Chlorination of charged buckyballs: reactions of C 60x+ cations ( x = 1–3) with Cl 2, CCl 4, CDCl 3, CH 2Cl 2, and CH 3Cl

Abstract

The chlorination of singly and multiply charged C 60 cations has been investigated with the selected-ion flow tube technique. Observations are reported for the reactions of C 60 ·+, C 60 2+ and C 60 ·3+ with Cl 2, CCl 4, CDCl 3, CH 2Cl 2 and CH 3Cl at room temperature (295 ± 2 K) in helium at a total pressure of 0.35 ± 0.02 Torr. C 60 ·+ and C 60 2+ were observed not to chlorinate, or react in any other way, with these five molecules. Chlorine also did not react with C 60 ·3+, but bimolecular chloride transfer and electron transfer reactions, reactions that result in charge reduction/charge separation, were observed to occur with CCl 4, CDCl 3, CH 2Cl 2 and CH 3Cl. Chloride transfer was the predominant channel seen with CCl 4, CDCl 3 and CH 2Cl 2 while electron transfer dominates the reaction with CH 3Cl. These results are consistent with trends in chloride affinity and ionization energy. The reluctant chlorination of the first two charge states of C 60 is attributed to the energy required to distort the carbon cage upon bond formation, while the observed chloride transfer to C 60 ·3+ is attributed to the greater electrostatic interactions with this ion.