Apparent activation of H2O and elimination of H2 from gas-phase mixed-metal complexes containing silver, calcium and deprotonated glycine.

Rationale: Ion trap mass spectrometry was used to study the reactivity of species derived from gas-phase, mixed-metal complexes, [Ag2 Xx(Gly-H)3 ](+) , where Xx = Ca, Mg, Sr and Ag, and in particular the apparent activation of an H2 O ligand added during an ion-molecule reaction.

Methods: Precursor [Ag2 Xx(Gly-H)3 ](+) complexes were formed by electrospray ionization (ESI) using spray solutions in which AgNO3 , XxNO3 and glycine were mixed in a 1:1:3 molar ratio. Specific species for study of ion-molecule reactions were created in a "top down" fashion using collision-induced dissociation (CID).

Even-electron [M-H](+) ions generated by loss of AgH from argentinated peptides with N-terminal imine groups.

Rationale: Experiments were performed to probe the creation of apparent even-electron, [M-H](+) ions by CID of Ag-cationized peptides with N-terminal imine groups (Schiff bases).

Methods: Imine-modified peptides were prepared using condensation reactions with aldehydes. Ag(+) -cationized precursors were generated by electrospray ionization (ESI).

Formation of bare UO2(2+) and NUO(+) by fragmentation of gas-phase uranyl-acetonitrile complexes.

In a prior study [Van Stipdonk; et al. J. Phys.