Negative‐ion‐negative‐ion neutralization‐reionization (⁻NR⁻)

Abstract

There are four neutralization-reionization processes which can be studied. In the first two, gaseous cations are collisionally reduced and the resulting fast neutrals are either oxidized by collisional electron removal (

Modeling nucleobase radicals in the mass spectrometer

“…Even-electron anions are also useful precursors for the formation of radicals.38,39 Collisional electron detachment is typically accomplished with molecular oxygen as target gas. 25,38 The second important feature of collisional electron transfer is that it occurs on an extremely short timescale. Interaction between the unoccupied orbitals in the fast ion that accept the electron and the Ðlled orbitals in the donor molecule fades away exponentially with distance.…”

Ethylenedione: An Intrinsically Short-Lived Molecule

“…The experiments are denoted according to the charges of projectile and recovery ions: [13] neutralization of the cation followed by reionization to cations ( NR ) or anions ( NR À ), charge reversal of the cation ( CR À ) or the anion ( À CR ), and neutralization of the anion followed by reionization to cations ( À NR ) or anions ( À NR À ). Another major aspect is an advanced theoretical treatment of ethylenedione with consideration of the coupling of the singlet and triplet surfaces, as suggested by Berson et al [2] [*] Prof. Dr. H. Schwarz, D. Schröder, C. Heinemann [ ] …”

Modeling deoxyribose radicals by neutralization-reionization mass spectrometry. Part 1. Preparation, dissociations, and energetics of 2-hydroxyoxolan-2-yl radical, neutral isomers, and cations

“…The generation of transient radicals by Ϯ NR Ϯ mass spectrometry [35] relies on the knowledge of precursor ion structures that are prepared by reliable methods of gas-phase ion chemistry. Since radical 1 corresponds to a hydrogen atom adduct, a logical strategy consists of site-selective protonation followed by collisional reduction of the stable cation (Scheme 2).…”

“…To aid the identification of the ring-cleavage products, we obtained an Ϫ NR ϩ mass spectrum [35] of Ϫ CH 2 COOH. The precursor anion was generated by gas-phase desilylation of (CH 3 ) 3 SiCH 2 COOH with F Ϫ [41].…”