Synthesis of higher diamondoids by pulsed laser ablation plasmas in supercritical CO2

Sho Nakahara, Sven Stauss, Toru Kato, Takehiko Sasaki, Kazuo Terashima

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40 Citations (Scopus)


Pulsed laser ablation (wavelength 532 nm; fluence 18 J/cm2; pulse width 7 ns; repetition rate 10 Hz) of highly oriented pyrolytic graphite was conducted in adamantane-dissolved supercritical CO2 with and without cyclohexane as a cosolvent. Micro-Raman spectroscopy of the products revealed the presence of hydrocarbons possessing sp3+-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 CO2 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 CO2 is proposed as a practical method for synthesizing diamondoids.

Original languageEnglish
Article number123304
JournalJournal of Applied Physics
Issue number12
Publication statusPublished - 2011 Jun 15
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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