Bifunctional N-P ligands as building blocks for construction of multilayered metallodendrimers

Article abstract of DOI:10.1016/j.jorganchem.2012.06.010

The synthesis of 4-amino(N-methylendiphenylphosphino)pyridine (1a) and its reaction with [PdCl₂(cod)], [PtCl₂(cod)], [AuCl(tht)], [RuCl₂(p-cymene)]₂, [RhCl(cod)]₂ and [Pd(η³-2-MeC₃

Full text of DOI:10.1016/j.jorganchem.2012.06.010

Journal of Organometallic Chemistry 716 (2012) 120e128
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Journal of Organometallic Chemistry
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Bifunctional NeP ligands as building blocks for construction of multilayered
metallodendrimers
,
a
a
a
,
b
Inmaculada Angurell a , Esther Puig , Oriol Rossell , Miquel Seco , Pilar Gómez-Sal ,
*
*
Avelino Martín b
a Departament de Química Inorgànica, Universitat de Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain
b Departamento de Química Inorgánica, Universidad de Alcalá, E-28071 Alcalá de Henares, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis of 4-amino(N-methylendiphenylphosphino)pyridine (1a) and its reaction with
[PdCl2(cod)], [PtCl2(cod)], [AuCl(tht)], [RuCl2(p-cymene)]2, [RhCl(cod)]2 and [Pd(
[PdCl2(1a)2] (2), [PtCl2(1a)2] (3), [AuCl(1a)] (4), [RuCl2(p-cymene)(1a)] (5), [RhCl(cod)(1a)] (6) and
[Pd(
3-2-MeC3H4)Cl(1a)] (7) respectively are described. The new chelate complex [Pd( 3-2-MeC3H4)
h
3-2-MeC3H4)Cl]2 to give
Received 4 May 2012
Received in revised form
7 June 2012
h
h
Accepted 13 June 2012
(pyeN(CH2ePPh2)2)](OTf) (8) is also reported. Compounds 5 and 8 were characterized by single crystal
X-ray diffraction. In all complexes prepared the metal atoms appear to be bonded through the P atom of
1a. The metalloligands 4, 5 and 8 have been reacted with the ruthenocarbosilanedendrimer 10 to afford
new RueAu and RuePd concentric metal layered dendrimers 11, 12 and 13.
Keywords:
Carbosilane dendrimer
Ditopic ligand
Phosphine
Ó 2012 Elsevier B.V. All rights reserved.
Metalloligands
1. Introduction
chelate complexes [6]. Recently, we have described a method for
the synthesis of metallodendrimers with up to four metal layers by
Dendrimer chemistry has been a subject with increasing
interest in last years [1]. This development has arisen because
dendrimers present unique properties, making them ideal candi-
dates as materials in a number of nanoscale and high value added
applications [2]. The unique qualities of dendrimers are attributed
mainly to their controlled globular structure resulting from an
internal framework in which all bonds emerge radially from
a central core growing through successive generations and also to
the possibility of containing a large number of functional groups
which can be present in the cavities or/and at its surface. It has been
shown that dendrimers are able to form complexes with a great
variety of ions and metal fragments [3]. However, carbosilane
dendrimers containing two or more transition metal units are
scarce due to the lack of synthetic strategies [4]. Thus, new strat-
egies for functionalization of dendrimers at the end of the branches
and the use of new ligands as connectors are required in order to
grow novel metalladendritic structures [5]. Bifunctional ligands
containing different donor atoms (N, O, P, S) can act selectively as
connectors combining soft and hard donor sites, but it should be
noted that this type of ligands tend to favour the formation of
grafting the carbosilane framework with the PeN ligands 4-
pyePPh2 and 4-pyeN(eCH2ePPh2)2 [7]. In the later case, the
trans arrangement of the pyridine substituent and the length of the
PeN chain preclude chelate formation so that the ligands act just as
connectors and spacers. In this paper we present the synthesis of
the PeN ligand 4-pyeNHeCH2ePPh2, its capability to form
a number of complexes with transition metal fragments and the
use of these species as new building blocks to create metal-
lodendrimers displaying concentric metal layers.
2. Results and discussion
2.1. Synthesis of 4-amino(N-methylendiphenylphosphino)pyridine
(1a) and related transition metal complexes
The synthesis of the new phosphinoaminopyridine ligand 1a
was readily accomplished by treatment of an equimolar mixture of
hydroxymethyldiphenylphosphine (obtained in situ from HPPh2
and (HCHO)n) and 4-aminopyridine in a 1:1 molar ratio at 85 ꢀC for
24 h (Scheme 1). It is interesting to underline that the use of the
same reagents in a 6:1 molar ratio leads to the ligand containing
two phosphine groups (1b) after reaction at 120 ꢀC for 6 days [7].
Ligand 1a was isolated as a white solid in high yield (82%) and could
routinely be prepared in gram quantities. The molecular ion peak
* Corresponding authors.
E-mail addresses: inmaculada.angurell@qi.ub.es (I. Angurell), miquel.seco@
qi.ub.es (M. Seco).
0022-328X/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2012.06.010

I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
121
Scheme 1.
was detected at m/z ¼ 292.8 [M þ H]þ in the (ESI-MS) spectrum,
atom and the metal centre. As a result, a polymeric structure is
formed. On the other hand, the J(PePt) values observed for 3 in
DMSO of 1845 Hz in their 31P NMR spectrum indicate a cis
arrangement for this molecule. The protonation of the pyridine
group in 2 and 3 with hydrogen chloride in CH2Cl2 solubilizes the
complexes through formation of the corresponding cationic species
[2eH]þ and [3eH]þ.
The gold complex [AuCl(tht)] reacts cleanly with 1a to give 4a as
a white solid in 96% yield. Likewise 4a reacts with AgOTf in CH2Cl2
to give the compound [Au(OTf)(P-1a)] (4b), which can be also
obtained by substitution of the PPh3 by 1a in [Au(OTf)(PPh3)]. This
indicates a more basic character of the P-1a than that of the PPh3.
The dimer [RuCl2(p-cymene)]2 reacts with 2 equiv of the ligand 1a
to give complex 5. The 31P resonance at 20.7 ppm confirms that the
coordination is via P atom. On the other hand, the ESI-MS spectrum
in CH3CN:H2O shows a peak due to the [M þ H]þ species. Single
crystals of this complex suitable for X-ray diffraction studies were
obtained by slow diffusion of hexane into a dichloromethane
solution of 5. The molecular structure is shown in Fig. 1 and
selected bond lengths and angles are reported in Table 1.
while the 31P NMR spectrum in CDCl3 showed a single resonance at
d
¼ ꢁ18.9 ppm. The signal at
d
¼ 4.15 ppm (NH) in the 1H NMR
spectrum and the IR band at 1599 cmꢁ1 that is assigned to
n(C]N)
stretching are other characteristic spectroscopic data for 1a.
Given the presence of two coordination centres in 1a, we
became interested in knowing if the metal coordination occurs
selectively and, in this case, which is the donor atom (N or P)
responsible for the complexation. We made to react the ditopic
ligand 1a with [PdCl2(cod)] (cod ¼ 1,5-cyclooctadiene), [PtCl2(cod)],
[AuCl(tht)] (tht ¼ tetrahydrothiophene), and with the dimeric
species [RuCl2(p-cymene)]2, [RhCl(cod)]2 and [Pd(h
3-2-MeC3H4)
Cl]2 in CH2Cl2. In all cases metallation took place very quickly and
the final mononuclear complexes 2e7 (Scheme 2) were isolated in
good yields and fully characterized spectroscopically. The n(C]N)
stretching for 4e7 did not change significantly from that of the free
ligand, thus indicating selective coordination through the phos-
phorous atoms in all cases. This is confirmed by the large shift of the
signals to low fields in their 31P NMR spectra (Experimental
section).
For 2 and 3, the
n
(C]N) was shifted up to 1600 cmꢁ1. This fact
The X-rayanalysis of complex 5 showed thatthe molecule displays
and the insolubility of these complexes in common solvents
a pseudo-octahedral geometry at Ru centre comprising one h
6-p-
suggest an intermolecular interaction between the N-pyridinic
cymene, one phosphorous and two chloride atoms as ligands
completing the metal coordination sphere. The moiety presents the
usual three-legged piano stool arrangement with an RueP distance of
ꢀ
2.3647(11) A, similarly to that observed in [RuCl2(p-cymene){o-
Fig. 1. Molecular structure of 5 with an atomic numbering scheme. Hydrogen atoms
Scheme 2.
have been removed for clarity.

122
I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
Table 1
the N-amine atom. The quality of the crystal allowed the localization
of the amine proton H(1) and the sum of thethree angles around N(1),
which is 359.4ꢀ, that implies an almost perfect planarity. On the other
ꢀ
Selected bond lengths (A) and angles (deg) for 5.
Ru(1)eCl(1)
Ru(1)eCl(2)
Ru(1)eP(1)
Ru(1)eC(1)
Ru(1)eC(2)
Ru(1)eC(3)
Ru(1)eC(4)
Ru(1)eC(5)
Ru(1)eC(6)
Ru(1)eCt
P(1)eC(11)
P(1)eC(21)
P(1)eC(31)
N(1)eC(12)
N(1)eC(11)
N(2)eC(14)
N(2)eC(15)
C(1)eC(6)
C(1)eC(2)
C(1)eC(7)
C(2)eC(3)
C(3)eC(4)
C(4)eC(5)
C(5)eC(6)
2.4248(11)
2.4236(11)
2.3647(11)
2.224(4)
2.233(4)
2.248(4)
2.229(4)
2.183(4)
2.178(4)
1.705
1.889(4)
1.812(4)
1.830(4)
1.364(5)
1.441(5)
1.329(5)
1.344(5)
1.417(6)
1.434(6)
1.545(6)
1.383(6)
1.421(6)
1.401(6)
1.434(6)
ꢀ
hand the N(1)eC(12) distance of 1.364(4) A is closer to an NeC double
bond. These data indicate that the electronic lone pair of N(1) is
delocalized to the aromatic ring through C(12) atom and, conse-
quently, it has very low coordinative capacity as have been observed
experimentally. An interesting feature of this structure is that the
packing of the molecules is governed mainly by hydrogen bondings.
Each molecule establishes two hydrogen bonds through the amino
group as the proton donor and the pyridinic ring nitrogen atom as the
ꢀ
proton acceptor with an N(1)eN(2) distance of 3.085(7) A. The ami-
nopyridinicsystem isplanar, andthehydrogen bonds lies inthisplane
producing a lineal planar system chain, with the rest of the molecules
located in alternated positions with respect to this plane (Fig. 2).
Square planar complex 6 was obtained by the reaction of the
rhodium dimer [RhCl(cod)]2 with 1a. Its 31P NMR spectrum showed
a signal at
d
¼ 23.1 ppm with a J(PeRh) value of 153 Hz. Both 1H and
13C NMR spectra revealed two signals due to the CH]CH cyclo-
octadiene group indicating two non-equivalent coordination metal
sites due to the different trans influence of 1a and Cl ligands.
When [Pd(
CH2Cl2 the 31P NMR of the solution showed that the phosphorous
resonance shifted to
¼ 18.1 ppm. Addition of hexane precipitated
the pale yellow complex 7. Like in the case of 2 and 3, the (C]N) is
h
3-2-MeC3H4)Cl]2 was treated with 2 equiv of 1a in
P(1)eRu(1)eCl(2)
P(1)eRu(1)eCl(1)
Cl(2)eRu(1)eCl(1)
Cl(1)-Ru(1)-Ct
83.16(4)
86.98(4)
87.98(4)
126.2
126.7
131.0
118.38(14)
109.22(13)
113.10(14)
104.53(19)
102.82(19)
108.0(2)
118.2(3)
113.4(4)
126.1(4)
109.2
d
n
shifted up to 1608 cmꢁ1 suggesting an intermolecular interaction
between the N-pyridinic atom and the palladium metal centre.
Since no suitable crystals of 7 could be grown, we tried to
synthesize and obtain single crystals of the analogous Pd complex
with the ligand 1b in an attempt to determine unambiguously its
Cl(2)-Ru(1)-Ct
Cl(2)eRu(1)eCl(1)
C(21)eP(1)eRu(1)
C(31)eP(1)eRu(1)
C(11)eP(1)eRu(1)
C(21)eP(1)eC(31)
C(21)eP(1)eC(11)
C(31)eP(1)eC(11)
N(1)eC(11)eP(1)
C(14)eN(2)eC(15)
C(12)eN(1)eC(11)
C(11)eN(1)eH(1)
C(12)eN(1)eC(11)
structure. Thus, the chelate complex [Pd(
h
3-2-MeC3H4)
(pyeN(CH2ePPh2)2)](OTf) (8) was obtained by reacting 1b with
1
equiv of [Pd(h
3-2-MeC3H4)(cod)](OTf) in CH2Cl2 at room
temperature [7]. The 31P NMR signal of the solution reaction shifts
from ꢁ27.1 (free 1b) to 5.0 ppm. After concentration and treatment
with diethylether, a light pink solid was obtained. This compound
shows a band at 1586 cmꢁ1 in its IR spectrum, which indicates that
the pyridine group is not coordinated to the metal.
124.5
Ct is the centroid of C(1),C(2),C(3),C(4),C(5),C(6).
Suitable crystals for X-ray diffraction study were obtained by slow
diffusion of hexane into a CH2Cl2 solution of 8. Aview of the molecule
appears in Fig. 3, and selected bond lengths and angles are given in
Table 2. One of the most relevant structural feature is the presence of
a six-membered PdP2C2N ring with an almost planar trigonal coor-
dination around the aminic nitrogen N(1). The bond length of C(3)e
ꢀ
Ph2PCH2NHC6H4(CH2OH)}] of 2.351 A [8] or in [RuCl2(p-cymene)(o-
ꢀ
PPh2Py)3] of 2.364 A [9]. Both RueCl distances are very similar in
contrast to the RueC ones, which range from 2.184(4) to 2.248(4) A
due tothe trans influence of the phosphine ligand onthe C(2) and C(3)
atoms of the ring. This and steric factors provoke that the arene
substituents adopt an alternate conformation respect to the other
ꢀ
ꢀ
ꢀ
N(1) 1.397(9) A is notably shorter than that of C(1)eN(1) 1.481 A or
ꢀ
C(2)eN(1) 1.478 A and of the same value observed in the ruthenium
ꢀ
ligands bonded to the metal. The angle CleRueCl of 87.98(4) A is
complex 5 described above. Therefore, there is a high degree of
delocalization of the N(1) lone pair between the dimethylene-amino
group and the pyridine ring. Similar effect has been observed in
complexes containing the 4-(N,N-dimethylamino)pyridine ligand
comparable
to
that
found
in
[RuCl2(p-cymene){o-
Ph2PCH2NHC6H4(CH2OH)}] (88.12ꢀ), and in other complexes with
bulky phosphines [10]. It is interesting to note the planarity around
Fig. 2. The molecules of 5 are connected via hydrogen bonding to form strings where all aminopyridine moieties are coplanar.

I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
123
that observed in other Pdeallyl complexes. In particular, the allyl
ꢀ
group is almost symmetrically bound [(PdeC9) 2.180 (7) A; (PdeC8)
ꢀ
ꢀ
2.196(7) A] and forms a dihedral angle of 113.1(5) with the plane
defined by the Pd atom and the phosphorous atoms, close to the
typical value found in
hand the PdeP and PeC distances are in the expected range observed
in other -allylic Pd(II) complexes containing phosphines and the 2-
h
3-allyl Pd and Pt complexes [12]. On the other
p
Meeallyl fragment [13].
2.2. Synthesis of polymetallodendrimers
As starting material for the synthesis of new metallodendrimers
we employed the carbosilane dendrimer 9, functionalized with
diphenylphosphine groups at surface described previously
(Scheme 3) [14].
The methodology for the construction of dendrimers containing
several metal layers involved three steps: i) grafting of organome-
tallic ruthenium moieties on the surface of a phosphine ended car-
bosilane dendrimer by reaction with [RuCl2(p-cymene)]2 to give the
metallodendrimer 9 and chloride substitution by OTf ligands to
obtain 10 (Scheme 3); ii) displacement of one OTf ligand by N-
coordination of 1a and iii) incorporation of a new metal fragment
taking advantage of the presence of free phosphine at the periphery.
Surprisingly, the solution resulting from step ii) showed broad signals
indicating the existence of dynamic processes in solution. The main
signals appeared at 29.5 and ꢁ1.0 ppm, which are assigned to the
ePPh2 group bonded to the Ru atom and to the free ePPh2 group of
1a, respectively. Besides, two minor signals appeared as doublets at
29.0 and 21.4 ppm. After several hours at room temperature, the 31P
NMR spectrum showed that the latter resonances increased until to
reach equilibrium. This equilibrium between the species resulting
from the coordination through the N or P donor atoms underlines the
lack of selectivity in the process, and finally the thermodynamically
more stable P-1a form predominates (Scheme 4).
Fig. 3. Crystal structure of the cationic moiety of 8 with a numbering scheme.
[11]. The delocalization of its lone pair on the pyridinic ring makes all
N-surrounding atoms of the (CH2)2eNepy fragment in the same
plane indicating that free rotation around the C(3)eN(1) bond is not
permitted. The presence of a trigonal planar nitrogen atom in the ring
makes 8 to adopt a chair conformation with the palladium atom
displaying a slightly distorted four-coordinate square planar coor-
dination. Thus, the geometry around the palladium atom is similar to
Table 2
ꢀ
ꢀ
Selected bond lengths (A) and angles ( ) for the solid-sate
structure of the cationic moiety of 8.
To overcome this drawback, we decided to block the phosphine
centre using 4a as metalloligand instead 1a. Thus, a CH2Cl2 solution
of the ruthenodendrimer 10 was reacted with 4a in a 1:4 molar
ratio. The yellow colour suddenly changed to deep orange and
a white suspension was formed. After filtration, the IR spectrum of
the white solid revealed the presence of the triflate anion, and the
Pd(1)eC(8)
Pd(1)eC(9)
Pd(1)eC(10)
Pd(1)eP(1)
Pd(1)eP(2)
P(1)eC(11)
P(1)eC(1)
P(1)eC(31)
P(2)eC(2)
P(2)eC(21)
P(2)eC(41)
C(1)eN(1)
C(2)eN(1)
C(3)eN(1)
N(2)eC(5)
N(2)eC(6)
2.196(7)
2.180(7)
2.215(8)
2.3125(18)
2.3335(19)
1.829(7)
1.873(7)
1.846(7)
1.852(7)
1.832(7)
1.842(7)
1.482(8)
1.478(9)
1.397(9)
1.364(10)
1.341(10)
bands at 1613 (n(C]
N)) and 1102 cmꢁ1 (PPh2 group) suggest that the
ligand 1a was coordinated to the metal by both N and P ended
donor atoms. The ESI-MS spectrum showed an intense peak at
2404.8 that can be assigned to the [4{Au(OTf)(1a)} ꢁ OTf]þ unit and
other minor peaks corresponding to the lost of {Au(OTf)(1a)}
fragments. These results suggest that the insoluble solid probably is
the result of the association of four {Au(1a)} units to give the
tetrameric species [{Au(1a)}4](OTf)4 (Scheme 5).
On the other hand, the 31P NMR spectrum of the solution evi-
denced only a signal at 22.2 ppm, not far from the one that appears
in the spectrum of 10. We suspected that the resulting compound
was the chiral ruthenium compound having four different ligands,
1a, Cl, OTf, and p-cymene. The 31P NMR resonance at 22.6 ppm of
P(1)ePd(1)eP(2)
C(9)ePd(1)eP(1)
C(8)ePd(1)eP(1)
C(10)ePd(1)eP(1)
C(9)ePd(1)eP(2)
C(8)ePd(1)eP(2)
C(10)ePd(1)eP(2)
C(9)ePd(1)eC(8)
C(9)ePd(1)eC(10)
C(8)ePd(1)eC(10)
C(1)eP(1)ePd(1)
C(2)eP(2)ePd(1)
N(1)eC(1)eP(1)
N(1)eC(2)eP(2)
C(1)eN(1)eC(2)
C(3)eN(1)eC(1)
C(3)eN(1)eC(2)
C(6)eN(2)eC(5)
97.71(7)
165.9(2)
99.4(2)
129.9(2)
96.3(2)
162.7(2)
128.3(2)
66.5(3)
37.6(3)
37.5(3)
110.4(2)
113.5(2)
115.2(4)
113.6(5)
113.1(6)
120.2(5)
124.1(6)
113.9(7)
Scheme 3. Metallodendrimers 9 and 10.

124
I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
species in solution that were not investigated. Probably the steric
crowding of the resulting species due to the higher volume of the
latter metalloligands is responsible for this behaviour.
These results made us to turn our attention to ligand 1b and, in
particular to [4-pyeN{CH2ePPh2AuOTf}2] that was chosen as met-
alloligand to react with 10. The reaction was performed in CH2Cl2 at
room temperature and the dendrimer 12 was isolated as an orange-
brown solid in high yield (Scheme 6). The 31P{1H} spectrum of this
compound showed signals at
d
¼ 25.8 (RuePPh2) and ¼ 19.4 ppm
d
(AuePPh2) and its 13C{1H} NMR spectrum a resonance at 152.5 ppm
assigned to the Ca of the pyridinic ring. However, solutions of the
new bimetallodendrimer showed progressive degradation in hours.
The lower stability of 12 in comparison tothat of 11 should be mainly
attributed to the higher steric hindrance expected for the first. Then,
we reasoned that the use of a chelating metalloligand such as 8,
where the arms are close one to another would favour the coordi-
nation and stabilization of the final product. Thereby, when a solu-
tion of 8 was treated with the dendrimer 10 a change of colour in the
solution was immediately observed. After 15 min the 31P{1H} spec-
trum of the solution showed the shifting of the signal (RuP) at
29.8 ppm confirming the coordination of 8 to the ruthenium atom.
After work up dendrimer 13 was obtained as a deep yellow solid
stable in solution (Scheme 7).
Scheme 4.
the product resulting after treatment of the chiral ruthenium
compound with AgOTf corroborated our assumption. In conclusion,
we postulate that the reaction of 10 with 4a takes place through
three paths: coordination of the metalloligand, migration of the
chloride from gold to the ruthenium atom, followed finally by the
decoordination of the ligands [15] (Scheme 5).
With these results in mind, we reasoned that dendrimers con-
taining both metal atoms only could be stabilized if the chloride
migration is prevented. Clearly, the use of metalloligand 4b could
favour this goal. Indeed, reaction of 4b with dendrimer 10 in a 4:1
molar ratio in CH2Cl2 at room temperature permitted to observe
only two signals in its 31P{1H} NMR spectrum at 29.6 ppm
(RuePPh2) and 35.6 ppm (AuePPh2). After work up the dendrimer
11 was isolated as an ochre-yellow solid in high yield. Compound 11
was fully characterized by IR, 1H and 13C NMR spectroscopy and
elemental analysis (Experimental section).
Although the ESI-MS spectrum showed great fragmentation,
both the NMR and IR data support the nature of the Ru/Pd den-
drimer (Experimental section).
3. Conclusions
The new aminophosphine ligand 1a was synthesized from 4-
aminopyridine and hydroxymethyldiphenylphosphine in high
yield. Metallocomplexes of Au, Pd, Pt, Ru, Rh are easily formed by
direct reaction between ligand 1a and the corresponding transition
metal compounds. The gold complex 4b has permitted to construct
a bimetallic carbosilane dendrimer containing two concentric metal
layers of Ru and Au. In contrast, Ru, Rh and Pd complexes gave
untreatable mixtures. However, the use of a chelate Pd complex with
Attempts to extend this methodology for the synthesis of other
bi-metallodendrimers were not successful: the reaction of 10 with
the metalloligands 5, 6 and 7 gave complicated mixture of different
Scheme 5.

I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
125
Scheme 6.
ligand 1b (4-amino[N,N0-bis(methylenediphenylphosphino)pyri-
dine]), that can be obtained by modification of the method described
for 1a, has allowed to form a new very stable dendrimer containing
two metal layers, one of Ru and the other of Pd.
[PdCl2(cod)] [21], [PtCl2(cod)] [22], and dendrimer 9 [14,23] were
prepared following published procedures. Other reagents were
purchased from commercial suppliers. It is noticeable that synthesis
forcompound 1a in benzene solution bya typical Mannich reaction in
71% yield has been described in the course of time of this work [24].
4. Experimental section
4.2. X-ray structure determination of compounds 5 and 8
4.1. General considerations
Suitable monocrystals of compounds 5 and 8 were obtained by
slow diffusion of hexane into a CH2Cl2 solution of them. A summary
of crystal data, data collection, and refinement parameters for the
structural analysis is given in Table 3. Crystals were glued to a glass
fibre using an inert polyfluorinated oil and mounted in the low
temperature N2 stream (200 K), in a Bruker-Nonius Kappa-CCD
All manipulations were performed under an atmosphere of dry
nitrogen using standard Schlenk techniques. All solvents were
distilled from appropriate drying agents prior to use. Gold complexes
were synthesized light protected to avoid metalreduction.1H,13C{1H}
and 31P{1H} NMRspectra were recorded on Bruker 250 and Varian
Mercury 400 spectrometers. Chemical shifts are reported in parts per
millionrelativetoexternalstandards(SiMe4 for1Hand13C,85%H3PO4
for 31P) and coupling constants are given in hertz. Infrared spectra
were recorded with an FTIR 520 Nicolet spectrophotometer (KBr
pellets). Elemental analyses of C, H and N were carried out at the
Serveis Científico-Tècnics in Barcelona. ESI-MS spectra were recorded
with an Agilent LC/MSD-TOF spectrometer. The starting materials,
Table 3
Summary of crystal data and structure refinement parameters for 5 and 8.
Compound
5
8
Empirical formula
C28H31Cl2N2PRu
C36H35F3N2O3P2
PdS
Formula weight
Crystal system
Space group
598.49
Monoclinic
P21/c
13.4476(19)
12.5288(5)
15.777(2)
96.270(13)
2642.2(5)
801.06
Monoclinic
P21/n
[Pd(h
3-2-MeC3H4)(cod)](OTf) [16], [AuCl(tht)] [17], [RuCl2(p-cym-
ene)]2 [18], 4-pyridyldiphenylphosphine [19], [RhCl(cod)]2 [20],
ꢀ
a/A
9.147(5)
ꢀ
b/A
24.545(5)
15.350(5)
96.060(5)
3427(2)
ꢀ
c/A
bꢀ
3
ꢀ
V/A
Z
4
4
Dc/g cmꢁ3
1.504
0.876
1224
1.553
0.752
1632
Absorption coeff./mmꢁ1
F(000)
Crystal size, mm
0.35 ꢂ 0.3 ꢂ 0.2
3.05e26.52ꢀ
ꢁ16 ꢃ h ꢃ 16
ꢁ15 ꢃ k ꢃ 15
ꢁ19 ꢃ l ꢃ 19
19,507
0.6 ꢂ 0.3 ꢂ 0.2
3.14e27.51ꢀ
ꢁ11 ꢃ h ꢃ 11
ꢁ31 ꢃ k ꢃ 31
ꢁ0 ꢃ l ꢃ 19
15,402
Q
Range for data collection
Limiting indices
Total reflections
Unique reflections
R(int)
5473
0.1335
7859
0.1144
Completeness to q
Max. and min. transm.
Refinement method
q ¼ 26.52 (99.8%)
0.853 and 0.728
Full-matrix
least-squares on F2
5473/0/319
0.802
q ¼ 27.51 (99.8%)
1.204 and 0.884
Full-matrix
least-squares on F2
7859/0/433
1.008
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2
s
(I)]
R1 ¼ 0.0400,
wR2 ¼ 0.0697
R1 ¼ 0.0992,
wR2 ¼ 0.0843
0.608 and ꢁ0.697
R1 ¼ 0.0817,
wR2 ¼ 0.1871
R1 ¼ 0.1570,
wR2 ¼ 0.2184
1.615 and ꢁ1.494
R indices (all data)
ꢀꢁ3
Largest diff. peak and hole/e A
Scheme 7.

126
I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
diffractometer with area detector equipped with an Oxford Cryo-
stream 700 unit. Intensities were collected using graphite mono-
4.3.3. Synthesis of 3
To a solution of 1a (0.309 g, 1.06 mmol) in 25 cm3 of CH2Cl2
complex [PtCl2(cod)] (0.132 g, 0.35 mmol) was added and the
mixture was stirred under reflux overnight. Then, the suspension
was filtered and the solid was washed with CHCl3 (3 ꢂ 5 cm3) and
dried under a vacuum. Compound 3 was obtained as a pale yellow
solid in 89% yield. 31P{1H} NMR (101.25 MHz, DMSO-d6)
ꢀ
chromated MoeKa radiation (l ¼ 0.71073 A). Data of compound 5
were measured with an exposure time of 10 s per frame (five sets;
237 frames;
exposure time of 13 s per frame (eight sets; 662 frames;
F/U
scans, 2.0ꢀ scan-width), compound 8 with an
F/U scans
1.3ꢀ scan-width). Raw data were corrected for Lorenz and polari-
zation effects. Structure was solved by direct methods, completed
by the subsequent difference Fourier techniques and refined by
full-matrix least-squares on F2(SHELXL-97) [25]. Anisotropic
thermal parameters were used in the last cycles of refinement for
the non hydrogen atoms in both structures. Absorption correction
procedures, semi-empirical from equivalents, were carried out
using the multiscan SORTAV program [26]. Most of the hydrogen
atoms were included from geometrical calculations and refined
using a riding model. The aminic Hydrogen H(1) and the methylene
hydrogen atoms H(11A) and H(11B) in 8 were located in the Fourier
difference map and refined isotropicaly. All the calculations were
made using the WINGX system [27].
d
(ppm) ¼ 5.8 (s, 1J(PePt) ¼ 1845 Hz, PPh2). IR (KBr)
n(C]N)py
1620 cmꢁ1. ESI-MS: (m/z) 815.1 [M ꢁ Cl]þ. Elem. anal. for
C36H34Cl2N4P2Pt (850.61): calcd (%) C, 50.83; H, 4.03. Found: C,
50.31; H, 3.85.
4.3.4. Synthesis of 4a
Ligand 1a (0.176 g, 0.60 mmol) was solved in 25 cm3 of CH2Cl2
and [AuCl(tht)] (0.183 g, 0.57 mmol) was added. The mixture was
stirred at room temperature, light protected, for 4 h. The resulted
solution was concentrated to 10 cm3 and 20 cm3 of hexane was
added. The mixture was filtered and the solid was washed with
hexane (3 ꢂ 5 cm3) and dried under vaccum. Compound 4a was
obtained as a white solid in 96% yield. 1H NMR (250.13 MHz, CDCl3)
d
(ppm) ¼ 4.28 (br s, 2H, CH2P), 5.06 (br s, 1H, NH), 6.49 (d, 2H,
4.3. Synthesis
3JHeH ¼ 4.6 Hz, Hb); 7.49e7.74 (m, 10H, C6H5), 8.13 (d, 2H,
3JHeH ¼ 4.2 Hz, Ha). 13C{1H} NMR (62.90 MHz, CDCl3)
(ppm) ¼ 42.9
d
4.3.1. Synthesis of 4-amino-(N-methylendiphenylphosphine)
pyridine (1a)
(d, 1JCeP ¼ 44.3 Hz, CH2P), 108.6 (s, Cb), 129.8 (d, 3JCeP ¼ 8.1 Hz, m-
2
C6H5), 132.9 (s, p-C6H5), 133.8 (d, JCeP ¼ 9.1 Hz, o-C6H5), 149.2 (s,
A mixture of p-formaldehyde (0.375 g, 12.5 mmol) and diphe-
nylphosphine (2.05 cm3, 11.9 mmol) was heated at 120 ꢀC for 5 h to
yield Ph2PCH2OH. The yellow oil obtained was left to reach room
temperature and 4-aminopyridine (1.037 g, 10.8 mmol) was added.
The reaction mixture was heated to 85 ꢀC for 24 h and the white
solid obtained was dissolved in THF and dried with anhydrous
Na2SO4. Then, the solvent was evaporated to dryness and the
resulted solid was washed with ethyl ether (2 ꢂ 50 cm3), filtered
and dried under vacuum. Compound 1a was obtained as a white
solid in 78% yield and is soluble in THF, CH2Cl2, MeOH and insoluble
Ca), 153.0 (br s, Cg). 31P{1H} NMR (101.25 MHz, CDCl3)
d
(ppm) ¼ 25.5 (s, PPh2). IR (KBr)
n
(C]N)py 1596 cmꢁ1. ESI-MS: (m/
z) 781 [2M ꢁ 2Cl]þ, 525 [M þ H]þ, 507 [M ꢁ Cl þ H2O]þ, 489
[M ꢁ Cl]þ, 293 [M ꢁ AuCl þ H]þ. Elem. anal. for C18H17AuClN2P
(524.74): calcd (%) C, 41.20; H, 3.27. Found: C, 40.91; H, 3.30.
4.3.5. Synthesis of 4b
To a solution of [AuCl(PPh3)] (0.069 g, 0.14 mmol) in 5 cm3 of
CH2Cl2, AgOTf (0.038 g, 0.15 mmol) was added and the mixture was
stirred at room temperature for 30 min, light protected. The solu-
tion was filtered off (Celite), concentrated to 5 cm3, and was slowly
added to 0.041 g (0.14 mmol) of ligand 1a solved in 5 cm3 of CH2Cl2.
The mixture was stirred for 1 h. The solution was concentrated to
half volume and ethyl ether was added to precipitate 4b as a white
solid, which was filtered, washed with Et2O (3 ꢂ 5 cm3) and
vacuum dried. Yield 98%. 1H NMR (250.13 MHz, CDCl3)
in acetone, ethyl acetate, Et2O, toluene and hexane. 1H NMR
2
(250.13 MHz, CDCl3)
d
(ppm) ¼ 3.84 (dd, 2H, JHeP ¼ 5.5 Hz,
3JHeH
¼
4.3 Hz, CH2P), 4.15 (br s, 1H, NH), 6.46 (dd, 2H,
3JHeH ¼ 4.9 Hz, JHeH ¼ 1.5 Hz, Hb), 7.36e7.48 (m, 10H, C6H5), 8.20
5
(dd, 2H, JHeH ¼ 4.9 Hz, JHeH ¼ 1.5 Hz, Ha). 13C{1H} NMR
3
5
(62.90 MHz, CDCl3)
d
(ppm) ¼ 42.2 (d, 1JCeP ¼ 13.1 Hz, CH2P), 107.9
(s, Cb), 128.9 (d, 3JCeP ¼ 6.7 Hz, m-C6H5), 129.4 (s, p-C6H5), 132.8 (d,
2JCeP ¼ 18.3 Hz, o-C6H5), 135.5 (d, 1J(CeP) ¼ 12.8 Hz, ipso-C6H5),
150.0 (s, Ca), 153.2 (d, 3JCeP ¼ 4.8 Hz, Cg). 31P{1H} NMR (101,25 MHz,
d
(ppm) ¼ 4.46 (dd, 2H, 2JHeP ¼ 11.5 Hz, 3JHeH ¼ 2.8 Hz, CH2P), 6.36
3
(d, 2H, JHeH ¼ 5.0 Hz, Hb), 6.57 (br s, 1H, NH), 7.38e7.55 (m, 10H,
C6H5), 7.94 (d, 2H, JHeH ¼ 5.0 Hz, Ha). 13C{1H} NMR (62.90 MHz,
3
CDCl3)
MS: (m/z) 292.8 [M
d
(ppm) ¼ ꢁ18.9 (s, PPh2). IR (KBr)
n
(C]N)py 1599 cmꢁ1. ESI-
CDCl3)
d
(ppm) ¼ 44.3 (d, 1J(CeP) ¼ 27.2 Hz, CH2P), 108.3 (s, Cb),
þ
H]þ, 202.2 [M
ꢁ
pyNH]þ, 187.1
129.9 (s, m-C6H5), 132.3 (s, p-C6H5), 133.5 (s, o-C6H5), 134.2 (br s, i-
[M ꢁ pyNHCH2]þ, 107.2 [M ꢁ PPh2]þ. Elem. anal. for C18H17N2P
C6H5), 149.7 (s, Ca), 153.0 (s, Cg). 31P{1H} RMN (101.25 MHz, CDCl3)
(290.32): calcd (%) C, 74.46; H, 5.20. Found: C, 73.85; H, 5.75.
d
d
(ppm) ¼ 34.2 (br s, PPh2). 19F NMR (376.48 MHz, CDCl3)
(ppm) ¼ ꢁ78.6 (s, CF3SO3). IR (KBr)
n
(C]N)py 1599 cmꢁ1. ESI-MS:
4.3.2. Synthesis of 2
(m/z) 931.3 [M þ 1 þ H]þ, 781.3 [M ꢁ OTf þ 1]þ, 639.1 [M þ H]þ,
293.2 [M ꢁ AuOTf þ H]þ. Elem. anal. for C19H17AuF3N2O3PS (638.3):
calcd (%) C, 35.75; H, 2.68. Found: C, 36.10; H, 2.76.
To a solution of 1a (0.237 g, 0.81 mmol) in 20 cm3 of CH2Cl2
complex [PdCl2(cod)] (0.112 g, 0.40 mmol) was added and the
mixture was stirred overnight. Then, the solid was filtered off and
washed with CH2Cl2 (3 ꢂ 5 cm3) and dried under reduced pressure.
A second fraction of compound is obtained by concentration of the
solution to dryness and washed the residue with CH2Cl2
(3 ꢂ 5 cm3). Finally the solid was dried under vacuum to obtain 2 as
an orange solid in 92% yield. 1H NMR (300.00 MHz, DMSO-d6)
4.3.6. Synthesis of 5
To a solution of 1a (0.051 g, 0.18 mmol) in 10 cm3 of CH2Cl2
complex [RuCl2(p-cymene)]2 (0.053 g, 0.09 mmol) was added and
the mixture was stirred at r.t. for 1 h. Then, the solvent was evap-
orated to dryness, and the residue was washed with Et2O
(3 ꢂ 5 cm3) and dried under reduced pressure. Compound 5 was
d
(ppm) ¼ 3.81 (m, 4H, CH2P), 4.08 (br s, 2H, NH), 6.56 (d, 4H,
3JHeH ¼ 7.2 Hz, Hb), 7.32e7.91 (m, 20H, C6H5), 8.00 (d, 4H,
obtained as an orange solid in 94% yield. 1H NMR (250.13 MHz,
3JHeH
d
¼
5.2 Hz, Ha). 31P{1H} NMR (101.25 MHz, CDCl3)
CDCl3)
d
(ppm) ¼ 0.92 (d, 6H, JHeH ¼ 7.0 Hz, CH3cym), 1.88 (s, 3H,
3
3
(ppm) ¼ 26.0 (s, PPh2). IR (KBr)
n
(C]N)py 1615 cmꢁ1. ESI-MS: (m/
CH3cym), 2.55 (m, 1H, JHeH ¼ 6.7 Hz, CHcym), 4.48 (dd, 2H,
z) 763.0 [M þ H]þ, 727.0 [M ꢁ Cl]þ, 362.9 [M ꢁ 2Cl þ 2H2O]2þ, 293.1
[1 þ H]þ. Elem. anal. for C36H34Cl2N4P2Pd (761.93): calcd (%) C,
56.75; H, 4.50. Found: C, 56.51; H, 4.35.
2JHeP ¼ 6.5 Hz, JHeH ¼ 2.1 Hz, 2H, CH2P), 5.19e5.30 (m, 5H, C6H4,
3
NH), 6.05 (dd, 2H, 3JHeH ¼ 6.4 Hz, 5JHeH ¼ 3.5 Hz, Hb), 7.40e7.44 (m,
6H, C6H5), 7.81e7.89 (m, 6H, C6H5 þ Ha). 13C{1H} NMR (62.90 MHz,

I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
127
CDCl3)
d
(ppm) ¼ 17.7 (s, CH3cym), 21.8 (s, CH3cym), 30.4 (s, CH3cym),
19.3 (s, CH3cym), 23.8 (m, CH3cym), 45.5 (br s, CH2P), 110.2 (s, Cb),
122.7 (q, 1JCeF ¼ 321.0 Hz),129.5e135.8 (m, C6H5),155.9 (s, Ca),148.7
41.2 (d, 1JCeP ¼ 29.2 Hz, CH2P), 86.2 (d, 2JCeP ¼ 5.0 Hz, Ccym), 90.2 (d,
2JCeP ¼ 4.0 Hz, Ccym), 95.6 (s, Ccym), 107.4 (s, Ccym), 109.3 (s, Ccym),
(br s, Cg). 31P{1H} NMR (101.25 MHz, CD2Cl2)
d
(ppm) ¼ 29.6 (s,
3
128.9 (d, JCeP ¼ 9.1 Hz, m-C6H5), 131.5 (br s, p-C6H5), 131.8 (d,
PPh2eAu), 35.6 (s, PPh2eRu). 19F{1H} NMR (376.48 MHz, CD2Cl2)
3JCeP ¼ 42.3 Hz, i-C6H5), 133.7 (d, JCeP ¼ 9.1 Hz, o-C6H5), 149.0 (s,
d
(ppm) ¼ ꢁ78.9 (s, CF3SO3). IR (KBr)
n
(C]N)py 1612 cmꢁ1. Elem.
2
Ca), 153.2 (br s, Cg). 31P{1H} NMR (101.25 MHz, CDCl3)
anal. for C204H212Au4F36N8O36P8Ru4S12Si5 (6001.2): calcd (%) C,
40.82; H, 3.56. Found: C, 41.38; H, 4.08.
d
(ppm) ¼ 20.7 (s, PPh2). IR (KBr)
n
(C]N)py 1602 cmꢁ1. ESI-MS: (m/
z) 598.9 [M þ H]þ, 563.0 [M ꢁ Cl]þ, 292.9 [M ꢁ RuCl2(p-
cymene) þ H]þ. Elem. anal. for C28H31Cl2N2PRu (598.5): calcd (%) C,
56.19; H, 5.22. Found: C, 55.70; H, 5.06.
4.3.10. Synthesis of 12
To a solution of [4-pyeN{CH2ePPh2AuCl}2] (0.049 g, 0.05 mmol)
in 5 cm3 of CH2Cl2, 0.029 g (0.11 mmol) of AgOTf was added. The
mixture was stirred 45 min at r.t. light protected. The final
suspension was filtered through Celite and the solution was
4.3.7. Synthesis of 6
To a solution of 1a (0.163 g, 0.56 mmol) in 25 cm3 of CH2Cl2,
complex [RhCl(cod)]2 (0.137 g, 0.28 mmol) was added and the
mixture was stirred at r.t. for 1 h. Then, the mixture was filtered
through Celite and the solution was concentrated to reduced the
volume to 5 cm3, and 10 cm3 of hexane was added to obtain 6 as
a yellow solid, which was filtered off, washed with toluene
(2 ꢂ 5 cm3) and dried under reduced pressure. Yield 83%. 1H NMR
concentrated to 5 cm3. Dendrimer 9 (0.030 g, 12.5 mol) in 5 cm3 of
m
CH2Cl2 and 0.054 g (0.21 mmol) of AgOTf were added and the
suspension is stirred for 2 h light protected. Then, it was filtered
through Celite and the bright-orange solution was concentrated to
5 cm3 and was slowly added to a solution of the [4-pyeN
{CH2ePPh2AuOTf}2] complex and was stirred for 1 h. The solution
was concentrated to dryness, and the solid was washed with Et2O
(3 ꢂ 2 cm3) and dried in vacuum. Compound 12 was obtained as an
orange-brown solid in 72% yield. 1H NMR (250.13 MHz, CD2Cl2)
(250.13 MHz, CDCl3)
d
(ppm) ¼ 2.44 (m, 8H, cod CH2), 3.05 (br s, 2H,
cod HC]CH), 4.19 (pt, 2H, 2JHeP ¼ 5.2 Hz, CH2P), 5.54 (br s, 2H, cod
3
HC]CH), 6.45 (d, 2H, JHeH ¼ 7.0 Hz, Hb), 6.59 (br s, 1H, NH),
7.12e7.67 (m, 10H, C6H5), 8.11 (d, 2H, JHeH ¼ 6.9 Hz, Ha). 13C{1H}
d
(ppm) ¼ ꢁ0.61e0.09 (m, 40H, CH3Si, CH2Si), 0.70 (d, 12H,
3
3
NMR (62.90 MHz, CDCl3)
d
(ppm) ¼ 28.7 (s, cod CH2), 33.1 (s, cod
3JHeH ¼ 6.8 Hz, CH3cym), 1.01 (d, 24H, JHeH ¼ 6.4 Hz, CH3cym),
1.62e1.77 (m, 36H, CH3allyl, (CH3)G, CH2P dend, CHcym), 3.14 (br s,
8H, CH2allyl), 4.00 (br s, 8H, CH2allyl), 4.78e5.11 (m, 16H, CH2P),
5.64e5.94 (m,16H, C6H4), 6.95e7.78 (m,136H, Hb, C6H5, Ha). 13C{1H}
CH2), 42.8 (d, 1JCeP ¼ 30.2 Hz, CH2P), 71.7 (s, cod HC]CH), 107.3 (br
3
s, cod HC]CH), 108.6 (s, Cb), 128.9 (d, JCeP ¼ 10.1 Hz, m-C6H5),
1
130.4 (d, JCeP ¼ 40.2 Hz, i-C6H5), 131.1 (s, p-C6H5), 133.7 (d,
2JCeP ¼ 11.1 Hz, o-C6H5), 150.4 (s, Ca), 153.8 (d, 3JCeP ¼ 7.0 Hz, Cg). 31
P
NMR (62.90 MHz, CD2Cl2)
d
(ppm) ¼ ꢁ1.3 (s, CH3Si1), 2.6 (s, CH2Si0),
{1H} NMR (101.25 MHz, CDCl3)
d
(ppm) ¼ 23.1 (d, 1JPeRh ¼ 153.1 Hz,
3.7 (s, C2H2Si0), 10.9 (m, CH2Pdend), 19.2 (s, CH3cym), 22.6 (m,
CH3cym), 32.4 (s, CHcym), 53.5 (d, 1J(CeP) ¼ 17.0 Hz, CH2P), 86.7e94.3
(m, C6H4), 114.3 (s, Cb), 131.3e135.9 (m, C6H5), 152.5 (s, Ca), 155.1 (br
PPh2). IR (KBr)
n
(C]N)py 1616 cmꢁ1. ESI-MS: (m/z) 539 [M þ H]þ,
503 [M ꢁ Cl]þ. Elem. anal. for C26H29ClN2PRh (538.8): calcd (%) C,
57.95; H, 5.42. Found: C, 55.70; H, 5.16.
s, Cg). 31P{1H} NMR (101.25 MHz, CD2Cl2)
d
(ppm) ¼ 19.4 (s,
PPh2eAu), 25.8 (s, PPh2eRu). 19F NMR (376.48 MHz, CD2Cl2)
(ppm) ¼ ꢁ78.8 (s, CF3SO3counterion), ꢁ78.3 (s, CF3SO3coordinated). IR
(KBr)
(C]N)py 1611 cmꢁ1. Elem. anal. for C260H256Au8F48N8O48
4.3.8. Synthesis of 7
d
To a solution of 1a (0.190 g, 0.65 mmol) in 20 cm3 of CH2Cl2,
n
-
complex [Pd(
h
3-2-MeC3H4)Cl]2 (0.128 g, 0.32 mmol) was added
P12Ru4S16Si5 (8178.3): calcd (%) C, 38.18; H, 3.15. Found:
C, 39.03; H, 3.43.
and the pale yellow solution was stirred at r.t. for 45 min. Then, the
solution was concentrated to half volume and hexane was added to
precipitate 7 as a yellow solid, which was filtered and recrystallized
in CH2Cl2/Et2O and vacuum dried. Yield 72%. 1H NMR (250.13 MHz,
4.3.11. Synthesis of 13
To a solution of 9 (0.030 g, 12.5 m
mol) in 5 cm3 of CH2Cl2, 0.055 g
CDCl3)
(br s, CH2P), 4.57 (s, NH), 6.30 (d, Hb), 7.40e7.70 (m, C6H4), 8.04 (s,
Ha). 13C{1H} NMR (100.61 MHz, CD2Cl2)
d
(ppm) ¼ 2.10 (br s, CH3allyl), 3.58e2.57 (br s, CH2allyl), 4.27
(0.21 mmol) of AgOTf was added, and the mixture was stirred for
2 h, light protected. Then, the solid was filtered through Celite and
the resulted bright-orange solution was concentrated to 5 cm3. This
solution was added slowly to a solution of 0.040 g (0.05 mmol) of 8
in 3 cm3 of CH2Cl2, and was stirred for 30 min. The solution was
concentrated to dryness and the solid was washed with Et2O
(3 ꢂ 5 cm3) and dried in vacuum. The metallodendrimer 13 was
obtained as a yellow solid in 93% yield. 1H NMR (250.13 MHz,
d
(ppm) ¼ 25.8 (s, CH3allyl),
42.6 (br s, CH2P), 58.2 (br s, CH2allyl), 76.2 (br s, CH2allyl), 110.4 (s, Cb),
128.7e140.5 (m, C6H5), 141.8 (s, Callyl), 150.4 (s, Ca), 153.7 (br s, Cg).
31P{1H} NMR (101.25 MHz, CD2Cl2)
d
(ppm) ¼ 18.2. IR (KBr)
n(C]
N)py 1604 cmꢁ1. Elem. anal. for C22H24ClN2PPd (489.2): calcd (%) C,
54.00; H, 4.94. Found: C, 53.60; H, 4.86.
CD2Cl2)
d
(ppm) ¼ ꢁ0.61e0.09 (m, 40H, CH3Si, CH2Si), 0.70 (d, 12H,
3
4.3.9. Synthesis of 11
3JHeH ¼ 6.8 Hz, CH3cym), 1.01 (d, 24H, JHeH ¼ 6.4 Hz, CH3cym),
1.62e1.77 (m, 36H, CH3allyl, CH3cym, CH2Pdend, CHcym), 3.14 (br s, 8H,
CH2allyl), 4.00 (br s, 8H, CH2allyl), 4.78e5.11 (m, 16H, CH2P),
5.64e5.94 (m, 22H, C6H4, Hb), 6.95e7.78 (m, 128H, C6H5, Ha). 13C
To a solution of 9 (0.030 g, 12.5 m
mol) in 5 cm3 of CH2Cl2, 0.054 g
(0.21 mmol) of AgOTf was added, and the mixture was stirred for
2 h light protected to obtain 10. Then, the solid was filtered through
Celite and the resulted bright-orange solution was concentrated to
5 cm3. This solution was added slowly to a solution of 0.033 g
(0.05 mmol) of 4b in 2 cm3 of CH2Cl2, and stirred for 30 min. The
solution was filtered and concentrated to dryness and the solid was
washed with Et2O (3 ꢂ 5 cm3) and dried under vacuum. Compound
11 was obtained as a yellow-ochre solid in 92% yield. 1H NMR
{1H} NMR (100.61 MHz, CD2Cl2)
d
(ppm) ¼ ꢁ0.2 (s, CH3Si1), 3.0 (s,
CH2Si0), 10.3 (s, CH2Si0), 11.9 (m, CH2Pdend), 19.8 (s, (CH3)G), 22.7 (s,
CH3cym), 24.6 (s, CH3cym), 25.8 (s, CH3allyl), 32.6 (s, CHcym), 52.6 (br s,
CH2P), 76.2 (s, CH2allyl), 76.5 (s, CH2allyl), 111.8 (s, Cb), 123.1 (m,
1JCeF ¼ 320.9 Hz, CF3SO3), 130.9e135,6 (m, C6H5), 140.8 (s, Callyl),
154.7 (s, Ca), 155.9 (br s, Cg). 31P{1H} NMR (101.25 MHz, CD2Cl2)
(400.11 MHz, CD2Cl2)
0.90 (m, 24H, CH3cym), 1.44 (m, 12H, CH3cym), 1.90 (m, 8H, CH2P
dend), 2.46 (br s, 4H, CHcym), 4.49 (br s, 8H, CH2P), 5.00e5.68 (m,
d
(ppm) ¼ ꢁ0.64e0.04 (m, 40H, CH3Si, CH2Si),
d
(ppm)
(376.48 MHz, CD2Cl2)
CF3SO3coordinated). IR (KBr)
(m/z) 3164 [10
TfO]þ, 651.3 [8
¼
7.2 (s, PPh2ePd), 29.8 (s, PPh2eRu). 19F NMR
(ppm) ¼ ꢁ78.9 (s, CF3SO3counterion), ꢁ78.4 (s,
(C]N)py 1612 cmꢁ1
ESI-MS
OTf]þ. Elem. anal. for
d
n
.
3
16H, C6H4), 6.54 (d, 8H, JHeH ¼ 5.1 Hz, Hb), 6.81 (br s, 4H, NH),
ꢁ
ꢁ
7.31e7.56 (m, 80H, C6H5), 7.73 (d, 8H, JHeH ¼ 4.6 Hz, Ha). 13C{1H}
C255H284F36N8O36P12Pd4Ru4S12Si5 (6447.8): calcd (%) C, 47.49; H,
4.44. Found: C, 48.61; H, 5.03.
3
NMR (62.90 MHz, CD2Cl2)
d
(ppm) ¼ ꢁ0.4 (s, CH3Si1), 2.7 (s, CH2Si0),

128
I. Angurell et al. / Journal of Organometallic Chemistry 716 (2012) 120e128
[5] M. Benito, O. Rossell, M. Seco, G. Segalés, Organometallics 18 (1999)
Acknowledgements
5191e5193;
M. Benito, O. Rossell, M. Seco, G. Muller, J.I. Ordinas, M. Font-Bardia, X. Solans,
Eur. J. Inorg. Chem. (2002) 2477e2487;
I. Angurell, J.C. Lima, L.-I. Rodríguez, L. Rodríguez, O. Rossell, M. Seco, New J.
Chem. 30 (2006) 1004e1008;
L.-I. Rodríguez, O. Rossell, M. Seco, A. Grabulosa, G. Muller, M. Rocamora,
Organometallics 25 (2006) 1368e1376;
Financial support from MICINN project CTQ2009-08795 is
acknowledged. P.G.S. and A.M. are supported by the Factoría de
CristalizacióndConsolider CSD2006-00015.
L.-I. Rodríguez, O. Rossell, M. Seco, G. Muller, Organometallics 27 (2008)
1328e1333.
Appendix A. Supplementary material
[6] J.A. Casares, P. Espinet, J.M. Martín-Álvarez, V. Santos, Inorg. Chem. 45 (2006)
6628e6636;
CCDC 879273 and 879274 (for 5 and 8) contain the supple-
mentary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
J.D.E.T. Wilton-Ely, A. Schier, N.W. Mitzel, S. Nogai, H. Schmidbaur,
J. Organomet. Chem. 643e644 (2002) 313e323;
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[7] I. Angurell, O. Rossell, M. Seco, Chem.dEur. J. 15 (2009) 2932e2940.
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