Chlorination of charged buckyballs: reactions of C-60(x+) cations (x = 1-3) with Cl-2, CCl4, CDCl3, CH2Cl2, and CH3Cl

The chlorination of singly and multiply charged C-60 cations has been inves tigated with the selected-ion flow tube technique. Observations are reporte d for the reactions of C-60(.+), C-60(2+) and C-60(. 3+) With Cl-2, CCl4, C DCl3, CH2Cl2 and CH3Cl at room temperature (295 +/- 2 K) in helium at a tot al 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. Chlori ne also did not react with C-60(. 3+), but bimolecular chloride transfer an d electron transfer reactions, reactions that result in charge reduction/ch arge separation, were observed to occur with CCl4, CDCl3, CH2Cl2 and CH3Cl. Chloride transfer was the predominant channel seen with CCl4, CDCl3 and CH 2Cl2 while electron transfer dominates the reaction with CH3Cl. These resul ts are consistent with trends in chloride affinity and ionization energy. T he reluctant chlorination of the first two charge states of C-60 is attribu ted 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 gre ater electrostatic interactions with this ion. (C) 1999 Elsevier Science B. V.