Separation Of Fullerenes Research Articles

New Materials Based on Endohedral Fullerenes: Mo@C<sub>60</sub> Complex

In this paper a short introduction of endohedral fullerenes is given. Both, theoretical and experimental investigations of endohedral Mo@C 60 are presented. Molybdenum consists of 42 electrons, but in the interaction with C 60 cage, only 6 valence electrons are involved. On the other hand. molecule C 60 has 360 electrons, but 240 electrons are included in molecular orbitales formation. Theoretical calculation was carried out using HyperChem 4.5 software package. Calculation predict that HOMO-LUMO gap is 8.06 eV. Basic procedure for preparing and producing of this complex is given. Results of this research are discussed. Our further investigation will be carried out with the aim of improving production, extraction, and separation of endohedral fullerenes. We will try to find out new possibilities for application of endohedral complexes.

Separation and identification of higher fullerenes by high‐performance liquid chromatography coupled with electrospray ionization mass spectrometry

The separation and identification of higher fullerenes extracted from carbon soot were studied using high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS). The mixture of fullerenes extracted from carbon soot was first separated by a preparative-scale column packed with monomeric octadecylsilica (ODS), which mainly controls the elution order of fullerenes by their relative molecular mass. Then five batches of the fraction which should contain higher fullerenes larger than C84 were collected and subsequently concentrated, followed by analytical-scale separation with a polymeric ODS column, which can elute fullerenes according to their shape and structure. Therefore, this stationary phase can separate many isomers of higher fullerenes. By identification using LC-ESI-MS, the existence of several higher fullerenes up to C98 and their isomers were confirmed. Temperature effects in the separation of fullerenes were also examined and the results indicated that separation of C82 and C84 isomers could be achieved at a column temperature lower than 15°C using a polymeric ODS column. © 1998 John Wiley & Sons, Inc. J Micro Sep 10: 79–88, 1998

Separation and identification of higher fullerenes by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry

The separation and identification of higher fullerenes extracted from carbon soot were studied using high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS). The mixture of fullerenes extracted from carbon soot was first separated by a preparative-scale column packed with monomeric octadecylsilica (ODS), which mainly controls the elution order of fullerenes by their relative molecular mass. Then five batches of the fraction which should contain higher fullerenes larger than C84 were collected and subsequently concentrated, followed by analytical-scale separation with a polymeric ODS column, which can elute fullerenes according to their shape and structure. Therefore, this stationary phase can separate many isomers of higher fullerenes. By identification using LC-ESI-MS, the existence of several higher fullerenes up to C98 and their isomers were confirmed. Temperature effects in the separation of fullerenes were also examined and the results indicated that separation of C82 and C84 isomers could be achieved at a column temperature lower than 15°C using a polymeric ODS column. © 1998 John Wiley & Sons, Inc. J Micro Sep10: 79–88, 1998

ChemInform Abstract: New Sorbents Based on Tetraphenylporphyrin Bound to Silica Gel for the Separation of C60 and C70 Fullerenes.

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.

Optimization of the high-performance liquid chromatographic separation of fullerenes using 1-methylnaphthalene as the mobile phase on a tetraphenylporphyrin-silica stationary phase

The separation of C 60 and C 70 was studied on four different stationary phases. The performance of three commercial products, Buckyclutchers, PYE and PBB and of a new phase, immobilized tetraphenylporphyrin on silica, were investigated. The influence of the surface chemistry on this separation is discussed. On all four phases, good resolution is obtained with pure toluene as the mobile phase. With some of them, this result is obtained with stronger eluents, mixtures of toluene and 1-methylnaphthalene. This allows the injection of much more concentrated and larger samples than on conventional systems and gives considerably improved production rates of purified compounds. The optimization of the temperature, the flow velocity, and the mobile phase composition for the separation of C 60 and C 70 on the tetraphenylporphyrin bonded phase is discussed. The overloading of this stationary phase was studied empirically in mixtures of toluene and 1-methylnaphthalene. The advantage and properties of this latter solvent are illustrated. Fractions of C 60 with 98.5% purity and C 70 with a purity better than 99%% were prepared with near total recovery yield from 5 mg samples.

Separation of C60 and C70 fullerenes on silica modified by polyaromatic and π-acid aromatic compounds

Separation of C60 and C70 fullerenes by HPLC was studied using sorbents synthesized by reaction of perylenedicarboxylic anhydride, dimethoxyviolanthrene, the tetramer of chromotropic acid with formaldehyde (TCA), trinitrobenzoyl chloride, or chlorotrinitrobenzene with γ-aminopropyl silica. These sorbents possess satisfactory chromatographic properties. The sorbent based on TCA is effective for separation of preparative amounts of fullerenes.

New sorbents based on tetraphenylporphyrin bound to silica gel for the separation of C 60 and C 70 fullerenes

Sorbents prepared by reactions of chloromethyl- and chlorosulfo-derivatives of tetraphenylporphyrin (H2TPP) with γ-aminopropyl-silica gel (γ-APS) exhibit good chromatographic characteristics in the separation of C60 and C70 fullerenes; the sorbent based on Al(X) tetraphenylporphyrin sorbed on hydroxydimethylsilyl-silica gel [TPPAl(X)] is suitable for the large-scale separation of C60 and C70 fullerenes.

Separation of C60 and C70 fullerenes on silica modified with phthalocyanines

A series of stationary phases have been prepared by attachment of different phthalocyanines (PcM) to γ-aminopropyl silica and tested for HPLC separation of C 60 and C 70 fullerenes; strong dependence of chromatographic properties on the central metal ion and substituents of attached complexes was found, and for the phase containing 3-(β-naphthyloxy)-substituted PcCo good results were achieved.

Effect of temperature on the mechanism of retention of fullerenes in liquid chromatography using various alkyl bonded stationary phases

The temperature-dependency of the separation of fullerenes in liquid chromatography (LC) has been examined using various alkyl bonded stationary phases. It has been found that a maximum retention temperature exists with long alkyl bonded stationary phases, whereas there is no similar effect with the newly synthesized alkyl bonded phases which have two phenyl groups at the base of the bonded phase. The interpretation of the retention behavior of fullerenes in the low temperature region on alkyl bonded stationary phases is discussed using information obtained by CP-MAS solid-state NMR spectroscopy and LC.

Use of cerium oxide (CeO 2) as a packing material for the chromatographic separation of C 60 and C 70 fullerenes

Cerium oxide (CeO 2) was tested as a packing material in liquid chromatography for the separation of C 60 and C 70 fullerenes. The separation of C 60 and C 70 fullerenes could be achieved within 20 min by using pure n-hexane as the mobile phase. Furthermore, some higher fullerenes could also be separated in less than 40 min. The peak area was reproducible to a large extent. The separation of fullerenes by liquid chromatography on CeO 2 is shown to be an effective method for their isolation in large amounts. The column efficiency of the CeO 2 column was compared with commercial silica gel and ODS columns. The main advantage of the CeO 2 column is its ability to separate large amounts of fullerenes (C 60 and C 70) in toluene.

Fullerenes: Synthesis, Separation, Characterization, Reaction Chemistry, and Applications—A Review

The recently discovered third allotrope of carbon, the fullerenes, are a subject of very active research, particularly for chemists. They have a closed-cage structure, made by interlocking pentagonal and hexagonal panels, and are the only soluble form of carbon. In this review an attempt has been made to summarize ongoing fullerene research. The review covers methods of fullerene production and separation, mechanisms leading to closed-cage structure formation, structural characterization, reaction chemistry, and applications of this novel material. The emerging directions of research are also discussed.

95/05929 Chromatographic separation of fullerenes on various coals

95/05929 Chromatographic separation of fullerenes on various coals

Separation and identification of higher fullerenes in soot extract by liquid chromatography-mass spectrometry

Two-step liquid chromatographic separation (LC) has been applied to soot extract and the identification of higher fullerenes has been accomplished by LC-MS measurements using an ESI interface. The first separation step is preparative-scale LC using a 50 mm i.d. column packed with monomeric octadecylisilica (ODS) because elution is mainly controlled by relative molecular mass. 39 batches of five fractions each were collected and then as the second separation step each fraction was analysed by analytical-scale LC using a conventional column of a polymeric ODS phase which can elute fullerenes according to shape and structure. This stationary phase can also separate many isomers of higher fullerenes, consequently the existence of several higher fullerenes larger than C86 has been confirmed and their UV-Vis spectra were obtained by the photodiode array detection system coupled to the analytical LC.

High-Capacity Stationary Phases Containing Heavy Atoms for HPLC Separation of Fullerenes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-Capacity Stationary Phases Containing Heavy Atoms for HPLC Separation of FullerenesKazuhiro. Kimata, Tsunehisa. Hirose, Kouji. Moriuchi, Ken. Hosoya, Takeo. Araki, and Nobuo. TanakaCite this: Anal. Chem. 1995, 67, 15, 2556–2561Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue 1 August 1995https://doi.org/10.1021/ac00111a010RIGHTS & PERMISSIONSArticle Views354Altmetric-Citations64LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (625 KB) Get e-Alerts Get e-Alerts

Separation of Fullerenes with Novel Stationary Phases in Microcolumn High Performance Liquid Chromatography

Abstract Newly designed bonded phases have been synthesized and evaluated for the separation of fullerene molecules. Further investigations about the retention behaviour of fullerenes with these phases have been carried out systematically. In this study we describe the separation of fullerenes with novel bonded stationary phases in microcolumn high performance liquid chromatography (micro-HPLC) and also propose the basic separation mechanism of those molecules obtained from the preliminary chromatographic observations. The results indicate that the octadecyldiphenyl bonded silica phases, which have been synthesized from octadecyldiphenylchlorosilane as the silanization reagent, possess a better retentivity for fullerenes than the octadecyldimethylsilica phase (i.e. monomeric ODS phase) having a similar surface coverage value.

The kinetics of the reaction of C 60 and C 70 fullerenes with sodium metal in toluene solution

The kinetics of the reaction of C 60 and C 70 with metallic sodium in toluene solution at room temperature has been studied. The initial stage of reaction gives the fullerene monoanion, and the ratio of the reaction rate constants k(C 70)/ k(C 60) = 2.5 ± 0.1. This ration does not depend on the relative fullerene concentrations and absolute reaction rates, the latter being sensitive to the condition of the metal surface and so varies in an irregular manner. The possibility of using the difference in the reaction rate constants for the development of a fullerene separation and purification technology is discussed.

95/01429 Separation of fullerenes by chromatography on coal

95/01429 Separation of fullerenes by chromatography on coal

An Evaluation of the Differential Partitioning and Separation of C60and C70Fullerenes in a Biphasic System Using Centrifugal Partition Chromatography (CPC)

Abstract The partition coefficients of C60 and C70 fullerenes were measured in several different organic, 2-phase (liquid-liquid) systems using centrifugal partition chromatography (CPC). The partition coefficients of C60 and C70 were sufficiently different in some biphasic solvent systems to provide a CPC separation of these fullerenes. A phase diagram was made of the best 2-phase system for fractionating C60 and C70 fullerenes. This system contained the solvents 1,2-dichlorobenzene, isooctane, and dimethylformamide (DMF). The separation times, selectivity, and efficiency are affected by the ratios of the major solvent components, the addition of small amounts of a quaternary solvent, and the temperature (in addition to the usual instrumental parameters). Preparative separations of fullerenes were done and a maximum batch production was calculated for one solvent system. It appears that a significantly greater amount of fullerenes can be purified per run in this system than in corresponding HPLC systems....

A Comparative Study of Buckminsterfullerene and Higher Fullerene Separations by HPLC

Abstract Several HPLC columns that have been recommended for the separation of fullerenes were compared. Each column (i.e., stationary phase) had a different optimum mobile phase. In general, mobile phases consisted of binary mixtures of a “good” fullerene solvent and a “poorer” fullerene solvent. Reversed phase stationary phases with alkyl (aliphatic) substituents produced superior analytical separations for all fullerenes. However, stationary phases with aromatic substituents were better for preparative separations. Increasing the proportion of the “poor” fullerene solvent in the mobile phase generally increased resolution and retention but decreased the mass load. Injecting too high a concentration of fullerenes in any column caused peak splitting to occur. The fullerene retention order was the same on all columns and with all mobile phases. The fullerene separation ability of all columns tended to deteriorate with time. Overloading the column or doing preparative separations greatly accelerated the deterioration process. It is believed that irreversible adsorption of fullerenes or fullerene by-products is responsible for the degradation of column performance.

95/01428 Separation of componets in coal tar with centrifuge

A crude mixture of C60 and C70 fullerenes was chromatographed on coals of rank varying from brown coal to ‘pseudo’ semianthracite to determine their capability as a separation medium for purifying C60 fullerene. Considerable variation in separation performance was found between the coals. Treatment of all these coals with tetrahydrofuran improved their subsequent performance, probably owing to swelling of the coal, resulting in a more favourable pore structure. No correlation was observed between separation performance and carbon aromaticity as measured by n.m.r. Coals which are expected to have a high porosity in the transitional (mesopore) range (2–50 nm) appear to perform best, probably because this pore size is appropriate for fullerene separation.