Singly-charged ions, large

The elder model of ion formation, the charged-residue model (CRM), assumes the complete desolvation of ions by successive loss of all solvent molecules from droplets that are sufficiently small to contain just one analyte molecule in the end of a cascade of Coulomb fissions. [9,42,84] The charges (protons) of this ultimate droplet are then transferred onto the molecule. This would allow that even large protein molecules can form singly charged ions, and indeed, CRM is supported by this fact. [23]... 

In principle, the mass range of MALDI is almost unlimited and MALDI sources preferentially generate singly-charged ions so that broad charge distributions can by and large be avoided. The laser beam is applied in the form of short shots, so... 

In general, it is not possible to add or remove a second electron from a small molecule to yield a stable species. In the case of a double positive charge, M., the molecule dissociates into two singly charged ions. would simply not be formed in detectable amounts. In both cases, however, as M becomes very large, stable, multiply charged species can exist. 

The molecular form of any ion in aqueous solution depends largely upon the size and charge (oxidation state) of the central atom. These two properties influence the extent of any interaction with the solvent water molecules. A large singly charged ion is likely to be simply hydrated. In the case of a transition metal ion, there are commonly six water... 

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