Reaction of ammonia with accelerated benzoyl ions under multiple‐collison conditions in a triple quadrupole instrument

Abstract

The reaction of benzoyl ion with ammonia in multiple-collision conditions in the second quadrupole assembly of a triple quadrupole mass spectrometer at (laboratory) ion kinetic energies from 0 to 20 eV produced the even-electron ions [CsH5]', [C6H5NH3.(NH3),l+ ( m = 0 , l ) and [C6H5CONH3-(NH3),]+ (n = 0,1,2,3) and the odd-electron ions [CsH4NH3-(NH3),]+' (p = 0, I). Thermochemical information could not be obtained under multiple-collision conditions: both exothermic and endothermic reactions were observed, with no translational-energy onset measurable for the endothermic processes, nor decrease in the yield of the exothermic processes at high energies. The behaviour of cluster-ion intensities as pressure varied was qualitatively as expected. There are pressure and energy regions where spectra change little; if this feature were to be general, it would point to some utility for these conditions in qualitative analysis.

Endothermic ion-molecule reactions: strategies for tandem mass spectrometric structural analyses of large biomolecules

“…CONCLUSIONS MS/MS experiments in which ammonia was used as the target gas have been reported by a number of other laboratories (32, 33). White et al (32) investigated the products formed from the reaction of benzoyl cation with NH3. They observed products for which the reaction is exothermic, e.g.…”

Hydrogen/deuterium exchange mass spectrometry in the world of small molecules

“…Very early on, the quadrupole RF-only collision cell of the TQ was used to produce ion/molecule reactions with low-kinetic-energy selected ions from the first quadrupole (White, 1987). The RF-only multipole collision cell of triple quadrupoles (or Qq/TOF with segmented quadrupole; Chudinov et al, 2010) is particularly used for reactive collisions such as HDXs.…”

Ion–molecule reactions in the gas phase. Collision energy influence on the competitive S N i/S N 2 orientation from adduct ions of epimeric 1,2‐indanediols prepared by ammonia chemical ionization

“…Less frequently, the following stepwise pathway (Eqn (2)) is implicated as a nucleophilic attachment via the formation of carbonium R + species: 16 (2) This reaction, proposed to account for the racemization of the product ion RNH 3 + , is considered as a 'like S N 1' mechanism.…”

“…Under these conditions, several processes such as proton transfer, nucleophilic reagent attachment, and dissociation, occur competitively. However, stereochemical effects can be particularly analysed via collisionally activated reaction (CAR) spectra, 16 …”