Aggregation tendency and reactivity toward AgX of cationic half-sandwich ruthenium(ii) complexes bearing neutral N,O-ligands

Article abstract of DOI:10.1039/b514269e

The aggregation tendency of complexes [Ru(η⁶-cymene)(N,O)Cl] X [N,O = 2-benzoylpyridine (2-bzpy), 1, and 2-acetylpyridine (2-acpy), 2, X ^- = BPh₄^- or PF₆^-] has been studied by means of PGSE NMR experiments. It was found that complexes with PF₆^- as counterion are mainly present in CD ₂Cl₂ as ion pairs at low concentration, as a mixture of ion triples and free anions at medium concentration and as ion quadruples at elevated concentration. ¹⁹F, ¹H-HOESY NMR experiments revealed that in ion triples and ion quadruples two cationic Ru-units pair up. Consistently, in the solid-state structure of 1PF₆, determined through X-ray single-crystal investigation, two cationic Ru-units are held together by an intermolecular π-π stacking interaction between the pyridyl rings. Complexes having BPh₄^- as counterion are only present in solution as even aggregates, namely ion pairs at low concentration and ion quadruples at elevated concentration. In such a case a counteranion bridges two cationic Ru-units as observed in the solid-state structure of 1BPh₄. The reactivity of complexes 1-2 toward AgX salts has been investigated in different solvents. Bicationic [Ru(η⁶-cymene)(N, O)(MeCN)]X₂ (N,O = 2-bzpy, 3, and 2-acpy, 4) and [Ru(MeCN) ₄(N,O)]X₂ (N,O = 2-bzpy, 5, and 2-acpy, 6) complexes were obtained by the reaction of 1 and 2 with AgX in the presence of three equivalents of acetonitrile or in acetonitrile, respectively. The reaction of 1 with AgPF₆ in acetone afforded complex [Ru(η⁶-cymene) (N,O,O)]PF₆ (7, where N,O,O = 4-alcoxide-4-phenyl-4-(pyridin-2-yl) butan-2-one) from the C-C coupling of a deprotonated methyl group of the coordinated acetone and the CO moiety of 2-bzpy ligand. The Royal Society of Chemistry 2006.

Full text of DOI:10.1039/b514269e

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PAPER
www.rsc.org/dalton | Dalton Transactions
Aggregation tendency and reactivity toward AgX of cationic half-sandwich
ruthenium(II) complexes bearing neutral N,O-ligands
Daniele Zuccaccia, Gianfranco Bellachioma, Giuseppe Cardaci, Cristiano Zuccaccia and Alceo Macchioni*
Received 7th October 2005, Accepted 5th January 2006
First published as an Advance Article on the web 18th January 2006
DOI: 10.1039/b514269e
6
The aggregation tendency of complexes [Ru(g -cymene)(N,O)Cl]X [N,O = 2-benzoylpyridine (2-bzpy),
1, and 2-acetylpyridine (2-acpy), 2, X− = BPh4 or PF6−] has been studied by means of PGSE NMR
−
−
experiments. It was found that complexes with PF6 as counterion are mainly present in CD2Cl2 as ion
pairs at low concentration, as a mixture of ion triples and free anions at medium concentration and as
ion quadruples at elevated concentration. 19F, 1H-HOESY NMR experiments revealed that in ion
triples and ion quadruples two cationic Ru-units pair up. Consistently, in the solid-state structure of
1PF6, determined through X-ray single-crystal investigation, two cationic Ru-units are held together by
−
an intermolecular p–p stacking interaction between the pyridyl rings. Complexes having BPh4 as
counterion are only present in solution as even aggregates, namely ion pairs at low concentration and
ion quadruples at elevated concentration. In such a case a counteranion bridges two cationic Ru-units
as observed in the solid-state structure of 1BPh4. The reactivity of complexes 1–2 toward AgX salts has
6
been investigated in different solvents. Bicationic [Ru(g -cymene)(N,O)(MeCN)]X2 (N,O = 2-bzpy, 3,
and 2-acpy, 4) and [Ru(MeCN)4(N,O)]X2 (N,O = 2-bzpy, 5, and 2-acpy, 6) complexes were obtained by
the reaction of 1 and 2 with AgX in the presence of three equivalents of acetonitrile or in acetonitrile,
6
respectively. The reaction of 1 with AgPF6 in acetone afforded complex [Ru(g -cymene)(N,O,O)]PF6 (7,
where N,O,O = 4-alcoxide-4-phenyl-4-(pyridin-2-yl)butan-2-one) from the C–C coupling of a
=
deprotonated methyl group of the coordinated acetone and the C O moiety of 2-bzpy ligand.
5
[2,5-Ph2-3,4-Tol2(g -C4COH)]Ru(CO)2H is a hydrogen bonded
Introduction
dimer in toluene,7 in our laboratory it has been found that
(g -arene)RuCl[N(Ts)CHPhCHPhNH2] and other Ru(II) arene
6
The successful utilization of transition-metal organometallics
in organic synthesis mainly stems from the alteration of the
derivatives containing a-amino acid ligands have a remarkable
reactivity of organic substrates that are coordinated to the metal
tendency to form dimers, and even higher aggregates, in several
center.1 Nevertheless, emerging evidence suggests that second-
coordination-sphere interactions (H-bonding, p–p stacking, CH–
p interaction, etc. . .) may play a significant role in such an
activation process.2 For example, it is now well-recognized that
ion-pairing drastically affects the reactivity and structure of ionic
organometallic catalysts.3
solvents including isopropanol.8 Cationic arene ruthenium com-
plexes bearing diimine or diamine ligands were also found to
undergo associative processes in several solvents leading to ion
triples and ion quadruples held together by classical N–H · · · X or
more unusual, and less energetic, CH · · · X H-bonds.9,10
Here we report PGSE and NOE (Nuclear Overhauser Effect)
results on the aggregation and interionic structure in solution of
In a few cases, it has been proposed that organometallics catalyse
organic reactions solely using second-coordination-sphere interac-
tions. For instance, the Shvo4 and Noyori5 catalysts, bearing both a
Y–H (Y = NR or O) proton donor and an M–H hydride donor, are
thought to hydrogenate ketones in the second-coordination-sphere
through a bifunctional mechanism that involves the interactions
6
novel [Ru(g -cymene)(N,O)Cl]X complexes that do not possess
peripheral functionalities particularly suited to hydrogen bonding.
The solution results are contrasted with those obtained in the solid
state through X-ray single-crystal studies. Finally, the reactivity of
such complexes toward silver salts is described.
d−
d+
Y–Hd+ · · · O C · · · d−H–M and does not need the coordination
=
of the ketone to the metal.
Results and discussion
Second-coordination-sphere catalysis needs peripheral “anchor
points” on the catalyst suitable for establishing favourable inter-
actions with the organic substrate to be activated. Nevertheless,
it seems reasonable that such “anchor points” can also lead to
the self-aggregation of the catalyst itself. PGSE (Pulsed Field
Gradient Spin-Echo) NMR experiments6 have demonstrated that
this indeed occurs in solution for the Shvo7 and Noyori8 catalysts.
In particular, while Casey and co-workers have shown that
Syntheses and characterization of compounds 1–2
6
Complexes [Ru(g -cymene)(N,O)Cl]X [N,O = 2-benzoylpyridine
(2-bzpy), 1, and 2-aceylpyridine (2-acpy), 2, X− = BPh4− or PF6
]
−
6
were synthesised by the reaction of [Ru2(g -cymene)2Cl2(l-Cl)2]
with the appropriate ligand in methanol at room temperature in
the presence of a large excess of NaBPh4 or NH4PF6 (Scheme 1).
They were characterised in solution by FT-IR and 1H, 13C, 19F, and
31P NMR spectroscopies. Data are reported in the Experimental
section. Numbering of carbon and proton resonances is illustrated
Dipartimento di Chimica, Via Elce di Sotto, 8-06123, Perugia, Italy. E-mail:
alceo@unipg.it; Fax: +39 075 5855598; Tel: +39 075 5855579
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©

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◦
˚
In the solid state, the Ru–O bond lengths found for 1PF6
Table 1 Selected bond lengths (A) and angles ( ) of complexes 1PF6 and
1BPh4 with estimated standard deviation in parentheses
˚
˚
(2.098 A) and 1BPh4 (2.091 A) were similar to those re-
˚
ported for cis-RuCl2(dppb)(2-bzpy) [2.035 A, dppb = 1,4-bis-
1PF6
1BPh4
(diphenylphosphino)butane]12 and [Ru(2,2ꢀ-bipy)2(2-bzpy)](PF6)2
ꢀ
ꢀ
13
˚
(2.058 A, 2,2 -bipy = 2,2 -bipyridine) but were significantly
Ru–N
Ru–O
2.093(3)
2.098(3)
2.3890(9)
1.671(5)
2.102(2)
2.091(2)
2.3755(10)
1.661(4)
shorter than that of trans-[Ru(PMe3)2(CO)(COMe)(2-bzpy)]BPh4
14
Ru–Cl
˚
(2.226 A).
Ru–Cya
Aggregation and relative anion–cation orientations through PGSE
and NOE NMR experiments
O–Ru–N
Cl–Ru–N
Cl–Ru–O
75.77(12)
84.60(8)
84.56(6)
75.66(9)
86.11(7)
82.88(7)
PGSE measurements were performed for all complexes in CD2Cl2
at 296 K as a function of the concentration (Table 2). In the
case of complex 1PF6, the effect of changing the solvent was
also investigated (Table 2). From the measured self-diffusion
coefficients (Dt), the average hydrodynamic radius (rH) and volume
(VH) of the diffusing particles were derived taking advantage of
the Stokes–Einstein eqn (1), where k is the Boltzmann constant,
T is the temperature, c is a numerical factor and g is the solution
viscosity.
a C13–C18 centroid.
kT
cpgrH
Dt =
(1)
TMSS [tetrakis(trimethylsilyl)silane], whose dimensions are
known from the literature, was used as internal standard.15
The methodology to obtain accurate rH and VH values has
been described elsewhere.10 The average hydrodynamic volumes
for cation (VH+) and anion (VH−), determined from 1H- and
Scheme 1
in Scheme 1. All the proton and carbon resonances were assigned
1
1
1
1
(see Experimental) through H, 13C, H-COSY, H-NOESY, H,
13C-HMQC NMR, and 1H, 13C HMBC NMR spectroscopies. The
solid-state structures for 1PF6 and 1BPh4 were determined by X-
ray single-crystal diffractometry. An ORTEP view of cation 1 is
shown in Fig. 1. Relevant bond lengths and angles are given in
Table 1.
Table 2 Diffusion coefficients (1010Dt/m2 s−1), hydrodynamic radii
˚
(rH/A) and aggregation number (N) for compounds 1 and 2 as a function
of solvent (er at 25 ◦C) and concentration (C/mM)
+
−
Dt+
Dt−
rH
rH
N+
N−
C
3
˚
1PF6 (Vip = 368 A )
1
2
3
4
5
6
7
8
9
CD2Cl2 (8.93)
CD2Cl2 (8.93)
CD2Cl2 (8.93)
CD2Cl2 (8.93)
CD2Cl2 (8.93)
CDCl3 (4.81a)
CDCl3 (4.81a)
C6D5Cl (5.61)
C6D5Cl (5.61)
11.6
9.8
9.3
8.7
7.8
7.5
7.2
5.6
5.1
12.5
11.0
10.9
9.31 5.7
8.53 5.9
7.7
7.3
5.7
5.2
4.5
5.4
5.6
4.3
4.9
4.9
5.4
5.5
5.6
5.8
4.9
5.6
1.0
1.8
2.0
2.1
2.3
2,1
2.2
1.4
2.0
0.9
1.3
1.3
1.8
1.8
2.0
2.2
1.4
2.0
5
15
41
70
113b
1
5.7
5.8
5.0
5.6
6b
1
6b
3
˚
1BPh4 (Vip = 600 A )
10 CD2Cl2 (8.93)
11 CD2Cl2 (8.93)
12 CD2Cl2 (8.93)
8.6
7.6
7.5
8.7
7.7
7.7
6.1
6.2
6.4
6.0
6.1
6.3
1.6
1.7
1.9
1.6
1.6
1.8
9
34
43b
3
˚
2PF6 (Vip = 322 A )
Fig. 1 An ORTEP diagram of the cation in 1PF6. Ellipsoids are drawn at
the 30% probability level.
13 CD2Cl2 (8.93)
14 CD2Cl2 (8.93)
15 CD2Cl2 (8.93)
16 CD2Cl2 (8.93)
10.2
9.8
9.7
8.6
10.4
10.0
9.7
4.2
5.3
5.3
5.7
4.2
4.9
5.3
5.7
1.0
1.9
2.0
2.4
1.0
1.5
2.0
2.4
6
12
31
80b
8.6
In solution, the coordination of the labile O-arm to ruthenium
=
was indicated by a decrease in the C O stretching frequency of
3
˚
2BPh4 (Vip = 554 A )
67 and 81 cm−1 for 2-bzpy and 2-acpy complexes, respectively,
with respect to the uncoordinated ligand.11 At the same time,
a deshielding of C13 was observed that passed from 194.7 and
200.8 ppm in the free ligands to 205.0 and 211.6 ppm in 1X and
2X, respectively.
17 CD2Cl2 (8.93)
18 CD2Cl2 (8.93)
8.5
7.1
8.6
7.1
6.0
6.5
5.9
6.5
1.6
2.1
1.6
2.1
7
24b
a 20 ◦C. b Saturated solution.
1964 | Dalton Trans., 2006, 1963–1971
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19F-PGSE experiments, respectively, were contrasted with the van
der Waals volume of the ion-pair (VIP) known from single-crystal
X-ray investigations or derived from them. The cationic and
anionic aggregation numbers (N+ and N−) were calculated as the
ratios VH+/VIP and VH−/VIP, respectively (Table 2).
Table 3 Relative NOE intensities in CD2Cl2 determined by arbitrarily
fixing the intensity of the NOE(s) between the anion resonances (o-H in
the case of BPh4−) and the aromatic proton 8 of pyridyl at 1. Quantification
was carried out by taking into account that the volumes of the NOE cross
peaks are proportional to (nInS/nI + nS) where nI and nS are the number
of equivalent I and S nuclei, respectively17
Complex 1PF6 was mainly present as ion-pair in CD2Cl2 at the
lowest concentration considered (5 mM). In fact, N+ and N− were
both equal to 1 (entry 1) within the experimental error that was
estimated to be ca. 10%. An increase of the concentration led
to a rapid increment of N+ that passed from 1.0 (5 mM) to 1.8
(15 mM, entry 2) and then up to 2.3 in the saturated solution
(113 mM, entry 5). N− also increased but in a less accentuated
manner and it only approached the value 2 at concentrations
higher than 70 mM (entries 4 and 5). These results indicate that
an increase in concentration initially causes the transformation
of ion pairs into ion triples and free anions. For a solution of
1PF6 containing 50% of PF6 and 50% of 12PF6 , N+ and N− are
expected to be 1.8 and 1.1, respectively, in good agreement with
the observed values for 15 and 41 mM solutions (entries 2 and
3). A further concentration increase led to the presence of mainly
ion quadruples in solution (entries 4 and 5). In CDCl3, 1PF6 was
already present as ion quadruples at 1 mM concentration (entry 6)
and it remained as ion quadruples in the saturated solution (entry
7). Complex 2PF6 showed a greater tendency to aggregate than
1PF6 in CD2Cl2 (entries 13–16). While the former afforded ion
quadruples at 31 mM, the latter needed a concentration higher
than 70 mM. The PGSE measurements for 2PF6 also indicated
that ion pairs were formed at low concentration, ion triples and
free anions at intermediate concentration and ion quadruples at
high concentration.
a
1PF6
1PF6
1PF6
1PF6
1PF6
1BPh4
5 mM
15 mM
41 mM
70 mM
6 mM
34 mM
N+ = 1.0 N+ = 1.8 N+ = 2.0 N+ = 2.1 N+ = 2.2 N+ = 1.7
N− = 0.9 N− = 1.3 N− = 1.3 N− = 1.8 N− = 2.2 N− = 1.6
1,1ꢀ 0.12
0.14
0.12
0.52
0.06
0.13
0.57
0.09
0.10
0.63
0.12
0.39
1.12
0.20
0.30
0.62
0.77
1.01
0.85
0.35
1
1.23
1.02
0.54
0.68
0.33
—
2
4
—
0.57
4ꢀ
5
0.57
0.52
0.74
0.91
5ꢀ
−
+
7
8
9
10
11
15
16
17
0.22
1
0.38
0.22
0.19
1
0.45
0.27
0.17
1
0.54
0.27
0.19
1
0.64
0.29
0.32
1
0.99b
0.46
0.26
—
—
0.26
0.04
—
0.42
0.05
—
0.42
0.06
—
0.99b
—
—
a In CDCl3, b 9 and 15 are superimposed.
The relative anion–cation orientations for complexes 1X in
CD2Cl2 were studied by detecting dipolar interionic interactions
−
in the 19F, 1H-HOESY (X− = PF6−) and 1H-NOESY (X− = BPh4
)
NMR spectra at room temperature (296 K).
In the 5 mM solution of 1PF6 where ion pairs were mainly
present (N+ = 1.0 and N− = 0.9, entry 1 of Table 2), strong NOEs
were observed between the F-atoms of the counterion and proton
8 and the aromatic cymene protons (Table 3). Interactions of
moderate intensity were detected with 9, 10, 11 and 15 resonances.
Weak interactions were observed with the methyl and isopropyl
groups of cymene. Only 2, 16 and 17 did not show any NOE with
the anion. These observations are consistent with a single relative
anion–cation orientation, where PF6− is located above the pyridyl
moiety in agreement with our previous findings.14,16
The formation of ion triples (15 mM solution, N+ = 1.8 and
N− = 1.3) had little effect on the relative intensities of interionic
NOEs (Table 3) with the exception of weak interionic NOEs
between 2 and 16 and the anion that became visible in the 19F,
1H-HOESY spectrum (Fig. 2). For the 70 mM solution in CD2Cl2
(entry 4, Table 2) and the 6 mM saturated solution in CDCl3
(entry 7, Table 2), which contained mainly ion quadruples, the
Fig. 2 19F, 1H-HOESY NMR spectrum (376.65 MHz, 296 K, CD2Cl2) of
complex 1PF6 at 15 mM; *denotes the residue of non-deuterated solvent.
relative intensities of the contacts between 5/5ꢀ, 9 and 15 and PF6
−
increased.
In the solid state, complex 1PF6 showed sinusoidal chains of
cations that lay parallel to the bc plane. The chains consisted of
pairs of cations of alternating chirality: R,R,S,S,R,R, etc. . . The
cations of opposite chirality exhibited face to face p–p stacking
interactions involving the pyridyl groups (Fig. 3). These were
completely coplanar, while the mean slip angle between the normal
of one pyridine plane and the centroid vector was 31.5◦ and the
˚
˚
centroid to centroid distance was 4.10 A. The latter values are
◦
higher than the mean ones of 20 and 3.80 A18,19 but similar to those
of other complexes.13,18 Kol and co-workers previously showed an
analogous chiral recognition, based on p-stacking interactions,
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pairs to ion triples and, finally, to ion quadruples, the average
anion position changes a little becoming more similar to the
orientation B observed in the solid state, as indicated by the
increased intensities of the PF6−/9 and 15 interionic NOEs.
PGSE measurements were made of 1PF6 in C6D5Cl to cor-
roborate the hypothesis that ion triples and ion quadruples in
solution are held together by pyridyl p-stacking. C6D5Cl has a
relative permittivity (er) comparable to that of CDCl3 (Table 1)
but it can compete with another molecule of 1PF6 in p-stacking
interactions and, consequently, it should reduce the aggregation
tendency. Consistently, at 1 mM the aggregation in C6D5Cl was
significantly lower than that in CDCl3 (compare entries 8 and 6
in Table 2) and, more importantly, the values of N+ and N− were
identical indicating that ion quadruples dissociate into two ion
pairs and not into ion triples and anions.
Fig. 3 Chiral recognition observed in the solid state for 1PF6 due to a
p–p stacking interaction between two pyridyl rings.
PGSE measurements carried out for complexes 1BPh4 and
2BPh4 in CD2Cl2 showed that at the lowest concentrations a
mixture of ion pairs and ion quadruples was present (Table 2,
entries 10–11 and 17). Ion quadruples were observed almost
exclusively in saturated solutions (Table 2, entries 12 and 18).
Interestingly, in all cases, N+ was equal to N− indicating that only
even aggregates (ion pairs and ion quadruples) were present in
solution. This is in marked contrast with the results obtained
for 1PF6 and 2PF6 for which ion triples and free ions formed
(compare entries 10–12 with 1–3 and 13–14 with 17–18 in Table 2).
The quantitative analysis of NOE measurements carried out for
a 34 mM solution of complex 1BPh4 in CD2Cl2 (Table 3) showed
that the counterion interacted with all protons except 17.
In contrast to 1PF6, the solid-state structure of 1BPh4 did not
exhibit any intercationic proximity; on the contrary, there was a
perfect alternation of cations and anions in all three directions.
Although NMR does not afford any direct evidence, based on the
solid-state structure, we propose that, in solution, ion quadruples
are constituted by an alternation of cations and anions.
in both solid state and solution for octahedral Ru(II) and Os(II)
complexes of eilatin.20
The cations with the same chirality did not show any spe-
cific interaction between them. Only very weak p–p stacking
interactions between the cymene group and a benzylic moiety
could be observed. The two planes made a 31.8◦ angle with an
˚
interplane minimum and maximum separation of 3.51 and 4.90 A,
˚
respectively, and a centroid to centroid distance of 4.16 A. The
mean slip angle between the normal of the cymene plane and the
centroid vector was 29.9◦. p–p Stacking interactions were also
observed between the benzylic groups of two different sinusoidal
cation chains. The benzyls were completely coplanar, while the
mean slip angle between the normal of the benzylic plane and the
centroid vector was 38.2◦ and the centroid to centroid distance
˚
was 4.91 A.
−
The PF6 anions were distributed as bridges between different
cations and formed linear chains that lay parallel to the ab faces
and form the diagonals of these with alternated slopes. Each
cationic unit was surrounded by four anions. The closest two
˚
were at a Ru · · · P distance of 5.825 and 5.883 A, respectively
(orientations A and B in Fig. 4).
Reactivity of complexes 1–2 with AgX salts
The reactivity of complexes 1–2 toward AgX salts was investigated
in different solvents. The species formed were completely charac-
terised in solution by means of multinuclear and multidimensional
NMR experiments. The results are summarised in Scheme 2.
By the reaction of complexes 1 or 2 with a stoichiometric
amount of AgBF4, in methylene chloride in the presence of ca. 3
equivalents of acetonitrile (MeCN), the bicationic 3 or 4 complexes
formed [Scheme 2, pathway (a)]. The coordination of a Me–
C≡N unit was ascertained by the presence in the 1H NMR spectra
of a resonance at 2.34 and 2.38 ppm for 3 and 4, respectively,
integrating for three protons. Two resonances were present in the
13C NMR spectra at 129.5 and 4.3 ppm for 3 and at 128.6 and
4.3 ppm for 4 due to CN and Me moieties, respectively. The O-
arm remained coordinated to the metal as indicated by the high-
Fig. 4 Two views of two ion pairs (A and B) present in the solid state for
compound 1PF6 (the PF6 A and B are represented as balls and sticks).
=
frequency value of C O that fell to 207.4 and 216.0 ppm for 3 and
In solution, the NOE measurements indicated that within an
ion pair the counterion is located between the pyridyl ring and
cymene ligand, i.e. in an intermediate position with respect to
A and B orientations. In such a position, the anion is affected
little by the formation of the ion triple that probably occurs
through a p-stacking interaction of the other face of the pyridyl
ring as observed in the solid state (Fig. 3). On passing from ion
4, respectively.
−
When the reactions of 1 and 2 with AgX (X− = BF4 and
PF6−) were carried out in MeCN, in addition to the Cl−/MeCN
substitution reaction, cymene was also replaced by three MeCN
molecules and complexes 5 and 6 were formed [Scheme 2,
pathway (b)]. Three resonances were observed for the carbons and
hydrogens of MeCN in both the H and 13C NMR spectra. Due
1
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Fig. 5 Two sections of the 1H-NOESY NMR spectrum (400.13 MHz,
296 K, CD2Cl2) of complex 7 showing the proximity of 18 with 20, 15 and
even 11.
Scheme 2
to the equivalence of the MeCN ligands in relative trans position,
one of these integrated twice as much as the other two. The O-arm
appeared to be still coordinated to ruthenium since the resonance
=
due to C O fell to 210.4 and 217.0 ppm for 5 and 6, respectively.
Complexes 5 and 6 were also obtained by dissolving 3 and 4 in
acetonitrile.
To the best of our knowledge, these are the first bicationic
solvento-complexes of ruthenium bearing a neutral N,O-ligand.
Since these complexes can be prepared in good yield and
contain up to five labile ligands they may be good start-
ing materials for the syntheses of other compounds. Mono-
2
cationic cycloruthenated [Ru(N,C)(CH3CN)4]PF6 and [Ru(g -
amidinate)(CH3CN)4]PF6 complexes were synthesised by Pfeffer
and co-workers21 and Hayashida and Nagashima,22 respectively,
and it has been demonstrated that acetonitrile ligands can be easily
replaced by other r-donor ligands such as pyridines, phosphines,
and isocyanides.22
In an attempt to synthesise a complex similar to 3 with acetone
coordinated to ruthenium instead of MeCN,23 the reactions of 1
with AgPF6 were carried out in acetone [Scheme 2, pathway (c)].
Interestingly enough, the monocationic complex 7 was obtained
in good yield from the C–C coupling of a deprotonated methyl
=
group of the coordinated acetone molecule and the C O moiety
of the N,O-ligand. All NMR information was consistent with
the formation of complex 7. In particular, an AB spin-system
attributed to 18 protons was observed in the 1H NMR spectrum
and only one singlet integrating for three protons (20) was
observed besides that due to 7. The 18 protons showed NOEs
with 20 and with the aromatic protons 15 and 11 (Fig. 5). They
also exhibited scalar correlation with carbon 18, 13, 14, 12 and 19,
as shown in Fig. 6.
Fig. 6 Scalar correlations of 18 protons with 18 (1JHC), 13 (2JHC), 14
(3JHC), 12 (3JHC) and 19 (2JHC) carbons; * indicates the C O resonance of
=
free acetone.
It is known that Rh(III)24 and Au(III)25 can activate a C–H
bond of coordinated acetone. It is also known that coordinated
acetone may undergo C–C coupling in metalloaromatic complexes
This journal is
The Royal Society of Chemistry 2006
Dalton Trans., 2006, 1963–1971 | 1967
©

View Article Online
of Ir(I).26,27 To the best of our knowledge, this is the first example
of both processes occurring in the same reaction.28
49.5, Cipso), 155.7 (s, 8), 150.3 (s, 12), 140.7 (s, 17), 136.4 (s, 10 and
o), 133.7 (s, 11), 133.4 (s, 14), 132.5 (s, 9), 130.6 (s, 15), 130.0 (s,
16), 126.1 (s, m), 122.3 (s, p), 105.4 (s, 3), 100.2 (s, 6), 85.0 (s, 4ꢀ),
84.5 (s, 5), 83.5 (s, 4), 82.3 (s, 5ꢀ), 31.8 (s, 2), 22.4 (s, 1 or 1ꢀ), 22.3
(s, 1 or 1ꢀ), 19.0 (s, 7). Anal. Calc. for C45H40BClNORu: C, 71.29;
H, 5.32; N, 1.85. Found: C, 71.45; H, 5.42; N, 1.78%.
Conclusions
PGSE NMR investigations indicate that arene ruthenium com-
plexes 1–2 aggregate in solution affording ion quadruples at the
highest concentration levels even though they do not possess
peripheral functionalities particularly suited to hydrogen bonding.
Combining the results coming from the investigations in solution
(NOE NMR) and in the solid state (X-Ray) it is deduced that
Complex 1PF6. Complex 1PF6 was obtained with the same
procedure as 1BPh4 using NH4PF6 (208 mg, 1.28 mmol) instead
1
of NaBPh4. Yield: 76%. H NMR (CD2Cl2, 298 K): d 9.51 (dd,
3J8,9 = 4.8, 4J8,10 = 0.7, 8), 8.36 (dd, 3J11,10 = 7.2, 4J11,9 = 0.8, 11),
3
8.28 (ddd, 3J10,11 = J10,9 = 7.7, 4J10,8 = 1.3, 10), 8.03 (ddd, 3J9,10
=
the structure of the quadruples depends on the nature of the
7.8, 3J9,8 = 5.4, 4J9,11 = 1.5, 9), 7.90 (dd, 3J15,16 = 7.2, 4J15,17 = 1.3,
−
counterion. While −+−+ quadruples were observed for BPh4
,
3
3
3
−
15), 7.85 (t, J17,16 = 7.5, 17), 7.69 (dd, J16,15 = J16,17 = 8.1, 16),
in the case of PF6 counterion −++− quadruples were more
probable. These deductions are in perfect agreement with our
previous findings for arene ruthenium diimine9 and diamine
complexes.10 These different types of ion quadruples undergo
different equilibria as the concentration is decreased. −+−+
dissociates into two −+ ion pairs, while −++− initially dissociates
into a free anion − and a ++− ion triple. A further decrease in
concentration leads to two ion pairs. In the solid-state structure
of 1PF6 two cationic units of opposite chirality are held together
by a p–p stacking interaction between two pyridyl rings; this also
seems to be responsible for the formation of ion quadruples and
6.06 (d, 3J4 ,5 = 5.6, 4ꢀ), 6.04 (d, 3J4,5 = 5.6, 4), 5.89 (d, 3J = 5.6,
ꢀ
ꢀ
5 or 5ꢀ), 5.87 (d, J = 5.6, 5 or 5ꢀ), 2.97 (sept, J2,1(1 ) = 6.9, 2),
3
3
ꢀ
2.37 (s, 7), 1.37 (d, 3J1,2 = 6.9, 1), 1.34 (d, 3J1 ,2 = 6.9, 1ꢀ). 13C{ H}
1
ꢀ
NMR (CD2Cl2, 298 K): d 205.1 (s, 13), 156.5 (s, 8), 150.6 (s, 12),
140.6 (s, 17), 136.2 (s, 10), 133.8 (s, 11), 133.6 (s, 14), 132.5 (s, 9),
130.8 (s, 15), 129.9 (s, 16), 105.4 (s, 3), 100.5 (s, 6), 85.5 (s, 4ꢀ), 84.6
(s, 5), 83.7 (s, 4), 82.6 (s, 5ꢀ), 31.8 (s, 2), 22.4 (s, 1 or 1ꢀ), 22.3 (s, 1
or 1ꢀ), 18.9 (s, 7). 19F NMR (CD2Cl2, 298 K): d −71.6 (d, JFP
=
1
711.0). 31P{ H} NMR (CD2Cl2, 298 K): d −141.0 (sept, JPF
=
1
1
711.0). Anal. Calc. for C22H23ClF6NOPRu: C, 44.12; H, 3.87; N,
2.34. Found: C, 44.25; H, 3.95; N, 2.28%.
−
ion triples in solution for complexes with PF6 as counterion.
Complex 2BPh4. Complex 2BPh4 was obtained with the same
procedure as 1BPh4. Yield: 76%. 1H NMR (CDCl3, 298 K): d 8.41
Experimental
(d, 3J8,9 = 4.7, 8), 7.43 (br, 10 and o), 7.19 (dd, 3J9,10 = 8.0, 3J9,8
=
All preparations and manipulations were carried out under
nitrogen atmosphere using standard Schlenk techniques. The com-
pounds were prepared using freshly distilled solvents (hexane with
Na, Et2O with Na/benzophenone, MeOH with CaH2, CH2Cl2
and CH3CN with P2O5). The solvents were also degassed by many
gas-pump-nitrogen cycles before use. IR spectra were measured at
room temperature in CH2Cl2 solution on a FT-IR 1725 X Perkin-
3
4.7, 9), 7.15 (d, 3J11,10 = 7.7, 11), 6.99 (dd, 3Jm,p = Jm,o = 7.4, m),
6.88 (t, 3Jp,m = 7.2, p), 5.38 (d, 3J4,5 = 6.0, 4), 5.31 (d, 3J4 ,5 = 5.8,
ꢀ
ꢀ
4ꢀ), 5.11 (br, 5 and 5ꢀ), 2.66 (sept, 3J2,1(1 ) = 5.4, 2), 2.03 (s, 14), 1.55
ꢀ
(s, 7), 1.24 (d, 3J1,2 = 5.4, 1), 1.23 (d, 3J1 ,2 = 5.4, 1ꢀ). 13C{ H} NMR
1
ꢀ
(CDCl3, 298 K): d 211.5 (s, 13), 164.3 (q, 1JC11B = 49.5, Cipso), 154.7
(s, 8), 150.3 (s, 12), 141.2 (s, 10), 136.6 (s, o), 132.7 (s, 9), 131.4 (s,
11), 126.3 (s, m), 122.6 (s, p), 104.7 (s, 3), 99.2 (s, 6), 84.8 (s, 4ꢀ),
84.2 (s, 5), 82.7 (s, 4), 82.3 (s, 5ꢀ), 31.7 (s, 2), 26.4 (s, 14), 22.6 (s, 1
or 1ꢀ), 22.5 (s, 1 or 1ꢀ), 19.0 (s, 7). Anal. Calc. for C41H41BClNORu:
C, 69.25; H, 5.81; N, 1.97. Found: C, 69.35; H, 5.91; N, 1.83%.
Elmer spectrophotometer. One- and two-dimensional 1H, 13C, 31
P
and 19F NMR spectra were measured on Bruker DPX 200 and
DRX 400 spectrometers. Referencing is relative to TMS (1H and
13C), and CCl3F (19F). Complex [Ru(g -cymene)Cl2]2 was prepared
6
according to Benneth et al.29
Complex 2PF6. TlPF6 (161 mg, 0.46 mmol) was added to a
solution of complex 2BPh4 (329 mg, 0.46 mmol) in CH2Cl2 (15 mL)
at room temperature. TlBPh4 formed as a white solid that was
filtered off. n-Hexane was added to the remaining solution and
a red–brown precipitate was obtained; it was filtered off, washed
Synthesis of complexes 1–7
Complex 1BPh4. 2-Bzpy (120 mg, 0.64 mmol) was added to
6
a suspension of [Ru(g -cymene)Cl2]2 (100 mg, 0.16 mmol) in
1
methanol (15 mL) at room temperature. The suspension became
a red–brown solution; after 1 h NaBPh4 (438 mg, 1.28 mmol) was
added and a yellow precipitate was obtained. The suspension was
stirred for 2 h and the precipitate became red–brown (complex
1BPh4); it was filtered off, washed with methanol, and dried under
with n-hexane, and dried under vacuum. Yield: 96%. H NMR
(CD2Cl2, 298 K): d 9.34 (dd, 3J8,9 = 5.4, 4J8,10 = 0.6, 8), 8.35 (dd,
3
3J11,9 = 7.8, 4J11,10 = 0.9, 11), 8.28 (ddd, 3J10,9 = J10,11 = 7.7, 4J10,8
=
1.4,10), 7.97 (ddd, 3J9,10 = 7.7, 3J9,8 = 5.4, 4J9,11 = 1.5, 9), 6.01 (d,
J4 ,5 = 6.2, 4ꢀ), 5.94 (d, 3J4,5 = 6.2, 4), 5.80 (d, 3J5 ,4 = 6.2, 5ꢀ), 5.78
3
ꢀ
ꢀ
ꢀ ꢀ
vacuum. Yield: 87%. 1H NMR (CD2Cl2, 298 K): d 8.90 (d, 3J8,9
=
(d, 3J5,4 = 6.2, 5), 2.98 (s, 14), 2.97 (sept, 3J2,1(1 ) = 6.9, 2), 2.33 (s,
ꢀ
3
3
3
1
ꢀ
4.8, 8), 8.13 (d, J11,10 = 7.2, 11), 7.92 (ddd, J10,11 = J10,9 = 7.8,
7), 1.37 (d, 3J1,2 = 6.9, 1), 1.36 (d, 3J1 ,2 = 6.9, 1ꢀ). 13C{ H} NMR
4J10,8 = 1.3, 10), 7.87 (t, 3J17,16 = 7.5, 17), 7.79 (d, 3J15,16 = 7.2, 15),
(CD2Cl2, 298 K): d 211.6 (s, 13), 155.4 (s, 8), 151.2 (s, 12), 141.0 (s,
10), 132.7 (s, 9), 131.0 (s, 11), 104.9 (s, 3), 100.3 (s, 6), 85.3 (s, 4ꢀ),
83.6 (s, 5), 83.5 (s, 4), 82.1 (s, 5ꢀ), 31.7 (s, 2), 26.3 (s, 14), 22.5 (s,
1 or 1ꢀ), 22.4 (s, 1 or 1ꢀ), 18.7 (s, 7). 19F NMR (CD2Cl2, 298 K): d
3
7.68 (dd, 3J16,15 = J16,17 = 7.6, 16), 7.57 (ddd, 3J9,10 = 7.7, 3J9,8
=
5.5, 4J9,11 = 1.3, 9), 7.38 (br, o), 7.03 (dd, 3Jm,p = Jm,o = 7.3, m), 6.89
3
(t, 3Jp,m = 7.2, p), 5.70 (d, 3J4,5 = 6.0, 4), 5.59 (d, 3J4 ,5 = 6.0, 4ꢀ),
ꢀ
ꢀ
5.47 (d, 3J5,4 = 6.1, 5), 5.36 (d, 3J5 ,4 = 6.0, 5ꢀ), 2.80 (sept, 3J2,1(1 )
=
−71.6 (d, 1JFP = 711.0). 31P{ H} NMR (CD2Cl2, 298 K): d −141.0
1
ꢀ
ꢀ
ꢀ
6.9, 2), 2.21 (s, 7), 1.31 (d, 3J1,2 = 7.0, 1), 1.29 (d, 3J1 ,2 = 7.0, 1ꢀ).
(sept, 1JPF = 711.0). Anal. Calc. for C17H21ClF6NOPRu: C, 38.03;
ꢀ
1
13C{ H} NMR (CD2Cl2, 298 K): d 204.8 (s, 13), 165.4 (q, 1JC11B
=
H, 3.94; N, 2.61. Found: C, 38.13; H, 4.00; N, 2.54%.
1968 | Dalton Trans., 2006, 1963–1971
This journal is
The Royal Society of Chemistry 2006
©

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3
Complex 3. AgBF4 (176 mg, 0.90 mmol) and CH3CN
(0.060 mL, 1.1 mmol) were added to a solution of complex 1BPh4
(264 mg, 0.34 mmol) in CH2Cl2 (15 mL) at room temperature. The
resulting suspension was stirred for 16 h. The formed AgCl and
AgBPh4 were filtered off. n-Hexane was added to the remaining
solution and a red–brown precipitate was obtained; it was filtered
off, washed with n-hexane, and dried under vacuum. Yield: 65%.
(ddd, 3J4,5 = J4,3 = 7.8, 4J4,6 = 1.4, 4), 8.17 (ddd, 3J5,4 = 7.8, 3J5,6
=
5.4, 4J5,3 = 1.4, 5), 3.15 (s, 8), 2.76 (s, 12), 2.71 (s, 14), 2.37 (s, 10).
13C{ H} NMR (CD2Cl2, 298 K): d 217.0 (s, 7), 155.8 (s, 6), 154.3
1
(s, 2), 139.5 (s, 4), 132.5 (s, 5), 131.8 (s, 3), 130.12 (s, 11), 126.9
(s, 13), 125.6 (s, 9), 26.4 (s, 8), 4.8 (s, 12), 4.5 (s, 14), 4.2 (s, 10).
19F NMR (CD2Cl2, 298 K): d −152.32 (br, 10BF4), −152.37 (br,
11BF4). Anal. Calc. for C17H23B2F8N6ORu: C, 33.91; H, 3.85; N,
13.96. Found: C, 34.02; H, 3.95; N, 13.84%.
1H NMR (CD2Cl2, 298 K): d 9.58 (dd, 3J8,9 = 4.8, 4J8,10 = 1.4, 8),
3
8.52 (dd, 3J11,10 = 7.2, 4J11,9 = 1.4, 11), 8.41 (ddd, 3J10,11 = J10,9
=
Complex 7. AgBF4 (50 mg, 0.23 mmol) was added to a solution
of complex 1PF6 (119 mg, 0.19 mmol) in acetone (15 mL) at room
temperature. The suspension was stirred for 16 h. The formed AgCl
was filtered off. n-Hexane was added to the remaining solution
and complex 7 was obtained as a brown–green precipitate; it was
filtered off, washed with n-hexane, and dried under vacuum. Yield:
7.2, 4J10,8 = 1.4, 10), 8.14 (ddd, 3J9,10 = 7.2, 3J9,8 = 4.8, 4J9,11 = 1.4,
3
4
3
9), 8.04 (dd, J15,16 = 7.3, J15,17 = 1.3, 15), 7.89 (td, J17,16 = 7.5,
4J17,15 = 1.3, 17), 7.71 (dd, J16,15 = 7.3, J16,17 = 7.6, 16), 6.34 (d,
3
3
J4,5 = 5.6, 4), 6.26 (d, 3J4 ,5 = 5.6, 4ꢀ), 6.15 (d, 3J5 ,4 = 5.6, 5ꢀ), 6.14
3
ꢀ
ꢀ
ꢀ ꢀ
3
3
ꢀ
(d, J5,4 = 5.6, 5), 2.98 (sept, J2,1(1 ) = 6.9, 2), 2.37 (s, 7), 2.34 (s,
19), 1.39 (d, 3J1,2 = 6.9, 1), 1.36 (d, 3J1 ,2 = 6.9, 1ꢀ). 13C{ H} NMR
1
ꢀ
65%. 1H NMR (CD2Cl2, 298 K): d 9.40 (d, 3J8,9 = 5.6, 8), 7.72 (ddd,
(CD2Cl2, 298 K): d 207.4 (s, 13), 157.4 (s, 8), 150.9 (s, 12), 141.9 (s,
10), 136.9 (s, 17), 135.5 (s, 11), 133.7 (s, 9), 133.2 (s, 14), 131.8 (s,
15), 129.9 (s, 16), 129.5 (s, 18), 108.2 (s, 6), 103.6 (s, 3), 87.0 (s, 4ꢀ),
86.7 (s, 4), 85.3 (s, 5ꢀ), 85.0 (s, 5), 31.7 (s, 2), 22.5 (s, 1), 22.3 (s, 1ꢀ),
18.4 (s, 7), 4.3 (s, 19). 19F NMR (CD2Cl2, 298 K): d −152.32 (br,
10BF4), −152.37 (br, 11BF4). Anal. Calc. for C24H26B2F8N2ORu: C,
45.53; H, 4.14; N, 4.42. Found: C, 45.64; H, 4.20; N, 4.32%.
3J10,11 = J10,9 = 7.8, 4J10,8 = 1.4, 10), 7.50 (ddd, 3J9,10 = 7.8, 3J9,8
=
3
5.6, 4J9,11 = 1.3, 9), 7.39 (m, aromatic proton 15, 16, 17), 6.78 (d,
3J11,10 = 7.8, 11), 5.89 (d, J4,5 = 5.8, 4), 5.77 (s, 4ꢀ and 5ꢀ), 5.47
3
(d, 3J5,4 = 5.8, 5), 3.49 (d, 2J18B,18A = 19.6, 18B), 3.37 (d, 2J18A,18B
=
19.6, 18A), 2.87 (sept, 3J2,1(1 ) = 6.9, 2), 2.29 (s, 7), 2.27 (s, 20), 1.37
ꢀ
(d, 3J1,2 = 6.9, 1), 1.28 (d, 3J1 ,2 = 6.9, 1ꢀ). 13C{ H} NMR (CD2Cl2,
1
ꢀ
298 K): d 221.6 (s, 19), 170.5 (s, 12), 152.5 (s, 8), 145.6 (s, 14), 140.4
(s, 10), 129.1, 128.8, 126.3 (s, aromatic carbon 15, 16, 17), 125.5 (s,
9), 123.27 (s, 11), 99.0 (s, 3), 97.8 (s, 6), 85.3 (s, 4), 83.8 (s, 5ꢀ and
13), 83.0 (s, 4ꢀ), 79.8 (s, 5), 49.8 (s, 18), 33.1 (s, 20), 31.3 (s, 2), 22.7
(s, 1), 22.4 (s, 1ꢀ), 18.1 (s, 7). 19F NMR (CD2Cl2, 298 K): d −72.1
Complex 4. Complex 4 was obtained with the same procedure
as complex 3. Yield: 62%. 1H NMR (CD2Cl2, 298 K): d 9.55 (dd,
3J8,9 = 4.9, 4J8,10 = 1.4, 8), 8.47 (dd, 3J11,10 = 7.6, 4J11,9 = 1.4, 11),
3
8.39 (ddd, 3J10,11 = J10,9 = 7.6, 4J10,8 = 1.4, 10), 8.11 (ddd, 3J9,10
=
(d, 1JFP = 711). 31P{ H} NMR (CD2Cl2, 298 K): d −143.2 (sept,
1
7.6, 3J9,8 = 4.9, 4J9,11 = 1.4, 9), 6.28 (m, 4 and 4ꢀ), 6.09 (m, 5 and
1JPF = 711). Anal. Calc. for C25H28F6NO2PRu: C, 48.39; H, 4.55;
5ꢀ), 3.11 (s, 14), 3.00 (sept, 3J2,1(1 ) = 6.9, 2), 2.38 (s, 16), 2.31 (s, 7),
ꢀ
1.43 (m, 1 and 1ꢀ). 13C{ H} NMR (CD2Cl2, 298 K): d 216.0 (s, 13),
1
N, 2.26. Found: C, 48.50; H, 4.63; N, 2.20%.
156.3 (s, 8), 152.0 (s, 12), 142.0 (s, 10), 133.6 (s, 9), 132.3 (s, 11),
128.6 (s, 15), 108.1 (s, 3), 104.5 (s, 6), 89.3 (s, 4ꢀ or 4), 87.4 (s, 4ꢀ or
4), 84.5 (s, 5ꢀ or 5), 83.7 (s, 5ꢀ or 5), 31.8 (s, 2), 26.6 (s, 14), 22.7 (s,
1 or 1ꢀ), 22.2 (s, 1 or 1ꢀ), 18.4 (s, 7), 4.3 (s, 16). 19F NMR (CD2Cl2,
298 K): d −152.32 (br, 10BF4), −152.37 (br, 11BF4). Anal. Calc. for
C19H24B2F8N2ORu: C, 39.96; H, 4.24; N, 4.91. Found: C, 40.02;
H, 4.29; N, 4.84%.
NOE measurements
The 1H-NOESY30 NMR experiments were acquired by the
standard three-pulse sequence or by the PFG version.31 Two-
dimensional 19F, H-HOESY NMR experiments were acquired
1
using the standard four-pulse sequence or the modified version.32
The number of transients and the number of data points were
chosen according to the sample concentration and to the desired
final digital resolution. Semi-quantitative spectra were acquired
using a 1 s relaxation delay and 800 ms mixing times. Quantitative
1H-NOESY and 19F, 1H-HOESY NMR experiments were carried
out with a relaxation delay of 10 s and a mixing time of 150 ms
(initial rate approximation).33
Complex 5. AgBF4 (63 mg, 0.32 mmol) was added to a solution
of complex 1PF6 (149 mg, 0.24 mmol) in CH3CN (15 mL) at room
temperature. The formed AgCl was filtered off. Diethyl ether was
added to the remaining solution and a red–brown precipitate was
obtained; it was filtered off, washed with n-hexane, and dried under
vacuum. Yield: 73%. 1H NMR (CD2Cl2, 298 K): d 9.36 (dd, 3J6,5
=
4.8, 4J6,4 = 1.4, 6), 8.55 (dd, 3J3,4 = 7.4, 4J3,5 = 1.4, 3), 8.30 (ddd,
3
4
3
3
3J4,5 = J4,3 = 7.7, J4,6 = 1.4, 4), 8.10 (ddd, J5,4 = 7.7, J5,6
=
PGSE Measurements
4.8, J5,3 = 1.4, 5), 8.03 (dd, 3J9,10 = 8.2, J9,11 = 1.2, 9), 7.87 (td,
3J11,10 = 7.6, 4J11,9 = 1.2, 11), 2.79 (s, 17), 2.73 (s, 15), 2.38 (s, 13).
4
4
1H and 19F PGSE NMR measurements were performed by
using the standard stimulated echo pulse sequence34 on a Bruker
AVANCE DRX 400 spectrometer equipped with a GREAT 1/10
gradient unit and a QNP probe with a Z-gradient coil, at 296 K
without spinning. The shape of the gradients was rectangular, their
duration (d) was 4–5 ms, and their strength (G) was varied during
the experiments. All the spectra were acquired using 32 K points,
a spectral width of 5000 (1H) and 18000 (19F) Hz, and processed
with a line broadening of 1.0 (1H) and 1.5 (19F) Hz. The semi-
logarithmic plots of ln(I/I0) vs. G2 were fitted using a standard
linear regression algorithm; the R factor was always higher than
0.99. Different values of D (delay between the midpoints of the
gradients), “nt” (number of transients) and number of different
13C{ H} NMR (CD2Cl2, 298 K): d 210.38 (s, 7), 156.8 (s, 6), 153.4
1
(s, 2), 139.2 (s, 4), 135.99 (s, 11), 134.3 (s, 3), 133.9 (s, 8), 132.6 (s,
5), 130.8 (s, 9), 130.5 (s, 16), 129.8 (s, 10), 127.0 (s, 14), 125.5 (s,
12), 4.8 (s, 17), 4.6 (s, 15), 4.2 (s, 13). 19F NMR (CD2Cl2, 298 K):
d −72.1 (d, 1JFP = 711), −152.32 (br, 10BF4), −152.37 (br, 11BF4).
31P{ H} NMR (CD2Cl2, 298 K): d −143.2 (sept, 1JPF = 711). Anal.
1
Calc. for C22H25BF10N6OPRu: C, 36.58; H, 3.49; N, 11.63. Found:
C, 36.66; H, 3.54; N, 11.55%.
Complex 6. Complex 6 was obtained with the same procedure
as complex 5. Yield: 73%. 1H NMR (CD2Cl2, 298 K): d 9.22 (dd,
3J6,5 = 5.4, 4J6,4 = 1.4, 6), 8.53 (dd, 3J3,4 = 7.8, 4J3,5 = 1.4, 3), 8.28
This journal is
The Royal Society of Chemistry 2006
Dalton Trans., 2006, 1963–1971 | 1969
©

View Article Online
Table 4 Crystallographic data
1PF6
Acknowledgements
1BPh4
We thank the Ministero dell’Istruzione, dell’Universita` e della
Ricerca (MIUR, Rome, Italy), Programma di Rilevante Interesse
Nazionale, Cofinanziamento 2004–2005 for support.
Formula
M
C23H27ClNO2RuPF6
630.94
C46H43BClNORu
773.14
Crystal system
Space group
Monoclinic
C2/c
Monoclinic
P21/c
˚
a/A
30.0777(18)
9.1795(5)
22.0930(12)
121.318(6)
5211.1(6)
8
1.598
0.832
22062
5121
Fo > 4r(Fo)
3434
342
0.0380
0.1079
0.999
3.25–26.27
12.498(2)
9.869(2)
30.431(2)
93.523(5)
3746.5(10)
4
1.371
0.527
32151
7234
Fo > 4r(Fo)
4910
470
0.0467
0.0892
1.004
2.91–26.49
References
˚
b/A
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˚
c/A
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3
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Dc/g cm−3
l(Mo-Ka)/mm−1
Total data collected
Unique obs. data
Criterion for obs.
Unique data used (No)
No. params refined (Nv)
Rint
wR(F2)
GOF
h Range/◦
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˚
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Dalton Trans., 2006, 1963–1971 | 1971
©