Presence Of Fullerene C60 Research Articles

Occurrence of natural fullerene C60 from the iridium-rich Cretaceous-Paleogene (K-Pg) boundary layers of the Um-Sohryngkew river section, Meghalaya, India

The presence of fullerene C60 in the iridium-rich Cretaceous-Palaeogene (K-Pg) boundary layer from the Um-Sohryngkew river section of Meghalaya is reported here for the first time. Different analytical methods, including transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared (FT-IR), and X-ray diffraction(XRD) techniques, have been used to characterize the presence of toluene-insoluble high-pressure phase of fullerene C60 in the acid resistant carbonaceous matter extracted from the Um-Sohryngkew river section, Meghalaya, India. Strong absorption peaks at wavenumbers 1427, 1181, 574, and 525 cm−1, which are indicative of pristine fullerene C60, can be seen in the FTIR spectroscopic study. The Raman spectrum also independently confirms the presence of fullerene, by exhibiting the characteristics peaks of pristine fullerene C60. The XRD technique provides further, independent validation of fullerenes, and the XRD pattern demonstrates fullerene presence. Fullerenes, high-pressure fullerene, the amorphous phase of C60, and iridium all coexist and offer conclusive proof of impact at the Cretaceous-Palaeogene (K-Pg) boundary extinction event.

An experimental investigation of the saturated vapor pressure of solutions proL pane in compressor oils in the presence of fullerene C60 in oil

An investigation of the saturated vapor pressure for the solutions of propane in the two type of industrial compressor oils ProEco®RF22S and RENISO SP46, also as in oil ProEco®RF22S containing fullerene C60 6.837·10-4kg·kg-1is presented in this paper. The measurement of the saturated vapor pressure was conducted using a static method in a temperature range (273…333) K and thepropanemass fraction (0.11…0.595) kg·kg-1.
 An analysis revealed that the expanded uncertainties of the measured saturated vapor pressure do not exceed 0.0419·105Pafor solutionpropane/ProEco®RF22S,0.0716·105Pa for solution propane /RENISO SP46, and 0.0095·105Pa for solution propane/ProEco®RF22 Scontaining C60.The temperature and concentration dependences of the saturated vapor pressure for the object of study have been discussed. The excess of saturated vapor pressure for the solution of propane in oil ProEco®RF22S over the pressure of the solution of propane in oil RENISO SP46 reaches 1.5 105 Pa at a temperature of 330 K and propane fractionof 0.1 kg·kg-1. This effect decreases with temperature decreasing and propane fraction increasing.It was proven that the additive of the fullerene C60 increase the saturated vapor pressure of the solution propane/ProEco® RF22S up to 0.4·105Pa at low temperature and low propane mass fraction insolution. 
 The results obtained proved the expediency of the introduction in the industry the solution of propane/compressor oil ProEco® RF22Scontaining the fullerene C60 as working fluid of vapor compression refrigeration system. The ability of C60additive in oil to increase the saturated vapor pressure of considered working fluid will contribute to increasing the energy efficiency of refrigeration systems.

Viability and phenotypic heterogeneity of Rhodococcus Rhodochrous CNMN-AC-05 in the presence of fullerene C60

Introduction. In recent years, due to wide applications of nanotechnologies in various fields, the safety of nanomaterials has become a pressing issue. Fullerene C60 is not an exception. Research on the activity of microorganisms and their interaction with nanoparticles is of major importance, both for microorganisms and for the ecosystem as a whole.
 Material and methods. Fullerene C60 powder was purchased from Sigma-Aldrich. The object of study was R. rhodochrous CNMN-Ac-05 strain. The number of viable bacterial cells was estimated by colony-forming units (CFU). The morphological features of the rhodococci colonies have been described according to the usual microbiological method.
 Results. It was established that fullerene C60 in concentrations of 1-25 mg/L fullerene C60 stimulated the growth of R. rhodochrous by 2.4-2.8 times. As the concentration of fullerene C60 increased up to 50-100 mg/L, the multiplication and growth of rhodococci decreased by 29.5% and 38% respectively. In the presence of 1-10 mg/L fullerene C60 the rhodococci population remained homogeneous, being composed of 100% S type colonies. The increase of fullerene C60 concentration led both to the decrease in the CFU number and to the appearance of R type colonies, up to 1.3% of population.
 Conclusions. Fullerene C60 in concentrations 1-100 mg/L had no obvious toxic effect on the rhodococci strain. The optimum concentration is 10 mg/L. The concentrations higher than 25 mg/L led to the dissociation of rhodococcal population and diminution in the CFU counts, but not to the total inhibition.

New Pd‐phosphorus ylide complexes based on FC60 as heterogeneous nano‐catalyst for H/D exchange reaction

In this account, new Pd(0) complexes of phosphorus ylides based on fullerene C60 (FC60) were synthesized and utilized as the first fullerene‐based heterogeneous nano‐catalysts for H/D exchange reaction. Four new palladacyclopropa‐[60]fullerene complexes 1–4, [(η2‐C60)Pd(Y1–4)2] (Y1 = PPh3CHC(O)C6H4‐p‐NO2, Y2 = PPh3CHC(O)C6H4‐p‐CH3, Y3 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐NO2, and Y4 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐CH3), were prepared through dissolving the related α‐keto stabilized phosphorus ylide in toluene solution in the presence of FC60 and Pd (dba)2 (dba = dibenzylideneacetone). All of the complexes were characterized using Nuclear magnetic resonance (NMR) (1H, 13C, and 31P), Infrared spectroscopy (IR), Ultraviolet‐visible spectroscopy (UV‐visible), fluorescence, Electrospray Ionisation Mass Spectrometry (ESI‐MS), and Energy‐dispersive X‐ray spectroscopy (EDX) spectroscopies, and scanning electron microscopy (SEM) and TEM techniques. The data proved that FC60 and two ylides were coordinated to Pd(0) center through two hexagons and two ylidic carbon atoms, respectively. An evaluation was also performed to compare the catalytic activity of synthesized Pd complex 1 and a conventional heterogeneous catalyst, 10% Pd on carbon, in H/D exchange reaction. The results indicate that the process of H/D exchange reaction in aromatic rings of benzoic acid derivatives progressed more efficiently by Pd complex 1.

Reactions of fullerene C60 with methyl methacrylate radicals: A density functional theory study

AbstractWe have investigated the stepwise addition of four growing methyl methacrylate (MMA) radicals to C60 fullerene, taking into account all possible types of the formed adducts. This reaction set is a reliable approximation for understanding the MMA polymerization process in the presence of C60 fullerene. We have analyzed the structures of the fullerene‐MMA adducts and energy parameters of their formation (heat effects and activation enthalpies). We found that up to three MMA growing radicals are favorably attached to C60 as the fullerene‐MMA trisadduct is a stable radical of the allyl type. It is inactive for further radical addition, and the elimination of the hydrogen atom from the growing MMA radical becomes preferable. The effects of steric factors and structures of the products of multiple growing MMA radical additions to C60 on the radical polymerization of MMA in the presence of C60 fullerene are considered.

Simulation of Potentially Possible Reactions at the Initial Stages of Free-Radical Polymerization of Styrene and Methyl Methacrylate in the Presence of Fullerene C60

The quantum-chemical simulation of possible reactions occurring at the initial stage of the free-radical polymerizations of styrene and methyl methacrylate in the presence of fullerene C60 is performed. The reactions of interaction between initiating and model short-chain growing radicals containing from one to three monomer units with fullerene are considered. It is shown that, at the initial stage of styrene polymerization, the addition of short-chain growing radicals to fullerene predominates (with respect to the reaction of chain propagation). In the case of methyl methacrylate polymerization in the presence of fullerene C60, the induction period is absent because of a higher probability of the initiation and chain propagation reactions (compared with the chain-termination reaction of short growing poly(methyl methacrylate) chains on fullerene C60). The formation of bis- and trisadducts of fullerene C60 with short-chain styrene and methyl methacrylate growing radicals is analyzed. The quantum-chemical simulation results are confirmed by electron spectroscopy and ESR studies.

Therapeutic reactive oxygen generation

An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica particles to generate reactive oxygen species (ROS) in cells of two types (rat thymocytes, and transformed cells of ascite Erlich carcinoma, EAC, and leucosis L1210) is demonstrated. The damaging effect of photo excited C60-composites are shown, which appeared to be selective and manifested in transformed cells, but not in thymocytes. It has been shown that after the irradiation of aqueous solutions or cell suspensions in the presence of fullerene C60, the generation of reactive oxygen species is observed. It has been shown that the influence of photo excited fullerene C60 on metabolic processes depends on the composition of C60-containing complex and on the type of the cells. The damaging effects of photo excited fullerene C60-containing composites were demonstrated to be selective. The data presented suggest that the application of fullerene C60-containing composites for the selective activation of ROS-dependent death program in certain types of tumor cells is very promising.

Quantum chemical analysis of the mechanism of the participation of C60 fullerene in the radical polymerization of styrene and mma initiated by benzoyl peroxide or azobisisobutyronitrile

The formation of various fullerenyl radicals during the polymerization of methyl methacrylate (MMA) and styrene in the presence of C60 fullerene is studied using the density functional method. It is shown that the interaction of an initiating radical with the fullerene molecule, yielding fullerenyl radical, is less favorable in energy terms than the initiation of the chain, i.e., the interaction of the same radical with a monomer. For radical polymerization of styrene, the termination of polystyrene chains on the fullerene is thermodynamically more probable than the growth of polystyrene chains, with the reactions being equiprobable in the case of MMA polymerization. The addition of monomer molecules to fullerenyl radicals is characterized by an enthalpy of activation exceeding that for conventional free radical chain growth by no more than 1.4 to 2.3 times; the thus formed growth radicals with fullerene molecules incorporated into the backbone polymer feature a reactivity not inferior to conventional polymer growth radicals.

Water-soluble fullerene С60 derivative obtained by radiation polymerization of N-vinylpyrrolidone in the presence of С60

Method of radiation polymerization of N-vinylpirrolidone (NVP) in the presence of fullerene C60 has been used to obtain water soluble compound containing fullerene C60. The yield of resulted product was ~10% in the case of low-temperature radiation polymerization of NVP—C60 mixture in ethanol and ~40% at 300 K. The content of C60 in obtained product was ~0.5 wt.%.

Introduction of Fullerene as a New Carrier in Electromembrane Extraction for the Determination of Ibuprofen and Sodium Diclofenac as Model Acidic Drugs in Real Urine Samples

Introducing new additives in supported liquid membrane (SLM) as carriers is an interesting and debatable issue in the field of microextraction methods, especially in electro membrane extraction (EME). In this study, C60 fullerene was used as a new carrier in the SLM, and EME followed by high-performance liquid chromatography coupled with ultraviolet detection was optimized and validated for the quantification of ibuprofen and sodium diclofenac as two model acidic drugs. Optimized conditions for extraction of the mentioned drugs from 4.0 mL aqueous sample were obtained as follows: 1-octanol containing 0.6% (w/v) C60 fullerene as the SLM, potential difference of 6 V, 28 min as the extraction time, 12.8 as the acceptor phase pH value and 10.5 as the donor phase pH value. Under the optimized conditions, the enrichment factors were obtained within the range of 166–188, which corresponds to extraction recoveries of 83–94%. The limits of detection and quantification were in the range of 5–10 and 15–30 ng mL−1, respectively. To understand the influence of C60 fullerene on extraction efficiency, a comparative study was carried out between conventional EME and modified EME methods. The results showed that the presence of C60 fullerene in the SLM increased the overall analyte partition coefficient in the membrane and, therefore, led to an enhancement in analyte transport. Finally, the applicability of this method was evaluated by the extraction and determination of these drugs in real urine samples.

On the initial stage of the free-radical polymerizations of styrene and methyl methacrylate in the presence of fullerene C60

It has been demonstrated experimentally and theoretically that the essentially different inhibiting effects of fullerene C60 on the initial stage of the polymerizations of styrene and methyl methacrylate (including complete hampering of styrene polymerization throughout a long induction period) are of common kinetic nature. The difference arises from the competition between C60 and the monomer not for initiating radicals but for radicals originating from the monomer; that is, the difference stems from the competition between the chain propagation reactions and the termination reactions on fullerene molecules. As a consequence, the further development of the process is determined by the relative reactivities of the radicals toward C60 and towards their parent monomers.

Quantum chemical modeling of the addition reactions of 1‐n‐phenylpropyl radicals to C60 fullerene

Modeling of the addition of various radicals to C60 fullerene is currently an active research area. However, the radicals considered are not able to adequately model polymeric radicals. In this work, we have performed a theoretical study of the possible reactions of C60 fullerene with 1‐n‐phenylpropyl radicals, which are used to model polystyrene radicals. Several possible ways of subsequent addition of up to four 1‐phenylpropyl radicals to C60 have been analyzed, the structures of the intermediates have been defined and thermal properties, such as the activation enthalpies of the corresponding reactions, have been calculated using density functional theory with the approximation of PBE/3z. It is shown that the topology of the spin density distribution on the fullerenyl radical causes regioselectivity for further radical addition. According to the energetic characteristics of the reactions, we assume the possibility of formation of products of one‐, two‐, three‐, and four‐ addition of the growth radical to the fullerene core in radical polymerization of styrene in the presence of C60 fullerene. © 2016 Wiley Periodicals, Inc.

Synthesis of water-soluble starlike poly(N-isopropylacrylamides) with fullerene C60 as a multifunctional core

New water-soluble starlike polymers with a fullerene core are synthesized via the radical polymerization of N-isopropylacrylamide in the presence of fullerene C60. The starlike structures of the polymers are studied by the methods of gel-permeation chromatography and scanning-electron microscopy.

C60-Catalyzed Preparation of Aryl and Heteroaryl Magnesium and Zinc Reagents Using Mg/LiCl

Addition of a catalytic amount of C60 fullerene (3 mol %) catalyzes the insertion of magnesium to polycyclic aromatic halides, allowing the preparation of the corresponding Grignard reagents in good yields. Furthermore, the use of a cocktail of metallic salts (Mg, ZnCl2, LiCl) in the presence of C60 fullerene (3 mol %) allows preparation of some functionalized polyaromatic zinc reagents. The resulting organomagnesium and organozinc reagents efficiently underwent reactions with electrophiles, such as an aldehyde, an acid chloride, an allylic bromide, or an aryl iodide.

Effect of C60 fullerene on metabolic and proliferative activity of PKE cell line

The effect of C60 fullerene aqueous colloid solution (C60 FAS) on activity of redox and proliferative processes in PKE (transplantable cell line of pig kidney embryo) cells has been studied. In particular, it was established that the presence of C60 fullerene (127 microM) in culturing medium of PKE cells during 48 h did not change their ability to reduce non-toxic AlamarBlue redox indicator and proliferative activity.

Influence of molecular structure peculiarities of phthalocyanine derivatives on their supramolecular organization and properties in the bulk and thin films

In order to study the influence of molecular structure peculiarities on supramolecular organization and properties in the bulk and thin films of discotic mesogens six new mix-substituted phthalocyanine derivatives with 3,6-dioctyloxyphthalonitrile and 3,4,5,6-tetrachlorophthalonitrile fragments were synthesized. Temperatures of phase transitions, types of mesophase and their dependence on molecule structure, chemical nature, position and ratio of different substituents as well as presence of holmium in the metal complexes were analyzed. The behavior of the studied molecules on the boundary between water and air was investigated and the peculiarity of supramolecular organization in floating layers as well as in thin films was determined. Quenching of luminescence in solutions of the studied compounds in the presence of fullerene C60 was determined, thus giving prospects for application of these compounds as sensors for fullerene microquantities.

Solvent effect on the kinetics of the free-radical polymerization of styrene in the presence of fullerene C60

The induction period in the kinetic curves of styrene polymerization in the presence of fullerene C60 was found to increase significantly at a solvent (benzene, toluene, ortho-dichlorobenzene, CCl4) concentration of ≥50 mol %. The free-radical polymerization rates of styrene in the presence of fullerene C60 and solvents, the ratio of chain propagation and termination rate constants kp/k01/2, and the stoichiometric inhibition coefficient were determined.

Structure of phase-inversion membranes from small-angle neutron scattering data

The structure of gradient-porous (asymmetric) membranes based on polyamide imide at different conditions of their formation has been investigated using small-angle neutron scattering. It has been shown that the membranes consist of rigid porous networks with well-defined interfaces between the polymer and the pores. It has been found that there are differences in the packings of structural elements of porous membranes-spherical pores with radii from 4 to 100 nm—depending on the membrane preformation time, drying regime, and the presence of fullerene C60 for modifying the mechanical and selective properties of membranes. The membranes also contain larger pores of micrometer sizes. Differences in the rates of saturation of membranes with water and their limiting swelling ratios are found, which can be explained by the structure of the dense layers of membranes (skin layer) and their different hydrophilities (depending on the fullerene content).

Free-radical chain oxidation of 1,4-dioxane and styrene in the presence of fullerene C60

The antiradical activity of fullerene C60 was studied for the oxidation of 1,4-dioxane and styrene initiated by azobisisobutyronitrile and benzoyl peroxide as model reactions. The effective rate constants of the reaction of peroxyl radicals with fullerene C60 (k7) and the stoichiometric inhibition factor (feff) were determined in air (\(P_{O_2 }\) = 0.21 atm) and oxygen (\(P_{O_2 }\) = 1.0 atm). The rate of the liquid-phase oxidation of 1,4-dioxane does not depend on \(P_{O_2 }\), and the effective rate constant of inhibition is k7 = (2.4 ± 0.2) × 104 L mol−1 s−1. Chain termination in the oxidation of styrene occurs when C60 reacts with both the peroxyl radicals (k7 = (1.2 ± 0.1) × 103 L mol−1 s−1) and alkyl (k8 = 1.07 × 107 L mol−1 s−1) radicals.

Uraemic toxins generated in the presence of fullerene C60, carbon-encapsulated magnetic nanoparticles, and multiwalled carbon nanotubes.

Uraemic toxins—creatol and N-methylguanidine—are generated in conversion of creatinine in water in the presence of various forms of carbon such as fullerene C60, carbon-encapsulated magnetic nanoparticles, and multiwalled carbon nanotubes and oxygen. The conversion degree for creatinine was different for fullerene C60, CEMNPs, and MWCNTs and was 9% (3.6% creatol, 5.4% N-methylguanidine), 35% (12% creatol, 23% N-methylguanidine), and 75% (16% creatol, 59% N-methylguanidine), respectively.