Reaction of diazocompounds with C70: unprecedented synthesis and characterization of isomeric [5,6]-fulleroids.

The synthesis of a variety of PCBM-type [5,6]-fulleroids and their further highly selective photoisomerization to the respective [6,6]-methanofullerenes is presented. Interestingly, the chemical reactivity of [5,6]-fulleroids reveals the same trend (a > b > c > d) to that observed for pristine C70 (α > ß > γ > δ).

Controlling the crystalline three-dimensional order in bulk materials by single-wall carbon nanotubes.

The construction of ordered single-wall carbon nanotube soft-materials at the nanoscale is currently an important challenge in science. Here we use single-wall carbon nanotubes as a tool to gain control over the crystalline ordering of three-dimensional bulk materials composed of suitably functionalized molecular building blocks. We prepare p-type nanofibres from tripeptide and pentapeptide-containing small molecules, which are covalently connected to both carboxylic and electron-donating 9,10-di(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene termini. Adding small amounts of single-wall carbon nanotubes to the so-prepared p-nanofibres together with the externally controlled self assembly by charge screening by means of Ca(2+) results in new and stable single-wall carbon nanotube-based supramolecular gels featuring remarkably long-range internal order.

Twisted but conjugated: building blocks for low bandgap polymers.

Here we report a novel twisted monomer based on a distorted CC double bond for low bandgap conjugated copolymers. This new building block provides several unique characteristics when compared to classical planar systems such as high solubility, electron accepting ability, and isomeric tunability. The resulting copolymers exhibit broad absorption spanning both visible and near-infrared regions leading to promising solar cell performance.

Power factor enhancement in solution-processed organic n-type thermoelectrics through molecular design.

A new class of high-performance n-type organic thermoelectric materials, self-doping perylene diimide derivatives with modified side chains, is reported. These materials achieve the highest n-type thermoelectric performance of solution-processed organic materials reported to date, with power factors as high as 1.4 µW/mK(2). These results demonstrate that molecular design is a promising strategy for enhancing organic thermoelectric performance.

Solubility-limited extrinsic n-type doping of a high electron mobility polymer for thermoelectric applications.

The thermoelectric properties of a highperformance electron-conducting polymer, (P(NDIOD-T2), extrinsically doped with dihydro-1H-benzoimidazol-2-yl (NDBI) derivatives, are reported. The highest thermoelectric power factor that has been reported for a solution-processed n-type polymer is achieved; and it is concluded that engineering polymerdopant miscibility is essential for the development of organic thermoelectrics.

Exploiting multivalent nanoparticles for the supramolecular functionalization of graphene with a nonplanar recognition motif.

The supramolecular modification of planar graphene with the geometrically mismatched, curved 9,10-di(1,3-dithiole-2-ylidene)-9,10-dihydroanthracene (exTTF) molecule is demonstrated. The exTTF-graphene interaction is governed by π-π and CH-π interactions, with a negligible contribution from charge transfer. We amplified these weak forces through multivalent gold nanoparticles. Our results show that planarity is not a prerequisite for recognition motifs for graphene.

"Deconvoluted fullerene" derivatives: synthesis and characterization.

We have designed the synthesis of "deconvoluted fullerene" derivatives that present an ordered pattern of hexagons and pentagons in the backbone of the molecule. We not only mimicked the fullerene structure in dihedral planes, but also preserved its electron accepting behavior and enlarged its optical absorption. Moreover, very preliminary photoluminescence (PL) quenching experiments also confirmed the potentiality of these materials as acceptors in the field of organic photovoltaics (OPV)s. A brief discussion of the surface morphology, based on AFM analysis, is also presented.

Microwave-induced multiple functionalization of carbon nanotubes.

We describe a new synthetic strategy to produce multifunctionalized carbon nanotubes using a combination of two different addition reactions, the 1,3-dipolar cycloaddition of azomethine ylides and the addition of diazonium salts, both via a simple and fast microwave-induced method. The presence of multifunctionality on the SWNTs has been confirmed using the most useful techniques for the characterization of carbon nanotubes. The doubly functionalized SWNTs can be considered potentially useful for many interesting applications.

Reversible microwave-assisted cycloaddition of aziridines to carbon nanotubes.

We report a new approach that uses microwaves to rapidly functionalize carbon nanotubes by using 1,3-dipolar cycloaddition of aziridines, well-known precursors to azomethine ylides, in solvent-free conditions. The efficiency of our microwave-mediated protocol is confirmed by comparison to a similar protocol in classical conditions for the azomethine ylides in DMF. Under these latter conditions, the reaction proceeds in 5 days (against 1 h under microwave irradiation), and the functionalization degree is much lower, as confirmed by thermogravimetric analysis and Raman spectroscopy. With our procedure, we easily scale-up the reaction up to 250 mg of functionalized MWNT in 1 h. We also provide an indirect proof of the covalent sidewall functionalization of the tubes.

Functionalisation of carbon nanohorns.

The functionalisation of single wall carbon nanohorns via 1,3-dipolar cycloaddition has been achieved, and the products have been characterised by spectroscopy, microscopy and thermogravimetry.