Nonreactive ligand concentration

Electrospray ionization will often produce ions that are fully coordinated, stable, and nonreactive in the gas phase. These ions may be probed by removal of ligands to form coordinatively unsaturated ions that are generally reactive. The chemical activity of metal cluster ions differs markedly and often shows size specific enhanced reactivity or lack of reactivity. Silver cluster ions Ag are fairly inert similar to Ag+. Platinum cluster ions PL are quite reactive similar to Pt+. Often, large cluster ions only appear to react with one donor molecule such as benzene this may be due to low concentrations of reactants or short reaction times. Similar clusters may react with a larger number of smaller molecules, and so until more information is available, rules for the coordination behavior of metal clusters are as yet not available. 

All monofunctional modifiers decrease the surface concentration of silanols by 50% (depending on the alkyl ligand) compared to original silica (7.6pmol/m ), while difunctional modifiers only slightly reduces the surface concentration of silanols by 12% and trifunctional modifiers apparently increases the amount of silanols. This reflects actual hydrolysis of nonreacted chlorine groups of the alkyl di- and trifunctional modifiers and their conversion into silanols. 

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