Chlorination of charged buckyballs: reactions

The chlorination of singly and multiply charged C60 cations has been investigated with the selected-ion flow tube technique. Observations are reported for the reactions of C60 , C60 21 and C60 z31 with Cl2, CCl4, CDCl3, CH2Cl2 and CH3Cl at room temperature (295 6 2 K) in helium at a total pressure of 0.35 6 0.02 Torr. C60 z1 and C60 21 were observed not to chlorinate, or react in any other way, with these five molecules. Chlorine also did not react with C60 , but bimolecular chloride transfer and electron transfer reactions, reactions that result in charge reduction/charge separation, were observed to occur with CCl4, CDCl3, CH2Cl2 and CH3Cl. Chloride transfer was the predominant channel seen with CCl4, CDCl3 and CH2Cl2 while electron transfer dominates the reaction with CH3Cl. These results are consistent with trends in chloride affinity and ionization energy. The reluctant chlorination of the first two charge states of C60 is attributed to the energy required to distort the carbon cage upon bond formation, while the observed chloride transfer to C60 z31 is attributed to the greater electrostatic interactions with this ion. (Int J Mass Spectrom 182/183 (1999) 349–356) © 1999 Elsevier Science B.V.