Determination of the structure and chiroptical properties of the parent nerve gas O-methyl methylphosphonofluoridate by ab initio calculations, electron diffraction analysis, and NMR spectroscopy
The geometry and electronic structure of O-methyl methylphosphonofluoridate (1) (MeOPOFMe) have been determined at the MP2/6-31G(D) and Becke3LYP/6-31G(D) levels. The calculations confirm the prior results of lower-level ab initio calculations which indicated that the experimental gas phase electron diffraction structure of 1 is substantially in error. The compound exists in a single conformation determined by the operation of an anomeric effect between the methoxy oxygen atom and the P-F bond as is evident from the nearly perpendicular orientation of the O-C and P-F bonds. A reanalysis of the published gas electron diffraction (GED) data yielded inconclusive results but underscored the inability of GED to distinguish between the conformations of 1. 1H and 13C NMR spectra are reported and are consistent with the existence of a single conformer. The lower excited singlet states of 1 are calculated to be Rydberg states originating from excitations from the p-type nonbonding orbitals of the monocoordinated oxygen atom into diffuse 3s- and 3p-type orbitals. The transitions are predicted to occur in the vacuum UV and have low oscillator strength. The first two transitions have moderate positive rotatory strength for the (R) enantiomer, leading to the prediction of absolute configuration, (+)-(R)-1.
Verification of the chemical weapons convention: mass spectrometry of alkyl methylphosphonofluoridates
Under the provisions of the United Nations Chemical Weapons Convention (CWC), certain parts of chemical industry will be monitored to verify compliance with the Convention. This will include analysis of samples from industrial sites to check for the presence or absence of chemical warfare related compounds. One of the problems in screening the chemicals to be monitored under the CWC is that certain classes of chemical warfare agents are represented as families of chemicals, with many of the individual chemicals having no analytical data available. One example is the alkyl methylphosphonofluoridate family with an alkyl ester substituent from CH3 to C10H21. In this work, the mass spectra of 60 alkyl methylphosphonofluoridate family members have been studied to enable the development of rapid on-site screening methods for this family of chemicals.
Borrett,Mathews,Mattson
p. 2065 - 2074
(2007/10/02)
The Use of Organosilicon Esters for the Synthesis of Alkyl Phosphonofluoridates
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Muller, August J.
p. 3364 - 3365
(2007/10/02)
REACTIONS OF P(III) ESTERS WITH P(III) HALIDES
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Belyalov, R. U.,Kibardin, A. M.,Gazizov, T. Kh.,Pudovik, A. N.