Charge-permutation reactions

Charge-permutation reaction. An ion/neutral reaction involving a change in the-magnitude-... 

Apart from the endoergic dissociation reactions mentioned above, a variety of other reactions can also be accessed in tandem mass spectrometry. In many such reactions, collectively termed charge-permutation reactions, there is a change in the charge of the colliding species during the collision-activation step. Some of the reactions are discussed here. For further reading, an excellent review on the subject can be consulted [32]. 

A major advantage of these sector instruments is that all four types of scan functions (Section 4.2) can be implemented. Multisector instruments also have the facility to perform MS" experiments. The number of stages, n, of MS analysis is, however, restricted to the number of sectors in that tandem instrument. In addition, the charge-permutation reactions of fast-moving species, mentioned in... 

What types of charge-permutation reactions can be implemented on magnetic-sector tandem MS/MS instruments ... 

M. He and S. A. McLuckey, Charge permutation reactions in tandem mass spectrometry, 7. Mass Spectrom. 39, 1231-1259 (2004). 

Isomerization of ionic structures is frequently observed. Several mass spectrometry techniques have been developed to identify the structure of the ion formed initially or its isomerized form. These methods are based on determination of the heat of formation, study of metastable ion spectra and CID spectra, experiments involving kinetic-energy-release measurements, isotope labeling, charge-permutation reactions, ion-molecule reactions, field ionization kinetics, and ab initio calculations. 

Ionic dissociation of carbon-carbon a-bonds in hydrocarbons and the formation of authentic hydrocarbon salts, 30, 173 Ionization potentials, 4, 31 Ion-pairing effects in carbanion reactions, 15, 153 Ions, organic, charge density-NMR chemical shift correlations, 11,125 Isomerization, permutational, of pentavalent phosphorus compounds, 9, 25 Isotope effects, hydrogen, in aromatic substitution reactions, 2,163... 

Besides these strict conservation laws (energy, momentum, angular momentum, permutation of identical particles, charge, and baryon and lepton numbers), there are also some approximate laws. Two of these parity and charge conjugation, will be discussed below. They are rooted in these strict laws, but are valid only in some conditions. For example, in most experiments, not only the baryon number, but also the nirmber of nuclei of each kind, are conserved. Despite the importance of this law in chemical reaction equations, this does not represent any strict conservation law, as shown by radioactive transmutations of elements. 

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