Fragmentation dissociation

Fragmentation/dissociation—the molecule breaks into two or more fragments ... 

Photodissociation (PD) occurs when a precursor ion is excited by one or more photons and is subsequently fragmented. Dissociation can be induced by photons of a wide range of energies. 

It is notable that the GC samples in Table 4.1 are much too short for the Intermediate Zone formula to apply out to 120 ns. The formulas for subsequent zones of C (t) (Eqs. 4.38—4.41) are employed as needed and yield the same value of a for both 230- and 590-bp samples.(146) The 590-bp sample initially exhibited a threefold higher value, which relaxed over several months, during which time many very small fragments dissociated from, or annealed out of, the predominant 590-bp species. This was tentatively attributed to the presence of branched structures, which exhibit high affinity sites for ethidiuny in the original material. Both gel electrophoretic and electron microscopic 147 1 evidence for branched structures in poly(dG-dC) were noted.(146) The 500-bp length from gel electrophoresis was confirmed by sedimentation.(146)... 

X-ray diffraction and NMR studies have shown that metal fragments add exclusively across the [6,6] fusions to give rj2-type adducts. In contrast, organic derivatives add either to the [6,6] to form a closed adduct, or to the [6,5] fusions to form either an open or closed adduct (66). The ease with which some metal fragments dissociate off and on to the cage, in contrast to the organic derivatives, may explain the exclusive formation of the thermodynamically most stable [6,61-adducts. 

Chemisorption on the other hand, describes a surface process in which chemical bonds are formed between surface atoms and a molecule, that either retains its structural integrity (molecular adsorption) or undergoes fragmentation (dissociative adsorption). Typical examples are the sorption of ammonia on strong acid sites, with the formation of ammonium ions (Figure 8), and of hydrogen on a metal surface forming M-FI species. 

Ions can act, typically they fragment, dissociate, rearrange, react, isomerize etc. 

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