DOCSLIB.ORG

Metallofullerene and Fullerene Formation from Condensing Carbon Gas Under Conditions of Stellar Outflows and Implication to Star

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Metallofullerene and Fullerene Formation from Condensing Carbon Gas Under Conditions of Stellar Outflows and Implication to Star Metallofullerene and fullerene formation from condensing carbon gas under conditions of stellar outflows and implication to stardust Paul W. Dunka,b,1, Jean-Joseph Adjizianc, Nathan K. Kaiserb, John P. Quinnb, Gregory T. Blakneyb, Christopher P. Ewelsc,1, Alan G. Marshalla,b,1, and Harold W. Krotoa,1 aDepartment of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306; bIon Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310; and cInstitut des Matériaux Jean Rouxel, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6502, Université de Nantes, BP 32229 Nantes, France Contributed by Harold W. Kroto, August 29, 2013 (sent for review June 13, 2013) Carbonaceous presolar grains of supernovae origin have long confirmed to exist in circumstellar and interstellar environments. been isolated and are determined to be the carrier of anomalous C60 and C70 were first unequivocally detected in a planetary 22Ne in ancient meteorites. That exotic 22Ne is, in fact, the decay nebula in 2010, which was thought to be hydrogen deficient (11). isotope of relatively short-lived 22Na formed by explosive nucleo- Thereafter, Buckminsterfullerene was detected in hydrogen- synthesis, and therefore, a selective and rapid Na physical trapping rich [including the least H-deficient R Coronae Borealis stars] mechanism must take place during carbon condensation in super- (12, 13) and oxygen-rich environments (14), as well as the ISM nova ejecta. Elucidation of the processes that trap Na and produce (15) and a protoplanetary nebula (16). Moreover, fullerenes large carbon molecules should yield insight into carbon stardust have been detected in a host of other circumstellar and in- enrichment and formation. Herein, we demonstrate that Na effec- terstellar sources, with new reports of cosmic fullerene de- tection constantly emerging. tively nucleates formation of Na@C60 and other metallofullerenes during carbon condensation under highly energetic conditions in Fullerenes have recently been experimentally shown to self- assemble in condensing carbon through a closed network growth oxygen- and hydrogen-rich environments. Thus, fundamental car- (CNG) mechanism (17, 18), in which small fullerenes form ini- bon chemistry that leads to trapping of Na is revealed, and should tially and then progress into larger species, such as C60, by in- be directly applicable to gas-phase chemistry involving stellar envi- corporation of atomic and diatomic carbon into growing cages. ronments, such as supernova ejecta. The results indicate that, in That process resolves how fullerenes form spontaneously under addition to empty fullerenes, metallofullerenes should be constit- highly energetic conditions from carbon vapor, as well as how uents of stellar/circumstellar and interstellar space. In addition, C60 forms as the most abundant species. The CNG mechanism gas-phase reactions of fullerenes with polycyclic aromatic hydro- for fullerene formation should occur in condensing carbon vapor carbons are investigated to probe “build-up” and formation of of stellar ejecta; although, formation by photochemical pro- carbon stardust, and provide insight into fullerene astrochemistry. cessing of existing carbonaceous materials, such as hydrogenated amorphous carbon (HACs), polycyclic aromatic hydrocarbons ne of the most profound findings in cosmochemistry has (PAHs), or PAH-like structures, could also be important for- Obeen the isolation and study of presolar grains recovered mation routes (12, 19, 20). Indeed, such photochemical pro- from carbonaceous chondrites, which are ancient meteorites (1– cessing could work in tandem with CNG formation to produce 3). A particularly striking example is the micrometer-sized low- density graphite grains of supernovae origin (1, 4). This discovery Significance was due to identification of noble gas isotopic anomalies iden- ASTRONOMY tified by mass spectrometry; upon stepwise heating of bulk samples We experimentally study the processes that result in fullerene 22 of carbonaceous chondrite, highly enriched Ne is released (3, 4). formation in oxygen- and hydrogen-rich carbon gas. Metal- 22 That observation led to the possibility that exotic Ne was a decay lofullerenes are found to form as readily as empty cages and 22 product of the extinct nuclide Na, produced from a supernova thus, like fullerenes, should be important constituents of (cir- 22 explosion (5). Subsequently, Ne was used as a guide to pinpoint cum)stellar/interstellar space. Element trapping by metal- the tiny carbonaceous grains embedded within the bulk meteorite, lofullerene formation is shown to be selective and rapid, which and the supernovae origin was further confirmed by other isotopic can explain long-standing astrophysical puzzles such as the “cosmic fingerprints” (2–4). Thus, these particular carbonaceous anomalous element enrichment of stardust. Infrared spectro- grains represent a direct chemical sample from a supernova. scopic signatures are simulated to provide an observational Despite many detailed experiments on presolar carbonaceous test for metallofullerenes in space. Further, energetic reactions 22 grains, the mechanism whereby Na is selectively trapped to between larger polycyclic aromatic hydrocarbons (PAHs) and enrich stardust remains a puzzle. The carbon chemistry of su- fullerenes are established form stable classes of complex mol- pernova ejecta, in part, determines the composition of carbon ecules that hold high astrochemical importance. Bottom-up stardust. Supernovae-originating dust is ejected into the in- fullerene growth is also demonstrated to result from PAH terstellar medium (ISM), directly impacting interstellar chemis- processing, another potentially important extraterrestrial for- try and subsequent stellar evolution. Furthermore, dust is mation mechanism. ubiquitous in the universe, and recent observational studies – suggest that supernovae are major dust contributors (6 8). Author contributions: P.W.D., C.P.E., A.G.M., and H.W.K. designed research; P.W.D. and Therefore, study of the gas-phase chemical processes that can J.-J.A. performed research; N.K.K., J.P.Q., and G.T.B. contributed new reagents/analytic operate under conditions of stellar outflows should provide in- tools; P.W.D., J.-J.A., C.P.E., A.G.M., and H.W.K. analyzed data; and P.W.D., J.-J.A., C.P.E., sight into a broad range of phenomena, including stellar and A.G.M., and H.W.K. wrote the paper. interstellar chemistry, distribution of carbon in the universe, and The authors declare no conflict of interest. supernova mixing. 1To whom correspondence may be addressed. E-mail: [email protected], chris.ewels@ Fullerenes have been principal astronomic molecular targets cnrs-imn.fr, [email protected], or [email protected]. since the discovery of Buckminsterfullerene, C60 (9, 10). The This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. closed-caged molecules, however, have only recently been 1073/pnas.1315928110/-/DCSupplemental. www.pnas.org/cgi/doi/10.1073/pnas.1315928110 PNAS | November 5, 2013 | vol. 110 | no. 45 | 18081–18086 Downloaded by guest on September 25, 2021 C60 and other larger fullerenes in lower-energy conditions, out- spectrometer provides ultrahigh resolution and high mass accu- side of stellar environments. We note that because energetic racy, and overcomes that experimental challenge (22, 25). barriers are low or nonexistent for incorporation of C and C2 To probe the ability of Na to nucleate metallofullerene for- into closed cages and carbon catalyzed bond rearrangements mation in carbon plasma, a Na-doped carbon rod (1.0 atom % − (17), CNG formation should also be possible in circumstellar Na) was subjected to laser ablation (∼35 mJ∙cm 2 fluence or environments, such as planetary nebula. 5 mJ per pulse) under a 10-psi He flow. Because 22Na is not Many investigations into the astronomical origin of these hol- available for experimental study, 23Na is used. Both isotopes low caged molecules are currently under way. By contrast, little exhibit the same essential chemical reactivity and kinetics, and consideration has been given to endohedral metallofullerenes, thus 23Na can be used to accurately elucidate interaction of 22Na which are cages that encapsulate metals and other elements, as with carbon plasma. Fig. 1 shows the cluster cations generated relevant astrochemical species. Understanding how large carbon under conditions that yield empty-caged fullerenes. The empty- molecules can form in the hostile environments of stellar out- caged species are observed, as expected, but an entire family of flows is a central issue that should offer valuable information on carbon clusters containing a single Na atom is also present. the origin and cosmic role of fullerenes. Critical insight into Na@C60 forms as the most abundant species, followed by Na@C70. that problem can be achieved by study of the key processes All Na@C2n are unequivocally resolved from the “overlapping” and resulting molecular products formed through carbon con- empty cages. For example, as shown in Fig. 1, Na@C60 is clearly densation reactions in high-energy oxygen- and hydrogen-rich resolved from empty cage C62,definitively showing that Na@C60 environments. spontaneously forms in condensing carbon. Fragmentation ex- Herein, we explore carbon condensation and interaction with periments unambiguously confirm that Na@C60 and all other Na under highly energetic conditions by use of
Load more

Recommended publications
  • A Post-Buckminsterfullerene View of Carbon Chemistry
    A POST-BUCKMINSTERFULLERENE VIEW OF CARBON CHEMISTRY Harold Kroto School of Chemistry and Molecular Sciences, University of Sussex, Brighton, BNI 9QJ UK Keywords: Cs0, Fullerenes, carbon particles INTRODUCTION The discovery of c60 Buckminsterfullerene, Fig 1, has its origins in a research programme involving synthetic chemistry, microwave spectroscopy and radioastronomyl. In 1915, at Sussex (with David Walton), the long chain polyyne H-CeC-CsC-CsN was synthesised and studied by microwave spectroscopy. Subsequently, with Takeshi Oka and NRC(0ttawa) astronomers, the molecule was discovered in space, Fig 2, by radioastronomy using the laboratory microwave frequencies. This discovery led on to the detection of the even longer carbon chain molecules HCTN, HCgN and HCl.lN in the space between the stars2. Further work aimed at understanding the formation of the chains in space focussed attention on the possibility that they are produced at the same time as carbon dust in red giant stars1,*. During experiments at Rice University in 1985 (with James Heath, Sean O'Brien, Robert Curl and Richard Smalley), designed to simulate the conditions in these stars and explore their capacity for carbon chain formation, the exciting discovery that C60 was remarkably stable was made3. It was found that under conditions where almost all the atoms in a carbon plasma had nucleated to form microparticles the molecule c60 remained behind - together with some CTO. This result was, as is now well 'known, rationalised on the basis of the closed cage structure shown in Fig 1. It was proposed that the geodesic and aromatic factors inherent in such a structure could account for the stability of the molecule.
    [Show full text]
  • Formation of Buckminsterfullerene (C60) in Interstellar Space
    Formation of buckminsterfullerene ( ) C60 in interstellar space Olivier Berné1 and A. G. G. M. Tielens Leiden Observatory, Leiden University, P.O. Box 9513, NL- 2300 RA Leiden, The Netherlands Edited by Neta A. Bahcall, Princeton University, Princeton, NJ, and approved November 2, 2011 (received for review August 31, 2011) Buckminsterfullerene (C60) was recently confirmed as the largest region, at high angular resolution (Fig. 1). This measurement can molecule identified in space. However, it remains unclear how be used to derive the integrated intensity radiated by the nebula, and where this molecule is formed. It is generally believed that which can be used as a calibrator, to convert the Spitzer observa- C60 is formed from the buildup of small carbonaceous compounds tions of the PAHs and C60 bands into absolute chemical abun- in the hot and dense envelopes of evolved stars. Analyzing infrared dances of these species, allowing a quantitive study of PAH and observations, obtained by Spitzer and Herschel, we found that C60 C60 chemical evolution. is efficiently formed in the tenuous and cold environment of an interstellar cloud illuminated by strong ultraviolet (UV) radiation Measurement of the Far Infrared Integrated Intensity of Dust Emission I fields. This implies that another formation pathway, efficient at in the Nebula. The far infrared integrated intensity FIR was ex- low densities, must exist. Based on recent laboratory and theore- tracted by fitting the spectral energy distribution (SED) at each tical studies, we argue that polycyclic aromatic hydrocarbons are position in the cross-cut shown in Fig. 1. For these positions, we converted into graphene, and subsequently C60, under UV irradia- have used the brightnesses as measured by Herschel Photodetec- tion from massive stars.
    [Show full text]
  • Reactions of Graphene Oxide and Buckminsterfullerene in the Aquatic Environment Yingcan Zhao Purdue University
    Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations 8-2016 Reactions of graphene oxide and buckminsterfullerene in the aquatic environment Yingcan Zhao Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Part of the Environmental Engineering Commons Recommended Citation Zhao, Yingcan, "Reactions of graphene oxide and buckminsterfullerene in the aquatic environment" (2016). Open Access Dissertations. 896. https://docs.lib.purdue.edu/open_access_dissertations/896 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School Form 30 Updated PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Yingcan Zhao Entitled REACTIONS OF GRAPHENE OXIDE AND BUCKMINSTERFULLERENE IN THE AQUATIC ENVIRONMENT For the degree of Doctor of Philosophy Is approved by the final examining committee: Chad T. Jafvert Chair Timothy R. Filley Inez Hua Ronald F. Turco To the best of my knowledge and as understood by the student in the Thesis/Dissertation Agreement, Publication Delay, and Certification Disclaimer (Graduate School Form 32), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy of Integrity in Research” and the use of copyright material. Approved by Major Professor(s): Chad T. Jafvert Approved by: Dulcy M. Abraham 6/21/2016 Head of the Departmental Graduate Program Date i REACTIONS OF GRAPHENE OXIDE AND BUCKMINSTERFULLERENE IN THE AQUATIC ENVIRONMENT A Dissertation Submitted to the Faculty of Purdue University by Yingcan Zhao In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2016 Purdue University West Lafayette, Indiana ii To my parents and Liang, for their love, support and encouragement.
    [Show full text]
  • Carbon-Based Nanomaterials/Allotropes: a Glimpse of Their Synthesis, Properties and Some Applications
    materials Review Carbon-Based Nanomaterials/Allotropes: A Glimpse of Their Synthesis, Properties and Some Applications Salisu Nasir 1,2,* ID , Mohd Zobir Hussein 1,* ID , Zulkarnain Zainal 3 and Nor Azah Yusof 3 1 Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2 Department of Chemistry, Faculty of Science, Federal University Dutse, 7156 Dutse, Jigawa State, Nigeria 3 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; [email protected] (Z.Z.); [email protected] (N.A.Y.) * Correspondence: [email protected] (S.N.); [email protected] (M.Z.H.); Tel.: +60-1-2343-3858 (M.Z.H.) Received: 19 November 2017; Accepted: 3 January 2018; Published: 13 February 2018 Abstract: Carbon in its single entity and various forms has been used in technology and human life for many centuries. Since prehistoric times, carbon-based materials such as graphite, charcoal and carbon black have been used as writing and drawing materials. In the past two and a half decades or so, conjugated carbon nanomaterials, especially carbon nanotubes, fullerenes, activated carbon and graphite have been used as energy materials due to their exclusive properties. Due to their outstanding chemical, mechanical, electrical and thermal properties, carbon nanostructures have recently found application in many diverse areas; including drug delivery, electronics, composite materials, sensors, field emission devices, energy storage and conversion, etc. Following the global energy outlook, it is forecasted that the world energy demand will double by 2050. This calls for a new and efficient means to double the energy supply in order to meet the challenges that forge ahead.
    [Show full text]
  • Molecular Vibrational Modes of C60 and C70 Via Finite Element Method
    European Journal of Mechanics A/Solids 28 (2009) 948–954 Contents lists available at ScienceDirect European Journal of Mechanics A/Solids journal homepage: www.elsevier.com/locate/ejmsol Molecular vibrational modes of C60 and C70 via finite element method Du Jing a,b, Zeng Pan a,b,* a Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China b Key Laboratory for Advanced Materials Processing Technology, Ministry of Education of China, China article info abstract Article history: Molecular vibration spectra are of great significance in the study of molecular structures and characters. Received 26 September 2006 A widely-used analytical method of structural mechanics, finite element method, is imported into the Accepted 17 February 2009 domain of micro-scaled molecular spectra. The vibrational modes of fullerenes C60 and C70 are calculated Available online 28 February 2009 depending on uniform carbon–carbon bonding elements, each of which has three force constants that are determined by fitting the C60 Raman spectra experimental data and one ratio factor which is the Keywords: bond lengths ratio between the single and double bonds. The computational result shows reasonable Finite element method agreement with both calculated and experimental results published before. Fullerene Ó 2009 Published by Elsevier Masson SAS. C70 Molecular spectra 1. Introduction overlap (MNDO) (Stanton and Newton, 1988), Quantum-mechan- ical Consistent Force Field Method for Pi-Electron Systems (QCFF/ Since Kroto et al. discovered C60 by laser vaporizing graphite PI) (Negri et al., 1988), Austin Model 1 (AM1) (Slanina et al., 1989), into a helium stream (Kroto et al., 1985); an impressive experi- density functional theory (Adams et al., 1991; Choi et al., 2000; mental and theoretical effort has been undertaken towards this Schettino et al., 2001; Sun and Kertesz, 2002; Schettino et al., 2002).
    [Show full text]
  • An Overview of Fullerene Chemistry
    Bull. Mater. So., Vol. 20, No. 2, April 1997, pp. 141-230. © Printed in India. An overview of fullerene chemistry S SAMAL* and S K SAHOO Department of Chemistry, gavenshawCollege, Cuttack 753 003, India MS received 4 April 1996; revised 3 October 1996 Abstract. Fullerenes which were thought to be 'superaromatics' are actually 'super- alkenes'. Reactions in fuUerenesare varied, ranging from the addition of simple molecules like H 2 to large moleculeslike dendrimers.The synthesis,structure, characterization,along with simple reactions like halogenation, oxygenation, metalation,cydoaddition, polymeri- zation and dendrimer addition are discussed. Keywards. Fullerenes;C6o; C7o; characterization;reactions. 1. Introduction Fullerenes and their derivatives possess a number of potentially useful physical, biological and chemical properties. Our interest in the chemistry of fullerenes led us to present this review in which we have attempted to furnish an overall picture of the properties of these novel molecules. The scope of the review is however limited. The conclusion of the authors contributing to this rapidly growing field of research are accepted and presented in a concise manner highlighting the salient features of the original work. The technique developed by Kr/itschmer et al (1990) for preparing and isolating macroscopic quantities of C6o, 'a new form of carbon', opened the way for exploring the molecular and bulk properties of these novel species. Kroto et al (1985) reported the nature and chemical reactivity of C6o species produced during the nucleation of carbon plasma. C6o , which was found to be stable, was named buckminsterfullerene after Buckminster Fuller, American architect, engineer and constructor of geodesic dome.
    [Show full text]
  • Buckminsterfullerene and Photodynamic Inactivation of Viruses
    Reviews in Medical Virology Rev. Med Virol. 8: 143–151 (1998) Buckminsterfullerene and Photodynamic Inactivation of } Viruses Fabian Käsermann1* and Christoph Kempf1,2 1Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland 2ZLB Central Laboratory, Blood Transfusion Service, Swiss Red Cross, Bern, Switzerland SUMMARY The development of new virus inactivation procedures has become an area of growing interest mainly due to increased demands concerning the safety of biological products. Photochemical processes represent the most promising methods for the future to inactivate viruses. In these methods, dyes are the most widely used photosensitising reagents. The current article covers a new interesting alternative, namely the use of buckminsterfullerene (C60). The unique properties of this molecule make it a valid candidate for future applications in the inactivation of viruses in biological fluids. 1998 John Wiley & Sons, Ltd. Accepted 14 November 1997 INTRODUCTION viruses. Enveloped viruses are inactivated more readily than nonenveloped, as destruction of the lipid membrane The development of new virus inactivation procedures, is accompanied by loss of virus infectivity. Fortunately, including studies with new compounds exhibiting the most important viruses that are transmitted by blood inactivation properties, has become a growing field of products are enveloped (Table 1). In addition to the research. New methods are needed because the safety of enveloped viruses listed in Table 1, two nonenveloped biological products (e.g. blood products, recombinant viruses, hepatitis A virus (HAV; positive-RNA virus; proteins used in medicine) has become a major issue Picornaviridae) and human parvovirus B19 (single- during the past few years. Although to date a high stranded DNA virus), were also discussed as possible 1–3 standard of safety has been achieved, it has to be borne in hazardous contaminants in blood products.
    [Show full text]
  • Electronic and Thermodynamic Properties of the Amino- and Carboxamido- Functionalized C-60-Based Fullerenes: Towards Non-Volatil
    Electronic and Thermodynamic Properties of the Amino- and Carboxamido- Functionalized C-60-Based Fullerenes: Towards Non-Volatile Carbon Dioxide Scavengers Nadezhda A. Andreeva(1) and Vitaly V. Chaban(2) (1) PRAMO, Saint Petersburg, Leningrad oblast, Russian Federation. (2) P.E.S., Vasilievsky Island, Saint Petersburg, Leningrad oblast, Russian Federation. Abstract. Development of new greenhouse gas scavengers is actively pursued nowadays. Volatility-caused solvent consumption and significant regeneration costs associated with the aqueous amine solutions motivate search for more technologically and economically advanced solutions. We hereby used hybrid density functional theory to characterize thermodynamics, structure, electronic and solvation properties of amino- and carboxamido-functionalized C60 fullerene. C60 is non-volatile and supports a large density of amino groups on its surface. Attachment of polar groups to fullerene C60 adjusts its dipole moment and band gap quite substantially, ultimately resulting in systematically better hydration thermodynamics. Reaction of polyaminofullerenes with CO2 is favored enthalpically, but prohibited entropically at standard conditions. Free energy of the CO2 capture by polyaminofullerenes is non-sensitive to the number of amino groups per fullerene. This result fosters consideration of polyaminofullerenes for CO2 fixation. Key words: buckyball; amine-functionalization; carbamate; CO2 capture; thermodynamics; DFT. 1 TOC image 2 Introduction Climate change constitutes one of the most significant global problems, which the humanity faces nowadays. According to some hypotheses, global warming is triggered by the concentration of the greenhouse gases (particularly carbon dioxide CO2) increase in the atmosphere. As CO2 has a number of industrial sources, many countries develop programs, which would allow them to decrease emission levels of CO2 during the next decades.
    [Show full text]
  • TOX-87: Fullerene C60 (1 Μm and 50 Nm) (CASRN 99685-96-8) Administered by Nose-Only Inhalation to Wistar Han [Crl:WI (Han)]
    NTP TECHNICAL R EPORT ON THE TOXICITY STUDIES OF Fullerene C60 (1μm and 50 nm) (CASRN 99685-96-8) Administered by Nose-only Inhalation to Wistar Han [Crl:WI (Han)] Rats and B6C3F1/N Me ic NTP TOX 87 JULY 2020 NTP Technical Report on the Toxicity Studies of Fullerene C60 (1 μm and 50 nm) (CASRN 99685-96-8) Administered by Nose-only Inhalation to Wistar Han [Crl:WI (Han)] Rats and B6C3F1/N Mice Toxicity Report 87 July 2020 National Toxicology Program Public Health Service U.S. Department of Health and Human Services ISSN: 2378-8992 Research Triangle Park, North Carolina, USA Fullerene C60, TOX 87 Foreword The National Toxicology Program (NTP), established in 1978, is an interagency program within the Public Health Service of the U.S. Department of Health and Human Services. Its activities are executed through a partnership of the National Institute for Occupational Safety and Health (part of the Centers for Disease Control and Prevention), the Food and Drug Administration (primarily at the National Center for Toxicological Research), and the National Institute of Environmental Health Sciences (part of the National Institutes of Health), where the program is administratively located. NTP offers a unique venue for the testing, research, and analysis of agents of concern to identify toxic and biological effects, provide information that strengthens the science base, and inform decisions by health regulatory and research agencies to safeguard public health. NTP also works to develop and apply new and improved methods and approaches that advance toxicology and better assess health effects from environmental exposures.
    [Show full text]
  • Rapid Communication Charge-Transfer Reactions of Fullerene Dications with Aromatic Hydrocarbon and Fullerene Molecules in the Ga
    International Journal of Mass Spectrometry and Ion Processes, 120 (1992) R5-R9 R5 Elsevier Science Publishers B.V., Amsterdam Rapid Communication Charge-transfer reactions of fullerene dications with aromatic hydrocarbon and fullerene molecules in the gas phase Gholamreza Javahery, Simon Petrie, Jinru Wang and Diethard K. Bohme Department of Chemistry and Centrefor Research in Earth and Space Science, York University, North York, Ont. M3J lP3 (Canada) (First received 22 May 1992; in final form 15 July 1992) ABSTRACT Results of selected-ion flow tube experiments are reported for reactions of Cg and C$ with benzene, naphthalene, anthracene, C, (buckminsterfullerene) and C,, at 294 i 2 K in helium gas at 0.35440 Torr. Charge transfer was the only observed product channel. No evidence was obtained for the occurrence of adduct formation. This rules out the ability of doubly-charged fullerene molecules to act as nuclei for the condensation of aromatic molecules and the formation of doubly-charged “strings of fullerene beads” by successive additions of fullerene molecules under these operating conditions. Keywork charge transfer; dications; fullerenes; aromatic hydrocarbons. INTRODUCTION The dications of fullerene molecules can be readily produced both by physical (e.g. electron or photon impact) and chemical ionization. The latter has been achieved only recently with unprecedented charge-transfer electron- detachment reactions at thermal energies between noble gas ions and fullerene molecules; we have drawn attention to the significance of such reactions with He’+ in the chemistry of interstellar environments [l]. Here we report ex- perimental results for reactions of the fullerene dications Cg and C$ with the aromatic hydrocarbon molecules benzene, naphthalene and anthracene, and the fullerene molecules C, and C,,.
    [Show full text]
  • Antitumor Activity and Potential Mechanism of Novel Fullerene Derivative Nanoparticles
    molecules Review Antitumor Activity and Potential Mechanism of Novel Fullerene Derivative Nanoparticles Lianjie Ye 1,2,† , Larwubah Kollie 1,†, Xing Liu 1, Wei Guo 1, Xiangxian Ying 3 , Jun Zhu 4, Shengjie Yang 2,4 and Meilan Yu 1,2,* 1 College of Life Science and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China; [email protected] (L.Y.); [email protected] (L.K.); [email protected] (X.L.); [email protected] (W.G.) 2 Shaoxing Academy of Biomedicine, Zhejiang Sci-Tech University, Shaoxing 312030, China; [email protected] 3 College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014, China; [email protected] 4 Hangzhou Wahaha Co., Ltd., Hangzhou 310018, China; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Abstract: The development of novel nanoparticles as a new generation therapeutic drug platform is an active field of chemistry and cancer research. In recent years, fullerene nanoparticles have received extensive attention due to their unique physical and chemical properties. Properly modified fullerene nanoparticles have excellent biocompatibility and significant anti-tumor activity, which makes them have broad application prospects in the field of cancer therapy. Therefore, understanding the anti- tumor mechanism of fullerene nanoparticles is of great significance for the design and development of Citation: Ye, L.; Kollie, L.; Liu, X.; anti-tumor drugs with low toxicity and high targeting. This review has focused on various anti-tumor Guo, W.; Ying, X.; Zhu, J.; Yang, S.; Yu, mechanisms of fullerene derivatives and discusses their toxicity and their distribution in organisms.
    [Show full text]
  • Thermally Metastable Fullerenes
    THERMALLY METASTABLE FULLERENES IN FLAMES BY TAPESH KUMAR YADAV Subnutted to the Department of Cherical Engineering in partial fulfillment of the requirements for the degree of DOCTOR OF PHELOSOPHY at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 1994 1994 Massachusetts Institute of Technology All rights reserved Signature of Author j;/ I,- -, I I - IV - , I-4)eMl --------t of Chemical- Engineering March 10, 1994 Certified by Jack B. Howard I---- Thesis Supervisor Accepted by !;dence RobertETohen "" Department Committee for Graduate Students JUN 6 994 Thermally Metastable Fullerenes in Flames by Tapesh Yadav Submitted to the Department of Chemical Engineering on March 10, 1994 in partial fulfillment of the requirements for the Degree of Philosophy in Chemical Engineering. ABSTRACT Fullerenes are closed caged molecules of pure carbon. These carbon molecules are produced in abundant quantities by certain sooting processes. In particular, fullerenes are observed in large quantities in the soot produced by low pressure (100 Torr), inert environment, vaporization of pure carbon and in the soot produced by low pressure 40 Torr) laminar combustion of premixed benzene/oxygen/inert vapors. Along with the observation of large quantities of fullerenes, many more observations can be made from the soot of the two processes. One particularly significant observation is the presence of many thermally metastable fullerenes in the soot produced by flames. This thesis focuses on an experimental and modeling study of one of the many thermally metastable fullerenes. Specifically, this thesis establishes the true identity of one of the thermally metastable ftillerene produced in flames; the thesis investigates where in the flame the thermally metastable fullerene forms; the thesis reports thermochernical.
    [Show full text]