Synthesis, photophysical and nonlinear optical properties of macromolecular architectures featuring octupolar tris(bipyridine) ruthenium(II) moieties: Evidence for a supramolecular self-ordering in a dentritic structure

Article abstract of DOI:10.1021/ja030296j

The synthesis, photophysical and nonlinear optical properties of several new multi-octupolar tris(bipyridine) ruthenium complexes are reported. The preparation on these complexes is based on the initial construction of multipodal 4,4′-dialkylaminostyryl-2,2′-bipyridine ligands (DAAS-bpy). Thermally stable polyimides featuring octupolar ruthenium trisbipyridyl complexes have been readily obtained by a polycondensation reaction. The controlled coordination strategy of dipodal and tripodal bipyridines to ruthenium(II) has also been successfully used to build bimetallic, trimetallic as well as the first metallodendrimer made of seven metallo-octupoles. These polymetallic species exhibit very intense absorption bands in the visible and long-lived luminescence. The quadratic NLO-susceptibilities β of these macromolecules have been characterized by harmonic light scattering at 1.91 μm and compared with those of the corresponding monometallic species. The NLO studies clearly demonstrates a quasi-supramolecular ordering in the metallodendrimer.

Full text of DOI:10.1021/ja030296j

Published on Web 09/16/2003
Synthesis, Photophysical and Nonlinear Optical Properties of
Macromolecular Architectures Featuring Octupolar
Tris(bipyridine) Ruthenium(II) Moieties: Evidence for a
Supramolecular Self-Ordering in a Dentritic Structure
Thomas Le Bouder,† Olivier Maury,† Arnaud Bondon,† Karine Costuas,‡
Edmond Amouyal,§ Isabelle Ledoux,| Joseph Zyss,| and Hubert Le Bozec*,†
Contribution from the Institut de Chimie de Rennes, UMR 6509 and 6511 CNRS-UniVersite´ de
Rennes 1, 35042 Rennes Cedex, France, Laboratoire de Chimie-Physique, UMR 8000
CNRS-UniVersite´ de Paris Sud, 91405 Orsay, France, and Laboratoire de Photonique Quantique
Mole´culaire, Institut d’Alembert IFR 121, UMR 8537 CNRS-ENS Cachan,
61 aVenue du Pre´sident Wilson, 94235 Cachan, France
Received May 16, 2003; E-mail: lebozec@univ-rennes1.fr
Abstract: The synthesis, photophysical and nonlinear optical properties of several new multi-octupolar
tris(bipyridine) ruthenium complexes are reported. The preparation on these complexes is based on the
initial construction of multipodal 4,4′-dialkylaminostyryl-2,2′-bipyridine ligands (DAAS-bpy). Thermally stable
polyimides featuring octupolar ruthenium trisbipyridyl complexes have been readily obtained by a
polycondensation reaction. The controlled coordination strategy of dipodal and tripodal bipyridines to
ruthenium(II) has also been successfully used to build bimetallic, trimetallic as well as the first
metallodendrimer made of seven metallo-octupoles. These polymetallic species exhibit very intense
absorption bands in the visible and long-lived luminescence. The quadratic NLO-susceptibilities â of these
macromolecules have been characterized by harmonic light scattering at 1.91 µm and compared with those
of the corresponding monometallic species. The NLO studies clearly demonstrates a quasi-supramolecular
ordering in the metallodendrimer.
Introduction
polarizability (â) and dipolar moment (µ) values. In addition,
an excellent thermal and chemical stability is required for further
The acentric arrangement of chromophores in molecule-based
materials for second-order nonlinear optics (NLO) is a critical
challenge for device applications.1 In this regard, several
strategies have been intensively investigated, such as statistical
orientation by electrical poling of NLO-polymers2, predeter-
mined orientation of NLO-phores by using the Langmuir-
Blodgett technique3 or stepwise construction of multilayers.4
Typically, the NLO-phores used for such purposes, are dipolar
molecules having the combination of large first-order hyper-
use in optoelectronic devices. To overcome the problems
associated with strong intermolecular interactions between such
high µâ chromophores, a significant breakthrough was recently
achieved by Dalton and co-workers who designed efficient poled
NLO-polymers in which dipole/dipole interactions were mini-
mized by spatial isolation of the NLO-phores either with a
dendritic envelope5 or with the introduction of bulky substitu-
ents.6 An alternative elegant approach to acentric materials
consists of the pre-organization of NLO active species within
a multi-chromophoric dipolar system. Interesting results have
been obtained with bis-chromophoric compounds 7,8,9 and with
the assembly of four dipoles in calix-[4]-arene derivatives.10
† Institut de Chimie de Rennes, UMR 6509 CNRS-Universite´ de
Rennes 1.
‡ Institut de Chimie de Rennes, UMR 6511 CNRS-Universite´ de
Rennes 1.
§ Laboratoire de Chimie-Physique, UMR 8000 CNRS-Universite´ de Paris
Sud.
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| Laboratoire de Photonique Quantique Mole´culaire, UMR 8537 CNRS-
ENS Cachan.
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12284
J. AM. CHEM. SOC. 2003, 125, 12284-12299
10.1021/ja030296j CCC: $25.00 © 2003 American Chemical Society

Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Chart 1
The pre-organization of a larger number of dipoles (from 7 up
to 64) within supermolecules such as â-cyclodextrin11 or
dendrimers12 has also recently been reported and opened the
route to new noncentrosymmetric nano-objects combining very
high molecular hyperpolarizability and huge dipole moment.
Nondipolar (Octupolar) materials would be able to overcome
the problem of intermolecular dipole-dipole interactions.13
However, whereas octupolar nonlinearity has been largely
demonstrated in molecular systems,14 its extension to supramo-
lecular and macromolecular architectures remains a challenge.15
We have previously demonstrated that metal ions can act as
powerful templates for the design of a variety of octupolar
arrangements with large optical nonlinearities.16 Pursuing this
work, we thought to use the wide possibilities offered by the
supramolecular coordination chemistry17 to design multi-octu-
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7875-7883.
polar compounds such as polymetallic complexes, metallo-
dendrimers or metallo-polymers.18
Among the variety of metallo-octupoles studied, tris(dialkyl-
aminostyryl-[2,2′]-bipyridine) zinc(II) or ruthenium(II) com-
plexes exhibit the best tradeoff between NLO activity and
thermal/chemical stability.19 Moreover, ruthenium(II) has the
ability to form heteroleptic complexes upon sequential coordina-
tion of different bipyridyl ligands.20 Therefore, for the design
of multi-octupolar complexes, we sought to apply this concept
which requires the initial construction of multipodal ligands
based on dialkylaminostyryl-[2,2′]-bipyridine (DAASbpy). In
the present paper, we describe the synthesis and characterization
of new polyimide, dipodal and tripodal ligands containing the
DAASbpy moieties. These ligands are good building blocks for
the construction of polymetallic octupolar architectures (dimer,
trimer, heptamer and polymer, Chart 1).21 Their absorption,
emission, and second-order nonlinear optical properties are
discussed in details and compared with those of the correspond-
ing monometallic species. The NLO studies performed at the
near-IR 1.91 µm fundamental wavelength clearly demonstrates
a quasi-supramolecular ordering in the dendrimer made of seven
ruthenium(II) complexes.
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Desce, M. Chem. Eur. J. 2001, 7, 4395-4402.
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P. M.; Meijer, E. W. Chem. Phys. Lett. 1996, 260, 136-141. (b) Yokoyama,
S.; Nakahama, T.; Otomo, A.; Mashiko, S. J. Am. Chem. Soc. 2000, 122,
3174-3181. For other dipole-based dendritic structures whose NLO
properties were not reported see: (c) Peng, Z.; Pan, Y.; Zhang, J. J. Am.
Chem. Soc. 2000, 122, 6619-6623. (d) Wang, J.; Lu, M.; Pan, Y.; Peng,
Z. J. Org. Chem. 2002, 67, 7881-7886. (e) Diez-Barra, E.; Garcia-Martinez,
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C.; Kra¨mer, P.; Matschiner, R.; Wolff, J. J.; Kraft, S.; Treptow, B.; Barbu,
E.; La¨ngle, D.; Go¨rlitz, G. Chem. Eur. J. 1997, 3, 1765-1773. (b) Lambert,
C.; No¨ll, G.; Schma¨lzlin, E.; Meerholz, K.; Bra¨uchle, C. Chem. Eur. J.
1998, 4, 2129-2135. (c) Cho, B. R.; Lee, S. K.; Kim, K. A.; Son, K. N.;
Kang, T. I.; Jeon, S. J. Tetrahedron Lett. 1998, 39, 9205-9208. (d) del
Rey, B.; Keller, U.; Torres, T.; Rojo, G.; Agullo-Lopez, F.; Nonell, S.;
Marti, C.; Brasselet, S.; Ledoux, I.; Zyss, J. J. Am. Chem. Soc. 1998, 120,
12 808-12 817. (e) Lambert, C.; Gaschler, W.; Schma¨lzlin, E.; Meerholz,
K.; Bra¨uchle, C. J. Chem. Soc., Perkin Trans.2 1999, 577-587. (f)
Blanchard-Desce, M.; Baudin, J.-B.; Jullien, L.; Lorne, R.; Ruel, O.;
Brasselet, S.; Zyss, J. Optical Materials 1999, 12, 333-338. (g) McDonagh,
A. M.; Humphrey, M. G.; Samoc, M.; Luther-Davies, B.; Houbrechts, S.;
Wada, T.; Sasabe, H.; Persoons, A. J. Am. Chem. Soc. 1999, 121, 1405-
1406. (h) Andraud, C.; Zabulon, T.; Collet, A.; Zyss, J. Chem. Phys. 1999,
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Commun. 2001, 923-924. (l) Cho, B. R.; Lee, S. J.; Lee, S. H.; Son, K.
H.; Kim, Y. H.; Doo, I.-Y.; Lee, G. J.; Kang, T. I.; Lee, Y. K.; Cho, M.;
Jeon, S.-J. Chem. Mater. 2001, 13, 1438-1440. (m) Cho, B. R.; Park, S.
B.; Lee, S. J.; Son, K. H.; Lee, S. H.; Lee, M.-J.; Yoo, J.; Lee, Y. K.; Lee,
G. J.; Kang, T. I.; Cho, M.; Jeon, S.-J. J. Am. Chem. Soc. 2001, 123, 6421-
6422.
Results and Discussion
I. Synthesis. (a) Main Chain Polyimides Containing
Octupolar Ruthenium(II) NLO-Phores. The first part deals
with the incorporation of tris(dialkylaminostyryl-[2,2′]-bipyridyl)
ruthenium(II) chromophores [alkyl ) ethyl, n-butyl] into a
polyimide backbone.22 Among the large variety of polymers
designed for nonlinear optical purposes, polyimides have
(17) Lehn, J.-M. Supramolecular Chemistry: Concept and PerspectiVe 1st ed.
VCH. Weinheim 1995.
(15) The only supramolecular self-organization examples described in the
literature for octupolar compounds concern crystal engineering or liquid
crystals. For crystal engineering examples, see: (a) Zyss, J.; Brasselet, S.;
Thalladi, V. R.; Desiraju, G. R. J. Chem. Phys. 1998, 109, 658-669. (b)
Thalladi, V. R.; Brasselet, S.; Weiss, H.-C.; Bla¨ser, D.; Katz, A. K.; Carrell,
H. L.; Boese, R.; Zyss, J.; Nangia, A.; Desiraju, G. R. J. Am. Chem. Soc.
1998, 120, 2563-2577. (c) Evans, R.; Lin, W. Acc. Chem. Res. 2002, 35,
511-522. For liquid crystals see: (d) Omenat, A.; Barbera, J.; Serrano, J.
L.; Houbrechts, S.; Persoons, A. AdV. Mater. 1999, 11, 1292-1295. (e)
Kang, S. H.; Kang, Y.-S.; Zin, W.-C.; Olbrechts, G.; Wostyn, K.; Clays,
K.; Persoons, A.; Kim, K. Chem. Commun. 1999, 1661-1662.
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Chem. Soc. 2002, 124, 4561-4562. (b) Renouard, T.; Le Bozec, H.;
Ledoux, I.; Zyss, J. Chem. Commun. 1999, 871-872. (c) Le Bozec, H.;
Renouard, T. Eur. J. Inorg. Chem. 2000, 229-239. (d) Dhenaut, C.; Ledoux,
I.; Samuel, I. D. W.; Zyss, J.; Bourgault, M.; Le Bozec, H. Nature 1995,
374, 339-342.
(18) (a) Schubert, U. S.; Eschbaumer, C. Angew. Chem., Int. Ed. Engl. 2002,
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Ledoux, I.; Zyss, J. Synth. Met. 2001, 124, 185-189.
(20) Treaway, J. A.; Meyer, T. J. Inorg. Chem. 1999, 38, 2267-2278.
(21) For preliminary communications see: (a) Le Bouder; T.; Maury, O.; Le
Bozec; H.; Ledoux, I.; Zyss, J. Chem. Commun. 2001, 2430-2431. (b) Le
Bozec, H.; Le Bouder; T.; Maury, O.; Bondon, A.; Ledoux, I.; Deveau, S.;
Zyss, J. AdV. Mater. 2001, 13, 1677-1681.
(22) For other examples of polymers featuring octupolar chromophores see: (a)
Cherioux, F.; Maillotte, H.; Audebert, P.; Zyss, J. Chem. Commun. 1999,
2083-2084. (b) Cho, B. R.; Chajara, K.; Oh, H. J.; Son, K. H.; Jeon, S.-J.
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9
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A R T I C L E S
Le Bouder et al.
Scheme 1. Synthesis of Monomer. (i) Phthalimide (2eq)/PPh3 (2eq) /DEAD (2eq), THF, Rt, 15h; (ii) N2H4 (10eq) THF, Reflux, 15h
Table 1. Optical and Thermal Properties of Polymer Ligand 5a,b
and Their Precursors 1-4a,b
Scheme 2. Synthesis of Polyimide Ligands 5a-b
a
a
b
compd
λ
max/nm
ꢀ/L.mol-1.cm-1
λ
em/nm
T /°C
d5
1a
1b
3a
3b
4a
4b
5a
5b
397
401
391
400
384
400
388
397
57000
65000
70000
57000
43000
38000
495
497
480
493
499
500
466
472
340
355
374
398
a Measured in dichloromethane. b Decomposition temperature at 5%
weight loss determined by TGA.
received a great deal of attention because of their high thermal
stability and high glass temperature (Tg). NLO polyimides are
generally prepared via a polycondensation reaction of a diamino
functionalized NLO-phore with a dianhydride. Therefore, to
achieve the synthesis of the desired main-chain polyimides, the
preparation of the proper diamino-substituted 4,4′-bis(dialkyl-
aminostyryl)-[2,2′]-bipyridine ligands was undertaken. The
synthesis of the starting dihydroxy functionalized 4,4′-dialkyl-
aminostyryl-[2,2′]-bipyridines 2a and 2b has been previously
reported.23 Treatment of 2a,b with phthalimide under Mitsunobu
conditions (diethyl azodicarboxylate/triphenylphosphine) in THF
at room temperature led to the formation of phthalimido
derivatives 3a,b (Scheme 1). Hydrazinolisis of 3a,b in refluxing
THF afforded the desired diamino-functionalized compounds
4a,b in 94 and 92% yield, respectively.24 All these precursors
were fully characterized by 1H NMR, absorption and emission
spectroscopies, high resolution mass spectrometry and gave
satisfactorily microanalysis. The comparison of their spectro-
scopic data with those of the parent ligands 1a,b25 clearly shows
that the chromophoric structure is not affected during the
reaction pathway (See the Supporting Information and Table
1).
selected hexafluoroisopropylidene diphthalic anhydride (6FDA)
which is known to enhance the polymer solubility with still high
Tg. Polyimides 5a,b were prepared by a two step synthesis
consisting in: (i) a room-temperature polycondensation between
4a,b and 6FDA in 1-methyl-2-pyrolidinone (NMP) followed
by (ii) an in-situ chemical imidization promoted by a pyridine/
acetic anhydride mixture (Scheme 2).26 The resulting brown-
yellow polymers are soluble in chlorinated and in polar solvents
As the choice of the dianhydride monomer has a strong
influence on the solubility of the resulting polymers, we have
(23) Le Bouder, T.; Viau, L.; Gue´gan, J.-P.; Maury, O.; Le Bozec, H. Eur. J.
Org. Chem. 2002, 3024-3033.
(24) (a) Liang, Z.; Dalton, L. R.; Garner, S. M.; Kalluri, S.; Chen, A.; Steier,
W. H. Chem. Mater. 1995, 7, 941-944.
(26) (a) Kenis, P. J. A.; Noordman, O. F. J.; van Hulst, N. F.; Engbersen, J. F.
J.; Reinhoudt, D. N.; Hams, B. H. M.; van der Vorst, C. P. J. M. Chem.
Mater. 1997, 9, 596-601. (b) Yu, D.; Gharavi, A.; Yu, L. J. Am. Chem.
Soc. 1995, 117, 11 680-11 686.
(25) Maury, O.; Gue´gan, J.-P.; Renouard, T.; Hilton, A.; Dupau, P.; Sandon,
N.; Toupet, L.; Le Bozec, H. New J. Chem. 2001, 25, 1553-1566.
9
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Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
the typical polyamic acid vibration band at 1676 cm-1 is not
observed, confirming again their complete conversion into
polyimide. The absorption and emission spectra of 5a,b (Table
1) display broad, intense and structureless intra-ligand charge-
transfer transition (ILCT) at ca. 390 nm (λabs) and 470 nm (λem),
similar to those of the parent ligands 1a,b. Moreover, these
bipyridine-polyimide ligands possess excellent thermal stability
(Table 1) with 5% weight loss occurring above 370 °C. Thermal
analysis by DSC also shows high glass transition temperatures
(Tg) at 210 °C for 5a and 165 °C for 5b (Table 2), as expected
for NLO-polyimides. It is worth noting that the Tg of 5b is
significantly lower than that of 5a (∆Tg ) 45 °C), in agreement
with the more flexible structure of 5b containing butyl linkers.
The sequential coordination ability of bipyridine ligands to
ruthenium(II) has been used to achieve the synthesis of metallo-
polyimides 7a and 7b. Bis(dialkylaminostyryl-[2,2′]-bipyridyl)
dichloro ruthenium complexes (alkyl ) ethyl, 6a ; butyl, 6b)
were first prepared by refluxing RuCl3,3H2O and two equiva-
lents of bipyridine 1a,b in DMF in the presence of lithium
chloride (Scheme 3). Final coordination of polymer ligands 5a,b
with 6a and 6b in refluxing DMF led to the almost quantitative
formation (> 90%) of polymer complexes 7a,b, isolated as their
hexafluorophosphate or tris(tetrachlorobenzendiolato)phosphate
(TRISPHAT)29 salts, respectively (Scheme 3). The use of the
TRISPHAT anion was found to greatly enhance the solubility
of the resulting polymer in chlorinated solvents. The complete
complexation of all bipyridyl units was established on the basis
of H NMR and UV-visible spectroscopy. In the H NMR
spectra, the signals at 8.51 (5a) and 8.53 ppm (5b) assigned to
the H6 protons of the bpy ligand (Figure 1) are upfield shifted
upon complexation. As usually observed, the magnitude of this
shift depends on the nature of the counteranion (∆δ ) 1 ppm
for the PF6 salt 7a, ∆δ ) 0.5 ppm for the TRISPHAT salt 7b).29b
In addition, the UV-visible spectra of the polymer complexes
7a,b display two maxima at 443 and 513 nm, characteristic of
the overlapping ILCT and MLCT transitions respectively in the
tris(dialkylaminostyryl-[2,2′]-bipyridyl))ruthenium (II) com-
plexes (vide supra). No shoulder at ca. 390 nm corresponding
to the absorption maxima of the free polymer ligands 5a,b could
be observed, confirming the complete coordination of all
bipyridyl subunits. In addition, it is worth noting that this new
metallo-polymers displays very high thermal stability with Td5
) 350 °C and 358 °C for 7a and 7b, respectively.
1
Figure 1. Aromatic part of the H NMR spectra of polyimides 5a,b.
Table 2. Molecular Weights and Glass Transition Temperature of
Polyimides 5a-b
polymer
Mw/Da
Mn/Da
PDI
N
T /°C
g
5a
5b
9300
19300
6600
14100
1.40
1.37
7
14
210
165
(CH2Cl2, THF, DMF, NMP). Gel permeation chromatography
in THF (polystyrene as standard) gave relatively low molecular
weights, indicating an average of ca. 7 and 14 bipyridyl units
in 5a and 5b, respectively (Table 2). This difference can be
explained by the enhanced solubility of monomer 4b featuring
butyl groups as compared to that of 4a featuring ethyl end
groups.
Both polymers were fully characterized by 1H and 19F NMR,
FTIR, absorption and emission spectroscopies, and elemental
analysis. Their H NMR spectra (the aromatic part is depicted
in Figure 1) displays two types of signals. The characteristic
peaks of the dialkylaminostyryl-[2,2′]-bipyridine moieties, as-
signed by analogy with the model chromophores 1a-b,25 clearly
indicate that the chromophoric structure remains intact in the
polymer. For example, the trans conformation of the styryl
double bands is clearly established by the 3J coupling constant
(JCHdCH ) 16.1 Hz). In addition, the spectrum exhibits a second
set of signals between 7.6 and 8 ppm, which can be assigned
to the aromatic protons Ha,b,c of the phthalimide moieties. The
absence of downfield signal corresponding to the polyamic acid
proton suggests that the imidization led to completion. More-
over, the aliphatic methylene protons connected to the amino
group in 4a,b (2.92 and 2.72 ppm, respectively) are downfield
shifted to 3.86 and 3.69 ppm in the polymer 5a,b indicating
the complete transformation of the amino into imido functions
during the polymerization process.27
1
1
1
(b) Controlled Polyoctupolar Architecture. In contrast to
polyimides, metallo-dendrimers possess a discrete and well-
controlled architecture. These macromolecules can be considered
as an ordered ensemble of monomeric building blocks and their
geometry can be predetermined by the nature of the connectivity.
For that purpose we have designed multipodal ligands containing
two (dipod) or three (tripod) dialkylaminostyryl-[2,2′]-bipyridine
chromophores, precursors to poly-octupoles based on tris-
(bipyridyl)ruthenium units.
Dipod (8) and tripod (9) ligands were readily prepared by a
nucleophilic substitution between monohydroxy functionalized
4,4′-bis(dialkylaminostyryl)-[2,2′]-bipyridine 2c23 and R,R′-
dibromo-p-xylene and 2,4,6-tris(bromomethyl)mesitylene, re-
spectively, in the presence of sodium hydride in DMF (Scheme
The FTIR spectra of polyimides 5a,b exhibit two character-
istic νCdO vibration bands at ca. 1780 and 1720 cm-1 and one
corresponding to the polyimide ring at 740 cm-1 28
. In addition,
(27) These chemical shifts are similar to those of the phthalimide functionalized
bipyridine intermediates, i.e. 3.88 and 3.71 ppm for 3a and b, respectively.
In addition such 0.9 ppm shift has already been described by Kenis et al.,
see ref (26a).
(28) Perry, R. J. R.; Tunney, S. E.; Wilson, B. D. Macromolecules 1996, 29,
1014-1020.
(29) (a) Lacour, J.; Glinglinger, C.; Grivet, C.; Bernardelli,G. Angew. Chem.,
Int. Ed. Engl. 1997, 36, 608-610. (b) Maury, O.; Lacour, J.; Le Bozec, H.
Eur. J. Inorg. Chem. 2001, 201-204 and references therein.
9
J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003 12287

A R T I C L E S
Le Bouder et al.
Scheme 3. Synthesis of Polyimide Complexes 7a-b
4). Both multipodal ligands were fully characterized by 1H, 13
C
complexes and allows their purification by silica gel column
chromatography with dichloromethane as eluent.
NMR, UV-visible spectroscopy, high-resolution mass spec-
1
trometry and elemental microanalysis. Their H NMR spectra
Both complexes were characterized by NMR spectroscopy
and gave satisfactorily elemental analysis. Unfortunately, mass
spectrometry measurements did not allow the determination of
the molecular ion exact mass and only fragmentations were
observed (see the Experimental section). However, their struc-
tures could be confirmed by 1H and 13C NMR, by using COSY
experiments for the determination of proton connectivities and
HMBC and HMQC sequences for the assignment of C-H and
quaternary carbons, respectively. Despite the presence of many
possible diastereoisomers, owing to the chiral nature (Λ and
∆) of (bipy)3Ru2+ and TRISPHAT-, the NMR spectra of 11
and 12 show only one set of signals. The simplicity of the NMR
spectra can be explained by (i) the homochiral self-assembling
between racemic (1a)3Ru(II) 10 and TRISPHAT ions;29b and
(ii) the length of the spacer and thus the large distance between
the chiral metal centers.30 The complete coordination was clearly
exhibit typical signals assigned to the bipyridyl units and to
the central core, with for example characteristic benzylic (8,
δCH2 ) 4.48 ppm; 9, δCH2 ) 4.53 ppm) and mesitylenic (9,
δCH3 ) 2.36 ppm) protons. The 13C NMR spectra (Table 3 and
the Experimental Section) clearly indicate the unsymmetrical
nature of these ligands with two and three sets of signals for
the styryl moieties (C4-C12/C4′-C12′, Table 3) and dialkylamino
fragments (C13,C14/C13′,C14′/C13”,C14”), respectively. FAB-mass
spectrometry shows weak peaks corresponding to the molecular
ions and strong peaks due to fragmentations of the alkyl amino
ether link. The UV-visible spectra of 8 and 9 exhibit classical
ILCT transitions centered at 395 nm (Table 4). The oscillator
strengths follow a 1/1.9/2.7 ratio for 2c, 8, 9, respectively, as
expected for non interacting sub-chromophores (1/2/3).14b,e
Reaction of (1a)2RuCl2 6a with dipod 8 and tripod 9 in
refluxing DMF led to the formation of deep red bimetallic
(dimer 11) and trimetallic (trimer 12) complexes, after precipita-
tion as their TRISPHAT salts (Figures 2 and 3). As for polymer
7b, this anion greatly enhances the solubility of the polymetallic
(30) (a) Ishow, E.; Gourdon, A.; Launay, J.-P.; Chiorboli, C.; Scandola, F. Inorg.
Chem. 1999, 38, 1504-1510. (b) Wa¨rnmark, K.; Baxter, P. N. W.; Lehn,
J.-M. Chem. Commun. 1999, 993-994. (c) Kaes, C.; Hosseini, M. W.; De
Cian, A.; Fischer, J. Tetrahedron Lett. 1997, 38, 3901-3904.
9
12288 J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003

Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Scheme 4. Synthesis of Polypyridyl Ligands 8 and 9, (i) NaH, DMF, R,R′-dibromo-p-xylene, (94%); (i) NaH, DMF,
2,4,6-(tribromomethyl)Mesitylene, (96%)
established by the quantitative 0.5 ppm upfield shift of the
resonance signal corresponding to the H6 protons and by 2/1
and 3/1 integration ratio between the H3 and benzylic H15 proton
signals 11 and 12, respectively. The 13C NMR spectra of
monomer 10, dimer 11 and trimer 12 are very similar with
chemical shift variations that do not exceed 0.1 ppm (Table 3).
Note that the 13C NMR signals are broader in the complexes as
compared to those of free ligands, resulting in the overlap of
signals belonging to the external bipyridine 1a and to the
multipodal ligands.
have applied this concept to design the first generation dendritic
architecture featuring seven metallo-octupoles. The synthesis
started with the preparation of the “metal as ligand” core [Ru-
(9)3][TRISPHAT]2 13 by mixing RuCl2(DMSO)4 with three
equivalents of tripod 9 in refluxing DMF (Figure 4).
Side reactions such as the formation of bi- and tri-metallic
compounds did not occurred since thin-layers chromatography
did not reveal the presence of any free ligand. Such behavior
has already been described for the synthesis of other “metal as
ligand” core like [Ru(dpp)3]2+ (dpp ) bis(2-pyridyl)-pyrazine)
reported by Denti, Campagna, Balzani and co-workers.32,33 NMR
Multipodal bipyridyl ligands are well-known building blocks
for the design of metallodendrimers with higher nuclearity18b,c
and the “metal as ligand”/”metal as complex” approach is an
elegant strategy for the synthesis of such supramolecules.31 We
(32) (a) Denti, G.; Campagna, S.; Serroni, S.; Ciano, M.; Balzani, V. J. Am.
Chem. Soc. 1992, 114, 2944-2950. (b) Serroni, S.; Denti, G.; Campagna,
S.; Juris, A.; Ciano, M.; Balzani, V. Angew. Chem., Int. Ed. Engl. 1992,
31, 1493-1495.
(33) In addition, the formation of mer and fac isomers can be envisaged on the
basis of molecular mechanics simulation. No difference between these
isomers could been detected by means of NMR spectroscopy.
(31) Balzani, V.; Campagna, S.; Denti, G.; Juris, A.; Serroni, S.; Venturi, M.
Acc. Chem. Res. 1998, 31, 26-34.
9
J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003 12289

A R T I C L E S
Le Bouder et al.
Table 3. Atom Numbering and 13C NMR Data of
Compounds 9-14
resonance signals, confirming the structure of 13. Further
evidence is given by the UV-visible spectrum (Figure 6) which
exhibits a strong transition band of free chromophores (λ )
400 nm) and the characteristic [(1a)3Ru]2+ spectra (λmax ) 518
nm).
Finally, reaction of 13 with six equivalents of 6a in refluxing
DMF, followed by anionic exchange from chloride to TRISPHAT
anion, led to the formation of the heptamer 14 in 91% yield
(Figure 7). It is worth noting that this 14 cationic charged
molecule was purified by chromatography column (silica gel-
dichloromethane/methanol as eluent), thanks to the strong ion-
pairing effect induced by the TRISPHAT anion. This reaction
was monitored by UV-visible spectroscopy (Figure 6), clearly
showing the disappearance of the 400 nm transition of the free
bipyridyl ligand. The final spectrum is similar to that of
[(1a)3Ru]2+ with a very broad, intense band (up to 690 000 L
mol-1 cm-1) with two maxima at 444 and 506 nm due to the
overlapping ILCT and MLCT transitions (Table 4).
carbona
(f or c)
tripod
9
momomerb trimerb
10 12
heptamerb
14
13
f
f
f
f
f
f
f
f
2
3
4-4′
5
156.81
117.86
146.99-146.90
120.60
156.70
117.86
147.01-146.91
120.64
149.64
120.97
133.82
123.59
6
149.67
7-7′
8-8′
9-9′
121.28-120.97
133.78-133.68
124.08-123.68
f
f
f
10-10′ 128.95-128-92
128.95
112.02-111.86
148.75-148.68
1H NMR signals of 14 are relatively broad, but integration
ratio between H3 and either benzylic H15 or mesitylenic H18
protons can be estimated to 2.32 (th. 2.33) and 1.47 (th. 1.55)
respectively, confirming the heptametallic stoechiometry. 13C
NMR spectrum (Figure 8 and Table 3) is similar to those of
10, 11, and 12; all the signals corresponding to the free bipyridyl
ligands have disappeared. In addition, the elemental analysis
shows that 14 precipitates with fourteen molecules of dichlo-
romethane, a ratio confirmed by the integration of the solvent
11-11′ 112.02-111.87
12-12′ 148.73-148.67
c
c
c
c
c
c
c
c
c
c
c
2
3
4
5
6
7
8
9
157.29 157.36 157.27
120.03 120.21 120.10
147.42 147.55 147.47
122.61 122.72 122.47
151.37 151.11 151.18
117.67 117.78 (-)
136.73 136.92 136.84
122.87 122.95 122.78
129.79 129.81 129.76
111.76 110.93 (-)
149.43 149.39 (-)
50.53 50.59
157.30
120.13
147.46
122.63
151.36
117.69
136.61
(-)
129.81
111.76
149.44
50.59
44.85
45.82
68.67
12.41
12.84
68.67
138.36
133.08
15.94
10
11
12
1
peak in the H NMR spectrum.
f/c 13
f/c 13′
f/c 13′′
f/c 14
f/c 14′′
f/c 14′
f/c 15
f/c 16
f/c 17
f/c 18
50.59
44.78
45.88
68.62
12.38
12.80
68.38
138.40
133.17
15.94
II. Physical Properties
44.85
44.83 44.77
45.84 45.87
68.42 68.36
12.40 12.39
12.84 12.81
68.65 68.61
138.37 138.41
133.10 133.02
15.92 15.94
(a) Photophysical Properties. Substantial attention is cur-
rently devoted to polynuclear complexes and supramolecular
architectures that are capable to absorb visible light and to
luminesce in solution at room temperature in view of their
potential utilization in many domains such as molecular
electronics and artificial photosynthesis.34 Of particular interest
are the dendritic structures based on ruthenium complexes of
polypyridine-type ligands.18,35 To examine the potential influ-
ence of dendritic structure on the photophysical behavior of the
trimer 12 and the heptamer 14, we have determined their
emission properties in tetrahydrofuran (THF) or methyltetrahy-
drofuran (MTHF) solutions, using the monomer 10 and [Ru-
(bpy)3]2+ as references. As observed for the polyimide com-
pounds 7b, the electronic absorption spectra of compounds 10,
12, and 14 (Figure 9, Table 4) exhibit in the visible region a
band with two maxima at about 440 and 510 nm (442 and 519
nm for the monomer in MTHF) attributed to ILCT and MLCT
transitions, respectively. Whatever the excitation wavelength in
the 300-600 nm range, the three compounds present a very
similar emission spectrum with a maximum at the same
12.81
a f ) carbon belonging to free ligand; c ) carbon belonging to
coordinated ligand. b Carbon belonging to the TRISPHAT anion are omitted
for clarity.
Table 4. Spectroscopic, Photophysical and Thermal Properties of
Multipodal Ligands and Corresponding Complexes
λ
abs/nm
(ꢀ/L.mol-1.cm-1 a
τ/µs d
T /°C
c
b
compd
2c
dipod8
tripod9
monomer
10
dimer
11
trimer
12
)
λem/nm
φem
d5
389 (43000)
395 (90000)
396 (130000)
447 (146000)
520 (143000)
440 (258000)
511 (239000)
443 (379000)
511 (354000)
444 (693000)
506 (648000)
496a
497a
498a
708c
325
366
348
365
4.15 × 10-3
5.15
325
328
321
708c
708c
2.60 × 10-3
1.85 × 10-3
4.14
3.08
heptamer
14
(34) (a) Meyer, T. J. Acc. Chem. Res. 1989, 22, 163-170. (b) Balzani, V.;
Scandola, F. Supramolecular Photochemistry, Ellis Horwood, New York,
1991. (c) Sauvage, J. P.; Collin, J. P.; Chambron, J. C.; Guillerez, S.;
Coudret, C.; Balzani, V.; Barigelletti, F.; De Cola, L.; Flamigni, L. Chem.
ReV. 1994, 94, 993-1019. (d) Amouyal, E. Sol. Energy Mater. Sol. Cells
1995, 38, 249-276. (e) Amouyal, E. in Homogeneous Photocatalysis,
Chanon, M. Ed., J. Wiley, Chichester, chapter 8, 1997; pp 263-307. (f)
Konstantaki, M.; Koudoumas, E.; Couris, S.; Laine´, P.; Amouyal, E.; Leach,
S. J. Phys. Chem. B 2001, 105, 10 797-10 804.
(35) (a) Balzani, V.; Juris, A.; Venturi, M.; Campagna, S.; Serroni, S. Chem.
ReV. 1996, 96, 759-833. (b) Newkome, G. R.; Patri, A. K.; Godinez, L.
A. Chem. Eur. J. 1999, 5, 1445-1451 (c) Balzani, V.; Ceroni, P.; Juris,
A.; Venturi, M.; Campagna, S.; Puntoriero, F.; Serroni, S. Coord. Chem.
ReV. 2001, 219-221, 545-572.
a Measured in dichloromethane. b Decomposition temperature at 5%
weight loss. c In MTHF. d In THF.
spectra (1H and 13C) exhibit the characteristic resonance signals
of coordinated and free dialkylaminostyryl-[2,2′]-bipyridine
(Table 3). Moreover, in the H NMR spectrum (Figure 5), an
integration ratio of 0.65 (th. 0.66) between H6f and H3f+H3c
1
can be estimated after deconvolution of the corresponding
9
12290 J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003

Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Figure 2. Chemical structure of bimetallic complex 11.
wavelength i.e., 708 nm and a shoulder at about 780 nm more
pronounced for the trimer 12 and the heptamer 14. The
luminescence excitation spectra, monitored at 708 nm, parallel
the absorption spectra recorded over the visible region (maxima
at 440 and 520 nm for 10, 438 and 522 nm for 12, 442 and 518
nm for 14 in MTHF), indicating that the observed emissions
are clearly due to the Ru sites. The value of 708 nm (14 120
cm-1) for the emission maximum corresponds to a bathochromic
shift of 2380 cm-1 with respect to [Ru(bpy)3]2+. This shift is
similar to that obtained for the absorption spectra. By analogy
with [Ru(bpy)3]2+, we assign the luminescence of compounds
10, 12, and 14 to MLCT triplet states. The luminescence
quantum yields φem determined for 12 and 14 are slightly lower
than that for the monomer 10 and decrease as the number of
metallic sites (N) increases (Table 4). The same trend is observed
for the luminescence lifetimes τ (Table 4). As the energy of
the excited triplet state (estimated from the maximum of the
emission spectra) for the three compounds is nearly the same,
the lowering of φem and τ, by a factor 2 in going from the
mononuclear to the heptanuclear complex, is probably due to
the increase with N of nonradiative deactivation processes rather
than to the quenching of the emitting triplet state by a metal-
centered excited state located at higher energy, as usually put
forward for polypyridine Ru complexes. In other words, and as
also stressed by the similarity of the excitation spectra, the
octahedral geometry around the metal sites is probably not
distorted by the dendritic structure. It should be emphasized
that the excited-state lifetime of 5.15 µs determined for the
monomer in THF is very long and more than five times greater
than that observed for [Ru(bpy)3]2+ (930 ns in THF). This can
be explained by the presence of the diethylaminostyryl conju-
gated substituents on bipyridine which extend the electronic
delocalization over the entire DEASbpy ligand.36 What is also
remarkable for homometallic polynuclear complexes such as
12 and 14 is that their excited-state lifetime remains very long
(4.14 and 3.08 µs, respectively; Table 4).35a,37 This result offers
interesting perspectives for the study of the photochemical
(36) Strouse, G. F.; Schoonover, J. R.; Duesing, R.; Boyde, S.; Jones W. E.,
Jr.; Meyer, T. J. Inorg. Chem. 1995, 34, 473-487.
(37) De Cola, L.; Belser, P. Coord. Chem. ReV. 1998, 177, 301-346.
9
J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003 12291

A R T I C L E S
Le Bouder et al.
Figure 3. Chemical structure of trimetallic complex 12.
reactivity of this kind of dendrimerssfor example as potential
multielectron-transfer elementssand for many applications. In
particular, besides the NLO properties of these multi-octupolar
compounds (vide infra), their long 3MLCT lifetimes associated
with a better overlapping of their absorption spectra with the
solar spectrum as compared to [Ru(bpy)3]2+ (red-shift of about
70 nm) make these complexes good candidates as components
of model systems for photochemical and photoelectrochemical
conversion of solar energy.
leading to overestimation of hyperpolarizability values.39 In the
case of monomer 10, previously uncorrected measurements at
λ ) 1.34 µm for the fundamental wavelength provided a â1.34
value of 2200 × 10-30 esu.16d Improvements in the harmonic
filtering system allowed to reduce the parasite fluorescence
emission, thus yielding a corrected â1.34 value of 1130 × 10-30
esu.19 The difference between uncorrected and corrected values
confirms the importance of the multiphoton fluorescence
contribution. New â measurements at the infrared shifted λ )
1.91 µm fundamental wavelength were performed as the second
harmonic wavelength at 955 nm lies in the transparency region
of the chromophores, then making any contribution from two-
photon fluorescence to HLS signal quite negligible. Indeed, â1.91
) 320 × 10-30 esu for 10 (Table 5) is far below the â value
inferred from HLS measurements at 1.34 µm, then confirming
the large two-photon fluorescence contribution to the HLS signal
(b) NLO Properties. As EFISH experiment, which requires
dipoles orientation in solution, is precluded for purely octupolar
molecules, Harmonic Light Scattering38 (HLS) technique was
used for the molecular hyperpolarizability (â) measurements.
Two-photon-induced fluorescence may significantly affects HLS
2+
measurements of Ru(bpy)3 derivatives in the visible range,
(38) (a) Terhune, R. W.; Maker, P. D.; Savage, C. M. Phys. ReV. Lett. 1965,
14, 681-684. (b) Clays, K.; Persoons, A. Phys. ReV. Lett. 1991, 66, 2980-
2983.
(39) Morrison, I. D.; Denning, R. G.; Laidlaw, W. M.; Stammers, M. A. ReV.
Sci. Instrum. 1996, 67, 1445-1453.
9
12292 J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003

Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Figure 4. Chemical structure of [(tripod)3Ru][TRISPHAT]2 13.
in the visible range. Therefore, the â1.91 values reported herein
can be considered as a fluorescence-free.
tris-(4′-(di-4-methoxyphenyl)aminophenylethynyl)truxen-
xxx
one14b [λmax ) 509 nm, â0 ) 169 × 10-30 esu, â0 ) 104 ×
10-30 esu].
Calculation of the static â0 value of monomer 10 is difficult
as the two ILCT and MLCT transitions may contribute to the
first hyperpolarizability.40 Nevertheless, it can be roughly
estimated from the two levels model using the more red-shifted
transition.41 It is worth noting that this underestimated value of
208 × 10-30 esu still remains very large, in the same order of
magnitude as the analogous zinc complex [λmax ) 466 nm, â1.91
) 340 × 10-30 esu, â0 ) 241 × 10-30 esu].16a It is significantly
higher than those of the most efficient organic chromophores
such as 1,3,5-triscyano-2,4,6-tris(dibutylaminobistyryl)benzene14l,m
[λmax ) 470 nm, â1.56 ) 219 × 10-30esu, â0 ) 116 × 10-30esu],
1,3,5-tris(methylsulfonylbistyryl)benzene14k [λmax ) 377 nm,
â1.34 ) 250 × 10-30 esu, â0 ) 157 × 10-30 esu] and 4,9,14-
The â1.91 values of multimetallic species 7, 11, 12, and 14
can be rigorously compared to that of 10 because (i) all these
species exhibit very similar absorption spectra (vide supra) and
(ii) all the HLS measurements were performed under similar
monomer concentration in dichloromethane solution. Table 5
summarizes the NLO data for the whole family of complexes
featuring from 1 to 14 octupolar elementary building-blocks.
The NLO activity increases from monomer to dimer (N ) 2),
trimer (N ) 3) and heptamer (N ) 7), but decreases from
heptamer to polymer (N ) 14). The â0 value of heptamer 14
(1271 × 10-30 esu) is the highest ever measured for an octupolar
compound and within the same range as that of the most efficient
dipolar polyenic molecule [λmax ) 826 nm, â0 ) 1470 × 10-30
esu].42 However, it still remains significantly lower than the â
value of a recently reported multichromophoric dipolar dendron
made of 15 azobenzene NLO-phores [λmax ) 475 nm, â0 )
3857 × 10-30 esu].12b
(40) For an evaluation to the contribution of each transition to the total NLO-
activity of 10 see: Vance, F. W.; Hupp, J. T. J. Am. Chem. Soc. 1999,
121, 4047-4053.
(41) The two levels model allows the determination of nonresonant molecular
2
2
hyperpolarizability â0 according to â0/â ) (ωmax - ω2)(ωmax - 4ω2)/
4
ωmax
,
where ω is the frequency of the incident photon and ωmax is the
absorption maximum frequency of the studied molecule. Oudar, J. L. J.
Chem. Phys. 1977, 67, 446-457.
9
J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003 12293

A R T I C L E S
Le Bouder et al.
Figure 5. 1H NMR spectrum (500 MHz, CD2Cl2, 298 K) of complex 13 with deconvolution of the signals assigned to H6c and H3c + H3f.
containing nsupra.N monomers, and the corresponding HLS
intensity is given by then
I
2ω ) G nsupra â2
) G. nsupra. N â(1)2
(2)
(3)
supra
x
N
â
supra(N)/â(1) )
where â(1) is the monomer (N ) 1) first hyperpolarizability.
The increase of âsupra(N) is simply the result of a concentration
effect. Figure 10 plots the ratio âsupra(N)/â(1) as a function of
the subunits number N. It appears clearly that polymer 7b (N
≈ 14) fits perfectly with eq 3; the experimental hyperpolariz-
ability ratio is about 4.0 very close to the theoretical value
x
14 ) 3.7. Such agreement accounts for the fully disordered
assembly of monomeric ruthenium building blocks in the linear
Figure 6. UV-visible monitoring for the synthesis of heptamer 14.
polymeric chain.
The HRS intensity of a supramolecular architecture containing
N monomeric subunits I2ω(N) is given by the eq 1
A totally different behavior is observed for the heptamer 14
(N ) 7) which exhibits a giant first hyperpolarizability of â1.91
-
2
I2ω(N)/I2ω(ref) ) G.[ns. âs2 + nsupra. âsupra
]
(1)
(7) ) 1900 × 10-30 esu, although containing half the number
of monomeric subunits as compared to 7b. In that case, the
first hyperpolarizability satisfactorily fits with a linear relation-
ship (4), as illustrated by Table 5 and Figure 10
where I2ω(ref) is the second harmonic intensity of a reference
compound (NPP, see Supporting Information), ns and nsupra are
the mole number of solvent and solute respectively, âs and âsupra
2
their first hyperpolarizability tensor, ‚âs,
refer to the
â
supra(N)/â(1) ) N
(4)
supra
orientational average of the âs, supraXâs, supra, tensor product and
G is a proportionality constant. In the following, â is defined
Such quasi-linear dependence is the signature of a quasi-
optimized ordering of the individual building blocks in the
heptamer. In this configuration, the HLS intensity can be
expressed as
as â2 ; owing to the high concentrations and large hyperpo-
x
larizability values of our molecules, the HLS contribution from
the pure solvent can be neglected. When the supramolecule is
made of N fully disordered monomers, the solution containing
nsupra molecules can be considered as a disordered medium
I
2ω ) G nsupra â2
) G. nsupra (Nâ(1))2
(5)
supra
(42) Blanchard-Desce, M.; Alain, V.; Bedworth, P. V.; Marder, S. R.; Fort, A.;
Runser, C.; Barzoukas, M.; Lebus, S.; Wortmann, R. Chem. Eur. J. 1997,
3, 1091-1104.
This means that in a highly ordered dendritic architecture, each
monomeric subunits coherently contributes to the HLS response.
9
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Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Figure 7. Chemical structure of the heptamer 14.
Figure 8. 13C NMR spectrum of heptamer 14 in CD2Cl2 at 298 K.
In the cases of dimer 11 and trimer 12, the experimental ratio
â(2)/â(1) ) 1.8 and â(3)/â(1) ) 2.2 are intermediates between
the two relationships described by equations (3) and (4).
However, the uncertainty inherent to HLS measurements ((
20%) precludes the possibility to draw any firm conclusion as
to supramolecular ordering in 11 and 12.
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Le Bouder et al.
first example of supramolecular octupolar self-ordering within
a dendritic architecture.45
Conclusions
The present results show that coordination chemistry can be
a useful tool for the design of molecular materials for nonlinear
optics by combining bipyridyl ligands with ruthenium(II). The
ability to substitute the pyridine rings with functional groups
offers the possibility of incorporating octupolar NLO-phores
into polymers. Thus, thermally stable polyimides featuring
octupolar ruthenium trisbipyridyl complexes can be readily
obtained by a polycondensation reaction. The controlled coor-
dination strategy of bipyridines to Ru(II) has also been suc-
cessfully used to build supramolecules such as the first
metallodendrimer made of seven metallo-octupoles. These
polymetallic species exhibit very intense absorption bands in
the visible and long-lived luminescence which make them good
candidates as components of model systems for photochemical
and photoelectrochemical conversion of solar energy. The
quadratic NLO-susceptibilities â of these macromolecules have
been characterized by harmonic light scattering at 1.91 µm in
order to rule out any two-photon fluorescence contribution to
the harmonic signal. A comparison with the fully disordered
NLO-polyimide provides clear evidence of a quasi-optimized
octupolar ordering in the metallodendrimer. The next challenge
is the macroscopic (bulk) noncentrosymmetric organization of
these chromophores. Because electric-field poling is not ap-
plicable due to the absence of permanent dipole moment, optical
poling has to be explored to tackle this problem.46 The
construction and control of nanosized objects with the goal of
miniaturizing photonic devices is another major challenge. The
results described in this paper are very promising and open new
perspectives toward nanoscale photonic applications.
Figure 9. UV-visible spectra of poly-octupolar containing complexes.
Table 5. Nonlinear Optical Properties of the Poly Octupolar
Complexes
xN
compd
â /10-30 esua
â(N)/â(1)
N
monomer10
dimer11
trimer12
heptamer14
polymer7b
320
570
700
1900
1300
1
1
2
3
7
14
1
1.8
2.2
5.9
4.1
1.41
1.73
2.65
3.74
a Measured by HLS at 1.91 µm (precision ( 20%). Correlation between
esu and SI units: â(SI) ) 4.172 × 10-10 â(esu)
Experimental Section
Polyimide Ligand 5a. To a solution of 4a (500 mg, 0.94 mmol) in
1-methyl-2-pyrrolidinone (NMP, 6 mL) was added dropwise a NMP
solution (4 mL) of 6FDA (416 mg, 0.94 mmol) at 0 °C. The mixture
was then stirred for 2 days at room temperature. After further addition
of pyridine (1.25 mL, 34 mmol) and acetic anhydride (3.25 mL, 34
mmol), the solution was heated overnight at 60 °C. The solution was
then cooled to room temperature and added dropwise in diethyl ether
(200 mL) under vigorous stirring. The resulting precipitate was filtered
off and recrystallized twice from dichloromethane (10 mL)-diethyl ether
(200 mL). After filtration, the resulting yellow solid was dried under
vacuum (690 mg, 82%). 1H NMR (200.13 MHz, CD2Cl2) δ : 8.51 (m
br, 2H, H6); 8.45 (s br, 2H, H3); 7.78 (m, 2H, H6FDA); 7.75 (m, 4H,
Figure 10. Plot of the ratio âsupra(N)/â(1) vs. N.
A similar linear variation (eq 3) has already been described
by Yokoyama and co-workers for dipolar NLO-phores included
in a cone-shape dipolar dendritic architecture.12b We report here
the generalization of such behavior in the case of D3 octupolar
NLO-phores included in a dendritic architecture featuring the
same D3 global symmetry. To illustrate the supramolecular D3
ordering, computer modeling of 14 was carried out on the basis
of molecular mechanics calculation (MMF94). Projection of the
heptamer structure along its C3 axis (Figure 11) clearly suggests
octupolar 3-fold symmetry at the supramolecular level. This
fairly agrees with a recent STM imaging and molecular
mechanics calculations on a heptanuclear ruthenium dendrimer.43
Such octupolar arrangement of octupolar subunits is the optimal
octupolar order and results in coherent second harmonic
emission from each individual building-blocks (eq 3).44 These
supramolecular order was first illustrated by crystal engineering
of functionalized triazines, but no clear NLO evidence was
given.15a To the best of our knowledge the present study is the
H6FDA); 7.40-7.20 (m, 8H, H5,8,10); 6.87 (d br, J ) 16.2 Hz, 2H, H7);
6.76 (d br, J ) 8.8 Hz, 4H, H11); 3.86 (m br, 4H, H14); 3.58 (m br, 4H,
H13); 3.40 (m br, 4H, H13′); 1.16 (m br, 6H, H14′); 19F NMR (CD2Cl2)
δ : - 63.9 (s); IR (KBr) ν (cm-1): 1778, 1718, 744; UV-visible
(CH2Cl2): λmax ) 388 nm; emission (CH2Cl2): λem ) 466 nm; TGA:
Td5 ) 374 °C; DSC analysis: Tg ) 210 °C; elemental analysis calcd
(%) for [C53H42N6O4F6.1 CH2Cl2]n: C 63.22, H 4.32, N: 8.19; found:
C 62.91, H 4.36, N 8.05.
(45) Examples of macromolecular architectures with octupolar symmetry, such
as molecularly bridged gold nanoparticules (Novak, J. P.; Brousseau, L.
C.; Vance, F. W.; Johnson, R. C.; Lemon, B. I.; Hupp, J. P.; Feldheim, D.
L. J. Am. Chem. Soc. 2000, 122, 12 029-12 030) and Bacteriorhodopsin
trimers in purple membrane suspensions (Hendricks, E.; Vinckier, A.; Clays,
K.; Persoons, A. J. Phys. Chem. 1996, 100, 19 672-19 680) have recently
been reported. However these macromolecules do not feature octupolar
subunits.
(43) Latterini, L.; Pourtois, G.; Moucheron, C.; Lazzaroni, R.; Bre´das, J.-L.;
Kirsch-De Mesmaeker, A.; De Schryver, F. C. Chem. Eur. J. 2000, 6,
1331-1335.
(44) Zyss, J. “Hypercubic octupolar molecular crystals for quadratic nonlinear
optics”, Conference on Lasers and Electrooptics (CLEO) 2000, paper
CM15, p 47.
(46) Piron, R.; Toussaere, E.; Josse, D.; Brasselet, S.; Zyss, J. Synth. Met. 2000,
115, 109-119.
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Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
Figure 11. Molecular mechanics representation of one possible isomer of heptamer 14.
Polyimide Ligand 5b. Following the previous procedure, polymer
5b was isolated as a yellow-orange powder (405 mg, 75%) from 4b
(350 mg, 0.54 mmol). 1H NMR (200.13 MHz, CD2Cl2) δ: 8.53 (d br,
J ) 5 Hz, 2H, H6); 8.46 (s br, 2H, H3 ; 7.85 (m, 2H, H6FDA); 7.77 (m,
4H, H6FDA); 7.40-7.29 (m, 8H, H5,8,10); 6.86 (d br, J ) 16.2 Hz, 2H,
H7); 6.61 (d, J ) 8.9 Hz, 4H, H11); 3.69 (m br, 4H, H16); 3.31 (m br,
8H, H13,13′); 1.78-1.42 (m, 12H, H14,14′,15); 1.40-1.18 (m, 4H, H15′);
0.91 (t br, J ) 7 Hz, 6H, H16′); RMN 19F (CD2Cl2) δ: - 63.9 (s); IR
(KBr) ν (cm-1): 1777, 1718, 743;UV-visible (CH2Cl2); λmax ) 401
nm; emission (CH2Cl2): λem ) 472 nm; TGA: Td5 ) 398 °C; DSC
analysis: Tg ) 165 °C; elemental analysis calcd (%) for [C57H50N6O4-
F6.1.5 CH2Cl2]n: C 62.49, H 4.75, N: 7.47; found: C 62.44, H 5.31,
N 6.78.
Polyimide Complex 7a. In a Schlenk flask, a DMF (12 mL) solution
of 4b (400 mg, 0.42 mmol) and 6a (500 mg, 0.42 mmol) was heated
under reflux for 6h. The dark-red solution was cooled to room
temperature and an aqueous solution of NH4PF6 (277 mg, 1.7 mmol in
150 mL of water) was added. After 30 min of stirring, the dark-red
precipitate was filtered off and washed successively with water (3 ×
15 mL) and diethyl ether (3 × 15 mL). After recrystallization from
dichloromethane-pentane, filtration and evaporation of the solvents, 7a
was recovered as a dark-red powder (922 mg, 93%). 1H NMR (200.13
MHz, CD2Cl2) δ : 8.4 (m br, 6H, H3); 7.85 (m br, 2H, H6FDA); 7.74
(m br, 4H, H6FDA); 7.50-7.20 (m, 30H, H5,6,8,10); 6.90 (d, br, J ) 16
Hz, 6H, H7); 6.80-6.50 (m br, 12H, H11); 3.90 (m br, 4H, H14); 3.60
(m br, 4H, H13); 3.40 (m br, 4H, H13′); 1.16 (m, 30H, H14′); 19F NMR
under reflux for 6h. The dark-red solution was cooled to room
temperature and [HNBu3][TRISPHAT] (362 mg, 0.76 mmol) was
added. After 30 min of stirring, a dark-red precipitate was obtained by
addition of water (120 mL). The product was filtered off and washed
successively with water (3 × 15 mL) and diethyl ether (3 × 15 mL).
After recrystallization from dichloromethane-diethyl ether and filtration,
7b was recovered as a dark-red powder (536 mg, 92%). 1H NMR
(200.13 MHz, CD2Cl2) δ : 8.44 (s br, 6H, H3), 8.02 (m br, 6H, H6);
7.90-7.72 (m, 6H, H6FDA); 7.42-7.10 (m, 24H, H5,8,10); 6.6 (m br, 18H,
H7,11); 3.73 (m br, 4H, H16); 3.37 (m br, 8H, H13,13′); 1.78-1.42 (m,
12H, H14,14′,15); 1.40-1.18 (m, 4H, H15′); 0.91 (t br, J ) 7 Hz, 6H,
H
16′); 19F NMR (CD2Cl2) δ : - 63.9 (s); 31P NMR (CD2Cl2) δ : -80.5
(s); IR (KBr) ν (cm-1): 1777, 1718, 743; UV-visible (CH2Cl2): λmax
) 445-513 nm; emission (CH2Cl2): λem ) 720 nm; TGA: Td5 ) 358
°C; elemental analysis calcd (%) for [C169H142N14O12Cl24F6P2Ru‚2H2O]n:
C 54.49, H: 3.95, N: 5.26; found: C 54.83, H 4.77, N 4.92.
Dipod 8. In a Schlenk flask, bipyridine 2c (156 mg, 0.3 mmol) was
dissolved in dimethylformamide (6 mL). The yellow solution turned
green during the slow addition of NaH (15 mg, 0.6 mmol). After stirring
1 h at 50 °C, a DMF solution (4 mL) of R,R′-dibromo-p-xylene (40
mg, 0.15 mmol) was added dropwise by mean of a syringe; the resulting
brown mixture was stirred 2 days at 50 °C. After cooling at room
temperature, the solution was added dropwise in water (250 mL)
resulting in the formation of a yellow precipitate. The solid was filtered
off and washed with water (3 × 50 mL) and diethyl ether (3 × 30
mL), dissolved in dichloromethane (30 mL) and dried over MgSO4.
After filtration and evaporation of the solvent under vacuum, a yellow
microcrystalline powder was recovered (161 mg, 94% yield). 1H RMN
(500.13 MHz, CD2Cl2) δ ppm: 8.52 (d, J ) 5 Hz, 4H, H6,6′), 8.46 (s,
(CD2Cl2) δ : - 63.9 (s); 31P NMR (CD2Cl2) δ : -143 (hept, J(P-F)
)
711 Hz); IR (KBr) ν (cm-1): 1777, 1718, 744; UV-visible (CH2Cl2):
λmax ) 441-509 nm; emission (CH2Cl2): λem ) 720 nm; TGA: Td5 )
350 °C.
4H, H3,3′), 7.35 (s, 4H, H17), 7.41-7.22 (m, 16H, H10,10′ 8 8′ 5 5′
, , , , ), 6.87-
Polyimide Complex 7b. In a Schlenk flask, a DMF (7 mL) solution
of 5b (200 mg, 0.19 mmol) and 6b (266 mg, 0.19 mmol) was heated
6.86 (2d, J ) 16 Hz, 4H, H7,7′), 6.64-6.63 (2d, 8H, H11,11′), 4.48 (s,
4H, H15), 3.61 (t, J ) 6 Hz, 4H, H14), 3.52 (t, J ) 6 Hz, 4H, H13), 3.41
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A R T I C L E S
Le Bouder et al.
(q, J ) 7 Hz, 4H, H13′′), 3.36 (q, J ) 7 Hz, 8H, H13′), 1.13 (t, J ) 7
Hz, 12H, H14′), 1.12 (t, J ) 7 Hz, 6H, H14′′); 13C RMN (125.33 MHz,
CD2Cl2) δ ppm: 156.85 (C2,2′), 149.69 (C6,6′), 148.76-148.68 (C12,12′),
146.99-146.92 (C4,4′), 138.25 (C16), 133.79-133.68 (C8,8′), 128.96-
128.88 (C10,10′), 127.96 (C17), 124.12-123.68 (C9,9′), 121.30-120.99
(C7,7′), 120.61 (C5,5′), 117.86 (C3,3′), 112.06-111.87 (C11,11′), 73.39 (C15),
68.41 (C14), 50.47 (C13), 45.84 (C13′′), 44.78 (C13′), 12.80 (C14′), 12.36
(C14′′); UV-visible (CH2Cl2): λmax ) 395 nm; ꢀmax ) 90 000
l.mol-1.cm-1. TGA: Td5 ) 366 °C; elemental analysis calcd (%) for
C76H82N8O2‚H2O: C 78.86, H 7.31, N 9.68; found: C 78.44, H 7.12,
N 9.65; HRMS (FAB+) calcd for C76H83N8O2: 1139.6639, found:
1139.6640 {M+H}+.
Tripod 9. In a Schlenk flask, bipyridine 2c (750 mg, 1.45 mmol)
was dissolved in DMF (15 mL). The yellow solution turned green
during the slow addition of NaH (70 mg, 2.9 mmol). After stirring 1
h at 50 °C, a DMF solution (4 mL) of tris-1,3,5-bromomethyl-2,4,6-
mesitylene (193 mg, 0.48 mmol) was added dropwise by mean of a
syringe; the resulting brown mixture was stirred 2 days at 50 °C. After
cooling to room temperature, the solution was added dropwise in water
(250 mL) resulting in the formation of a yellow precipitate. The solid
was filtered off and washed with water (3 × 50 mL) and diethyl ether
(3 × 30 mL), dissolved in dichloromethane (50 mL) and dried over
MgSO4. After filtration and evaporation of the solvent under vacuum,
a yellow microcrystalline powder was recovered (800 mg, 96% yield).
1H NMR (500.13 MHz, CD2Cl2): δ ) 8.53-8.51 (d, J ) 5 Hz, 6H,
H6 H6′), 8.46 (s, 6H, H3 H3′ ), 7.4-7.2 (m, 24H, H10 H10′ H8 H8′ H5
H5′), 6.86-6.87-6.88 (d, J ) 16 Hz, 6H, H7 H7′ ), 6.64 (m, 12H, H11
511 nm; ꢀmax ) 239 000 l.mol-1.cm-1; TGA: Td5 ) 325 °C; elemental
analysis calcd (%) for C284H234N24Cl48O26P4Ru2,2CH2Cl2: C 52.07, H
3.64, N: 5.10; found: C 52.21, H 3.57, N 5.26; LRMS (FAB+): only
fragmentation peaks were observed: {[DEASbipy2Ru(2)][TRISPHAT]}+
2393.4, {[DEASbipy3Ru][TRISPHAT]}+, 2377.4, {DEASbipy2Ru-
(2)}2+, 812.3, {DEASbipy3Ru}2+ 804.3.
[(DEASbipy2Ru)3tripod][TRISPHAT]6 or Trimer 12. In a Schlenk
flask, ligand 9 (100 mg, 5.84 10-5 mol) and complex 6a (206 mg,
1.75 10-4 mol) were dissolved in DMF (10 mL) and stirred during 5
h under reflux. After cooling to room temperature, [TRISPHAT]-
[HNBu3] (335 mg, 0.3.5 mmol) was added. After stirring 30 min at
room temperature, a dark red solid was precipitated by addition of water
(200 mL). Complex 12 was filtered off, washed with water (3 × 50
mL) and diethyl ether (3 × 30 mL), dissolved in dichloromethane (50
mL) and dried over MgSO4. After recrystallization from a mixture of
CH2Cl2-pentane, the solvents were removed under vacuum and a dark
red microcrystalline powder was recovered (520 mg, 92% yield).
All diethylaminostyryl bipyridyl fragments have the same chemical
shifts (1H and 13C). The only difference appears in the ethyl fragment
1
of N-CH2CH2-O linked to the phenyl core. H NMR (500.13 MHz
CD2Cl2 ): δ ) 8.46 (s, 18H, H3 H3′ ), 7.91 (d, J ) 5 Hz, 18H, H6 H6′),
7.4-7.3 (m, 54H, H10 H10′ H8 H8′ ), 7.14 (d, J ) 5 Hz, 18H, H5 H5′),
6.68 (d, J ) 16 Hz, 18H, H7 H7′ ), 6.62 (d, J ) 9 Hz, 36H, H11 H11′),
4.49 (s br, 6H, H15), 3.64 (s br, 6H, H14), 3.47 (s br, 6H, H13), 3.36 (m,
60H, H13′ ), 3.16 (s br, 6H, H13" ), 2.36 (br, 9H, H18 ), 1.13 (m, 99H,
H14 H14′′); 13C NMR (125.33 MHz CD2Cl2): δ ) 157.36 (C2 C2′ ),
′
151.11 (C6 C6′ ), 149.39 (C12 C12′ ), 147.55 (C4 C4′ ), 138.37 (C16), 136.92
(C8 C8′ ), 133.10 (C17), 129.81 (C10 C10′ ), 122.95 (C9 C9′ ), 122.72 (C5),
120.21 (C3), 117.78 (C7 C7′ ), 110.93 (C11 C11′ ), 68.65 (C15), 68.42
(C14), 50.53 (C13), 45.84 (C13′′ ), 44.83 (C13′ ), 15.92 (C18), 12.84 (C14′
), 12.40 (C14′′ ), TRISPHAT: 142.04 (d, J ) 7 Hz), 123.05 (s), 114.38
(d, J ) 20 Hz); 31P NMR (81 MHz CD2Cl2): δ ) - 80.50; UV-
visible (CH2Cl2): λmax ) 511 nm (354000), λmax ) 443 nm (379000);
TGA: Td5 ) 328 °C, Td10 ) 352 °C; elemental analysis calcd (%) for
H11′), 4.53 (s, 6H, H15), 3.67 (t, J ) 5.8 Hz, 6H, H14), 3.51 (t, J ) 5.8
Hz, 6H, H13), 3.40 (q, J ) 7 Hz, 6H, H13′′ ), 3.36 (q, J ) 7 Hz, 6H, H13′
), 2.36 (s, 9H, H18 ), 1.15 (t, J ) 7 Hz, 18H, H14′ ), 1.11 (t, J ) 7 Hz,
9H, H14′′ ); 13C NMR (125.33 MHz, CD2Cl2): δ ) 156.81 (C2 C2′ ),
149.67 (C6 C6′ ), 148.73-148.67 (C12 C12′ ), 146.99-146.90 (C4 C4′ ),
138.40 (C16), 133.78-133.68 (C8 C8′ ), 133.17 (C17), 128.95-128.92
(C10 C10′ ), 124.08-123.68 (C9 C9′ ), 121.28-120.97 (C7 C7′ ), 120.60
(C5), 117.86 (C3), 112.02-111.87 (C11 C11′ ), 68.62 (C15), 68.38 (C14),
50.59 (C13), 45.88 (C13′′ ), 44.78 (C13′ ), 15.94 (C18), 12.80 (C14′′ ), 12.38
C426H354N36Cl72O39P6Ru3.3CH2Cl2: C 52.06, H 3.67, N: 5.09; found:
C 52.53, H 3.68, N 5.35; LRMS (FAB+): only fragmentation peaks
were observed: {[DEASbipy2Ru(2)][TRISPHAT]}+ 2393.4, {[DEAS-
bipy3Ru][TRISPHAT]}+ 2377.4, {DEASbipy2Ru(2)}2+ 812.3, {DEAS-
bipy3Ru}2+ 804.3.
(C14′ ); UV-visible (CH2Cl2): λmax ) 396 nm (130000); TGA: Td5
)
348 °C, Td10 ) 370 °C; elemental analysis calcd (%) for C114H126N12O3‚
2H2O: C: 78.32, H: 7.49, N: 9.61; found: C 78.14, H 7.20. N 9.51;
HRMS (FAB+) calcd for C114H127N12O3 1712.0154; found 1712.0256-
{M+H}+.
[Ru(tripod)3][TRISPHAT]2 13. In a Schlenk flask, ligand 9 (250
mg, 1.46 10-4 mol) and RuCl2(DMSO)4 (23.6 mg, 4.9 10-5 mol) were
dissolved in DMF (6 mL) and the dark red solution was stirred during
5 h under reflux. After cooling to room temperature, [TRISPHAT]-
[HNBu3] (93 mg, 9.7 10-5 mol) was added. After stirring 30 min at
room temperature a dark red solid was precipitated by addition of water
(200 mL), then filtered off, washed with water (3 × 50 mL) and diethyl
ether (3 × 30 mL), disssolved in dichloromethane (50 mL) and dried
over MgSO4. After recrystallization from a CH2Cl2-pentane mixture, a
dark red microcrystalline powder was obtained (310 mg, 94% yield).
As 1H NMR signals are broad, their multiplicity are not given. However
two types of bipyridyl protons and carbons can be distinguished:
coordinated ligand noted c and free ligand noted f. C12c, C7c, and C4c
[(DEASbipy2Ru)2dipod][TRISPHAT]4 or Dimer 11. In a Schlenk
flask, ligand 8 (50 mg, 4.4 10-5 mol) and 6a (103 mg, 8.8 10-5 mol)
were dissolved in DMF (5 mL) and stirred during 5 h under reflux.
After cooling to room temperature, [TRISPHAT][HNBu3] (170 mg,
0.18 mmol) was added. After strirring 30 min at room temperature a
dark red solid was precipitated by addition of water (150 mL). The
complex was filtered off, washed with water (3 × 50 mL) and diethyl
ether (3 × 30 mL), dissolved in dichloromethane (25 mL) and dried
over MgSO4. After recrystallization from a mixture of CH2Cl2-pentane,
the solvents were removed under vacuum and a dark red microcrys-
talline powder was recovered (255 mg, 90% yield).
1
All diethylaminostyryl bipyridyl fragments have the same chemical
shifts (1H and 13C). The only difference appears in the ethyl fragment
are not observed as they are masked by the TRISPHAT signals. H
NMR (500.13 MHz CD2Cl2): δ ) 8.46 (br, 12H, H6f ), 8.42 (br, 18H,
H3f H3c), 7.9 (br, 6H, H6c), 7.4-7.2 (m, 72H, H10 H8 H5f H5c), 6.8 (d,
12H, H7f), 6.60 (br, 42H, H7c H11 ), 4.50 (s br, 18H, H15 ), 3.63 (s br,
18H, H14), 3.47 (s br, 18H, H13), 3.32 (q br, 54H, H13 H13"), 2.33 (s br,
27H, H18 ), 1.10 (t br, 81H, H14′ H14′′); 13C NMR (125.33 MHz CD2-
Cl2): δ ) 157.27 (C2c C2′c ), 156.70 (C2f C2f), 151.18 (C6c C6′c ), 149.64
(C6f C6′f ), 148.75-148.68 (C12f C12′f ), 147.47 (C4c C4′c ), 147.01-146.91
(C4f C4′f ), 138.41 (C16), 136.84 (C8c C8′c ), 133.82 (C8f C8′f ), 133.02
(C17), 129.76 (C10c C10′c ), 128.95 (C10f C10′f ), 123.59 (C9f C9′f ), 122.78
(C9c C9′c ), 122.47 (C5c ), 120.97 (C7f C7′f ), 120.64 (C5f ), 120.10 (C3c ),
117.86 (C3f ), 112.02-111.86 (C11f C11′f ), 68.61 (C14), 68.36 (C15), 50.59
(C13), 45.87 (C13′′ ), 44.77 (C13′ ), 15.94 (C18), 12.81 (C14′′ ), 12.39 (C14′
). TRISPHAT: 142.06 (br), 123.03 (s), 114.36 (d, J ) 20 Hz); 31P
1
of N-CH2CH2-O linked to the phenyl core. H RMN (500.13 MHz,
CD2Cl2) δ ppm: 8.35 (s, 12H, H3,3′), 8.01 (d, J ) 5 Hz, 12H, H6,6′),
7.4-7.2 (m, 28H, H10,10′,17,8,8′,5,5′), 6.7-6.5 (m, 18H, H11,11′,7,7′), 4.46
(s, 4H, H15), 3.59 (s, 4H, H14), 3.51 (s, 4H, H13), 3.36 (m, 40H, H13′),
3.17 (s, 4H, H13"), 1.15 (m, 66H, H14′,14′′). 13C RMN (125.33 MHz,
CD2Cl2) δ ppm: 157.34 (C2,2′), 151.37 (C6,6′), 149.44 (C12,12′), 147.55
(C4,4′), 138.18 (C16), 136.75 (C8,8′), 127.89 (C17), 129.81 (C10,10′), 122.90
(C9,9′), 122.67 (C5,5′), 120.05 (C3,3′), 117.72 (C7,7′), 111.79 (C11,11′), 73.41
(C15), 68.42 (C14), 50.49 (C13), 45.81 (C13′′), 44.86 (C13′), 12.84 (C14′),
12.41 (C14′′), TRISPHAT: 142.05 (d, J ) 7 Hz), 123.06 (s), 114.38 (d,
J ) 20 Hz). 31P RMN (81 MHz, CD2Cl2) δ ppm: - 80.50 (s); UV-
visible (CH2Cl2): λmax ) 440 nm; ꢀmax ) 258 000 l.mol-1.cm-1, λmax
)
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12298 J. AM. CHEM. SOC. VOL. 125, NO. 40, 2003

Supramolecular Self-Ordering in Dentritic Structures
A R T I C L E S
NMR (81 MHz CD2Cl2): δ ) - 80.5; UV-visible (CH2Cl2): λmax
)
(C12 C12′ ), 147.46 (C4 C4′ ), 138.36 (C16), 136.61 (C8 C8′ ), 133.08 (C17),
129.81 (C10 C10′ ), (C9 C9′ ), 122.63 (C5), 120.13 (C3), 117.69 (C7 C7′ ),
111.76 (C11 C11′ ), 68.67 (C15), 68.67 (C14), 50.59 (C13), 45.82 (C13′′ ),
44.85 (C13′ ), 15.94 (C18), 12.84 (C14′ ), 12.41 (C14′′ ), TRISPHAT: 142.05
(d, J ) 7 Hz), 123.04 (s), 114.39 (d, J ) 20 Hz); 31P NMR (81 MHz
CD2Cl2): δ ) - 80.5; UV-visible (CH2Cl2): λmax ) 444 nm (693000),
λmax ) 506 nm (648000); TGA: Td5 ) 321 °C, Td10 ) 355 °C; elemental
analysis calcd (%) for C1002H834N84Cl168O93P14Ru7.14CH2Cl2: C 51.22,
H 3.65, N 4.94; found: C 50.71, H 3.58, N 5.34.
518 nm (97000), λmax ) 400 nm (306000); elemental analysis calcd
(%) for C378H378N36Cl24O21P2Ru,6CH2Cl2: C 63.31, H 5.40, N 6.92;
found: C 63.22, H 5.26, N 6.84.
[(DEASbipy2Ru)6(tripod)3Ru][TRIPSPHAT]14 or Heptamer 14.
In a Schlenk flask, [Ru(tripod)3][TRISPHAT]2 13 (150 mg, 2.2 10-5
mol) and complex 6a (156 mg, 0.13 mmol) were dissolved in DMF (6
mL) and stirred during 6 h under reflux. The solution turned from green-
brown to deep red. After cooling to room temperature, [TRISPHAT]-
[HNBu3] (253 mg, 0.26 mmol) was added. After stirring 1h. at room
temperature, a dark red solid was precipitated by addition of water (200
mL). The resulting complex was filtered off, washed with water (3 ×
50 mL) and diethyl ether (3 × 30 mL), dissolved in dichloromethane
(50 mL) and dried over MgSO4. After recrystallization from a CH2-
Cl2-pentane mixture, the solvents were removed under vacuum and a
dark red microcrystalline powder was obtained (450 mg, 91% yield).
As 1H NMR signals are broad, their multiplicity are not given. 1H NMR
(500.13 MHz CD2Cl2 5.28): δ ) 8.3 (br, 42H, H3 H3′ ), 8.0 (br, 42H,
H6 H6′), 7.4-7.0 (b, 168H, H10 H10′ H8 H8′ H5 H5′), 6.6 (br, 126H, H7
H7′ H11 H11′), 4.5 (s br, 18H, H15), 3.6-3.0 (m br, 182H, H14 H13 H13′
H13" ), 2.3 (br, 27H, H18 ), 1.1 (m br, 231H, H14′ H14′′). C9 and C9′ are
not visible, they are fused in one of the TRISPHAT signals; 13C NMR
(125.33 MHz CD2Cl2): δ ) 157.30 (C2 C2′ ), 151.36 (C6 C6′ ), 149.44
Acknowledgment. This research was supported by the
Ministe`re de la recherche (FNS-Program nanostructure), the
CNRS, the Re´gion Bretagne (PRIR A2CA16) and the CNET
(France-Telecom) for a grant to T.L.B.
Supporting Information Available: General considerations
on spectroscopic, thermal analysis, photophysical and NLO
measurements and theoretical calculations. Synthetic procedures
and characterization data of bipyridines 3a, 3b, 4a, 4b, and
ruthenium complex 6b. This material is available free of charge
via the Internet at http://pubs.acs.org.
JA030296J
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