Organometallic derivatives at the core of phosphorus-containing dendrimers

Article abstract of DOI:10.1002/zaac.200500213

The synthesis of a new family of phosphorus-containing dendrimers is described up to the fourth generation. These compounds are built from a ferrocene core substituted by two electron withdrawing P=N-P=S linkages, which dramatically modify the electrochemical properties of the ferrocene. These substituents are able to complex instantaneously group 11 metals, and the structure of one of these complexes has been determined by X-ray diffraction.

Full text of DOI:10.1002/zaac.200500213

Organometallic Derivatives at the Core of Phosphorus-Containing Dendrimers
´
Cedric-Olivier Turrin, Bruno Donnadieu, Anne-Marie Caminade*, Jean-Pierre Majoral*
Toulouse/ France, Laboratoire de Chimie de Coordination du CNRS
Received March 6th, 2005.
Dedicated to Professor Herbert W. Roesky on the Occasion of his 70th Birthday
Abstract. The synthesis of a new family of phosphorus-containing
dendrimers is described up to the fourth generation. These com-
pounds are built from a ferrocene core substituted by two electron
withdrawing PϭN-PϭS linkages, which dramatically modify the
electrochemical properties of the ferrocene. These substituents are
able to complex instantaneously group 11 metals, and the structure
of one of these complexes has been determined by X-ray diffrac-
tion.
Keywords: Dendrimers; Phosphorus; Ferrocene; Hydrazones;
S ligands
Introduction
Results and Discussion
The first reaction carried out to synthesize the ferrocene-
cored dendrimer is a Staudinger reaction between bis di-
phenylphosphino ferrocene (1-G0) and two equivalents of
the azide N3P(S)(OC6H4CHO)2 (2) [12], leading to the
tetraaldehyde 1-GЈ0 [13] (Scheme 1). This reaction is charac-
terized in particular by 31P NMR spectroscopy, with the
appearance of two doublets at 16.1 (PPh2) and 49.2 (PϭS)
ppm with 2JPP ϭ 32 Hz, very characteristic of the formation
of the PϭN-PϭS linkages [14] (Table 1). The second reac-
tion carried out is in fact the first step of the reiterative
synthesis which will be used to synthesize the dendrimer. It
consists of a condensation reaction between 1-GЈ0 and the
phosphorhydrazide H2NNMeP(S)Cl2 (3). This reaction af-
fords the first generation of the dendrimer 1-G1 and induces
the disappearance of the signal corresponding to the alde-
Dendrimers [1] are highly branched and multifunctional-
ized macromolecules of well defined three-dimensional size,
shape, and topology. The attractive beauty of these nano-
sized compounds has been inducing an exponential devel-
opment since more than ten years, in which metallodendri-
mers attract an increasing amount of interest. Several topics
take advantage of the use of metals in dendrimers chemis-
try, such as their construction [2], their use as molecular
antennae [3], or their use as recoverable catalysts [4]. One
of the most widely used organometallic derivatives for the
elaboration of organometallic dendrimers is ferrocene [5].
In most cases, it is linked to the surface of dendrimers, and
relatively few reports concern dendrimers having ferrocene
derivatives located in their internal structure [6].
In the course of our research concerning phosphorus-
containing dendrimers [7], we have already grafted or-
ganometallic derivatives of various metals (Pd, Pt, Ru, Rh,
Au, W, Fe) to the surface of dendrimers [8], or within the
branches [9]. We have in particular used ferrocene deriva-
tives to functionalize the surface of dendrimers [10], and
built dendrimers incorporating ferrocene derivatives within
the interior [11], in order to study the modification of their
electrochemical properties induced by the hiding of the fer-
rocene. We report here the use of bis(diphenylphosphino)
ferrocene as core of phosphorus-containing dendrimers, at-
tempted electrochemical studies of the ferrocene moieties,
and the complexation properties of one of these com-
pounds, characterized by X-ray diffraction.
1
hydes in H and 13C NMR. It also induces the appearance
of a new signal in 31P NMR corresponding to the P(S)Cl2
groups, together with a slight modification of the chemical
shifts corresponding to the PϭN-PϭS linkage (15.5 and
50.8 ppm, respectively). The next reaction (i.e. the second
step of the reiterative synthesis) is the nucleophilic substi-
tution of chlorine by hydroxybenzaldehyde sodium salt 4,
leading to the octaaldehyde 1-GЈ1 (Scheme 1). This substi-
tution reaction is characterized in 31P NMR by the shift of
Table 1 31P NMR data of dendrimers in CDCl3 (δ in ppm)
Dendrimer
PPh2
P0
2JPP (Hz)
P1
P2
P3
P4
1-GЈ0
1-G1
1-GЈ1
1-G2
1-GЈ2
1-G3
1-GЈ3
1-G4
16.1
15.5
15.6
15.7
15.5
15.6
15.4
15.4
17.6
19.7
49.2
50.8
51.1
51.0
51.1
51.0
51.0
50.9
45.0
35.0
32
32
32
33
33
32
32
32
22
27
63.4
60.8
62.3
62.7
62.7
63.1
62.7
63.0
60.5
62.1
62.4
62.4
* Dr. Jean-Pierre Majoral, Dr. Anne-Marie Caminade
Laboratoire de Chimie de Coordination du CNRS,
205 route de Narbonne,
63.1
60.5
62.1
63.1
31077 Toulouse Cedex 4, France
6a-GЈ0
6b-GЈ0
Fax: ϩ 33 (0)5 61 55 30 03
E-mails: majoral@lcc-toulouse.fr, caminade@lcc-toulouse.fr
Z. Anorg. Allg. Chem. 2005, 631, 2881Ϫ2887
DOI: 10.1002/zaac.200500213
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C.-O. Turrin, B. Donnadieu, A.-M. Caminade, J.-P. Majoral
Scheme 1
the signal corresponding to the most external PϭS groups
from 63.4 for P(S)Cl2 to 60.8 ppm for P(S)(O-Ar)2.
All these compounds are characterized by 1H and 13C
NMR, IR spectra and elemental analyses. However, the
most informative data are obtained by 31P NMR, as shown
in Table 1 in particular by the modification of the chemical
shifts corresponding to the two most external layers. The
substitution reaction induces a shielding of the signal from
63 to 60.5 ppm corresponding to the phosphorus under-
going the reaction, whereas the condensation reaction in-
duces both the appearance of a new signal at 63 ppm and
The growing of dendrimer 1-Gn is then pursued, using
our classical method of synthesis of dendrimers [7a], whose
first two steps are described above, i.e. the condensation
reaction with the phosphorhydrazide 3 and the nucleophilic
substitution of chlorine using the sodium salt 4. These reac-
tions have successively been carried out up to the fourth
generation 1-G4 possessing 32 P(S)Cl2 end groups (Scheme 1).
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Organometallic Derivatives at the Core of Phosphorus-Containing Dendrimers
a slight deshielding of the signal from 60.5 to 62 ppm corre-
sponding to the phosphorus of the previous generation. The
synthesis could have been pursued to higher generations but
most properties of dendrimers are generally already detect-
able for the third or fourth generation, thus we decided to
stop the synthesis at this step.
We have already demonstrated that modification of the
electrochemical properties occurs when ferrocenes are bu-
ried inside dendrimers; we intended to check if changing the
substituents of ferrocenes, that is replacing the hydrazone
substituents of our previous dendrimers [11a] by the PϭN-
PϭS groups, could modify the electrochemical behavior.
The experiments were carried out with compound 1-GЈ0 in
acetone/THF (2:1), using a Pt working electrode and
Bu4NBF4 as supporting electrolyte. The cyclic voltammog-
ram displays a well defined single oxydo-reduction wave
centered at 1.25 V vs SCE, which could correspond to a
ferrocene disubstituted by electron-withdrawing groups [15]
(Figure 1). However, coulometric measurements at fixed
potential show the transfer of two electrons instead of the
single electron expected for the couple FeII/FeIII. Taking
into account that the occurrence of FeIV is unlikely and that
the molecule is symmetrical, it could be anticipated that the
orbitals involved by the electronic transfer should widely be
located at the substituents of the cyclopentadienyl groups
and not on iron. This assumption is supported by the 31P
NMR spectrum obtained after electrolysis: both doublets
characteristic of 1-GЈ0 have disappeared on behalf of a mul-
titude of signals between Ϫ10 and ϩ60 ppm. This obser-
vation implies the occurrence of an EC process, that is an
electronic transformation followed by a chemical trans-
formation.
Figure 1 Cyclic voltammograms of compounds 1-GЈ0 and 5.
11 metals [9a]. The occurrence of the same reaction for
compounds 1-Gn could afford three metallic centers of two
types in relatively close proximity. The reaction was first
carried out with one equivalent of [(CuCF3SO3)2,C6H6] and
compound 1-GЈ0 in CH2Cl2. The color of the solution in-
stantaneously changes from orange for 1-GЈ0 to maroon for
the complex 6a-GЈ0 (Scheme 2). The complexation induces
a slight deshielding of the signal corresponding to Ph2P in
31P NMR (δ∆ ϭ ϩ1 ppm) and a shielding of the signal
corresponding to PϭS (δ∆ ϭ Ϫ4 ppm), as well as a de-
2
crease of the JPP coupling constant from 32 Hz for 1-GЈ0
to 22 Hz for 6a-GЈ0. These results indicate that the com-
plexation occurred as expected on the sulfur of the PϭS
group, due to a partial negative charge on sulfur induced
by an electronic delocalization (form B in Scheme 3). At-
tempted crystallization of this complex failed, thus we de-
cided to use a heavier metal for complexation experiments,
and we choose AuCl(tht) (tht ϭ tetrahydrothiophene). A
slight bleaching of the solution of 1-GЈ0 is observed when
two equivalents of AuCl(tht) are added, leading to 6b-GЈ0.
The complexation is easily detected by 31P NMR, which
displays phenomena analogous to those observed with cop-
per, but with larger amplitude: the signal corresponding to
In order to confirm the implication of the ligands in
the electrochemical transformation, we have synthesized
compound 5, including
a single PϭN-PϭS linkage
(5: MePh2PϭN-P(S)(OPh)2) [13]. The cyclic voltammogram
of this compound possesses a single wave characteristic of
an irreversible oxidation (Figure 1), and coulometric meas-
urements show the transfer of a single electron. Also in this
case an EC process occurs, as shown by 31P NMR, with the
occurrence of a multitude of signals in the same area as for
1-GЈ0. Thus, the presence of the PϭN-PϭS linkages pre-
cludes any electrochemical studies of the modifications in-
duced by the hiding of the ferrocene core, depending on the
generation of the dendrimer.
On the other hand, we have already shown that
PϭN-PϭS linkages can behave as S ligands toward group
Scheme 3
Scheme 2
Z. Anorg. Allg. Chem. 2005, 631, 2881Ϫ2887
zaac.wiley-vch.de
 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2883

C.-O. Turrin, B. Donnadieu, A.-M. Caminade, J.-P. Majoral
It means that there is a larger contribution of the form B
shown in Scheme 3 to the electronic distribution in the com-
plex compared to the free compound. These X-ray data
corroborate the 31P NMR data: the deshielding of the sig-
nal corresponding to PPh2 indicates a more pronounced
phosphonium character of this atom, whereas the shielding
of the signal corresponding to P(S) indicates an increased
iminophosphorane character of this phosphorus atom.
Conclusion
We have synthesized a new family of phosphorus-contain-
ing dendrimers elaborated from a ferrocene core substituted
by electron withdrawing PϭN-PϭS groups. The series of
compounds synthesized here are stable even for years, but
they are destroyed by the electrochemical studies, which in-
duce an electrochemical reaction followed by a chemical re-
action, due to the PϭN-PϭS linkages. This fact reminds
that the electrochemical behavior of ferrocenes is directly
influenced by their proximal chemical environment; never-
theless, the disappearance of the activity of the ferrocene
observed here on behalf of its substituents is atypical in
dendrimers chemistry. However, due to their electron with-
drawing character, the PϭN-PϭS linkages are good com-
plexing agents: the complexation of group 11 elements such
as copper and gold occurs instantaneously, illustrating the
behavior as S ligands of these linkages.
Figure 2 Molecular view of compound 6b-GЈ0 (ORTEP drawing)
PPh2 is deshielded (δ∆ ϭ ϩ4 ppm), whereas the signal cor-
responding to PϭS is largely shielded (δ∆ ϭϪ14 ppm). In
order to ascertain the structure of 6b-GЈ0, single crystals
were grown in CH2Cl2/pentane, and characterized by X-ray
diffraction. The ORTEP drawing of 6b-GЈ0 is shown in Fig-
ure 2, and selected bond length and bond angles concerning
the PϭN-PϭS linkage are gathered in Table 2. The corre-
sponding data previously obtained for compound 1-GЈ0 [13]
are also included in this Table. The comparison between
both data shows a lengthening of the Ph2PϭN and PϭS
bonds, whereas the N-P(S) and P-OAr bonds are shortened.
Experimental Section
General. All manipulations were carried out with standard high
vacuum and dry-argon techniques. The solvents were freshly dried
and distilled (THF and ether over sodium/benzophenone, pentane
and CH2Cl2 over phosphorus pentoxide), they were degassed prior
to use in the case of experiments using tricoordinated phosphorus
atoms derivatives. 1H, 13C, 31P NMR spectra were recorded with
Bruker AC 200, AC 250, DPX 300 or AMX 400 spectrometers.
References for NMR chemical shifts are 85 % H3PO4 for 31P NMR,
˚
Table 2 Selected bond lengths/A and bond angles/° for 6b-GЈ0
and comparison with 1-GЈ0 [13]
6b-GЈ0
1-GЈ0 [13]
Diff.
P(1) Ϫ N(1)
N(1) Ϫ P(2)
P(2) Ϫ S
P(1) Ϫ C(1)
P(1) Ϫ C(6)
P(1) Ϫ C(12)
P(2) Ϫ O(1)
P(2) Ϫ O(2)
S Ϫ Au
1.584(5)
1.552(5)
1.994(2)
1.785(5)
1.801(6)
1.792(5)
1.592(4)
1.592(4)
2.2707(16)
2.284(2)
1.559(4)
1.569(4)
1.918(2)
1.784(4)
1.795(4)
1.788(5)
1.630(3)
1.632(3)
ϩ 0.025
Ϫ 0.017
ϩ 0.076
ϩ 0.001
ϩ 0.006
ϩ 0.004
Ϫ 0.038
Ϫ 0.040
1
SiMe4 for H and 13C NMR. The attribution of 13C NMR signals
has been done using Jmod, two dimensional HMBC, and HMQC,
Broad Band or CW 31P decoupling experiments when necessary (bs
means broad singlet). The number scheme used for NMR assign-
ments is shown in Figure 3. Compounds 1-GЈ0 [13] and 2 [12] were
synthesized according to published procedures.
Au Ϫ Cl
P(1) Ϫ N(1) Ϫ P(2)
N(1) Ϫ P(2) Ϫ S
P(2) Ϫ S Ϫ Au
S Ϫ Au Ϫ Cl
139.9(3)
115.8(2)
103.06(8)
177.87(8)
137.2(3)
121.9(2)
ϩ 2.7
Ϫ 6.1
General procedure for the synthesis of dendrimers 1-Gn (P(S)Cl2 end
groups, n ؍ 1-4). To a solution of 1 to 3 g of dendrimer 1-GЈn؊1
(aldehyde end groups) in chloroform (15 to 50 mL) was added at
room temperature 5 % molar excess of a solution of phosphor-
Figure 3 Numbering used for NMR.
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Organometallic Derivatives at the Core of Phosphorus-Containing Dendrimers
hydrazide 3 in chloroform (0.3 M). The resulting solution was
stirred overnight, then evaporated to dryness to afford 1-Gn as an
orange powder, which was washed three times with ether/pentane
1/1.
Dendrimer 1-G3. yield 97 %. Orange powder. Ϫ Anal. for
C258H252Cl32FeN58O28P32S30 (7757 g/mol): calcd. C 39.95, H 3.27,
N 10.47 %; found: C 40.01, H 3.30, N, 10.21 %.
3
1H NMR: δ ϭ 3.32 (d, JHP1
ϭ
3JHP2 ϭ 10.6 Hz, 36 H, CH3-N-P1,2), 3.40
(d, 3 HP3 ϭ 14.0 Hz, 48 H, CH3-N-P3), 4.36 (br s, 4 H, C2H), 4.52 (br s, 4 H,
J
C3H), 7.22-7.69 (m, 160 H, C6H4, C6H5, CHϭN). Ϫ 13C{1H} NMR: δ ϭ
31.7 (d, 2JCP3 ϭ 12.1 Hz, CH3-N-P3), 32.8 (d, 2JCP1 ϭ 2JCP2 ϭ 12.3 Hz, CH3-
General procedure for the synthesis of dendrimers 1-GЈn (aldehyde
end groups, n ؍ 1-4). To a solution of 1 to 3 g of dendrimer 1-Gn
(P(S)Cl2 end groups) in THF (15 to 50 mL) was added at room
temperature 3 % molar excess of sodium salt 4 (powder). The re-
sulting heterogeneous mixture was stirred overnight, then centri-
fuged (10000 turns per mn). The solution was recovered and evapo-
rated to dryness to give 1-GЈn as an orange powder, which was
washed three times with ether.
N-P1,2), 71.7 (d, JCPЈ ϭ 120.7 Hz, C1), 74.1 (d, JCPЈ ϭ 14.9 Hz, C2), 74.6
1
2
2
(d, 3JCPЈ ϭ 10.5 Hz, C3), 121.7 (d, 3
J
CP0 ϭ 3JCP1 ϭ 3JCP2 ϭ 3.8 Hz, C02, C1
,
C22), 128.0 (s, C03), 128.1 (s, C13), 128.2 (d, JCPЈ ϭ 12.0 Hz, CЈ3), 128.5
3
(s, C23), 129.5 (br d, JCPЈ ϭ 109.1 Hz, CЈ1), 130.7 (s, C04), 131.3 (s, C24),
1
131.7 (d, 2JCPЈ ϭ 10.4 Hz, CЈ2), 131.8 (s, C14), 132.4 (s, CЈ4), 139.0 (d, 3JCP2 ϭ
3
3
13.5 Hz, CHϭN), 139.4 (d, JCP1 ϭ 13.5 Hz, CHϭN), 140.6 (d, JCP3
ϭ
18.7 Hz, CHϭN), 151.2 (d, JCP1 ϭ 6.9 Hz, C11), 151.6 (d, JCP0 ϭ 7.3 Hz,
2
2
C01), 153.0 (d, JCP2 ϭ 9.1 Hz, C21).
2
Dendrimer 1-GЈ3. yield 97 %. Orange powder.
C482H412FeN58O92P32S30 (10498 g/mol): calcd. C 55.15, H 3.96, N
7.74 %; found: C 55.03, H 4.08, N 7.51 %.
Ϫ Anal. for
Dendrimer 1-G1. yield 96 %. Orange powder.
C66H60Cl8FeN10O4P8S6 (1837 g/mol): calcd. C 43.16, H 3.29, N
7.63 %; found: C 43.44, H 3.38, N 7.50 %.
Ϫ Anal. for
3
1H NMR: δ ϭ 3.34 (br d, JHP1
ϭ ϭ
3JHP2 3JHP3 ϭ 10.5 Hz, 84 H, CH3-N-
3
1H NMR: δ ϭ 3.44 (d, JHP1 ϭ 14.0 Hz, 12 H, CH3-N-P1), 4.40 (s, 4 H,
P1,2,3), 4.33 (br s, 4 H, C2H), 4.56 (br s, 4 H, C3H), 7.18-7.82 (m, 288 H,
C2H), 4.50 (s, 4 H, C3H), 7.20-7.70 (m, 40 H, C6H4, C6H5, CHϭN). Ϫ
C6H4, C6H5, CHϭN), 9.88 (s, 32 H, CHO). Ϫ 13C{1H} NMR: δ ϭ 32.7 (d,
2
1
13C{1H} NMR: δ ϭ 31.7 (d, JCP1 ϭ 13.0 Hz, CH3-N-P1), 71.8 (dd, JCPЈ
ϭ
2JCP3 ϭ 13.7 Hz, CH3-N-P3), 32.8 (d, 2 CP1 ϭ 2JCP2 ϭ 12.0 Hz, CH3-N-P1,2),
J
120.5 Hz, 3 CP0 ϭ 3.3 Hz, C1), 74.2 (d, 2JCPЈ ϭ 13.8 Hz, C2), 75.0 (d, 3JCPЈ
J
ϭ
71.7 (d, 1JCPЈ ϭ 119.9 Hz, C1), 74.1 (d, 2JCPЈ ϭ 14.8 Hz, C2), 75.1 (d, 3JCPЈ
ϭ
11.0 Hz, C3), 121.6 (d, 3JCP0 ϭ 5.0 Hz, C02), 128.2 (d, 3JCPЈ ϭ 13.4 Hz, CЈ3),
10.6 Hz, C3), 121.7 (br d, 3JCP0 ϭ 3JCP1 ϭ 3JCP2 ϭ 3JCP3 ϭ 4.6 Hz, C02, C1
,
2
1
3
129.3 (dd, JCPЈ ϭ 107.6 Hz, JCP0 ϭ 3.5 Hz, CЈ1), 128.4 (s, C03), 130.1 (s,
C22, C32), 128.1 (br s, C03, C13, C23, CЈ3), 129.4 (br d, 1JCPЈ ϭ 109.2 Hz, CЈ1),
C04), 131.9 (d, 2JCPЈ ϭ 11.1 Hz, CЈ2), 132.4 (s, CЈ4), 141.2 (d, 3JCP1 ϭ 18.8 Hz,
130.7 (s, C04), 131.2 (br s, C33, CЈ2), 131.6 (s, C24), 131.9 (s, C14), 132.3
CHϭN), 153.5 (d, JCP0 ϭ 9.3 Hz, C01).
2
(s, CЈ4), 133.4 (s, C34), 139.0 (d, JCP1
ϭ
3JCP2 ϭ 13.5 Hz, CHϭN), 139.5
3
(d, JCP3 ϭ 13.6 Hz, CHϭN), 151.1 (d, JCP1 ϭ 7.6 Hz, C11), 151.2 (d,
3
2
2JCP2 ϭ 7.4 Hz, C21), 153.0 (d, 2JCP0 ϭ 8.9 Hz, C01), 154.9 (d, 2JCP3 ϭ 7.3 Hz,
Dendrimer 1-GЈ1. yield 97 %. Orange powder.
C122H100FeN10O20P8S6 (2522 g/mol): calcd. C 58.10, H 4.00, N
5.55 %; found: C 58.46, H 4.02, N 5.40 %.
Ϫ Anal. for
C31), 190.6 (s, CHO). Ϫ IR (KBr): 1704 (νCϭO) cmϪ1
.
Dendrimer 1-G4. yield 97 %. Pale orange powder. Ϫ Anal. for
514H508Cl64FeN122O60P64S62 (15650 g/mol): calcd. C 39.45, H
3
1H NMR: δ ϭ 3.34 (d, JHP1 ϭ 11.0 Hz, 12 H, CH3-N-P1), 4.45 (s, 4 H,
C
C2H), 4.52 (s, 4 H, C3H), 7.20-7.90 (m, 72 H, C6H4, C6H5, CHϭN), 9.90
3.27, N 10.92 %; found: C 39.45, H 3.22, N 10.87 %.
2
(s, 8 H, CHO). Ϫ 13C{1H} NMR: δ ϭ 32.7 (d, JCP1 ϭ 13.9 Hz, CH3-N-P1),
3
1H NMR: δ ϭ 3.33 (br d, JHP1
ϭ ϭ
3JHP2 3JHP3 ϭ 10.2 Hz, 84 H, CH3-N-
71.7 (d, 1JCPЈ ϭ 119.7 Hz, C1), 74.2 (d, 2JCPЈ ϭ 13.3 Hz, C2), 74.9 (d, 3JCPЈ
ϭ
3
3
3
P1,2,3), 3.38 (d, JHP4 ϭ 14.0 Hz, 96 H, CH3-N-P4), 4.33 (br s, 4 H, C2H),
10.8 Hz, C3), 121.5 (d, JCP0 ϭ 4.7 Hz, C02), 121.8 (d, JCP1 ϭ 5.0 Hz, C12),
1
4.57 (br s, 4 H, C3H), 7.21-7.68 (m, 320 H, C6H4, C6H5, CHϭN). Ϫ 13C{1H}
127.9 (s, C03), 128.2 (d, 3JCPЈ ϭ 13.7 Hz, CЈ3), 129.3 (br d, JCPЈ ϭ 109.6 Hz,
2
2
2JCP2
CЈ1), 130.4 (s, C04), 131.2 (s, C13), 131.8 (d, JCPЈ ϭ 11.4 Hz, CЈ2), 132.4
2
NMR: δ ϭ 31.7 (d, JCP4 ϭ 13.2 Hz, CH3-N-P4), 32.9 (d, JCP1 ϭ ϭ
2JCP23
ϭ
12.9 Hz, CH3-N-P1,2,3), 71.6 (d, JCPЈ
ϭ
119.2 Hz, C1), 74.1
1
(s, CЈ4), 133.4 (s, C14), 140.0 (d, 3JCP1 ϭ 14.1 Hz, CHϭN), 153.1 (d, 2JCP0
ϭ
3
3
9.2 Hz, C01), 154.9 (d, JCP1 ϭ 7.3 Hz, C11), 190.6 (s, CHO). Ϫ IR (KBr):
2
(d, JCPЈ ϭ 13.8 Hz, C2), 75.0 (d, JCPЈ ϭ 10.0 Hz, C3), 121.7 (br d, JCP0
ϭ
3
3JCP1
ϭ ϭ ,
3JCP2 3JCP3 ϭ 3.0 Hz, C02, C12, C22, C32), 128.1 (br s, C03, C1
1699 (νCϭO) cmϪ1
.
C23, CЈ3), 128.5 (s, C33), 129.5 (br d, JCPЈ ϭ 109.5 Hz, CЈ1), 130.7 (s, C04),
1
131.2 (br s, C34), 131.8 (s, C14, C24, CЈ2), 132.4 (s, CЈ4), 138.9 (d, JCP1
ϭ
3
3JCP22 ϭ 3JCP3 ϭ 13.4 Hz, CHϭN), 140.5 (d, 3JCP4 ϭ 18.8 Hz, CHϭN), 151.2
Dendrimer 1-G2. yield 97 %. Orange powder.
C130H124Cl16FeN26O12P16S14 (3810 g/mol): calcd. C 40.98, H 3.28,
N 9.56 %; found: C 41.16, H 3.31, N 9.40 %.
Ϫ Anal. for
2
(d, JCP1
ϭ
2JCP2 ϭ 6.4 Hz, C11, C21), 151.6 (d, JCP3 ϭ 7.3 Hz, C31), 152.9
(d, JCP0 ϭ 9.4 Hz, C01).
2
3
3
1H NMR: δ ϭ 3.36 (d, JHP1 ϭ 14.7 Hz, 12 H, CH3-N-P1), 3.41 (d, JHP2
ϭ
Synthesis of complex 6a-GЈ0. To a solution of compound 1-GЈ0
(1.00 g, 0.83 mmol) in dichloromethane (15 mL) was added one
equivalent of [(CuSO3CF3)2C6H6] (0.42 g, 0.83 mmol). The color
of the solution changed instantaneously from orange to maroon.
The solution was stirred for 1/2 h at room temperature, then evapo-
rated to dryness. The resulting maroon powder was washed with
dichloromethane/pentane 1/5 to afford compound 6a-GЈ0. yield
96 %. Maroon powder. Ϫ Anal. for C64H48Cu2F6FeN2O14P4S4
(1618 g/mol): calcd. C 47.50, H 2.99, N 1.73 %; found: C 47.55, H
3.05, N 1.69 %.
14.2 Hz, 24 H, CH3-N-P2), 4.36 (br s, 4 H, C2H), 4.58 (br s, 4 H, C3H), 7.24-
7.73 (m, 80 H, C6H4, C6H5, CHϭN). Ϫ 13C{1H} NMR: δ ϭ 32.0 (d, 2JCP2 ϭ
2
1
12.9 Hz, CH3-N-P2), 33.1 (d, JCP1 ϭ 13.0 Hz, CH3-N-P1), 72.1 (d, JCPЈ
ϭ
2
3
120.0 Hz, C1), 74.4 (d, JCPЈ ϭ 13.3 Hz, C2), 75.3 (d, JCPЈ ϭ 10.7 Hz, C3),
3
3
122.0 (d, JCP0
ϭ
3JCP1 ϭ 4.8 Hz, C02, C12), 128.1 (s, C03), 128.5 (d, JCPЈ
ϭ
13.2 Hz, CЈ3), 128.7 (s, C13), 129.3 (br d, JCPЈ ϭ 109.0 Hz, CЈ1), 131.1
1
(s, C04), 131.7 (s, C14), 132.1 (d, JCPЈ ϭ 11.0 Hz, CЈ2), 132.7 (s, CЈ4), 139.9
2
3
3
(d, JCP1 ϭ 13.7 Hz, CHϭN), 141.1 (d, JCP2 ϭ 18.9 Hz, CHϭN), 152.0
(d, JCP1 ϭ 7.1 Hz, C11), 153.4 (d, JCP0 ϭ 8.8 Hz, C01).
2
2
Dendrimer 1-GЈ2. yield 96 %. Orange powder.
C242H204FeN26O44P16S14 (5181 g/mol): calcd. C 56.11, H 3.97, N
7.03 %; found: C 56.05, H 4.07, N 6.92 %.
Ϫ
Anal. for
1H NMR: δ ϭ 4.37 (br s, 4 H, C2H), 4.41 (br s, 4 H, C3H), 7.17-7.79 (m,
36 H, C6H4, C6H5), 9.91 (s, 4 H, CHO). Ϫ 19F NMR: δ ϭ Ϫ1.89 (s, CF3SO3).
1
Ϫ
13C{1H} NMR: δ ϭ 71.4 (dd, JCPЈ ϭ 127.7 Hz, 3JCP0 ϭ 3.3 Hz, C1), 74.0
1H NMR: δ ϭ 3.33 (d, JHP1
ϭ
3JHP2 ϭ 10.6 Hz, 36 H, CH3-N-P1,2), 4.36
(d, JCPЈ ϭ 13.5 Hz, C2), 75.0 (d, JCPЈ ϭ 11.1 Hz, C3), 121.5 (d, JCP0
ϭ
3
2
3
3
(br s, 4 H, C2H), 4.55 (br s, 4 H, C3H), 7.19-7.84 (m, 144 H, C6H4, C6H5,
4.9 Hz, C02), 128.5 (dd, JCPЈ ϭ 108.9 Hz, JCP20 ϭ 3.4 Hz, CЈ1), 128.6 (d,
3JCPЈ ϭ 13.1 Hz, CЈ3), 131.2 (s, C03), 131.7 (d, JCPЈ ϭ 11.2 Hz, CЈ2), 132.9
1
3
CHϭN), 9.90 (s, 16 H, CHO). Ϫ 13C{1H} NMR: δ ϭ 32.7 (d, JCP2
ϭ
ϭ
2
13.8 Hz, CH3-N-P2), 32.8 (d, JCP1 ϭ 11.1 Hz, CH3-N-P1), 71.8 (d, JCPЈ
(s, CЈ4), 133.0 (s, C04), 156.0 (d, JCP0 ϭ 9.4 Hz, C01), 190.8 (s, CHO). Ϫ IR
2
1
2
2
3
121.1 Hz, C1), 74.1 (d, JCPЈ ϭ 13.2 Hz, C2), 75.0 (d, JCPЈ ϭ 10.2 Hz, C3),
(KBr): 1699 (νCϭO) cmϪ1
.
121.7 (d, 3JCP0 ϭ 3JCP1 ϭ 3JCP2 ϭ 3.0 Hz, C02, C12, C22), 128.0 (s, C03), 128.1
(s, C13), 128.2 (d, JCPЈ ϭ 12.1 Hz, CЈ3), 129.4 (br d, JCPЈ ϭ 109.1 Hz, CЈ1),
3
1
Synthesis of complex 6b-GЈ0. To a solution of compound 1-GЈ0
(1.00 g, 0.83 mmol) in dichloromethane (15 mL) were added two
equivalents of AuCl(tht) (0.53 g, 1.66 mmol). The solution was
stirred for 1/2 h at room temperature, then evaporated to dryness.
130.7 (s, C04), 131.2 (s, C23), 131.6 (s, C14), 131.7 (d, JCPЈ ϭ 11.0 Hz, CЈ2),
2
132.3 (s, CЈ4), 133.4 (s, C24), 139.5 (d, JCP1
ϭ
3JCP2 ϭ 11.0 Hz, CHϭN),
2
3
151.3 (d, JCP1 ϭ 5.0 Hz, C11), 153.0 (d, JCP0 ϭ 7.2 Hz, C01), 154.9
2
(d, JCP2 ϭ 5.6 Hz, C21), 190.6 (s, CHO). Ϫ IR (KBr): 1699 (νCϭO) cmϪ1
.
2
Z. Anorg. Allg. Chem. 2005, 631, 2881Ϫ2887
zaac.wiley-vch.de
 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2885

C.-O. Turrin, B. Donnadieu, A.-M. Caminade, J.-P. Majoral
The resulting orange powder was washed with dichloromethane/
pentane 1/5 to give 6b-GЈ0. Crystals of 6b-GЈ0 suitable for X-rays
diffraction were grown at Ϫ30 °C in dichloromethane/pentane.
yield 97 %. Pale orange powder. Ϫ Anal. for C62H48Au2Cl2FeN2-
O8P4S2 (1658 g/mol): calcd. C 44.92, H 2.92, N 1.69 %; found: C
44.95, H 2.92, N 1.64 %.
(1 mm diameter) for cycling voltammetry and a Pt gauze electrode
for bulk electrolysis. E1/2 values were determined as the average
of the cathodic and the anodic peak potentials. The supporting
electrolyte [nBu4N][BF4] (Fluka, electrochemical grade) was used
as received.
Supporting information available. Crystallographic data for the
structure have been deposited with the Cambridge Crystallographic
Data Centre, CCDC 264684. Copies of the data can be obtained
free of charge on application to The Director, CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (Fax: Int.codeϩ(1223)336-033;
e-mail for inquiry: fileserv@ccdc.cam.ac.uk).
1H NMR: δ ϭ 4.40 (br s, 4 H, C2H), 4.59 (br s, 4 H, C3H), 7.22-7.87 (m,
36 H, C6H4, C6H5), 9.96 (s, 4 H, CHO). Ϫ 13C{1H} NMR: δ ϭ 70.4 (dd,
3
2
1JCP3Ј ϭ 124.1 Hz, JCP0 ϭ 4.7 Hz, C1), 74.0 (d, JCPЈ ϭ 14.0 Hz, C2), 75.6
(d, JCPЈ ϭ 11.1 Hz, C3), 121.7 (d, JCP0 ϭ 4.2 Hz, C02), 128.4 (d, JCPЈ
ϭ
3
1
108.1 Hz, CЈ1), 129.0 (d, JCPЈ ϭ 13.3 Hz, CЈ3), 131.5 (s, C03), 131.9
3
(d, JCPЈ ϭ 11.5 Hz, CЈ2), 133.5 (s, C04), 133.7 (s, CЈ4), 155.0 (d, JCP0
ϭ
2
2
10.2 Hz, C01), 190.6 (s, CHO). Ϫ IR (KBr) 345 (νAuCl), 1699 (νCϭO) cmϪ1
.
Acknowledgement. Thanks are due to (the late) Dominique de
Montauzon for the electrochemical measurements, and to the
CNRS for financial support.
Crystal structure determination
6b-GЈ0: C31H24NO4P2ClSFe0.5Au, M ϭ 828.86, crystal size 0.35 x
3
˚
¯
0.23 x 0.14 mm , triclinic, space group P1: a ϭ 9.0366(11) A, b ϭ
˚
˚
c ϭ 14.0156(19) A, Ͱ ϭ 91.556(14)°, β ϭ
3
12.2181(15) A,
˚
References
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Z. Anorg. Allg. Chem. 2005, 631, 2881Ϫ2887
zaac.wiley-vch.de
 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2887