Carbon cluster ions from low- and high-temperature glassy carbon, highly oriented pyrolytic graphite, and polycrystalline graphite

• Published in: Chemistry of materials Vol. 5; no. 5; pp. 648 - 651
• Main Authors: May, Michael A, Huston, Michael E, Callstrom, Matthew R, Marshall, Alan G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.1993
• Subjects: 400201 - Chemical & Physicochemical Properties; Applied sciences; CARBON; CHARGED PARTICLES; CYCLOTRON RESONANCE; DESORPTION; ELECTROMAGNETIC RADIATION; ELEMENTAL MINERALS; ELEMENTS; Exact sciences and technology; FULLERENES; GRAPHITE; Inorganic and organomineral polymers; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ION CYCLOTRON-RESONANCE; IONS; LASER RADIATION; MASS SPECTROSCOPY; MINERALS; NONMETALS; Physicochemistry of polymers; Preparation; RADIATIONS; RESONANCE; SORPTION; SPECTROSCOPY; SYNTHESIS; Fullerene; Cage compound; Glassy polymer; Polycrystal; Temperature effect; Ions; Aggregate; Orientation; Carbon Compounds; Pyrographite
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm00029a012

Carbon cluster ions have been produced by pulsed Nd:YAG laser desorption of four sp[sup 2]-hybridized carbon solids: glassy carbon-6 (GC-6), glassy carbons-25 (GC-25), highly oriented pyrolytic graphite (HOPG), polycrystalline graphite, and the oligomeric precursor to GC-6, poly(phenylenediacetylene). The desorbed ions were detected by Fourier transform ion cyclotron resonance mass spectrometry. Under similar laser and mass spectrometry conditions, polycrystalline graphite yielded abundant fullerene ions (C[sub 44][sup +] to C[sub 124][sup +]). GC-6, synthesized by a low-temperature route, gave increased ion populations from C[sub 14][minus] to C[sub 25][minus] relative to conventional GC-25. Laser desorption of the organic precursor, poly(phenylenediacetylene), yielded fullerenes from C[sub 60][sup +] to C[sub 15-][sup +] in positive-ion mode, and C[sub 3][minus] to C[sub 10][minus] in negative-ion mode. The present results show that (a) pulsed laser desorption of polycrystalline graphite produces a higher yield of fullerence cations compared to other sp[sup 2]-type carbon solids, (b) low-mass carbon cluster ions from C[sub 14] to C[sub 30] are consistently produced from all four carbon solids as positive ions but not as negative ions, and (c) no fullerene anions are produced from any of the carbon solids under these experimental conditions, implying different formation mechanisms for positive and negative carbon cluster ions. 59 refs., 3 figs., 1 tab.