Nanosciences


We have been working on dendrimers and metallodendrimers since our 1979 finding of one of the first reaction iterations (namely the series of deprotonation-alkylation of polymethylbenzenes ; see our comprehensive 1995 dendrimer review4). An original strategy5 for the synthesis of giant dendrimers (actually the largest known dendrimers, far beyond the de Gennes dense packing limit) has been reported in by our group in the recent years,6 and suitable functionalization has also been recently published by us whereby functions as sensors and catalysts are attached and have proved efficient.7

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Recently, we have designed dendrimers of various kinds using either and organic or metallic cores. For instance, organic dendrimers with an octahedral metal-cluster core have been prepared and decorated with redox systems able to carry out molecular recognition of oxo-anions.8 We have also synthesized among the first nanoparticle-centered dendrimers in 2001,9 and these Au-nanoparticle-cored dendrimers have been decorated with ferrocenyl termini at the periphery, so that these nanomaterials are excellent, recoverable nanosensors for the recognition of ATP dianion, a DNA fragment.10 In 2005, we have reported decoration with Fe4 clusters at the dendrimer periphery, and for the first time the redox activity and size effect of these clusters allowed us to recognize ATP dianion better than its H2PO4- model.11


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In 1997, our research group had reported in J. Am. Chem. Soc. the first molecular recognition using dendrimers in a very highly cited article.12 Therefore, we used the hydrogen bonding between amido groups of polyamidoferrocenyl dendrimers and oxoanions in electrochemical sensing. We have also utilized simple hydrogen bonding between primary amino group of polyamino dendrimers and the hydroxy group of phenoldendrons to assemble dendrimers (instead of synthesizing them !), and supramolecular ferrocenyl dendrimers assembled in this way also recognize oxo-anions including ATP dianion.

It is this direction towards biologically-relevant studies14,23,25 that now leads us towards water soluble dendrimers, nanoparticles and dendronized nanoparticles and their use as selective drug vectors and catalysts. Our first success in solubilizing our polyolefin dendrimers in water has recently (2005) been met by the remarkably chemio-, regio- and stereoselective cross-metathesis reaction15 with acrylic acid, a strategy that we are now extending to other nanomaterials for various applications in nanotechnology.

Our research towards regenerable and re-usable molecular catalysts has led us first design organometallic models, then compare star-shape and dendrimer-shaped catalysts and investigate dendritic and shape effects in Ru-catalyzed metathesis (ROMP),17 Pd-catalyzed cross C-C coupling (Suzuki, Sonogashira)18 and oxidation with polyoxophosphotungstate anions.19 Research is continuing towards novel recyclable catalysts for Green Chemistry20 in which supramolecular metallodendrimers, dendronized nanoparticles and other nanocomposites are suitably encapsulated or functionalized.

In parallel, we are persuing the molecular electronic properties of these nanomaterials as electron reservoirs or molecular batteries21 using the attachment of our sandwich-shape electron-reservoir 19-electron complexes RCpFe(arene) linked to the nanomaterials through the Cp substituent R. These molecular materials can be deposited onto metal electrodes or used for nanodevice as electric molecular connectors that we envisage to utilize for diodes and transistors.



1. D. Astruc, F. Chardac
Dendritic Catalysts and Dendrimers in Catalysis
Chem. Rev., 2001, 101, 2991-3031.
D. Méry, D. Astruc
Metallodendritic Catalysts : Recent Progress
Coord. Chem. Rev., 2006, 250 (15-16), 1965-1979.

2. M.-C. Daniel, D. Astruc,
Gold Nanoparticles : Assembly, Supramolecular Chemistry, Quantum-size Related Properties, and Applications towards Biology, Catalysis and Nanotechnology
Chem. Rev. 2004, 104, 293-346.

3. D. Astruc, F. Lu, J. Ruiz A.
Nanoparticle Catalysis
Angew. Chem. Int. Ed. 2005, 44, 7852-7872.

4. N. Ardoin, D. Astruc
The Molecular Trees : from Syntheses towards Applications
Bull. Soc. Chim. Fr. 1995, 132, 875-909.

5. Sartor, V., Djakovitch, L., Fillaut J.-L., Moulines F., Neveu F., Marvaud V, Guittard J., Blais J.-C., Astruc D.
Organoiron Routes to a New Dendron for Fast Dendritic Syntheses Using Divergent and Convergent Methods
J. Am.Chem. Soc. 1999, 121, 2929-2930.

6. J. Ruiz, G. Lafuente, S. Marcen, C. Ornelas, S. Lazare, E. Cloutet, J.-C. Blais, D. Astruc
Construction of Giant Dendrimers Using a Tripodal Buiding Block,
J. Am. Chem. Soc., 2003, 125, 7250-7257.

7. D. Astruc
Organometallic Chemistry at the Nanoscale : Dendrimers for Redox Processes and Catalysis
Pure Appl. Chem. 2003, 75, N° 4, 461-481.

8. D. Méry, L. Plault, S. Cordier, K. Karicki, S. Nlate, J. Ruiz, C. Perrin, D. Astruc
From Simple Monopyridine Clusters [Mo6Br13(Py-R)6][n-Bu4N] and Hexapyridine Clusters [Mo6X8(Py-R)6][OSO2CF3]4 (X = Br or I) Cluster-cored Organometallic Stars, Dendrons and Dendrimers
Inorg. Chem. 2006, 45 (3), 1156-1167.

9. M.-C. Daniel, J. Ruiz, S. Nlate, J. Palumbo, J.-C. Blais, D. Astruc
Gold Nanoparticles Containing Redox-Active Supramolecular Dendrons that Recognize H2PO4-
Chem. Commun., 2001, 2000-2001.

10. M.-C. Daniel, J. Ruiz, S. Nlate, J.-C. Blais, D. Astruc
Nanoscopic Assemblies Between Supramolecular Redox Active Metallodendrons and Gold Nanoparticles : Syntheses, Charaterization and Selective Recognition of H2PO4-, HSO4- and Adenosine-5-Triphosphate (ATP2-) Anions
J. Am. Chem. Soc., 2003, 125, 2617-2628.

11. J. Ruiz, C. Belin, D. Astruc
Functionalization of the (CpFeCO)4 Cluster and Derivatization of 9, 16 and 27-polyamino- Dendrimers for the Selective Recognition of Adenosine-triphophate
Angew. Chem. 2006, 118, 138-142 Angew. Chem. Int. Ed., 2006, 45 (1), 132-136.

12. C. Valério, J.-L. Fillaut,J. Ruiz, J. Guittard, J.-C. Blais, D. Astruc
The Dendritic Effect in Molecular Recognition : Ferrocene Dendrimers and their Use as Supramolecular Redox Sensors for the Recognition of Small Inorganic Anions
J. Am. Chem. Soc. 1997, 119, 2588-2589.

13. M.-C. Daniel, J. Ruiz, D. Astruc
Supramolecular H-bonded Assemblies of Redox-Active Metallodendrimers and Positive and Unusual Dendritic Effects on the Recognition of H2PO4-
J. Am. Chem. Soc., 2003, 125, 1150-1151.

14. D. Astruc, M.-C. Daniel, J. Ruiz
Dendrimers and gold nanoparticles as exo-receptors sensing biologically important anions
Chem. Commun (feature article), 2004, 2637-2649.

15. D. Astruc
La métathèse de Chauvin à la chimie verte
L’Actualité Chimique, Mars 2004, pp. 3-11, 273
D. Astruc
The Metathesis Reactions : From Historical Perspective to Recent Development
New J. Chem., 2005, 29, 42-56 (special issue of the members of the Editorial board, January 2005).

16. C. Ornelas, D. Méry, J. Ruiz, J.C. Blais, D. Astruc
Synthesis of Water-soluble Dendrimers by Selective Cross-Metathesis
Angew. Chem. Int. Ed. 2005, 44, 7399-7404.

17. S. Gatard, S. Nlate, E. Cloutet, G. Bravic, J.-C. Blais, D. Astruc
Dendritic Stars by Ring-Opening-Metathesis Polymerization From Ruthenium-Carbene Dendrimers
Angew. Chem. Int. Ed., 2003, 42, 452-456.

18. K. Heuzé, D. Méry, D. Gauss, J.-C. Blais, D. Astruc
Copper-Free Monomeric and Dendritic Palladium Catalysts for the Sonogashira Reaction : Substituent Effects, Synthetic Applications, and the Recovery and Re-Use of the Catalysts
Chem. Eur. J., 2004, 10, 3936-3944.

19. L. Plault A. Hauseler, S. Nlate, D. Astruc, S. Gatard, R. Neumann
Synthesis of Dendritic Polyoxometalate Complexes Assembled by Ionic Bonding and Their Function as Recoverable and Reusable Oxidation Catalyst
Angew. Chem. Int. Ed. 2004, 43, 2924-2928.

20. D. Astruc, K. Heuze, S. Gatard, D. Méry, S. Nlate, L. Plault
Metallodendritic Catalysis for Redox and C-C Bond Formation Reactions : A Step towards Green Chemistry
Advan Syn. Catal., 2005, 347, 329-338 (special issue dedicated to R. R. Schrock).

21. J. Ruiz, C. Pradet, D. Varret, D. Astruc
Molecular batteries : synthesis and characterization of a dendritic 19-electron Fe(I) complex that reduces C60 to its mono-anion
Chem. Commun., 2002, 1108-1109.

22. C. Ornelas, J. Ruiz Aranzaes, E. Cloutet, S. Alves, D. Astruc
Click Assembly of 1,2,3-Triazole-Linked Dendrimers Including Ferrocenyl Dendrimers that Sense Both Oxo-anions and Metal Cations
Angew. Chem. Int. Ed, 2007, 46 (1) 872-877.

23. C. Ornelas, E. Boisselier, V. Martinez, I. Pianet, J. Ruiz Aranzaes, D. Astruc
New Water-soluble Polyanionic Dendrimers and Binding to Acetylcholin in Water By Means of Supramolecular Interactions
Chem. Commun. 2007, 5093-5095.

24. A. Diallo, C. Ornelas, L. Salmon, J. Ruiz Aranzaes, D. Astruc
Homeopathic Catalytic Activity and Atom-Leaching Mechanism in the Miyaura-Suzuki Reactions under Ambient Conditions Using Precise "Click" Dendrimer-Stabilized Pd Nanoparticles
Angew. Chem. Int. Ed. Engl. Volume 46, Issue 45, Date:November 19, 2007, Pages:8644-8648.

25. E. Boisselier, C. Ornelas, I. Pianet, J. Ruiz, D. Astruc
Four Generations of Water Soluble Dendrimers with 9 to 243 Benzoate Tethers : Synthesis and Dendritic Effects on Their Ion Paring with Acetylcholine, Benzyltriethylammonium and Dopamine in Water
Chemistry, Eur. J., 2008, 14 (x) ASAP.

26. C. Ornelas, L. Salmon, J. Ruiz Aranzaes, D. Astruc
Dendrimers : Synthesis, Redox Sensing of Pd(OAc)2, and Remarkable Catalytic Hydrogenation Activity of Precise Pd Nanoparticles Stabilized by 1,2,3-Triazole-Containing Dendrimers
Chem. Eur. J. , 2008, 14 (1) 50-64.

27. C. Ornelas, D. Méry, E. Cloutet, J. Ruiz Aranzaes, D. Astruc
Cross Olefin Metathesis for the Selective Functionalization, Ferrocenylation, and Solubilization in Water of Olefin-terminated Dendrimers, Polymers and GoldNanoparticles and for a Divergent Dendrimer Construction
J. Am. Chem. Soc. 2008, 130, 1495-1506.



Books :

D. Astruc "Electron-Transfer and Radical Processes in Transition-Metal Chemistry" VCH, New York, 1995, 630 pages. ISBN 1-56081-642-2, available at Wiley-VCH.

D. Astruc : "Chimie Organométallique" EDP Sciences, 2000 (550 pages), ISBN 2-86883-493-0 with corrected exercises - references and summaries of each chapter - history - fundamental concepts - molecular orbitals - all metals - bio-organometallic chemistry - catalysis - applications in organic synthesis (pharmacy and natural products). Available at EDP Sciences, 7 , avenue du Hoggar, Parc d’Activités de Courtaboeuf, BP 112, 91944 Les Ulis Cedex A, France. Spanish version, translated by Profs. Carmen Claver and Beatriz Alonso (Reverte, 2003).

D. Astruc : "Organometallic Chemistry and Catalysis", Springer, Berlin, 2007.





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