Pronounced changes in atomistic mechanisms for the Cl⁻ + CH₃I S_N2 reaction with increasing collision energy

Abstract

A sudden change from indirect to direct mechanism for Cl− + CH3I at Erel of 0.27–0.28 eV in a relatively small collision energy range of 0.15–0.40 eV is revealed and many indirect mechanisms are identified.

Simulation of the electron ionization mass spectra of the Novichok nerve agent

“…QCEIMS combines quantum chemical methods and statistical mechanics concepts 29,42 . This use of molecular dynamics to model mass spectrometry is relatively new and was pioneered by the late Bill Hase 31,42–45 . The International Journal of Mass Spectrometry recently dedicated a memorial issue to his contributions for the mass spectrometry field 46 …”

“…29,42 This use of molecular dynamics to model mass spectrometry is relatively new and was pioneered by the late Bill Hase. 31,[42][43][44][45] The International Journal of Mass Spectrometry recently dedicated a memorial issue to his contributions for the mass spectrometry field. 46 T A B L E 1 Novichok family nerve agents added to the CWC 6…”

Synthesis, experimental and molecular dynamics simulation of the ESI-CID spectrum of the nerve agent Novichok analog O-2-methoxyethyl N- [bis(dimethylamino)methylidene]-P-methylphosphonamidate

“…Recently, the QCEIMS program extended to determine CID spectra was renamed as QCxMS [37][38][39]. Although MD methods to simulate CID experiments have been proposed before [33,[40][41][42][43], now explicit collisions between ions and collision gas could be included in a friendly and accurate software specifically designed to determine CID mass spectra from MD simulations [37].…”

Competitive dynamics of E2 and SN2 reaction driven by collision energy and leaving group

“…10 Backward scattered events are characteristic of the direct rebound mechanism known for S N 2. [11][12][13][14] However, Wester et al 9 reported that less than half of the reactive collisions follow the direct rebound mechanism and the forward scattered ions exhibit a narrow range of product angle for CN À + CH 3 CH 2 I reaction at E coll = 1.9 eV by using crossed beam velocity map imaging. Thus, the competitive results of E2 and S N 2 reactions are still indistinct.…”