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

The comprehensive and accurate analysis of mass spectral data is critical for the unequivocal identification environmental samples containing compounds short-listed by Chemical Weapons Convention (CWC). In particular, experiments with nerve agents are limited high risks involved in their handling. Therefore, possibility studying fragmentation pathways a theoretical approach especially welcome. this work, first time, O-2-methoxyethyl N- [bis(dimethylamino)methylidene]-P-methylphosphonamidate, an analog Novichok agent A-242, was synthesized employing one-pot microscale synthesis. Electron ionization (EI) electrospray (ESI) spectra (MS) were measured to provide CWC verification purposes. Considering that ESI-MS/MS powerful method analyzing non-volatile, highly polar, very water-soluble compounds, such as degradation products agents, we extensively investigated time ESI-(collision-induced dissociation) CID selected molecule. For purpose, molecular dynamics simulations using Quantum Mass Spectrometry (QCxMS) semiempirical electronic structure GFN2-xTB compared Triple Quadrupole experimental positive ion mode. base peak EI spectrum molecule found be m/z 151, which strongly suggests McLafferty +1 (ML+1) rearrangement involving 2-methoxyethyl moiety. formation 106 ESI-CID spectrum, according simulations, results from transfer one dimethylamino group phosphorus atom, mechanism would difficult identify without methods.