Special Feature: Perspective
Charge inversion mass spectrometry: dissociation of resonantly neutralized molecules
Article first published online: 18 FEB 2004
Copyright © 2004 John Wiley & Sons, Ltd.
Journal of Mass Spectrometry
Volume 39, Issue 2, pages 111–135, February 2004
How to Cite
Hayakawa, S. (2004), Charge inversion mass spectrometry: dissociation of resonantly neutralized molecules. J. Mass Spectrom., 39: 111–135. doi: 10.1002/jms.613
- Issue published online: 18 FEB 2004
- Article first published online: 18 FEB 2004
- Manuscript Accepted: 27 OCT 2003
- Manuscript Received: 14 APR 2003
- Ministry of Education, Culture, Sports, Science and Technology. Grant Number: 13640515.
Charge inversion mass spectrometry is an MS/MS method in which the electric charge of the precursor ions is opposite to that of the secondary product ions. Charge inversion mass spectrometry is classified into four types depending on the electric charge and time scale of collisions. Charge inversion mass spectrometry using collisions with gaseous targets in the keV energy collision range has provided insights into the structures and reactions of ions and neutral molecules. The characteristics of charge inversion experiments are presented in terms of the reaction endothermicities and the cross sections and their dependence on the target species. In the case of rare-gas or simple molecular targets, double-electron transfer in one collision is effective to form positive ions from negative ions, while, in the case of alkali metal targets, successive single-electron transfers in two collisions is effective to form negative ions from positive ions. On the basis of the observed target-density dependence of the product ion intensity and thermochemical considerations for internal energy distribution using thermometer molecules, the charge inversion processes using alkali metal targets have been confirmed to occur by electron transfers in successive collisions and the dissociation processes are found to occur in energy-selected neutral species formed from near-resonant neutralization with alkali metal targets. While collisionally activated dissociation (CAD) is due to dissociation of activated ions with broad internal energy distributions, the charge inversion process using alkali metal targets is due to dissociation of energy-selected neutral species with narrow internal energy distributions. The charge inversion/alkali metal spectra provide clear differentiation of the isomeric cations of C2H2, C3H4 and dichlorobenzenes. The CAD spectra of these isomeric cations are similar. Copyright © 2004 John Wiley & Sons, Ltd.