Charge separation processes of highly charged fullerene ions

Using high sensitivity two sector field mass spectrometric techniques (in particular MIKE scans) we have studied quantitatively (and systematically) the energetics of the superasymmetric spontaneous decay reactions (involving either C(2)(+) or C(4)(+) loss) of triply. quadruply, quintuply, and sextuply charged carbon clusters ions C(n)(z+) in the size range from n = 36 up to n = 70. From the kinetic energy release data determined, the apparent intercharge distance has been derived using different models including the simple point charges model, the movable charges model and the charged conducting sphere model. As in earlier but less extensive studies the intercharge distance obtained is for all three models used larger than the cage radius of the respective precursor fullerene ion. It is shown that this and other experimental results are only compatible with the recently suggested auto charge transfer (ACT) reaction as the decay mechanism responsible for the superasymmetric charge separation reactions, whereas two other conceivable decay mechanisms (ball-chain-propagation and decay of charged conducting liquid sphere) are nor consistent with all of the experimental fingerprints observed. (C) 1998 American Institute of Physics. [S0021-9606(97)02348-9].