In this study, the effect of helium pressure of plasma chamber upon yield of soot and fullerenes is reported. Making plasma discharge between two graphite rods, fullerenes were prepared and separated. In pressure range, 50-200 Torr, soot was produced in high yield of average 24%. Also, in the same pressure range, $C_{60}$ and $C_{70}$ were extracted from soot in high yield of 10% and 2%, respectively. And a trend was found that the yield of fullerenes from soot was proportional to the yield of soot. That is, the higher soot yield, the higher fullerenes yield from soot. The Soxhlet extract in benzene was composed of 50% $C_{60}$, 10% $C_{70}$, and 40% the others. Making an adsorption of the benzene extract on neutral alumina, and loading the adsorbed alumina onto column prepacked with neutral alumina, elution with hexane-toluene(95:5 v/v) mixed solvent afforded 74% recovery of pure $C_[60}$. Spectroscopic analyses of chromatographically separated $C_{60}$ were reported by high performance liquid chromatography(HPLC), FT-IR spectroscopy, and $C^{13}$ NMR spectroscopy.
Redox properties of $C_{60}$ in solution and film were studied through electrochemical methods, and the diffusion coefficient of $C_{60}$ in dichloromethane was measured. The diffusion coefficit of $C_{60}$ was by nonlinear regression analysis with Szabo theory of current as a function of time at finite disk electrode. And, the study of redox properties of $C_{60}$ in solution is accomplished through cyclic voltammetry(CV) and differential pulse voltammetry(DPV) using diameter 10㎛ carbon, 100 ㎛ platinum, and 2 mm platinum disk electrodes. The generation of $C_{60}^{n-}$ (n = 1-5) in solution was confirmed from the observation of five continuous reduction waves in benzene-acetonotrile(4:1 v/v) mixed solvent, but the generation of $C_{60}^{6-}$ in solution was confirmed from the observation of six continuous reduction waves in toluene-acetonotrile(5:1 v/v) mixed solvent. In particular, at 10 ㎛ carbon ultramicroelectrode, cyclic voltammogram of $C_{60}$ in dichloromethane showed three plateau with similar increasing height in a ratio of 1.0:1.1:1.0. This fact suggests that diffusion coefficients of $C_{60}$, $C_{60}^{-1}$, and $C_{60}^{-2}$ are very similar to one another.
