Structural characterization of Chemical Weapons Convention‐related phosphonoselenoates by electron ionization and electrospray ionization mass spectrometry

Abstract

Rationale Organophosphorus compounds with phosphorus atom bonded to one methyl, ethyl or propyl (normal or iso) group are listed in Schedule 2 of the Chemical Weapons Convention (CWC). Selenophosphorus compounds, listed in Schedule 2.B.4, have very limited representation in mass spectral libraries and the open literature. Methods Members of a new category of selenophosphorus compounds were prepared via microsynthetic protocols and their fragmentation pathways were investigated using electron ionization (EI) and positive electrospray ionization (ESI) mass spectrometry. The EI and ESI fragmentation pathways were suggested and supported by acquired fragment ions of deuterated analogs and density functional theory calculations. Results Mass spectrometric investigations showed some interesting fragmentation pathways, such as McLafferty‐type, selenono–selenolo rearrangements, intramolecular electrophilic aromatic substitution reaction and α‐cleavage. Conclusions Efficient microsynthesis was conducted, and EI‐MS spectra and ESI‐MS/MS spectra of a series of selenophosphorus compounds were collected and studied with the purpose of identifying CWC‐related chemicals during on‐site inspection and/or off‐site analysis.

A-agents, misleadingly known as “Novichoks”: a narrative review

“…

Fig. 4 The final structure shown is O -alkyl N -(bis(dimethylamino)methylidene)- P -methylphosphonamidate, and the intermediate has a bis(dimethylamino)methylene moiety; DCM dichloromethane, TEA triethylamine; according to (Hosseini et al 2016 , 2021 ; Eskandari et al 2022 ; Carvalho-Silva et al 2023 ; Noga and Jurowski 2023 )

…”

“…The same group released two more studies related to chemistry. They described the microsynthesis of selenophosphorus compounds as close analogs to A-series agents in 2021 (Hosseini et al 2021 ). A year later, they disclosed new data on synthesizing A-230, A-232, A-234, and six other compounds using previously published procedure (Eskandari et al 2022 ).…”

“…Iranian scientists were the first to publish analytical data on A-series compounds (Hosseini et al 2016 , 2021 ; Eskandari et al 2022 ). They used the microsynthesis mentioned above to produce deuterated analogs of A-series agents and performed mass spectrometric (MS) analysis via electron ionization and positive electrospray ionization methods.…”

“…Later, they revealed product ion mass spectra of A-230, A-232, A-234, other A-series analogs, and selenophosphorus compounds that they provided to the Central Analytical Database maintained by the OPCW (OCAD) to improve MS detection. The database assists in verification and on-/off-site analysis (Hosseini et al 2016 , 2021 ; Eskandari et al 2022 ). Vibrational spectra modeled by Tan et al ( 2019 ) and nuclear magnetic resonance (NMR) characteristics reported by Jeong et al ( 2022b ) and Jung et al ( 2023 ) can also be exploited.…”