Synthesis of the Higher-Order Diamondoid Hexamantane Using Low-Temperature Plasmas Generated in Supercritical Xenon

Diamondoid molecules were synthesized from adamantane (C(10)H(16)) using low-temperature plasmas generated in supercritical xenon. The carbon content of the synthesized materials was verified by energy dispersive X-ray spectroscopy, while micro-Raman spectroscopy measurements confirmed that the synthesized materials contained sp(3) bonds, the features in the Raman spectra being similar to those found in the Raman spectra of higher order diamondoids. Mass peaks at m/z = 396 were most abundant and might be attributed to C(30)H(36) isomers of hexamantane. The synthesis of this particular type of diamondoid is explained by the fewer necessary cleavages of C-C bonds or C-H occurring to form the diamondoid. (C) 2010 The Japan Society of Applied Physics