Search

The cycloaddition of azomethine ylides to [60]fullerene (C-60) has been studied in ortho-dichlorobenzene (o-DCB) by evaluating the impact of an ionic liquid (IL) additive. The solvent effect has been addressed by evaluating the activation parameters of the cycloaddition and the boosting effect of the microwave (MW) induced dielectric heating. The IL additive plays a twofold role of stabilizing the dipolar ylide intermediate and favoring the retro-cycloaddition at high temperature regime. Under the conditions explored, a combined kinetic and thermodynamic preference favors the selective formation of trans bis-fulleropyrrolidine regioisomers, in agreement with the DFT computational analysis.

The Cover Feature shows a kaleidoscopic vision of the frontier empty orbitals of [60]fulleropyrrolidine embracing diverse [6,6] bonds, which poses a severe regioselectivity challenge for further ylide cycloaddition, resulting in a multitude of polyfunctionalization products. A combined kinetic and mechanistic study is reported to interrogate the thermodynamic drivers, leading to stable fulleropyrrolidine bis-adducts, using MW-assisted heating and ionic liquids additives.

Artificial photosynthesis aims at efficient water splitting into hydrogen and oxygen, by exploiting solar light. As a priority requirement, this process entails the integration of suitable multi-electron catalysts with light absorbing units, where charge separation is generated in order to drive the catalytic routines. The final goal could be the transposition of such an asset into a photoelectrocatalytic cell, where the two half-reactions, proton reduction to hydrogen and water oxidation to oxygen, take place at two appropriately engineered photoelectrodes. We herein report a covalent approach to anchor a Co(II) water oxidation catalyst to a Ru(II) polypyridine photosensitizer unit; photophysical characterisation and the catalytic activity of such a dyad in a light activated cycle are reported, and implications for the development of regenerative systems are discussed.

A salophen cobalt(II) complex enables water oxidation at neutral pH in photoactivated sacrificial cycles under visible light, thus confirming the high appeal of earth abundant single site catalysis for artificial photosynthesis.

The artificial leaf project calls for new materials enabling multielectron catalysis with minimal overpotential, high turnover frequency, and long-term stability. Is graphene a better material than carbon nanotubes to enhance water oxidation catalysis for energy applications? Here we show that functionalized graphene with a tailored distribution of polycationic, quaternized, ammonium pendants provides an sp(2) carbon nanoplatform to anchor a totally inorganic tetraruthenate catalyst, mimicking the oxygen evolving center of natural PSII. The resulting hybrid material displays oxygen evolution at overpotential as low as 300 mV at neutral pH with negligible loss of performance after 4 h testing. This multilayer electroactive asset enhances the turnover frequency by 1 order of magnitude with respect to the isolated catalyst, and provides a definite up-grade of the carbon nanotube material, with a similar surface functionalization. Our innovation is based on a noninvasive, synthetic protocol for graphene functionalization that goes beyond the ill-defined oxidation-reduction methods, allowing a definite control of the surface properties.

The synthesis, characterization and DNA binding studies of a series of polycationic fullerene adducts are reported. These cationic species, exhibiting reasonably high water solubility and a heterogeneous distribution of positive charges, can efficiently complex plasmid DNA. Electrophoresis studies show different DNA binding efficiencies for different adducts, some of which can be considered excellent candidates for DNA binding therapies.

The fullerene family, and especially C(60), has delighted the scientific community during the last 25 years with perspective applications in a wide variety of fields, including the biological and the biomedical domains. Several biomedical uses have been explored using water-soluble C(60)-derivatives. However, the employment of fullerenes for drug delivery is still at an early stage of development. The design and synthesis of multifunctionalized and multimodal C(60) systems able to cross the cell membranes and efficiently deliver active molecules is an attracting challenge that involves multidisciplinary strategies. Promising results have emerged in the last years, bringing fullerenes again to the front of interest. Herein, the state of the art of this emerging field is presented and illustrated with some of the most representative examples.

The fullerene family, and especially C(60), has delighted the scientific community during the last 25 years with perspective applications in a wide variety of fields, including the biological and the biomedical domains. Several biomedical uses have been explored using water-soluble C(60)-derivatives. However, the employment of fullerenes for drug delivery is still at an early stage of development. The design and synthesis of multifunctionalized and multimodal C(60) systems able to cross the cell membranes and efficiently deliver active molecules is an attracting challenge that involves multidisciplinary strategies. Promising results have emerged in the last years, bringing fullerenes again to the front of interest. Herein, the state of the art of this emerging field is presented and illustrated with some of the most representative examples.

In this chapter, the most important applications of fullerene derivatives in materials science are presented especially to understand the significant contributions of fullerene chemistry to the development of new materials. A general overview of the state-of-the-art in this interesting field is given, including a number of representative and most recent examples of donor–acceptor systems, organic electron devices, superconductors, fullerene aggregates, nonlinear optics applications, liquid crystals and fullerene–inorganic hybrids.

Graphene sheets have been functionalized with a PAMAM dendron, finding that graphene can be efficiently functionalized all over the surface, or only at the edges, depending on the reactions used in the functionalization process.

Quantitative cycloreversion of fulleropyrrolidines to [60]fullerene is achieved in ionic liquids within minutes under microwave irradiation without any further additives.

Quantitative cycloreversion of fulleropyrrolidines to [60]fullerene is achieved in ionic liquids within minutes under microwave irradiation without any further additives.

The effect of microwave (MW) irradiation and ionic liquids (IL) on the cycloaddition of azomethine ylides to [60]fullerene has been investigated by screening the reaction protocol with regard to the IL medium composition, the applied MW power, and the simultaneous cooling of the system. [60]Fullerene conversion up to 98 % is achieved in 2―10 min, by using a 1:3 mixture of the IL 1-methyl-3-n-octyl imidazolium tetrafluoroborate ([omim]BF 4 ) and o-dichlorobenzene, and an applied power as low as 12 W. The mono- versus poly-addition selectivity to [60]fullerene can be tuned as a function of fullerene concentration. The reaction scope includes aliphatic, aromatic, and fluorous-tagged (FT) derivatives. MW irradiation of IL-structured bucky gels is instrumental for the functionalization of single-walled carbon nanotubes (SWNTs), yielding group coverages of up to one functional group per 60 carbon atoms of the SWNT network. An improved performance is obtained in low viscosity bucky gels, in the order [bmim]BF 4 > [omim]BF 4 > [hvim]TF 2 N (bmim=1-methyl-3-n-butyl imidazolium; hvim= 1-vinyl-3-n-hexadecyl imidazolium). With this protocol, the introduction of fluorous-tagged pyrrolidine moieties onto the SWNT surface (1/108 functional coverage) yields novel FT-CNS (carbon nanostructures) with high affinity for fluorinated phases.

not Available.