AbstractThe neutral products eliminated upon the collisionally activated dissociation (CAD) of C 60+zions (z= 1–4) are post‐ionized to cations or anions and collected in neutral fragment‐reionization (+NfR+,−) mass spectra. These spectra provide conclusive evidence that the decompositions C 60+ z→ C x+z+ C2n(wherex>30 and2n<30) proceed by cleavage of whole C2nclusters, not consecutive losses ofnC2. As teh charge of the fullerene precursor ion increases, the largest detectable neutral loss decreases, from C28forz= 1 to C12forz= 4. Post‐ionization of C2nto cations preferentially produces odd‐carbon cluster ions (e.g., C5+, C7+, C11+, C+15) whereas post‐ionization to anions yields abundant even‐carbon