Ion/Molecule Equilibria in the Vapors of the Systems Containing Higher Fullerenes

L.N. Sidorov, O.V. Boltalina, A.Ya. Borshchevsky and I.N. Ioffe

" Fullerenes. Recent advances in the chemistry and physics of fullerenes and related materials", edited by Karl M.Kadish and Rodney S. Ruoff, published by: the Electrochemical Society, Inc. 10 South Main Street, Pennington, New Jersey , v. 5, pp. 474-483, (1998)

ABSTRACT. Ion/molecule reactions in the saturated vapors of the systems, containing C60, C70 and higher fullerenes were studied in the temperature range 800-1000 K by Knudsen Cell Mass Spectrometry in order to verify the attainment of chemical equilibrium . For the electron exchange reactions the equilibrium was proved from the independence of the equilibrium constants upon the sharp change of the saturated vapor composition. This fact was utilized for measuring the EA's of some endohedral gadolinium metallofullerenes Gd@Cn It was shown, that for the reactions, supposing the exchange with carbon atom groups the equilibrium couldn't be attained irrespective of the objects (anions or neutral species) between which the exchange occurs. This eliminates any thermodynamic approach to the explanation of fullerene distribution similarity in the fullerene soot produced in KH processes. A simple bimolecular discrete-kinetic model was proposed to demonstrate carbon claster and fullerene distribution in KH process.

Laboratory of Thermochemistry