I. Resolution improvement in Fourier transform mass spectrometry by harmonic detection. II. Mechanistic study on ligand substitution reactions of seventeen electron transition metal carbonyl radical anions in gas phase.

摘要

I. Ion cyclotron resonance signals at higher harmonics of the cyclotron frequency are discussed. If dissipation of the charge in an orbiting charge packet depends only on time, the linewidths of the signals at all harmonics are the same. The spacing between mass lines increases in direct proportion with harmonic order; therefore resolution increases in direct proportion with harmonic order. Selection rules are developed for a class of detection schemes that will detect selected harmonics. Both theory and experimental data suggest that it is possible to detect harmonics of arbitrary order in the absence of harmonic signals of lower order. Harmonic signal detection can be useful in improving resolution in ion cyclotron resonance mass spectroscopy without increasing data acquisition time or magnetic field strength. Application of harmonic detection in high pressure FT-ICR are discussed.;II. Rate constants for reactions of 17-electron transition metal carbonyl radical anions Ni(CO)