Methanofullerene Derivatives Research Articles

A Supramolecular Oligophenylenevinylene—C60 Conjugate.

Abstract A new methanofullerene derivative with an ammonium subunit has been prepared and its ability to form a supramolecular complex with an oligophenylenevinylene (OPV)–crown ether conjugate evidenced by NMR, electrospray mass spectrometry and luminescence experiments.

Nanoscale aggregation of fullerene in Nafion membrane with strong optical limiting capability

Nanoscale aggregation of a new methanofullerene derivative with peripheral hydrophilic moieties was achieved within the confined space of a Nafion membrane. The aggregation was characterized by UV-Vis absorption, and transmission electron microscopy. The resulting film showed strong optical limiting capability attractive for many potential applications.

Photovoltaic properties of MEH-PPV doped with new methanofullerene derivatives

The photophysical and photovoltaic properties of MEH-PPV doped with two new mono-methanofullerenes were studied systematically. The different quenching of the luminescence of MEH-PPV by the two methanofullerenes is corresponding to the photovoltaic performances of the blends, which suggested that the photovoltaic properties of bulk heterojunction polymer photovoltaic devices could be improved by the select doping of fullerene derivatives.

A supramolecular oligophenylenevinylene–C60 conjugate

A new methanofullerene derivative with an ammonium subunit has been prepared and its ability to form a supramolecular complex with an oligophenylenevinylene (OPV)–crown ether conjugate evidenced by NMR, electrospray mass spectrometry and luminescence experiments.

Thermal and Catalytic Reactions of Diazoacetylmetallocenes with [60]Fullerene

Diazoacetyl derivatives of ferrocene (2) and cymantrene (4) were submitted to thermal and dirhodium(II)tetraacetate catalyzed reactions with [60]fullerene (1). Thermal reaction of 2 afforded methanofullerene 3a and fulleroids 3b,c in variable amounts according to the reaction conditions, while 4 gave the methanofullerene 6 and the dihydrofuranofullerene 5 in ca. 1:1 ratio. Rh2(OAc)4-catalyzed reaction of 2 and 4 with C60 selectively afforded the corresponding methanofullerene derivatives 3a and 6, respectively, in high yields.

Nanoscale Aggregation of Fullerene in Nafion Membrane

Nanoscale aggregation of a new methanofullerene derivative with peripheral hydrophilic moieties was achieved within the confined space of a Nafion membrane. Transmission electron microscopic examination revealed an average size of 5.0 nm for the aggregates, while optical, fluorescence, and X-ray photoelectron spectroscopic measurements indicated excimer formation within the well-defined aggregated structure. These nanocomposites based on fullerene derivatives exhibit a significant optical-limiting capability attractive for many potential applications.

Photovoltaic Devices with Methanofullerenes as Electron Acceptors

In this paper, the electrochemical and photophysical properties of two well-solubilized monofunctionalized methanofullerene derivatives (TDC60 and TC60) were investigated by cyclic voltammetry, UV−visible absorption, and fluorescence spectroscopic methods. These two methanofullerenes show almost the same electron acceptor properties. The MEH-PPV/methanofullerene blends were made, and it was found that the photoluminescence of MEH-PPV could be quenched more efficiently by TDC60. The two methanofullerenes were used to fabricate organic photovoltaic devices by taking MEH-PPV as the electron donor. Although the photovoltaic properties of the MEH-PPV/methanofullerene devices are better than those of the pristine MEH-PPV, the MEH-PPV/TDC60 device system shows even better performances. Considering the similarities of the structures as well as the electron acceptor abilities, the better performance of the MEH-PPV/TDC60 photovoltaic device should be due to the better compatibility of TDC60 with MEH-PPV, which was confirmed by AFM investigation.

Polysiloxane-supported fullerene derivative as a new heterogeneous sensitiser for the selective photooxidation of sulfides to sulfoxides by 1O2

A heterogeneous photosensitiser for the generation of singlet oxygen was synthesized by covalent attachment of a methanofullerene derivative to polysiloxane-based Deloxan® DAP beads and its performance in the photooxidation of sulfides to sulfoxides was investigated. As opposed to C60 and many of its derivatives, the heterogeneous sensitiser can be readily used in protic solvents such as methanol which makes the photooxygenation highly selective, affording good to excellent yields of sulfoxides with aliphatic and benzylic sulfides. Moreover, the sensitiser is easily recovered at the end of the reaction by simple filtration.

Photovoltaic properties of nanocrystalline cuins 2 /methanofullerene solar cells

First attempts were made to use nanocrystalline CuInS 2 with the fullerene derivatives to form flat interface donor-acceptor heterojunction solar cells. We synthesized nanocrystalline CuInS 2 in a colloidal route, the particle surfaces were shielded by an organic surfactant. We present photovoltaic data ofnanocrystalline CuInS 2 Schottky diodes in comparison with heterojunctions of CuInS 2 and methanofullerene derivatives. Flat interface heterojunction solar cells show significant better photovoltaic response than solar cells consist of nanocrystalline CuInS 2 single-layers. In comparison to the single-layers, anincrease of cell efficiency about factor 25 is received.

Degradation of bulk heterojunction solar cells operated in an inert gas atmosphere: a systematic study

We present a systematic study on the degradation of polymer / fullerene bulk heterojunction solar cells. Degradation behavior of photovoltaic devices based on poly [2-methoxy, 5-(3',7'-dimethyl-octyloxy)]-p-phenylene vinylene (MDMO-PPV) mixed with the soluble methanofullerene derivative [6,6]-Phenyl C 61 -butyric acid methyl ester (PCBM) were investigated under inert gas atmosphere in the dark at room temperature, under enhanced temperature and under enhanced temperature together with illumination by white light at 80 mW/cm 2 light intensity. The influence on the degradation for exchanging the top electrode (Au instead of Al) was also investigated. Photothermal defect localization was performed on sealed polymer / fullerene photovoltaic devices.

Induced absorption of C60 and a water-soluble C60-Derivative in SiO2 sol-gel matrices

Porous sol-gel glasses, either impregnated with pure C60 or doped with a methanofullerene derivative, have been studied and induced absorption or “reverse saturable absorption” (RSA) has been observed in both types of solid materials. The samples impregnated by pure C60 mainly contain well-dispersed fullerene molecules. Unlike crystalline films of C60, their absorption dynamics can be well described by a 5-level model, developed for non-interacting C60-molecules in solutions. Methanofullerene samples, on the other hand, show signs of micellar aggregation and therefore RSA dynamics that are influenced by solid state effects. We observe an important decrease of transmission at high fluences for both kinds of samples, a shortened singlet-state lifetime to that observed in solution, but nonetheless, a triplet yield, that cannot be considered as negligible. In the case of pure C60 in a sol-gel matrix, we can explain the faster de-excitation dynamics, relative to behavior in solution, mainly by the absence of stabilizing aromatic solvents and also by the interaction of the amorphous environment with the molecules. Concerning the methanofullerene samples, the acceleration of the de-excitation dynamics can be principally attributed to solid-state effects due to the micellar aggregation.

All-Carbon [60]Fullerene Oligomers of Pearl-Necklace Type

The formation of all-carbon [60]fullerene derivatives was observed in the course of the thermolysis of methano-fullerene derivatives. IR, UV-Vis, GPC, 13C-NMR, TG-MS, TOF-MS and STM data are consistent with the formation of all-carbon [60]fullerene oligomers without a direct connection between fullerene cages but through one or two carbon atoms as bridges. Molecular masses up to 8000 amu have been detected by mass spectroscopy.

Synthesis and characterization of water-soluble amino fullerene derivatives

[formula: see text] A series of amino-substituted methanofullerene derivatives were prepared by mono-, tris-, and hexa-Bingel-Hirsch reactions using an N-protected malonate derivative. Upon scission of the protecting groups, the e,e,e-tris- and octahedral Th hexa-methano amino fullerenes were found to be among the most water-soluble fullerene derivatives yet prepared. 3He NMR data on corresponding adducts of 3He/C60 helped verify the assigned structures. UV spectral studies confirmed the influence of aggregation on solubility of these adducts in water.

A water soluble methanofullerene derivative: synthesis, micellar aggregation in aqueous solutions, and incorporation in sol–gel glasses for optical limiting applications

Amphiphilic methanofullerene derivative 1 is water soluble and micellar aggregation has been evidenced by small-angle X-ray scattering measurements and UV/Vis spectroscopy. Thanks to the high solubility of 1 in polar solvents widely used in sol–gel processing, successful inclusion of 1 in the sol–gel could be easily achieved. The optical limiting properties of the doped sol–gel samples have been evaluated and a fast S1–S0 relaxation has been observed for these samples. This observation appears to be consistent with the presence of micellar aggregates of 1 in the sol–gel. Indeed, the interactions between the fullerene spheres of neighbouring molecules in the clusters may be at the origin of this fast S1–S0 relaxation as already shown in solid C60-films.

A new pyridyl-substituted methanofullerene derivative. Photophysics, electrochemistry and self-assembly with zinc(II) meso-tetraphenylporphyrin (ZnTPP)

A new methanofullerene derivative with a pyridine residue at the methano bridge (PC60) has been synthesized. Its electrochemical and photophysical properties have been investigated in toluene solution along with those of the analogous fullerene mono-malonate adduct RC60, which does not contain the pyridyl moiety. PC60 and RC60 display almost identical steady state absorption and luminescence properties and transient absorption spectra, as shown by means of nano- and picosecond laser flash photolysis. Their markedly different spectroscopic features with respect to plain C60 are discussed, with the aid of semi-empirical calculations. PC60 binds zinc(II) meso-tetraphenylporphyrin (ZnTPP) through coordination of the pyridyl moiety to the zinc ion giving, to the best of our knowledge, the first non-covalent assembly of a porphyrin–fullerene diad. The association constant of the 1:1 complex between PC60 and ZnTPP has been determined at 300 K by 1H NMR (Ka=3600±150 L mol-1, C6D6 solution) and fluorescence titrations (Ka=3000±400 L mol-1, toluene solution). Mixtures of RC60 and ZnTPP have also been investigated, giving no evidence of association. Extremely fast ZnTPP luminescence quenching in the PC60–ZnTPP complex was observed by time-resolved luminescence spectroscopy (k>5×1010 s-1), tentatively attributed to an energy transfer mechanism. The bimolecular quenching constant of the lowest triplet excited state of ZnTPP by PC60 was determined via a Stern–Volmer analysis (kq=6.7×109 s-1).

Thermal Decomposition of Fullerene Derivatives A Synthesis Method of New Fullerene Based Molecules

The thermal decomposition of methano-fullerene derivatives such as ethoxycarbonyl methano[60] fullerene and various isomers of bis-(ethoxycarbonyl methano)[60] fullerene leads to new fullerene derivatives, which have been preliminary characterized. The analysis of separated species was performed by UV-VIS, IR, H- and C-NMR, STM, FAB, LDI and MALDI-TOF MS spectroscopy. One of the isolated phases is a C122 molecule with a dumbbell-like structure.

Photophysical Properties of Three Methanofullerene Derivatives

The three [6,6]-ring bridged methanofullerenes 1, 2, and 3 were synthesized; their ground-state absorption spectra in toluene and cyclohexane solutions are presented and possible assignments discussed. Although these three molecules are very different, they have very similar triplet–triplet spectra and near-unity values for the quantum yield for O2(1Δg) production by energy transfer from the triplet states, implying that the quantum yield of triplet production is approximately 1.

ChemInform Abstract: Chemoselective Synthesis and Resolution of Chiral (1,9) Methanofullerene(70) Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Quinone-Type Methanofullerene Acceptors: Precursors for Organic Metals

We report details on the synthesis and electrochemistry of quinone-type methanofullerene derivatives in which, depending upon the substitution pattern on the cyclohexanedienone moiety, the reduction potential can be tuned, leading to novel fullerene derivatives exhibiting better acceptor properties than C60. We also present the lowest energy conformers of these spiroannulated methanofullerenes. As expected, the anthrone derivative is not coplanar and is not perpendicular to the ball's surface.

Fullerene induced c-n bond breaking and formation: synthesis of fullerene pyrrolidine and methanofullerene sarcosine derivatives by photochemical addition of sarcosine ester to c 60

Sarcusine esters react with C 60 to produce both fullerene pyrrolidine and methanofullerene derivatives. A radical mechanism is proposed.