Synthesis of higher diamondoids by pulsed laser ablation plasmas in supercritical CO{sub 2}

Journal Article · Wed Jun 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3599887· OSTI ID:21538432

Nakahara, Sho; Stauss, Sven; Kato, Toru; Terashima, Kazuo ^[1]; Sasaki, Takehiko ^[2]

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1. Department of Advanced Materials Science, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba (Japan)
2. Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba (Japan)

Pulsed laser ablation (wavelength 532 nm; fluence 18 J/cm{sup 2}; pulse width 7 ns; repetition rate 10 Hz) of highly oriented pyrolytic graphite was conducted in adamantane-dissolved supercritical CO{sub 2} with and without cyclohexane as a cosolvent. Micro-Raman spectroscopy of the products revealed the presence of hydrocarbons possessing sp{sup 3}-hybridized carbons similar to diamond structures. The synthesis of diamantane and other possible diamondoids consisting of up to 12 cages was confirmed by gas chromatography-mass spectrometry. Furthermore, gas chromatography-mass spectrometry measurements of samples before and after pyrolysis treatment indicate the synthesis of the most compact decamantane, namely, superadamantane. It is thought that oxidant species originating from CO{sub 2} during pulsed laser ablation might lead to the selective dissociation of C-H bonds, enabling the synthesis of low H/C ratio molecules. Therefore, laser ablation in supercritical CO{sub 2} is proposed as a practical method for synthesizing diamondoids.

• OSTI ID: 21538432
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 12; Other Information: DOI: 10.1063/1.3599887; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
ABLATION
BREEDING
CARBON DIOXIDE
DISSOCIATION
GAS CHROMATOGRAPHY
LASER RADIATION
MASS SPECTROSCOPY
OPERATION
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RECOMMENDATIONS
WAVELENGTHS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHROMATOGRAPHY
ELECTROMAGNETIC RADIATION
LASER SPECTROSCOPY
NUCLEAR FUEL CONVERSION
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SEPARATION PROCESSES
SPECTRA
SPECTROSCOPY