution. All
compounds are soluble in acetone, nitromethane, acetonitrile
and chlorinated solvents, and insoluble in diethyl ether, ethanol
and hydrocarbons. Compound 6 reacts in chlorinated solvents
to afford compound (η6-C6Me6)Ru(η3-CH2CHCHCHO)Cl
(8).[3] Several attempts to improve the synthetic procedure for
obtaining 6 were unsuccessful, and there was no evidence of
coordination of the pyridine molecule to the ruthenium atom.
* Prof. Dr. M. A. Paz-Sandoval
E-Mail: mpaz@cinvestav.mx
[a] Departamento de Química
Centro de Investigación y de Estudios Avanzados del IPN
Av. IPN # 2508, Zacatenco
07360, Mexico City, Mexico
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201300104 or from the au-
thor.
1160
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2013, 639, (7), 1160–1165

η6-Arene Ruthenium Complexes Bearing Oxopentadienyl and Phosphine Ligands
Scheme 2. Synthesis of compounds 1–8.
A
similar P-coordination neutral complex [(η6- Cl, δ = 30.3],[7b] [(η6-C6H6)RuCl2]2(μ2-dppe) [δ = 23.3 (s)],[7c]
C6Me6)Ru(κ1-P-PPh2EtPy)Cl2] has been reported from reac-
tion of the dimer [(η6-C6Me6)RuCl2]2 and PPh2EtPy.[6] Also,
the P,N-chelated cationic complex [(η6-C6Me6)Ru(κ2-P-N-
PPh2EtPy)Cl]PF6 has been isolated.[6]
[{CpRu(N3)}2(μ2-dppe)2] [δ = 39.19],[8a] [{CpRuCl}2(μ2-
dppe)2] [δ = 37.10],[8a] and [{CpRu(SnCl3)2}2(μ2-dppe)] [δ =
43.5 (s)],[8b] as well as three intermediates species observed in
the phosphine substitution reactions between CpRuCl(PPh3)2
and dppe: CpRuCl(PPh3)(κ1-dppe) [δ = 41.51 (d), –12.10],[8a]
IR spectra of compounds 2–6 show evidence of an uncoordi-
nated C=O group of the oxopentadienyl ligand (1665–
1674 cm–1, KBr). The IR spectrum of 7 revealed the presence
of the carbonyl group of the oxopentadienyl ligand at
1675 cm–1 and the metal-carbonyl ligand at 2034 cm–1.
The 31P{1H} NMR spectra of compounds 2–4 and 6 show
a single singlet resonance at 5.9, 50.7, 34.9 and 39.0 ppm,
respectively; while the spectrum of compound 5 shows a doub-
let at 41.5 with J = 14.9 Hz, which indicates the inequivalence
of the two phosphorus nuclei of the bidentate ligand in a spec-
tral region typical of non-chelating phosphines. During moni-
toring of the formation of 5 through the 31P{1H} NMR spectra,
after 1.5 h, under mild heating acetone, two phosphorus signals
CpRuCl(κ1-dppe)2 [δ
=
40.72 (d), –12.31],[8a] and
[{CpRuCl(PPh3)}2(μ2-dppe)] [δ = 43.11 (d), 42.76 (d)].[8a] In
agreement with the presence of a bridging dppe ligand in com-
pound 5, the 31P NMR shows an upfield shift compared to
complexes where the dppe is acting as a chelate in mononu-
clear ruthenium derivatives, such as: [(η6-C6H6)Ru(κ2-
dppe)Cl]Cl [δ = 70.4 (s)],[7c] CpRuCl(κ2-dppe) [δ = 79.9],[9]
[CpRu(L)(κ2-dppe)]BPh4 [δ = 78.3–82.9],[9] Cp*RuX(κ2-
dppe) [X = Cl, δ = 73.5–74.6],[10,11] [X = N3, δ = 75.7],[11]
[X = H, δ = 90.2],[12] [Cp*RuX(κ2-dppe)]BF4 [X = (H)2,
δ = 71.3, (η2-H2), δ = 77.4],[12] and CpRu(κ2-dppe)SnCl3
[δ = 77.8 (s)],[8b] or dinuclear compounds where the
bidentate dppe is also coordinated only to one metal atom,
are observed as doublets at 41.8 and –10.5 ppm with JPP
=
34.7 Hz, another doublet at δ = 41.5 ppm with JPP = 14.8 Hz,
and free dppe. These three resonances are observed in
1.0:0.6:0.4 ratio, and after 2h they change to 0.3:1.0:0.0 ratio,
which indicates the presence of both κ1- and μ2- coordination
modes for the dppe ligand: an intermediate species 5Ј, where
one end of the dppe ligand is not coordinated to the metal
atom (δ = –10.5 ppm) and another end which is coordinated to
ruthenium (δ = 41.8 ppm) and the final product 5 with the
bridging ligand (δ = 41.5 ppm). Finally, after 3 h there is evi-
dence of total conversion to 5. The same results were obtained
after monitoring the reaction at room temperature, but longer
such
as
{Cp(PPh3)2Ru}CϵC-CϵC{Ru(κ2-dppe)Cp}
δ = 86.1 and {Cp(κ2-dppe)2Ru}CϵC-CϵC{Ru(κ2-dppe)Cp}
δ = 86.7 ppm.[13]
The 1H and 13C NMR spectroscopy of compounds 2–7 gave
evidence of the η3-exo-syn-oxodienyl coordination to the metal
center, as well as the expected η6-C6Me6 ligand. The chemical
shifts are quite similar, and typical of those found for enyl
moieties coordinated to ruthenium,[1,3] singlet signals at δ =
1.82–2.44 ppm are assigned to the hydrogen atoms of the hexa-
methylbenzene ligand, where the lower frequency is observed
1
times were required, see Supporting Information. A similar 31
NMR spectroscopic behavior has been reported for compounds
[{(η6-p-cymene)RuClN3}2(μ2-dppe)] [δ 26.7 (d)],[7a]
P
in 5. H NMR demonstrated that compound 7 and the neutral
analogue Cp*Ru(η3-exo-syn-CH2C(Me)CHC(Me)O)CO have
similar trends, showing higher frequency chemical shifts com-
=
[{(η6-C6Me6)RuXN3}2(μ2-dppe)] [X = N3, δ = 31.1],[7b] [X = pare to those of the corresponding cationic and neutral phos-
Z. Anorg. Allg. Chem. 2013, 1160–1165
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J. I. d. l. Cruz-Cruz, J. C. Romano-Tequimila, P. Juarez-Saavedra, M. A. Paz-Sandoval
ARTICLE
phine derivatives. Compound 6 was only assigned by 1H NMR
spectroscopy.
High resolution mass spectrometry shows a parent ion corre-
sponding to mononuclear structures for 2–4 and 6. In the case
of compounds 2–4 and 6, the base peak correspond to the mo-
lecular ion, giving evidence of the stability of the monodentate
phosphine derivatives, while 5 shows the fragment [(η6-
C6Me6)Ru(dppe)(C4H5O)]+ and 7 easily loose CO to afford
the base peak at 333 m/z. The peak signal at 333 is present in
all compounds, which suggest that either (η6-C6Me6)Ru(η3-
CH2CHCH2)(CO) or (η6-C6Me6)Ru(η3-CH2CHCHCHO) frag-
ments are favored. The former is proposed based on the easy
decarbonylation observed in compound (η6-C6Me6)Ru(η5-
CH2CHCHCHO) affording the exo and endo-allylic deriva-
tives (η6-C6Me6)Ru(η3-CH2CHCH2)(CO).[3]
Crystal Structures of 2 and 3
Perspective views of the molecular structures of compounds
2 and 3 are shown in Figure 1 and 2, respectively. Crystal data,
experimental parameters, and selected bond and angles are
given in Table 1 and 2, respectively.
Figure 2. Molecular structure of 3. (ORTEP plot, 45% probabilities).
Hydrogen atoms have been omitted for clarity.
Table 1. Crystal and structure refinement data for compounds 2 and 3.
Compound
2
3
Empirical formula
Formula weight
Crystal system
Space group
C19H32ORuPBF4 C34H39ORuPBF4
495.30
682.50
Monoclinic
P21
Othorrombic
Pna21
Unit cell dimensions
/Å, °
a = 9.2682(4)
b = 8.9115(4)
c = 13.1031(7)
β = 97.92(2)°
1071.91(9)
2
a = 10.6876(2)
b = 29.4988(2)
c = 9.9956(6)
β = 90°
3151.3(2)
4
V /Å3
Z
Crystal size /mm
0.51 ϫ 0.21 ϫ
0.15
1.535
508
0.846
0.75 ϫ 0.67 ϫ
0.56
1.439
1404
0.598
Dcalc /g·cm–3
F(000)
Absor. coeff. /mm–1
Absor. correction
T /K
Multi-Scan
293(2)
Spherical
293(2)
θ Range for data collection / 3.14 to 54.90
4.06 to 54.92
deg
Index ranges
Figure 1. Molecular structure of 2. (ORTEP plot, 45% probabilities).
Hydrogen atoms have been omitted for clarity.
–12 Յ h Յ 5
–11 Յ k Յ 9
–16 Յ l Յ 16
5765
–9 Յ h Յ 13
–28 Յ k Յ 38
–10 Յ l Յ 10
12077
X-ray crystallography confirmed the structures proposed for
2 and 3 on the basis of spectroscopic data. Compounds 2 and
3 are discrete cationic molecules where the oxodienyl ligand
is very similar in the two complexes, with respective values
for the Ru-oxopentadienyl fragment of Ru–C1 [2.215(10),
2.201(6) Å], Ru–C2 [2.124(8), 2.132(7) Å], Ru–C3 [2.222(8),
2.230(7) Å]. The latter is not significantly different from com-
pounds with exo conformation with respect to the arene ligand
no. of reflns collcd
no. of indpt reflns
4073 (Rint
=
5238 (Rint
0.0274)
4450
=
0.0494)
no. indpt obsd [F Ͼ 4σ(F)] 3035
Final R1 [F Ͼ 4σ(F)]
Final wR2 [F Ͼ 4σ(F)]
GOF
0.0598
0.1211
1.035
0.0583
0.1094
1.260
in 1 [2.204(4), 2.142(4), 2.221(3) Å] and (η6-C6Me6)Ru(η3- bond lengths within the enyl ligand show an asymmetrical
exo-CH2CHCH2)(CO) [2.235(5), 2.150(5), 2.228(6) Å][3] and bond to the metal atom [C1–C2 1.387(16), 1.394(11); C2–C3
clearly different from characteristic d4 configuration of the ru- 1.425(14), 1.437(10) Å] in 2 and 3, which can be compared to
thenium atom,[14] as the neutral endo RuIV derivatives: (η6-arene)Ru(η3-exo-syn-CH2C(Me)CHC(Me)O)Cl (arene =
Cp*Ru(η3-endo-syn-CH2C(Me)CHC(Me)O)Cl2
[2.187(3), C6H6, C6Me6) [C1–C2 1.434(6), 1.417(4); C2–C3 1.411(5),
2.196(3), 2.238(3) Å] and Cp*Ru(η3-endo-syn-CH(Me)- 1.438(4) Å].[3] The C1–C2–C3 angle [118.7(10), 117.6(8)] is
CHCHOEt)Cl2 [2.207(4), 2.172(4), 2.410(4) Å]. The C–C close to 120°, as typically observed in η3-allyl ruthenium
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© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2013, 1160–1165

η6-Arene Ruthenium Complexes Bearing Oxopentadienyl and Phosphine Ligands
structures.[3,14–16] The long bond length for Ru–C4 [3, mixture with Cp*Ru(η5-CH2C(Me)CHC(Me)O). Compound 1
3.0637(122); 4, 3.1504(103) Å] and the corresponding short did not underwent addition reactions with nitrogen ligands,
distance for C4–O1 [3, 1.222(13); 4, 1.217(11) Å] confirmed such as piperazine and the unsaturated 1,2-di-tert-butyl-
the exclusive η3- coordination of the oxopentadienyl ligand.
The dihedral angles corresponding to the oxopentadienyl li-
gands in 2 and 3 show similar deviation from planarity [2,
7.22(1.08°); 3, 6.14(0.89°)] and can be compared with (η6-
(ethylenediamine).
Conclusions
arene)Ru(η3-CH2C(Me)CHC(Me)O)Cl [arene
=
C6Me6,
As a result of this study, it is clear the preference of the
phosphorus vs. nitrogen as ligands in cationic arene-oxopenta-
dienyl derivatives. Once dimer 5 is formed, it does not tend to
dissociate to yield the entropy-favored chelate monomer. The
same behavior is observed in the cationic mononuclear com-
plex 6, where the nitrogen atom is not coordinated to the metal.
It is apparent that the reactivity of 1 and their oxopentadienyl
neutral analogues is strongly influenced by electronic proper-
ties of both the metal complex, and a more reactive bridging
η3,1-oxopentadienyl vs. η5-oxopentadienyl ligands. According
to the time of reaction, the addition of different reactants to 1
shows the following trend: 2 Ͼ 3 Ͼ 4 Ͼ 5 Ͼ 7, which are
in agreement with the steric and electronic properties of the
corresponding donor ligands.
18.5(4°). C6H6, 1.3(6°)], where a greater and slight distortion
is observed. The metal–arene bond lengths C–C reflect the ex-
pected higher steric demand of the methyl substituents in the
hexamethylbenzene ligands, Table 2. Consistent with the crys-
tallographically characterized Cp*Ru(η3-CH2C(Me)CHC-
(Me)O)PPh3, a longer bond Ru-PPh3 is observed for the cat-
ionic oxopentadienyl complex 3 compare to the isoelectronic
neutral complex.
Table 2. Selected bond lenghts /Å and angles /° for compounds 2 and
3.
Compound
2
3
Bond lenghts
C1–C2
C2–C3
C3–C4
C4–O1
Ru1–C1
Ru1–C2
Ru1–C3
Ru1–P1
Ru1–C6Me6 (centroid)
Bond Angles
C1–C2–C3
C2–C3–C4
C3–C4–O1
C1–Ru1–C2
C1–Ru1–C3
C2–Ru1–C3
C2–Ru1–C12
C3–Ru1–C11
C3–Ru1–C14
C1–Ru1–P1
C3–Ru1–P1
C11–Ru1–P1
C12–Ru1–P1
C15–Ru1–P1
1.387(16)
1.425(14)
1.422(13)
1.222(13)
2.215(10)
2.124(8)
2.222(8)
2.3407(19)
1.783(10)
1.394(11)
1.437(10)
1.454(11)
1.217(11)
2.201(6)
2.132(7)
2.230(7)
2.362(2)
1.807(10)
Experimental Section
Synthetic work was carried out in a dry nitrogen atmosphere using
standard Schlenk-techniques. All solvents were purified by conven-
tional procedures and distilled under nitrogen prior to use. Deuterated
solvents were degassed. The RuCl3·3H2O and phosphines were used
as received from Pressure Chemicals, Sigma–Aldrich and Strem
Chemicals, and CO was industrial grade. Compounds
[(η6-C10H14)RuCl2]2,[17] [(η6-C6Me6)RuCl2]2,[17] and 1[3] were pre-
pared by published methods.
118.7(10)
121.9(10)
127.7(11)
37.2(4)
66.1(4)
38.2(4)
163.3(3)
174.8(3)
102.1(3)
87.0(4)
117.6(8)
121.2(8)
121.8(9)
37.5(3)
66.3(4)
38.4(3)
The 1H, 13C{1H} and 31P{1H} NMR spectra were recorded with a
Bruker 300, Jeol GSX-270 and Jeol Eclipse 400 MHz instruments and
referenced internally using the residual protio and carbon solvent reso-
nances relative to tetramethylsilane. External standard for 31P was
91.4(3)
100.7(2)
167.6(3)
88.0(2)
1
H3PO4 (85%). Assignment of H and 13C NMR signals are based on
1D and 2D spectra. High resolution mass spectra were obtained by
LC/MSD TOF on an Agilent Technologies instrument with APCI as
ionization source. Infrared spectra were recorded with a FT-IR Perkin–
Elmer 1600 spectrometer using KBr pellets (4000–400 cm–1). Melting
points were determined in a Melt-Temp Gallenkamp (digital) and are
uncorrected.
81.3(3)
84.6(2)
97.91(14)
92.13(15)
162.10(14)
156.04(19)
154.4(2)
95.38(14)
A comparative investigation into the reactivity of the cat-
ionic arene derivatives 2–4 and the corresponding isoelectronic
Cp*Ru(η3-CH2C(Me)CHC(Me)O)PR3 (R = Me, Ph or R3 =
PHPh2) provides an important assessment of the electronic fac-
tors, which shows that the addition reactions proceed more
selectively (2, 70%; 3, 79%; 4, 88%) in the case of derivatives
of 1. Also strong Ru–P bond became evident in the isolated
cationic complex 3, whereas a facile dissociation of PPh3,
along with the consequent formation of Cp*Ru(η5-
CH2C(Me)CHC(Me)O), occurs in solution for the neutral com-
plex Cp*Ru(η3-CH2C(Me)CHC(Me)O)PPh3.[1] The highest
yield of all phosphine adducts Cp*Ru(η3-CH2C(Me)-
CHC(Me)O)PR3 was obtained for R = Me (70%), likely due
to the strong basicity and small size of PMe3, while the PR3 =
General Method for the Preparation of Compounds
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)](L)(BF4)
(L = PMe3, 2; PPh3, 3; PHPh2, 4; Ph2CH2CH2Ph2) and
[{(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)}2(μ2-
dppe)](BF4)2 (5)
A mixture of 1 (100 mg, 0.12 mmol) and the phosphine in acetone
(20 mL) was heated in an oil bath until 1H and 31P NMR spectroscopic
monitoring of the reaction mixture showed complete consumption of
the starting material and no further change in the spectrum was ob-
served. The reaction times were the following: 2, 40 min; 3, 70 min;
4, 2.5 h; 5, 3 h. After reach room temperature, the solution was filtered
and the volume of the solvent was reduced to approx. 2 mL. Addition
PHPh2 derivative, analogue to 4, was always obtained in a of diethyl ether afforded precipitation of yellow or yellow-orange sol-
Z. Anorg. Allg. Chem. 2013, 1160–1165
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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J. I. d. l. Cruz-Cruz, J. C. Romano-Tequimila, P. Juarez-Saavedra, M. A. Paz-Sandoval
ids, which were filtered and washed with diethyl ether (2 ϫ 3 mL) and 0.06 mmol). M. p. 185–187 °C. IR (KBr): ν˜ = 3056 cm–1 (m, br), 3024
ARTICLE
samples were dried under vacuum. All compounds melt with decompo-
sition.
(m, br), 2928 (m), 2861 (w, sh), 1975 (w, br), 1674 (vs), 1610 (vw,
sh), 1488 (m), 1439 (s), 1393 (m), 1288 (w), 1186 (vw, sh), 1057 (vs,
br), 876 (w), 824 (w), 751 (m), 703 (s), 616 (w), 521 (s), 492 (w, sh),
449 (w) cm–1. ESI+TOF: m/z 731.2071 [(η6-C6Me6)Ru(dppe)-
(C4H5O)]+, 662.1741 [(η6-C6Me6)Ru(dppe)]+, 333.07547 [(η6-
C6Me6)Ru(dppe)(C3H5)(CO)]+, 305.080297 [(η6-C6Me6)Ru(C3H5)]+.
5: C58H70B2F8O2P2Ru2: C, 56.32; H, 5.70. Found: C, 56.44; H, 5.57.
31P NMR (CD3NO2): δ = 41.5 (d, 14.9). 1H NMR (CD3NO2): δ =
1.81–1.85 (overlapped, H1anti), 2.91 (d, 7.3, H1syn), 4.18 (m, 7.4, 10.2,
H2), 2.29 (m, H3), 9.11 (dd, 2.0, 6.1, H4), 1.82 (s, C6Me6), 7.36–7.72
(m, Ph2, dppe), 1.88–2.08 (m, CH2, dppe). 31P NMR [(CD3)2CO]: δ
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)(PMe3)] (BF4) (2)
PMe3 (27.0 μL, 0.26 mmol). Oil bath at 45 °C. The yellow-orange
crystalline solid was obtained in 70% yield (82.0 mg, 0.17 mmol). M.
p. 206–207 °C. IR (KBr): ν˜ = 2982 cm–1 (s), 2920 (s), 2219 (w), 1947
(s, br), 1669 (vs), 1552 (m), 1433 (s), 1392 (s), 1296 (s), 1057 (vs,
br), 957 (s), 854 (m), 728 (m), 676 (m), 622 (w), 520 (m), 456 (w)
cm–1. ESI+TOF: m/z 409.1229 error 0.0556 ppm; DBE 4.5. 2:
C19H32BF4OPRu: C, 46.07; H, 6.51. Found: C, 46.34; H, 6.46. 31P
1
= 42.3 (d, 22.3). H NMR [(CD3)2CO]: δ = 1.88 (overlapped, H1anti),
1
NMR (CD3NO2): δ = 5.9 (s). H NMR (CD3NO2): δ = 1.79 (m, ap-
3.02 (d, ap, 7.2, H1syn), 4.34 (m, 9.4, 13.0, H2), 2.30 (overlapped, H3),
9.23 (dd, 2.0, 5.7, H4), 1.88 (s, C6Me6), 7.40–7.95 (m, Ph2, dppe),
1.70–2.00 (m, CH2, dppe).13C NMR [(CD3)2CO]: δ = 44.2 (s, C1),
82.3 (d, 7.7, C2), 56.8 (s, C3), 197.8 (d, 3.1, C4), 105.6 (s, C6Me6),
15.6 (s, C6Me6), 133.8 (m, o), 132.0 (m, m), 129.7 (s, p) 24.2 (br,
CH2). The intermediate species 5’ was detected through the monitoring
the reaction of 5: 31P NMR (CD3NO2): δ = 41.8 (d, 34.7), –10.5 (d,
37.2). 1H NMR (CD3NO2): δ = approx. 2.15 (m, H1anti), 2.94 (dd, 1.9,
7.4, H1syn), approx. 4.20 (m, 1.8, 7.0, 9.7 H2), 2.50 (m, H3), 9.14 (d,
6.1, H4), 1.92 (s, C6Me6), 7.30–7.70 (m, Ph2, dppe), 2.07, 2.11 (s,
CH2, dppe), 1.70–2.40 (m, CH2, dppe). 13C NMR (CD3NO2): δ = 43.7
(d, 4.6, C1), 82.4 (s, C2), 56.9 (s, C3), 198.3 (s, C4), 105.4 (s, C6Me6),
15.7 (s, C6Me6), [dppe: 133.4 (t, 8.5), 132.9 (d, 7.7), 132.7 (d, 7.7),
131.2 (s), 129.1 (d, 10.0), 128.3–128.8 (m), 25.6 (dd, 7.7, 24.6), 23.7
(dd, 6.2, 16.6)].
prox. 13.0, H1anti), 2.78 (dd, 2.5, 10.0, H1syn), 4.21 (m, 10.0, H2), 2.38
(m, overlapped, H3), 9.10 (d, 5.1, H4), 2.26 (s, C6Me6), 1.42 (d, 9.5,
PMe3).13C NMR (CD3NO2): δ = 43.6 (t, 1.5, C1), 80.5 (d, 2.7, C2),
56.4 (s, ap, C3), 198.1 (d, 7.0, C4), 104.9 (s, C6Me6), 15.7 (s, over-
lapped, C6Me6), 15.7 (m, PMe3).
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)(PPh3)] (BF4) (3)
PPh3 (62.6 mg, 0.24 mmol). A pale yellow crystalline solid was ob-
tained in 79% yield (128.7 mg, 0.19 mmol). M. p. 208–209 °C. IR
(KBr): ν˜ = 3027 cm–1 (w, br), 2000–1750 (w, br), 1665 (vs), 1483 (m),
1437 (s), 1390 (m), 1288 (w), 1057 (vs, br), 803 (w), 750 (s), 701(s),
621 (w), 529 (s), 488 (m), 422 (w) cm–1. ESI+TOF: m/z 595.1700
1
error 0.2881 ppm; DBE 16.5. 31P NMR (CD3NO2): δ = 50.7 (s). H
NMR (CD3NO2): δ = 1.87 (m, approx. 14.0, H1anti), 3.06 (dd, 1.8, 7.2,
H1syn), 4.22 (m, 7.0, 10.1, H2), 2.29 (m, 7.0, 9.5, H3), 9.18 (d, 6.8,
H4), 1.94 (s, C6Me6), 7.58 (br. s, PPh3).13C NMR (CD3NO2): δ = 43.9
(s, C1), 83.0 (s, C2), 58.0 (s, C3), 198.4 (s, C4), 106.0 (s, C6Me6),
15.2 (s, C6Me6), 135.0 (d, 9.6, o), 128.8 (d, 10.5, m), 131.4 (s, p),
130.0 (d, 31.5, i).
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)(Ph2PEtPy)]
(BF4) (6)
A mixture of 1 (100 mg, 0.12 mmol) and 2-(2-diphenylphosphino-
ethyl)pyridine (Ph2PEtPy) (34.7 mg, 0.12 mmol) was heated in re-
fluxing chloroform/acetone (2:1) (20 mL). No further change was ob-
1
served even after 4 h. The H and 31P NMR showed a mixture of 1, 6
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)(PHPh2)] (BF4)
and the previously isolated (η6-C6Me6)Ru(η3-CH2CHCHCHO)Cl
(8).[3] The solution was filtered through Celite® 545 removing com-
pound 1. The volume of the remaining yellow solution was reduced to
a minimum and a chromatographic column with desactivated alu-
mina[18] and elution of dicholoromethane/acetone (1:1) gave 3 frac-
tions, from the first orange band compound 8 as an orange powder
was isolated in 15.3% (56.5 mg, 0.15 mmol), while in the second yel-
low band, 6 was isolated as yellow powder in 18.4% (27.6 mg,
0.04 mmol). Compound 6: ESI+TOF: m/z 624.1964 error 0.0358 ppm;
DBE 16.5. 31P NMR [(CD3)2CO]: δ = 39.0 (s). 1H NMR [(CD3)2CO]:
δ = approx. 2.05 (overlapped, H1anti), approx. 3.00 (overlapped, H1syn),
4.39 (dd, 7.5, 9.9, H2), 2.47 (overlapped, H3), 9.30 (d, 6.1, H4), 2.50
(s, C6Me6), 7.10–7.35, 7.50–7.98 (m, Ph2, Ph2PEtPy), 2.90–3.20 (m,
CH2, Ph2PEtPy), 8.58 (m, 4.8). Compound 8: M. p. 182–185 °C (dec).
IR (KBr): 3319 (w), 3066 (s), 2919 (s, br), 2802 (s), 2731 (s), 2269
(w), 2110 (w), 1940 (w), 1815 (w), 1666 (vs), 1490 (s), 1441 (s, br),
1390 (s, br), 1136 (s), 1007 (s, br), 907 (s) cm–1. ESI+TOF: m/z
369.0553 error 0.4 ppm. 1H NMR (CDCl3): δ = 2.66 (dd, 0.8, 11.3,
H1anti), 3.20 (d, 6.9, H1syn), 4.49 (ddd, 7.1, 9.9, 11.3, H2), 3.40 (dd,
10.1, H3), 9.73 (d, 3.3, H4), 2.06 (s, C6Me6). 13C NMR (CDCl3): δ =
56.7 (s, C1), 87.9 (s, C2), 66.0 (s, C3), 199.0 (s, C4), 97.8 (s, C6Me6),
15.5 (s, C6Me6).
(4)
PHPh2 (10 wt.-% in hexane) (0.72 mL, 0.24 mmol). Oil bath at 52 °C.
A
canary-yellow solid was obtained in 88% yield (126.0 mg,
0.21 mmol). M. p. 214–215 °C. IR (KBr): ν˜ = 3026 cm–1 (w, br), 2922
(w, br), 2851 (w, br), 2752 (vw), 2345 (m), 2000–1750 (w, br), 1670
(vs), 1585 (vw), 1542 (m), 1483 (m), 1439 (s), 1389 (m), 1320 (w),
1287 (w), 1190 (w, sh), 1137 (s, sh), 1059 (vs, br), 910 (m), 868 (s),
746 (s), 700(s), 622 (m), 511 (s), 477 (w), 438 (s) cm–1. ESI+TOF:
m/z 519.1385 error 0.0321 ppm; DBE 12.5. 4: C28H34BF4OPRu: C,
55.55; H, 5.66. Found: C, 55.25; H, 5.62. 31P NMR (CD3NO2): δ =
34.9 (s). 1H NMR (CD3NO2): δ = 1.52 (dd, approx. 12.0, H1anti), 2.96
(d, 7.0, H1syn), approx. 4.30 (overlapped, H2), 2.10–2.20 (overlapped,
H3), 9.13 (d, 6.3, H4), 2.17 (s, C6Me6), 7.30–7.65 (m, PHPh2) 6.88
(d, approx. 370.0, PH). 1H NMR [(CD3)2CO]: δ = 1.45 (m, approx.
12.5, H1anti), 3.02 (d, 6.7, H1syn), 4.60 (m, 7.7, 9.5, H2), 2.21 (m,
overlapped, H3), 9.22 (d, 6.2, H4), 2.21 (s, C6Me6), 7.09 (d, 374.1,
Ph2PH), 7.24–7.58 (m, PHPh2), 7.09 (d, 374.0, PH). 13C NMR
[(CD3)2CO]: δ = 46.6 (s, C1), 83.6 (s, C2), 57.1 (s, C3), 197.2 (s, C4),
105.0 (s, C6Me6), 15.3 (s, C6Me6), 133.6 (d, 8.8, o), 134.1 (d, 9.7, o),
129.3 (d, ap, m), 129.4 (d, ap, m), 131.1 (s, p), 131.7 (s, p).
[{(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)}2(μ2-
Ph2CH2CH2Ph2)](BF4)2 (5)
[(η6-C6Me6)Ru(η3-exo-syn-CH2CHCHCHO)(CO)] (BF4) (7)
1,2-diphenylphosphinoethane (dppe) (57.0 mg, 0.14 mmol). Oil bath at
52 °C. A pale yellow solid was obtained in 52% yield (76 mg,
A solution of 1 (100 mg, 0.12 mmol) in acetone (20 mL) was placed
in a glass reactor and CO was introduced at 1.5 bar. After stirring 16
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© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2013, 1160–1165

η6-Arene Ruthenium Complexes Bearing Oxopentadienyl and Phosphine Ligands
[3] A. Ramirez-Monroy, M. A. Paz-Sandoval, M. J. Ferguson, J. M.
h, an amber suspension was observed; it was filtered and the lemon-
yellow solution was evaporated under reduced pressure to yield a
lemon-yellow solid in 76% (86.0 mg, 0.19 mmol). M. p. 256–257 °C.
IR (KBr): ν˜ = 3433 cm–1 (m, br), 2999 (w, br), 2953 (w, br), 2862 (w,
sh), 2346 (w, br), 2035 (vs), 1675 (vs), 1497 (m), 1451 (s), 1394 (s),
1294 (m), 1251 (w, sh), 1128 (vs, sh), 1128 (vs, sh), 1059 (vs), 881
(w, sh), 741 (m), 619 (w), 586 (w), 538 (m), 519 (m), 499 (s), 471
(m) cm–1. ESI+TOF: m/z 361.0739 error 0.7225 ppm; DBE 6.5. 7:
C17H23BF4O2Ru: C, 45.65; H, 5.18. Found: C, 46.01; H, 4.99. 1H
NMR (CD3NO2): δ = 2.70 (d, 10.0, H1anti), 3.26 (dd, 1.8, 7.0, H1syn),
4.64 (dddd, 5.9, 7.2, 10.2 H2), 3.11 (dd, 4.6, 10.0, H3), 9.32 (d, 4.5,
H4), 2.44 (s, C6Me6). 13C NMR [(CD3)2CO]: δ = 46.6 (s, C1), 85.4
(s, C2), 56.9 (s, C3), 195.8 (s, C4), 111.3 (s, C6Me6), 16.0 (s, over-
lapped, C6Me6), 196.4 (s, Ru-CO).
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Financial support by Conacyt, Mexico (46556-E, 152280, 128411) is
gratefully acknowledged. JICC and JCRT thank Conacyt for graduate
and undergraduated scholarship, respectively. Thanks to M. A. Leyva-
Ramirez and G. Cuellar for helping us with X-ray diffraction studies
and HRMS, respectively.
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Received: February 20, 2013
Published Online: May 15, 2013
Z. Anorg. Allg. Chem. 2013, 1160–1165
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
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