Charge inversion

Charge-inversion mass spectrum. Charge-inversion processes of the type ... 

Besteman K, Zevenbergen MAG, Heering HA, Lemay SG. 2004. Direct observation of charge inversion by multivalent ions as a universal electrostatic phenomenon. Phys Rev Lett 93 170802/1-170802/4. 

Numerous processes may be linked to proton transfer and protonation/deprotonation reactions (for general descriptions of proton transfer see, for instance, [8.214-8.217]). Proton-triggered yes/no or +/- switching is contained in the ability of polyamine receptors and carriers to bind and transport cations when unproton-ated and anions when protonated also, zwitterions such as amino acids may change from bound to unbound or vice versa, when they undergo charge inversion as a function of pH. 

Zakett, D., Ciupek, J. D., and Cooks, R. G. (1981). Determination of polycyclic aromatic hydrocarbons in solvent-refined coal by negative chemical ionisation-charge inversion mass spectrometry/mass spectrometry. Anal. Chem. 53, 723-726. 

A new theory was proposed in which the adsorption of the ions of the electrolyte generates surface ion pairs (dipoles), which induce an electric field. In addition, the neighboring dip oles in water also generate a field in water. The restabilization of the colloidal dispersion at sufficiently high ionic strengths appears to be an effect of these fields. The charge inversion produced by the adsorption of the ions of the electrolyte plays also a role particularly for the high valency ions. 

Ionization, charge stripping or charge inversion (normally observed at collision energies of about 1 keV) ... 

Charge-inversion reaction. An ion/neutral reaction wherein the charge on the reactant ion is reversed in sign. 

Other types of reactions have been studied in collisional conditions, especially charge-inversion reactions. 

Bowie and co-worker [160,161] used the MIKE technique to measure such spectra in a study of compounds which led to practically no fragmentations. The charge inversion produced during collisions can be utilized to obtain a larger number of types of fragment ions ... 

Then the [M-H] ions may undergo a collisional charge inversion. 

A typical example is furnished by the study of p-chlorobenzoic acid. Indeed, the m/z 157 ion eliminates only CO2 to produce the m/z 113 negative ion. On the other hand, charge inversion generates a larger number of fragment ions (Figs. 33 and 34). 

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