PRODUCTION AND DECAY OF HIGHLY-CHARGED FULLERENE IONS

Highly-charged fullerene ions C-60(z+) and C-70(z+) with charge states up to z = 7 have been produced in an electron impact ion source of a two sector field mass spectrometer by using ion source operating condi tions similar to those used in EBIT sources. The stability of these io ns was investigated quantitatively in the two field free regions of th e mass spectrometer. It was found that besides C-2 evaporation the dom inant fission process for ions with charges larger than +2 is the loss of a charged C-2(+) unit via a super-asymmetric charge separation rea ction C-60(z+) --> C-58((z+1)+) + C-2(+) and C-70(z+) --> C-68((z-1)+) + C-2(+), respectively. The most important finding from 68 these stud ies is that this super-asymmetric dissociation reaction proceeds via a three stage reaction sequence involving an electron transfer reaction at the second stage between a receding C-2 unit and the remaining hig hly-charged fullerene cage.