993-43-1Relevant articles and documents
Mass spectral characterization of the CWC-related isomeric dialkyl alkylphosphonothiolates/alkylphosphonothionates under gas chromatography/mass spectrometry conditions
Karthikraj,Sridhar,Prabhakar,Raju, N. Prasada,Murty,Vairamani
, p. 1461 - 1472 (2013/07/27)
RATIONALE The isomeric dialkyl alkylphosphonothiolates and dialkyl alkylphosphonothionates are listed as scheduled chemicals of the Chemical Weapons Convention (CWC) implemented by the OPCW. The P-S and P-R bond connectivity has to be correctly identified for the verification of the CWC. The present study demonstrates successful identification of the target isomers by selective fragmentation under electron ionization (EI) or chemical ionization (CI) conditions. METHODS All the studied isomeric compounds (27 in total) were synthesized in our laboratory using established methods, then analyzed by EI and CI gas chromatography/mass spectrometry (GC/MS) using an Agilent 6890 gas chromatograph equipped with a HP-5MS capillary column and interfaced to a 5973 N mass-selective detector. The retention index (RI) values of all the compounds were calculated using Van den Dool's formula. GC/MS/MS and GC/HRMS experiments were also performed using a VG-Autospec (magnetic sector) and JEOL-AccuToF (time-of-flight) mass spectrometer, respectively. RESULTS The EI mass spectra of all the compounds had an abundant molecular ion at m/z 182, except in the case of a few selected butyl-substituted compounds, where this ion was of low abundance. The EI fragmentation pathways include α-cleavage, McLafferty rearrangement, McLafferty + 1 rearrangement, O/S-alkyl radical loss, and an alkene loss with a hydrogen shift. The characteristic fragment ions and their relative abundances are significant in elucidating the alkyl group attached to the P/S/O-atoms as well as the P-S/P = S bond connectivity. The EI and CI mass spectra together with RI values enable unambiguous identification of all the studied isomeric compounds. CONCLUSIONS The present study highlights the structural characterization of the isomeric phosphonothiolates and phosphonothionates based on their selective EI fragmentation. The assigned fragmentation pathway helps in the assignment of P-S and P-alkyl connectivity in phosphonothiolates and phosphonothionates, consequently the structure of the unknown compounds. The EI mass spectra (27 compounds) of isomeric compounds are immensely useful in the OPCW official proficiency tests and for off-site analysis. Copyright 2013 John Wiley & Sons, Ltd. Copyright
Synthesis and chiral recognition ability of O-phenyl ethylphosphonothioic acid with a conformationally flexible phenoxy group for CH/π interaction
Kobayashi, Yuka,Maeda, Jin,Morisawa, Fumi,Saigo, Kazuhiko
, p. 967 - 974 (2007/10/03)
Enantiopure O-phenyl ethylphosphonothioic acid 1 was easily obtained by the enantioseparation of racemic 1, which was prepared from commercially available phosphorothioic trichloride in four steps. Enantiopure 1 was found to show an excellent chiral recognition ability for various 1-arylethylamine derivatives during the diastereomeric salt formation. In particular, enantiopure 1 was able to recognize the chirality of o- and m-substituted 1-arylethylamine derivatives, of which the chirality is generally difficult to establish by conventional resolving agents. X-ray crystallographic analyses of the less-soluble diastereomeric salts revealed that the conformation of the phenoxy group in enantiopure 1 could change in the diastereomeric salt crystals and that the excellent chiral recognition ability of enantiopure 1 resulted from the effective CH/π interaction of the phenoxy phenyl group.
DIE STRUKTUR VON ALKYL- UND ARYLPERTHIOPHOSPHONSAEUREANHYDRIDEN IN LOESUNG
Ohms, Gisela,Treichler, Antje,Grossmann, Gisbert
, p. 95 - 102 (2007/10/02)
The analysis of 1H-, 31P- and 13C-NMR spectra of different alkyl- and arylperthiophosphonic acid anhydrides shows that these compounds prefer a dimeric structure in solution.They exist as 2,4-diorganyl-2,4-dithioxo-1,3,2λ5,4λ5-dithiadiphosphetanes.Most of the perthiophosphonic acid anhydrides form configuration isomers which differ in the position of the thioxo groups relatively to the ring plane.The concentration of the trans-isomer is generally larger than that of the cis-isomer.The ratio of the concentration of both isomers is obviously determined by the polarity of the solvent used.Mixing of solutions of different perthiophosphonic acid anhydrides results in unsymmetrical compounds also existing in cis- and trans-configuration. 31P chemical shifts and geminal P-P coupling constants for symmetrical and unsymmetrical perthiophosphonic acid anhydrides are presented and discussed. - Key words: 31P chemical shifts; P-P coupling constants; perthiophosphonic acid anhydrides; mixed perthiophosphonic acid anhydrides; configuration isomers; 2,4-diorganyl-2,4-dithioxo-1,3,2λ5,4λ5-dithiadiphosphetanes.
