A significant asymmetry in the intensities of the observed covariances was noted. On the one hand, in Figure , we see clear signals for the small reference ions (C + 2 -C + 5 ) of interest recoiling against larger monocations (C + 8 -C + 11 ) in the pairwise dissociation of the parent and of the acetylene-loss fragment C 11 H 2+ 8 . On the other hand, the inverted covariances, e.g., C 10 H + y ion of interest against C 3 H + x , are significantly less intense (however, present). This asymmetry is also a signature of sequential fragmentation, in which the fraction of events producing stable large fragments is much lower than the fraction of metastable large fragments that undergo further fragmentation, producing smaller ions without larger counterparts.