Laser‐induced molecular ion formation and gas‐phase ion formation from polycyclic aromatic hydrocarbons, coals and coal products detected by Fourier transform mass spectrometry

Greenwood, Paul F.; Strachan, Michael G.; Willett, Gary D.; Wilson, Michael

doi:10.1002/oms.1210250703

Cited by 67 publications

(18 citation statements)

References 31 publications

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“…rather than as [M + Na] + , even when the sample is doped with NaCl. 23 Fullerenes. The laser ablation FT/ICR mass spectrometry experiment shows that KCT-pitch pyrolysis residues can readily produce fullerene ions at the low-laser power range of between 20 and 2000 kW cm -2 .…”

Section: Resultsmentioning

confidence: 99%

Laser Ablation Mass Spectrometry of Pyrolyzed Koppers Coal-Tar Pitch: A Precursor for Fullerenes and Metallofullerenes

et al. 1999

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Pyrolyzed Koppers coal-tar pitch samples consisting mainly of polycyclic aromatic hydrocarbons were studied by direct laser vaporization Fourier transform ion cyclotron resonance and time-of-flight mass spectrometry. Fullerene cations were readily formed from these carbonaceous precursors over a wide range of low-laser ablation power densities. The laser-desorption ionization of the pyrolyzed coal-tar pitches shows the presence of a range of polyaromatic hydrocarbons some containing as many as 70 carbon atoms, which should require only small amounts of laser energy to convert them into fullerenes. Metallofullerene formation also occurs with low power laser ablation of pyrolyzed mixtures of metal oxides, metal sulfides, or metal carbonates and the Koppers coal-tar pitch. Ablation with two different laser pulse widths of 230 µs and 8 ns, at a laser wavelength of 1064 nm, shows that only the long-pulse low-power (200-2000 kW cm -2 ) laser radiation produces metallofullerene ions. The short-pulse high-power (1-2300 MW cm -2 ) laser ablation results only in the formation of small metal carbide cluster and fullerene ions. Collision-induced dissociation experiments were used to study the structures of the small metal carbide clusters and the endohedral metallofullerene ion, La@C 60 + . IntroductionShortly after the discovery of the hollow carbon cage molecules now known as fullerenes, Heath et al. reported that lanthanum atom(s) could be encapsulated in the fullerene cage. 1 The name endohedral metallofullerene written as A m @C 2n , where the symbol @ denotes that the metal atom (A) is located inside fullerene cage and m ) 1-3, n ) 30-70, has been assigned to this new family of fullerenes. 2,3 The novel properties and possible applications of these new molecules as nonlinear optical devices and catalysts, 4 superconductors, 5 lasers, and ferroelectric materials 4,6 have encouraged many researchers to commence macroscale production 3,7-9 and spectroscopic characterization 10-19 of metallofullerenes.Laboratory scale chemical studies on endohedral metallofullerenes are difficult because these species can only be produced with very low yields and so there is a demand for other methods of production or the discovery of new precursors. 20 To date, most of preparations have used graphite/metal or metal oxide mixtures as precursors with different vaporization sources. 8,9,21,22 Our studies on the other hand have been focused on the search for new fullerene and metallofullerene carbon precursors. [22][23][24][25][26][27][28][29][30][31][32][33][34] The use of metal-doped graphite rods with the arc vaporization method 35 and the laser ablation-furnace method 36,37 represent the two major methods for metallofullerene production. Of these two methods, the arc technique is preferred for macroscopic production and yields of less than 0.1% are still common for even the most abundant of the metallofullerenes (for example, La@C 82 ) 38 that can be isolated.

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Section: Resultsmentioning

confidence: 99%

Laser Ablation Mass Spectrometry of Pyrolyzed Koppers Coal-Tar Pitch: A Precursor for Fullerenes and Metallofullerenes

et al. 1999

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“…ablation of polymers (Creasy and Brenna, 1988), coal (Greenwood et al, 1990), and oil shales (Fisher et al, 1996). However, laser ablation power densities (e.g., >lo8 W are clearly different from those used for the detection of fullerenes in natural samples (e.g., lo5 to lo7 W Buseck et Daly et al, 1993;di Brozolo et al, 1994).…”

Section: 90gmentioning

confidence: 99%

Fullerenes, fulleranes and polycyclic aromatic hydrocarbons in the Allende meteorite

Becker

Bunch

1997

Meteorit & Planetary Scien

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Abstract-In this paper, we c o n f m our earlier observations of fullerenes (c60 and C70) in the Allende meteorite (Becker et al., 1994a(Becker et al., , 1995. Fullerene c60 was also detected in two separate C-rich (4.5-1.0%) dark inclusions (Heymann et al., 1987) that were hand picked from the Allende sample. The amounts of c 6 0 detected were -5 and -10 ppb, respectively, which is considerably less than what was detected in the Allende 15/21 sample (-100 ppb; Becker et al., 1994a, 1995). This suggests that fullerenes are heterogeneously distributed in the meteorite. In addition, we present evidence for fulleranes, (CSOH,), detected in separate samples by laser desorption (reflectron) time-of-flight (TOF) mass spectrometry (LDMS). The LDMS spectra for the Allende extracts were remarkably similar to the spectra generated for the synthetic fullerane mixtures. Several fullerane products were synthesized using a Rh catalyst (Becker et al., 1993a) and separated using highperformance liquid chromatography (HPLC). Polycyclic aromatic hydrocarbons (PAHs) were also observed (ppm levels) that included benzofluoranthene and corannulene, a cup-shaped molecule that has been proposed as a precursor molecule to the formation of fullerenes in the gas phase (Pope et al., 1993).

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“…For example, in the combustion process, fullerenes form in the presence of hydrogen and oxygen (4,5). In the laser ablation of polymers as well as of coals, fullerenes form in vapors containing nitrogen, sulfur, hydrogen, and oxygen (26)(27)(28). Bombardment of a polymer containing fluorine and hydrogen by a 1 2 7~1 4 ' -~e~ ion beam also produced fullerenes (6).…”

Section: Sciencementioning

confidence: 99%

Fullerenes from a Fulgurite

Daly

Buseck

Williams

et al. 1993

Science

110

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Peaks at 720 and 840 atomic mass units were identified by mass spectrometry in a sample extracted from a fulgurite, which is a glassy rock that forms where lightning strikes the ground. The peaks are interpreted as arising from C(60) and C(70) and the associated peaks as produced from other fullerenes. The intense conditions generated by the lightning not only melted the rock it struck and fused the associated soil but also allowed fullerenes to form, presumably from the organic debris in the soil.

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Laser‐induced molecular ion formation and gas‐phase ion formation from polycyclic aromatic hydrocarbons, coals and coal products detected by Fourier transform mass spectrometry

Cited by 67 publications

References 31 publications

Laser Ablation Mass Spectrometry of Pyrolyzed Koppers Coal-Tar Pitch: A Precursor for Fullerenes and Metallofullerenes

Laser Ablation Mass Spectrometry of Pyrolyzed Koppers Coal-Tar Pitch: A Precursor for Fullerenes and Metallofullerenes

Fullerenes, fulleranes and polycyclic aromatic hydrocarbons in the Allende meteorite

Fullerenes from a Fulgurite

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