Fundamental Aspects of Gas Phase Ion Chemistry Studied Using the Selected Ion Flow Tube Technique

Abstract

Gas phase ion chemistry using the selected ion flow tube (SIFT) technique is discussed with the focus on fundamental studies on ion structure, energetics, reactivity, and dynamics: Laser-induced fluorescence (LIF) kinetics/dynamics of N 2 ῍ (v) ions (vibrationally state-selected ion῎molecule reactions; energy transfer processes), mechanisms of prototypical organic ion reactions (S N 2 nucleophilic substitution and kinetic isotope e#ects; hydrogen/deuterium exchange; isotope e#ects in termolecular association), and ion῎molecule reactions with biological implications (S N 2 reactions at a nitrogen center; E CO 2 elimination reactions of alkyl hydroperoxides). Anion chemistry of small nitroalkanes is also presented. A powerful combination of SIFT and negative ion photoelectron spectroscopy is used to study thermochemistry and structure of energetic and exotic ions (alkyl peroxides; anionic derivatives of diazo and azole compounds, cyclooctatetraene, and cyclopentanone). Finally, some of the new directions in SIFT research are discussed, i.e., reactions of ions with polyatomic organic radicals, and chemical ionization mass spectrometry with new detection schemes.

Reactions of Atomic Metal Anions in the Gas phase: Competition between Electron Transfer, Proton Abstraction and Bond Activation

“…Oxidative addition/reductive elimination involves the loss of stereochemistry, while bimolecular nucleophilic substitution reactions, notably S N 2 reactions, involve the inversion of stereochemistry. These reactions have been explored extensively in solution and the gas phase. − The differences between solution and gas-phase behavior have been used to explore the role of the solvent in these reactions. While organic nucleophiles and substrates have been extensively studied, the use of metallic nucleophilic systems has been limited to a small class of organometallic complexes, both in solution and the gas phase.…”

Organic gas-phase ion chemistry

“…For organizational purposes, this material is broken up into three sections: anion, cation, and radical ion reactions. Topical reviews by Kato 142 and Bo¨hme and Schwarz 143 are worth noting.…”

From Ignition to Photoelectron Spectroscopy Conical Intersection Impact the Study of Energetic Materials

“…The (CH) m N 5-m -heterocycle anions are of programmatic interest as potential anionic components of ionic liquids and as tools to infer properties of pentaazolide, N 5 -. 9,36 The thermodynamics of these anions was studied both experimentally and computationally by Lineberger's group at the University of Colorado. [5][6][7][8]37,38 The azolyls are substitutional isomers of the D 5h cyclodentadienyl radical, (CH) 5 whose 2 E 1 '' ground state is Jahn-Teller distorted.…”