Ion–molecule reactions of C60Rh+ with CH3X, C6H5X(X = Cl, Br, I) and CH2I2

The gas-phase ion-molecule chemistry of exohedrally bound C60Rh+ with CH3X, C6H5X (X = Cl, Br, and I) and CH2I2 is studied using Fourier transform ion cyclotron resonance mass spectrometry. Reactions with CH3I and CH2I2 yield the buckminsterfullerene derivatives, C60CH3+ and C60CH2+, respectively. Energy resolved collisional activation experiments on these two product ions indicate that the methylene group is more strongly bound to C60 than the methyl group. This is consistent with methylene being bound by two carbon-carbon bonds to C60, while methyl is bound by a single carbon-carbon bond. Unlike CH3I, CH3Cl and CH3Br react with C60Rh+ in a stepwise fashion to yield C60Rh(CH2)n+ (n = 1 − 3). Interestingly, C60Rh(CH2)2,3+ are shown to be isomers of C60RhX+ (X = ethene, propene), possibly with a carbon-carbon bond formed with C60. Products containing more than three CH2 moieties were not observed. Reactions of C60Rh+ with C6H5X(X = Cl, Br, and I) yield C60Rh(C6H4)n+ (n = 1, 2), in a stepwise fashion via losses of HX. C60Rh(C6H4)2+ is unreactive with C6H5X. Again, indirect evidence for CC bond formation to C60 is obtained. Consistent with previous observations on C60Fe+ C60Co+, the Rh+–C60 bond energy is found to fall between those of Rh+–propene and Rh+–benzene, due to the alkene behavior of C60.