Amphiphilic fullerene

Hawker C J, Seville P M and White J W 1994 The synthesis and characterization of a self-assembling amphiphilic fullerene J. Org. Chem. 59 3503-5... 

Various covalent and non-covalent approaches for the incorporation of fullerene building blocks into liquid crystalline mesomorphic materials have been developed [35]. Lyotropic mesophases (buckysomes) were obtained upon dissolving globular amphiphilic fullerene dendrimers in water [145]. 

However, transfer of the monolayers to solid substrates was inefficient because of the small size of the hydrophilic anchor, which imparted a hydrophobic/hydrophilic imbalance. Accordingly, increasing the size of the hydrophilic anchor facilitated the formation of stable Langmuir films that could be transferred to sohd substrates with a transfer ratio of 1 (Nierengarten et al. 2001). Bayer s research group reported a related approach in which the fullerene was modified with carboxylate-terminated dendrons and alkyl chains (Maierhofer et al. 2000). This amphiphilic fullerene derivative formed stable monolayers that could be compressed and expanded without hysteresis (Fig. 11.46d Maierhofer et al. 2000). 

Figure 11.46 Typical sttuctures of amphiphilic fullerene dendritic derivatives that form Langmuir-Blodgett films.

Figure 14.8 Amphiphilic fullerene and calixarene derivatives with dendritic branches that form long-lived micelles (Copyright Wiley-VCH Verlag GmbH Co. KGaA. Reproduced by permission).

Burghardt, S., Hirsch, A., Schade, B., Ludwig, K., Bottcher, C., Switchable supramolecular organization of structurally defined micelles based on an amphiphilic fullerene. Angew. Chem., Int. Ed. 2005, 44, 2976-2979. 

The construction of fullerene ultrathin films with an ordered structure is of interest from both a fundamental and practical point of view [20-22]. Geo alone and amphiphilic fullerene derivatives form mono-layers at the air-water interface and these monolayers can be transferred onto solid substrates [23-27]. The authors [28-38] and others [39-43] have been interested in combining fullerene chemistry and the... 

In recent years the number of studies on pol5uner vesicles or polymersomes has strongly increased after first reports hy the groups of Eisenherg (11,12), and Bates and Discher (7,13). Since then, amphiphilic block copolymers, rod-coil polymers (14-16), dendrimers (17), and amphiphilic fullerene derivatives (18) have been reported to form vesicular structures. Vesicles can now be made from various pol5uners, from modified biological to wholly synthetic, from dihlock, triblock,... 

Brown, T. Clipston, N.L. Simjee, N. Luftmann, H. Hungebiihler, H. Drewello, T. Matrix-Assisted Laser Desorption/Ionization of Amphiphilic Fullerene Derivatives. Int. J. Mass Spectrom. 2001,210/211,249-263. 

Diederich F, Jonas U, Gramlich V, Herrmann A, Ringsdorf H and Thilgen C 1993 Synthesis of a fullerene derivative of benzo[18]crown-6 by Diels-Alder reaction complexation ability, amphiphilic properties, and x-ray crystal structure of a dimethoxy-1,9-(methano[1, 2]benzomethano)fullerene[60] benzene clathrate Helv. Chim. Acta 76 2445-53... 

Nierengarten J-F, Schall C, Nicoud J-F, Fleinrich B and Guillen D 1998 Amphiphilic cyclic fullerene bisadducts synthesis and Langmuir films at the air-water interface Tetrahedron Lett. 39 5747-50... 

All the fullerene-containing dendrimers reported to date have been prepared with a Cgo core but never with fullerene units at their surface or with Cgg spheres in the dendritic branches. We have recently started a research program on the synthesis of dendrons substituted with fullerene moieties. These fulleroden-drons are interesting building blocks for the preparation of monodisperse fullerene-rich macromolecules. In addition, they are also amphiphilic compounds capable of forming stable Langmuir films at the air-water interface. 

In conclusion, by varying the number and kind of the attached substructures for exohedrally functionalized fullerenes the solubility in water can be fine-tuned. From a pharmacological point of view, a well-balanced arrangement of both hydrophilic and lipophilic behaviour is required in order to achieve favourable biodistribution. Amphiphilic monoadducts containing long lipophilic alkyl chains like 8 are promising candidates for potential medical applications. 

A benzo[18]crown-6 adduct (72) of Cgg (not shown) has been synthesized by the addition of the corresponding o-quinodimethane 71 in toluene [58]. The solubility of 72 in pro tic solvents such as MeOH strongly increases after the complexation of ions, as shown by extraction experiments. The combination of the crown ether and the fullerene moiety in 72 provides a highly amphiphilic character. This behavior allowed the preparation of Langmuir-Blodgett films of monolayers on mica of 72 and its complex. 

Gayathri SS, Patnaik A (2006) Electrical rectification from a fullerene[60]-dyad based metal-organic-metal junction. Chem Commun (Cambridge, UK) 1977-1979 Matino F, Arima V, Piacenza M et al (2009) Rectification in supramolecular zinc porphyrin/ fulleropyrrolidine dyads self-organized on gold(lll). Chemphyschem 10 2633-2641 Acharya S, Song H, Lee J et al (2009) An amphiphilic Cgo penta-addition derivative as a new U-type molecular rectifier. Org Electron 10 85-94... 

As with other systems discussed in this book, only a few out of the numerous dendrimers synthesized up-to-date can be mentioned. A thin film formed by amphiphilic dendrimers bearing peripheral fullerene units 299 [16], a glycocalix... 

A range of amphiphilic dendrimers have been reported based on fullerene C60 or a calix[4]arene core with dendritic branches on one side and long aliphatic tails on the other, Figure 14.8. The amphiphiles self-assemble into micelles with the aliphatic chains buried in the micelle core and the more hydrophilic dendritic portion facing out.14... 

Langmuir-Blodgett (LB) technique has been also used for the preparation of Pc-based OFET, as it allows the fine control of both the structure and the thickness of the film at the molecular level [226,227], OFET devices based on amphiphilic tris(phthalocyaninato) rare earth, triple-decker complexes have been prepared by LB technique, showing good OFET performances [228], More recently, ambipolar transport has also been realized in OFET devices through a combination of holeconducting CuPc and n-conducting Cgo fullerene, in which the asymmetry of the... 

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